Bump to 0.12.0 (#1538)

* Add configurations for table headers

* lint

Co-authored-by: Amanita-Muscaria <nope>

.azure/azure-pipelines.yml

@@ -1,20 +1,29 @@
-variables:
-  lkg-rust-nightly: "2019-08-08"
-
 trigger:
   - master
 
 strategy:
   matrix:
-    linux-nightly:
-      image: ubuntu-16.04
-      toolchain: nightly-$(lkg-rust-nightly)
-    macos-nightly:
-      image: macos-10.13
-      toolchain: nightly-$(lkg-rust-nightly)
-    windows-nightly:
-      image: vs2017-win2016
-      toolchain: nightly-$(lkg-rust-nightly)
+    linux-stable:
+      image: ubuntu-18.04
+      style: 'unflagged'
+    macos-stable:
+      image: macos-10.14
+      style: 'unflagged'
+    windows-stable:
+      image: windows-2019
+      style: 'unflagged'
+    linux-nightly-canary:
+      image: ubuntu-18.04
+      style: 'canary'
+    macos-nightly-canary:
+      image: macos-10.14
+      style: 'canary'
+    windows-nightly-canary:
+      image: windows-2019
+      style: 'canary'
+    fmt:
+      image: ubuntu-18.04
+      style: 'fmt'
 
 pool:
   vmImage: $(image)
@@ -22,14 +31,31 @@ pool:
 steps:
   - bash: |
       set -e
-      curl https://sh.rustup.rs -sSf | sh -s -- -y --no-modify-path --default-toolchain none
+      if [ -e /etc/debian_version ]
+      then
+        sudo apt-get -y install libxcb-composite0-dev libx11-dev
+      fi
+      if [ "$(uname)" == "Darwin" ]; then
+        curl https://sh.rustup.rs -sSf | sh -s -- -y --no-modify-path --default-toolchain "stable"
         export PATH=$HOME/.cargo/bin:$PATH
-      rustup install --no-self-update $(toolchain)
-      rustup default $(toolchain)
+      fi
+      rustup update
       rustc -Vv
       echo "##vso[task.prependpath]$HOME/.cargo/bin"
+      rustup component add rustfmt
     displayName: Install Rust
-  - bash: RUSTFLAGS="-D warnings" cargo build
-    displayName: Build source
-  - bash: cargo test
+  - bash: RUSTFLAGS="-D warnings" cargo test --all --features stable,test-bins
+    condition: eq(variables['style'], 'unflagged')
     displayName: Run tests
+  - bash: RUSTFLAGS="-D warnings" cargo clippy --all --features=stable -- -D clippy::result_unwrap_used -D clippy::option_unwrap_used
+    condition: eq(variables['style'], 'unflagged')
+    displayName: Check clippy lints
+  - bash: NUSHELL_ENABLE_ALL_FLAGS=1 RUSTFLAGS="-D warnings" cargo test --all --features stable,test-bins
+    condition: eq(variables['style'], 'canary')
+    displayName: Run tests
+  - bash: NUSHELL_ENABLE_ALL_FLAGS=1 RUSTFLAGS="-D warnings" cargo clippy --all --features=stable -- -D clippy::result_unwrap_used -D clippy::option_unwrap_used
+    condition: eq(variables['style'], 'canary')
+    displayName: Check clippy lints
+  - bash: cargo fmt --all -- --check
+    condition: eq(variables['style'], 'fmt')
+    displayName: Lint

.cargo/config

@@ -0,0 +1,3 @@
+[build]
+
+#rustflags = ["--cfg", "data_processing_primitives"]

.circleci/config.yml

@@ -0,0 +1,165 @@
+# CircleCI 2.0 configuration file
+#
+# Check https://circleci.com/docs/2.0/configuration-reference/ for more details
+# See https://circleci.com/docs/2.0/config-intro/#section=configuration for spec
+#
+version: 2.1
+
+# Commands
+
+commands:
+
+  pull_cache:
+    description: Pulls Quay.io docker images (latest) for our cache
+    parameters:
+      tag:
+        type: string
+        default: "devel"
+    steps:
+      - run: echo "Tag is << parameters.tag >>"
+      - run: docker pull quay.io/nushell/nu:<< parameters.tag >>
+      - run: docker pull quay.io/nushell/nu-base:<< parameters.tag >>
+
+orbs:
+  # https://circleci.com/orbs/registry/orb/circleci/docker
+  docker: circleci/docker@0.5.13
+
+workflows:
+  version: 2.0
+
+  # This builds on all pull requests to test, and ignores master
+  build_without_deploy:
+    jobs:
+      - docker/publish:
+          deploy: false
+          image: nushell/nu-base
+          tag: latest
+          dockerfile: docker/Dockerfile.nu-base
+          extra_build_args: --cache-from=quay.io/nushell/nu-base:devel
+          filters:
+            branches:
+              ignore:
+                - master
+          before_build:
+            - pull_cache
+          after_build:
+            - run:
+                name: Build Multistage (smaller) container
+                command: |
+                  docker build -f docker/Dockerfile -t quay.io/nushell/nu .
+            - run:
+                name: Preview Docker Tag for Nushell Build
+                command: |
+                   DOCKER_TAG=$(docker run quay.io/nushell/nu --version | cut -d' ' -f2)
+                   echo "Version that would be used for Docker tag is v${DOCKER_TAG}"
+            - run:
+                name: Test Executable
+                command: |
+                   docker run --rm quay.io/nushell/nu-base --help
+                   docker run --rm quay.io/nushell/nu --help
+
+  # workflow publishes to Docker Hub, with each job having different triggers
+  build_with_deploy:
+    jobs:
+
+        # Deploy versioned and latest images on tags (releases) only - builds --release.
+      - docker/publish:
+          image: nushell/nu-base
+          registry: quay.io
+          tag: latest
+          dockerfile: docker/Dockerfile.nu-base
+          extra_build_args: --cache-from=quay.io/nushell/nu-base:latest,quay.io/nushell/nu:latest --build-arg RELEASE=true
+          filters:
+            branches:
+              ignore: /.*/
+            tags:
+              only: /^v.*/
+          before_build:
+            - run: docker pull quay.io/nushell/nu:latest
+            - run: docker pull quay.io/nushell/nu-base:latest
+          after_build:
+            - run:
+                name: Build Multistage (smaller) container
+                command: |
+                  docker build -f docker/Dockerfile -t quay.io/nushell/nu .
+            - run:
+                name: Test Executable
+                command: |
+                   docker run --rm quay.io/nushell/nu --help
+                   docker run --rm quay.io/nushell/nu-base --help
+            - run:
+                name: Publish Docker Tag with Nushell Version
+                command: |
+                   DOCKER_TAG=$(docker run quay.io/nushell/nu --version | cut -d' ' -f2)
+                   echo "Version for Docker tag is ${DOCKER_TAG}"
+                   docker tag quay.io/nushell/nu-base:latest quay.io/nushell/nu-base:${DOCKER_TAG}
+                   docker tag quay.io/nushell/nu:latest quay.io/nushell/nu:${DOCKER_TAG}
+                   docker push quay.io/nushell/nu-base
+                   docker push quay.io/nushell/nu
+
+
+  # publish devel to Docker Hub on merge to master (doesn't build --release)
+  build_with_deploy_devel:
+    jobs:
+
+      # Deploy devel tag on merge to master
+      - docker/publish:
+          image: nushell/nu-base
+          registry: quay.io
+          tag: devel
+          dockerfile: docker/Dockerfile.nu-base
+          extra_build_args: --cache-from=quay.io/nushell/nu-base:devel
+          before_build:
+            - pull_cache
+          filters:
+            branches:
+              only: master
+          after_build:
+            - run:
+                name: Build Multistage (smaller) container
+                command: |
+                  docker build --build-arg FROMTAG=devel -f docker/Dockerfile -t quay.io/nushell/nu:devel .
+            - run:
+                name: Test Executable
+                command: |
+                   docker run --rm quay.io/nushell/nu:devel --help
+                   docker run --rm quay.io/nushell/nu-base:devel --help
+            - run:
+                name: Publish Development Docker Tags
+                command: |
+                   docker push quay.io/nushell/nu-base:devel
+                   docker push quay.io/nushell/nu:devel
+
+  nightly:
+    triggers:
+      - schedule:
+          cron: "0 0 * * *"
+          filters:
+            branches:
+              only:
+                - master
+    jobs:
+      - docker/publish:
+          image: nushell/nu-base
+          registry: quay.io
+          tag: nightly
+          dockerfile: docker/Dockerfile.nu-base
+          extra_build_args: --cache-from=quay.io/nushell/nu-base:nightly --build-arg RELEASE=true
+          before_build:
+            - run: docker pull quay.io/nushell/nu:nightly
+            - run: docker pull quay.io/nushell/nu-base:nightly
+          after_build:
+            - run:
+                name: Build Multistage (smaller) container
+                command: |
+                  docker build -f docker/Dockerfile -t quay.io/nushell/nu:nightly .
+            - run:
+                name: Test Executable
+                command: |
+                   docker run --rm quay.io/nushell/nu:nightly --help
+                   docker run --rm quay.io/nushell/nu-base:nightly --help
+            - run:
+                name: Publish Nightly Nushell Containers
+                command: |
+                   docker push quay.io/nushell/nu-base:nightly
+                   docker push quay.io/nushell/nu:nightly

.dockerignore

@@ -0,0 +1 @@
+target

.editorconfig

@@ -4,6 +4,11 @@ root = true
 indent_style = space
 indent_size = 4
 charset = utf-8
-trim_trailing_whitespace = false
+trim_trailing_whitespace = true
 insert_final_newline = false
 end_of_line = lf
+
+[*.{yml,yaml}]
+indent_size = 2
+charset = utf-8
+insert_final_newline = true

.github/ISSUE_TEMPLATE/bug_report.md

@@ -0,0 +1,30 @@
+---
+name: Bug report
+about: Create a report to help us improve
+title: ''
+labels: ''
+assignees: ''
+
+---
+
+**Describe the bug**
+A clear and concise description of what the bug is.
+
+**To Reproduce**
+Steps to reproduce the behavior:
+1. 
+2. 
+3. 
+
+**Expected behavior**
+A clear and concise description of what you expected to happen.
+
+**Screenshots**
+If applicable, add screenshots to help explain your problem.
+
+**Configuration (please complete the following information):**
+ - OS: [e.g. Windows]
+ - Version [e.g. 0.4.0]
+ - Optional features (if any)
+
+Add any other context about the problem here.

.github/ISSUE_TEMPLATE/feature_request.md

@@ -0,0 +1,20 @@
+---
+name: Feature request
+about: Suggest an idea for this project
+title: ''
+labels: ''
+assignees: ''
+
+---
+
+**Is your feature request related to a problem? Please describe.**
+A clear and concise description of what the problem is. Ex. I'm always frustrated when [...]
+
+**Describe the solution you'd like**
+A clear and concise description of what you want to happen.
+
+**Describe alternatives you've considered**
+A clear and concise description of any alternative solutions or features you've considered.
+
+**Additional context**
+Add any other context or screenshots about the feature request here.

.github/workflows/docker-publish.yml

@@ -0,0 +1,118 @@
+name: Publish consumable Docker images
+
+on:
+  push:
+    tags: ['v?[0-9]+.[0-9]+.[0-9]+*']
+
+jobs:
+  compile:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        arch:
+        - x86_64-unknown-linux-musl
+        - x86_64-unknown-linux-gnu
+    steps:
+    - uses: actions/checkout@v1
+    - name: Install rust-embedded/cross
+      env: { VERSION: v0.1.16 }
+      run: >-
+        wget -nv https://github.com/rust-embedded/cross/releases/download/${VERSION}/cross-${VERSION}-x86_64-unknown-linux-gnu.tar.gz
+        -O- | sudo tar xz -C /usr/local/bin/
+    - name: compile for specific target
+      env: { arch: '${{ matrix.arch }}' }
+      run: |
+        cross build --target ${{ matrix.arch }} --release
+        # leave only the executable file
+        rm -rd target/${{ matrix.arch }}/release/{*/*,*.d,*.rlib,.fingerprint}
+        find . -empty -delete
+    - uses: actions/upload-artifact@master
+      with:
+        name: ${{ matrix.arch }}
+        path: target/${{ matrix.arch }}/release
+
+  docker:
+    name: Build and publish docker images
+    needs: compile
+    runs-on: ubuntu-latest
+    env:
+      DOCKER_REGISTRY: quay.io/nushell
+      DOCKER_PASSWORD: ${{ secrets.DOCKER_REGISTRY }}
+      DOCKER_USER: ${{ secrets.DOCKER_USER }}
+    strategy:
+      matrix:
+        tag:
+        - alpine
+        - slim
+        - debian
+        - glibc-busybox
+        - musl-busybox
+        - musl-distroless
+        - glibc-distroless
+        - glibc
+        - musl
+        include:
+        - { tag: alpine,           base-image: alpine,                     arch: x86_64-unknown-linux-musl, plugin: true,  use-patch: false}
+        - { tag: slim,             base-image: 'debian:stable-slim',       arch: x86_64-unknown-linux-gnu,  plugin: true,  use-patch: false}
+        - { tag: debian,           base-image: debian,                     arch: x86_64-unknown-linux-gnu,  plugin: true,  use-patch: false}
+        - { tag: glibc-busybox,    base-image: 'busybox:glibc',            arch: x86_64-unknown-linux-gnu,  plugin: false, use-patch: true }
+        - { tag: musl-busybox,     base-image: 'busybox:musl',             arch: x86_64-unknown-linux-musl, plugin: false, use-patch: false}
+        - { tag: musl-distroless,  base-image: 'gcr.io/distroless/static', arch: x86_64-unknown-linux-musl, plugin: false, use-patch: false}
+        - { tag: glibc-distroless, base-image: 'gcr.io/distroless/cc',     arch: x86_64-unknown-linux-gnu,  plugin: false, use-patch: true }
+        - { tag: glibc,            base-image: scratch,                    arch: x86_64-unknown-linux-gnu,  plugin: false, use-patch: false}
+        - { tag: musl,             base-image: scratch,                    arch: x86_64-unknown-linux-musl, plugin: false, use-patch: false}
+    steps:
+    - uses: actions/checkout@v1
+    - uses: actions/download-artifact@master
+      with: { name: '${{ matrix.arch }}', path: target/release }
+    - name: Build and publish exact version
+      run: |-
+        export DOCKER_TAG=${GITHUB_REF##*/}-${{ matrix.tag }}
+        export NU_BINS=target/release/$( [ ${{ matrix.plugin }} = true ] && echo nu* || echo nu )
+        export PATCH=$([ ${{ matrix.use-patch }} = true ] && echo .${{ matrix.tag }} || echo '')
+        chmod +x $NU_BINS
+
+        echo ${DOCKER_PASSWORD} | docker login ${DOCKER_REGISTRY} -u ${DOCKER_USER} --password-stdin
+        docker-compose --file docker/docker-compose.package.yml build
+        docker-compose --file docker/docker-compose.package.yml push              # exact version
+      env:
+        BASE_IMAGE: ${{ matrix.base-image }}
+
+    #region semantics tagging
+    - name: Retag and push with suffixed version
+      run: |-
+        VERSION=${GITHUB_REF##*/}
+
+        latest_version=${VERSION%%%.*}-${{ matrix.tag }}
+        latest_feature=${VERSION%%.*}-${{ matrix.tag }}
+        latest_patch=${VERSION%.*}-${{ matrix.tag }}
+        exact_version=${VERSION}-${{ matrix.tag }}
+
+        tags=( ${latest_version} ${latest_feature} ${latest_patch} ${exact_version} )
+
+        for tag in ${tags[@]}; do
+          docker tag ${DOCKER_REGISTRY}/nu:${VERSION}-${{ matrix.tag }} ${DOCKER_REGISTRY}/nu:${tag}
+          docker push ${DOCKER_REGISTRY}/nu:${tag}
+        done
+
+        # latest version
+        docker tag ${DOCKER_REGISTRY}/nu:${VERSION}-${{ matrix.tag }} ${DOCKER_REGISTRY}/nu:${{ matrix.tag }}
+        docker push ${DOCKER_REGISTRY}/nu:${{ matrix.tag }}
+
+    - name: Retag and push debian as latest
+      if: matrix.tag == 'debian'
+      run: |-
+        VERSION=${GITHUB_REF##*/}
+
+        # ${latest features} ${latest patch} ${exact version}
+        tags=( ${VERSION%%.*} ${VERSION%.*} ${VERSION} )
+
+        for tag in ${tags[@]}; do
+          docker tag ${DOCKER_REGISTRY}/nu:${VERSION}-${{ matrix.tag }} ${DOCKER_REGISTRY}/nu:${tag}
+          docker push ${DOCKER_REGISTRY}/nu:${tag}
+        done
+
+        # latest version
+        docker tag ${DOCKER_REGISTRY}/nu:${{ matrix.tag }} ${DOCKER_REGISTRY}/nu:latest
+        docker push ${DOCKER_REGISTRY}/nu:latest
+    #endregion semantics tagging

.gitignore

@@ -1,4 +1,13 @@
 /target
+/scratch
 **/*.rs.bk
 history.txt
 tests/fixtures/nuplayground
+crates/*/target
+
+# Debian/Ubuntu
+debian/.debhelper/
+debian/debhelper-build-stamp
+debian/files
+debian/nu.substvars
+debian/nu/

.gitpod.Dockerfile

@@ -0,0 +1,9 @@
+FROM gitpod/workspace-full
+
+USER gitpod
+
+RUN sudo apt-get update && \
+    sudo apt-get install -y \
+        libssl-dev \
+        libxcb-composite0-dev \
+        pkg-config

.gitpod.yml

@@ -0,0 +1,29 @@
+image:
+  file: .gitpod.Dockerfile
+tasks:
+  - init: cargo install --path . --force --features=stable
+    command: nu
+github:
+  prebuilds:
+    # enable for the master/default branch (defaults to true)
+    master: true
+    # enable for all branches in this repo (defaults to false)
+    branches: true
+    # enable for pull requests coming from this repo (defaults to true)
+    pullRequests: true
+    # enable for pull requests coming from forks (defaults to false)
+    pullRequestsFromForks: true
+    # add a "Review in Gitpod" button as a comment to pull requests (defaults to true)
+    addComment: true
+    # add a "Review in Gitpod" button to pull requests (defaults to false)
+    addBadge: false
+    # add a label once the prebuild is ready to pull requests (defaults to false)
+    addLabel: prebuilt-in-gitpod
+vscode:
+  extensions:
+    - hbenl.vscode-test-explorer@2.15.0:koqDUMWDPJzELp/hdS/lWw==
+    - Swellaby.vscode-rust-test-adapter@0.11.0:Xg+YeZZQiVpVUsIkH+uiiw==
+    - serayuzgur.crates@0.4.7:HMkoguLcXp9M3ud7ac3eIw==
+    - belfz.search-crates-io@1.2.1:kSLnyrOhXtYPjQpKnMr4eQ==
+    - vadimcn.vscode-lldb@1.4.5:lwHCNwtm0kmOBXeQUIPGMQ==
+    - bungcip.better-toml@0.3.2:3QfgGxxYtGHfJKQU7H0nEw==

CODE_OF_CONDUCT.md

@@ -0,0 +1,76 @@
+# Contributor Covenant Code of Conduct
+
+## Our Pledge
+
+In the interest of fostering an open and welcoming environment, we as
+contributors and maintainers pledge to make participation in our project and
+our community a harassment-free experience for everyone, regardless of age, body
+size, disability, ethnicity, sex characteristics, gender identity and expression,
+level of experience, education, socio-economic status, nationality, personal
+appearance, race, religion, or sexual identity and orientation.
+
+## Our Standards
+
+Examples of behavior that contributes to creating a positive environment
+include:
+
+* Using welcoming and inclusive language
+* Being respectful of differing viewpoints and experiences
+* Gracefully accepting constructive criticism
+* Focusing on what is best for the community
+* Showing empathy towards other community members
+
+Examples of unacceptable behavior by participants include:
+
+* The use of sexualized language or imagery and unwelcome sexual attention or
+  advances
+* Trolling, insulting/derogatory comments, and personal or political attacks
+* Public or private harassment
+* Publishing others' private information, such as a physical or electronic
+  address, without explicit permission
+* Other conduct which could reasonably be considered inappropriate in a
+  professional setting
+
+## Our Responsibilities
+
+Project maintainers are responsible for clarifying the standards of acceptable
+behavior and are expected to take appropriate and fair corrective action in
+response to any instances of unacceptable behavior.
+
+Project maintainers have the right and responsibility to remove, edit, or
+reject comments, commits, code, wiki edits, issues, and other contributions
+that are not aligned to this Code of Conduct, or to ban temporarily or
+permanently any contributor for other behaviors that they deem inappropriate,
+threatening, offensive, or harmful.
+
+## Scope
+
+This Code of Conduct applies within all project spaces, and it also applies when
+an individual is representing the project or its community in public spaces.
+Examples of representing a project or community include using an official
+project e-mail address, posting via an official social media account, or acting
+as an appointed representative at an online or offline event. Representation of
+a project may be further defined and clarified by project maintainers.
+
+## Enforcement
+
+Instances of abusive, harassing, or otherwise unacceptable behavior may be
+reported by contacting the project team at wycats@gmail.com. All
+complaints will be reviewed and investigated and will result in a response that
+is deemed necessary and appropriate to the circumstances. The project team is
+obligated to maintain confidentiality with regard to the reporter of an incident.
+Further details of specific enforcement policies may be posted separately.
+
+Project maintainers who do not follow or enforce the Code of Conduct in good
+faith may face temporary or permanent repercussions as determined by other
+members of the project's leadership.
+
+## Attribution
+
+This Code of Conduct is adapted from the [Contributor Covenant][homepage], version 1.4,
+available at https://www.contributor-covenant.org/version/1/4/code-of-conduct.html
+
+[homepage]: https://www.contributor-covenant.org
+
+For answers to common questions about this code of conduct, see
+https://www.contributor-covenant.org/faq

Cargo.toml

@@ -1,141 +1,176 @@
 [package]
 name = "nu"
-version = "0.2.0"
-authors = ["Yehuda Katz <wycats@gmail.com>", "Jonathan Turner <jonathan.d.turner@gmail.com>", "Andrés N. Robalino <andres@androbtech.com>"]
-description = "A shell for the GitHub era"
+version = "0.12.0"
+authors = ["The Nu Project Contributors"]
+description = "A new kind of shell"
 license = "MIT"
 edition = "2018"
 readme = "README.md"
 default-run = "nu"
 repository = "https://github.com/nushell/nushell"
-homepage = "http://nushell.sh"
-documentation = "https://book.nushell.sh"
+homepage = "https://www.nushell.sh"
+documentation = "https://www.nushell.sh/book/"
+exclude = ["images"]
+
+[workspace]
+members = ["crates/*/"]
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-rustyline = "5.0.2"
-sysinfo = "0.9"
-chrono = { version = "0.4.7", features = ["serde"] }
-chrono-tz = "0.5.1"
-derive-new = "0.5.7"
-prettytable-rs = "0.8.0"
-itertools = "0.8.0"
-ansi_term = "0.12.0"
-nom = "5.0.0"
-dunce = "1.0.0"
-indexmap = { version = "1.0.2", features = ["serde-1"] }
-chrono-humanize = "0.0.11"
-byte-unit = "3.0.1"
-ordered-float = {version = "1.0.2", features = ["serde"]}
-prettyprint = "0.7.0"
-futures-preview = { version = "=0.3.0-alpha.18", features = ["compat", "io-compat"] }
-futures-sink-preview = "=0.3.0-alpha.18"
-futures-async-stream = "0.1.0-alpha.1"
-async-trait = "0.1.10"
-futures_codec = "0.2.5"
-term = "0.5.2"
-bytes = "0.4.12"
-log = "0.4.8"
-pretty_env_logger = "0.3.1"
-serde = { version = "1.0.98", features = ["derive"] }
-serde_json = "1.0.40"
-serde-hjson = "0.9.1"
-serde_yaml = "0.8"
-serde_bytes = "0.11.2"
-getset = "0.0.7"
-logos = "0.10.0-rc2"
-logos-derive = "0.10.0-rc2"
-language-reporting = "0.3.1"
-app_dirs = "1.2.1"
-csv = "1.1"
-toml = "0.5.3"
-toml-query = "0.9.2"
+nu-cli = { version = "0.12.0", path = "./crates/nu-cli" }
+nu-source = { version = "0.12.0", path = "./crates/nu-source" }
+nu-plugin = { version = "0.12.0", path = "./crates/nu-plugin" }
+nu-protocol = { version = "0.12.0", path = "./crates/nu-protocol" }
+nu-errors = { version = "0.12.0", path = "./crates/nu-errors" }
+nu-parser = { version = "0.12.0", path = "./crates/nu-parser" }
+nu-value-ext = { version = "0.12.0", path = "./crates/nu-value-ext" }
+nu_plugin_average = { version = "0.12.0", path = "./crates/nu_plugin_average", optional=true }
+nu_plugin_binaryview = { version = "0.12.0", path = "./crates/nu_plugin_binaryview", optional=true }
+nu_plugin_fetch = { version = "0.12.0", path = "./crates/nu_plugin_fetch", optional=true }
+nu_plugin_inc = { version = "0.12.0", path = "./crates/nu_plugin_inc", optional=true }
+nu_plugin_match = { version = "0.12.0", path = "./crates/nu_plugin_match", optional=true }
+nu_plugin_post = { version = "0.12.0", path = "./crates/nu_plugin_post", optional=true }
+nu_plugin_ps = { version = "0.12.0", path = "./crates/nu_plugin_ps", optional=true }
+nu_plugin_str = { version = "0.12.0", path = "./crates/nu_plugin_str", optional=true }
+nu_plugin_sys = { version = "0.12.0", path = "./crates/nu_plugin_sys", optional=true }
+nu_plugin_textview = { version = "0.12.0", path = "./crates/nu_plugin_textview", optional=true }
+nu_plugin_tree = { version = "0.12.0", path = "./crates/nu_plugin_tree", optional=true }
+nu-macros = { version = "0.12.0", path = "./crates/nu-macros" }
+
+crossterm = { version = "0.16.0", optional = true }
+onig_sys = { version = "=69.1.0", optional = true }
+semver = { version = "0.9.0", optional = true }
+syntect = { version = "3.2.0", optional = true }
+url = { version = "2.1.1", optional = true }
+
 clap = "2.33.0"
-enum_derive = "0.1.7"
-adhoc_derive = "0.1.2"
-lazy_static = "1.3.0"
-git2 = { version = "0.9.2", default_features = false }
-dirs = "2.0.2"
-glob = "0.3.0"
-ctrlc = "3.1.3"
-ptree = "0.2"
-reqwest = "0.9"
-roxmltree = "0.7.0"
-nom5_locate = "0.1.1"
-derive_more = "0.15.0"
-enum-utils = "0.1.1"
-unicode-xid = "0.2.0"
-serde_ini = "0.2.0"
-subprocess = "0.1.18"
-mime = "0.3.13"
-regex = "1.2.1"
-pretty-hex = "0.1.0"
-neso = "0.5.0"
-crossterm = "0.10.2"
-tempfile = "3.1.0"
-image = "0.22.1"
-semver = "0.9.0"
-uuid = {version = "0.7.4", features = [ "v4", "serde" ]}
-syntect = "3.2.0"
-strip-ansi-escapes = "0.1.0"
-onig_sys = "=69.1.0"
-heim = "0.0.6"
-which = "2.0.1"
-battery = "0.7.4"
-textwrap = {version = "0.11.0", features = ["term_size"]}
-unicode-width = "0.1.6"
-rawkey = {version = "0.1.2", optional = true }
-clipboard = {version = "0.5", optional = true }
+ctrlc = "3.1.4"
+dunce = "1.0.0"
+futures = { version = "0.3", features = ["compat", "io-compat"] }
+log = "0.4.8"
+pretty_env_logger = "0.4.0"
 
 [dev-dependencies]
 pretty_assertions = "0.6.1"
-tempdir = "0.3.7"
+nu-test-support = { version = "0.12.0", path = "./crates/nu-test-support" }
 
-[lib]
-name = "nu"
-path = "src/lib.rs"
+[build-dependencies]
+toml = "0.5.6"
+serde = { version = "1.0.105", features = ["derive"] }
+nu-build = { version = "0.12.0", path = "./crates/nu-build" }
+
+[features]
+# Test executables
+test-bins = []
+
+default = ["sys", "ps", "textview", "inc", "str"]
+stable = ["default", "starship-prompt", "binaryview", "match", "tree", "average", "post", "fetch", "clipboard-cli"]
+
+# Default
+textview = ["crossterm", "syntect", "onig_sys", "url", "nu_plugin_textview"]
+sys = ["nu_plugin_sys"]
+ps = ["nu_plugin_ps"]
+inc = ["semver", "nu_plugin_inc"]
+str = ["nu_plugin_str"]
+
+# Stable
+average = ["nu_plugin_average"]
+binaryview = ["nu_plugin_binaryview"]
+fetch = ["nu_plugin_fetch"]
+match = ["nu_plugin_match"]
+post = ["nu_plugin_post"]
+trace = ["nu-parser/trace"]
+tree = ["nu_plugin_tree"]
+
+clipboard-cli = ["nu-cli/clipboard-cli"]
+starship-prompt = ["nu-cli/starship-prompt"]
 
 [[bin]]
-name = "nu_plugin_inc"
-path = "src/plugins/inc.rs"
+name = "fail"
+path = "crates/nu-test-support/src/bins/fail.rs"
+required-features = ["test-bins"]
 
 [[bin]]
-name = "nu_plugin_sum"
-path = "src/plugins/sum.rs"
+name = "chop"
+path = "crates/nu-test-support/src/bins/chop.rs"
+required-features = ["test-bins"]
 
 [[bin]]
-name = "nu_plugin_add"
-path = "src/plugins/add.rs"
+name = "cococo"
+path = "crates/nu-test-support/src/bins/cococo.rs"
+required-features = ["test-bins"]
 
 [[bin]]
-name = "nu_plugin_edit"
-path = "src/plugins/edit.rs"
+name = "nonu"
+path = "crates/nu-test-support/src/bins/nonu.rs"
+required-features = ["test-bins"]
 
 [[bin]]
-name = "nu_plugin_str"
-path = "src/plugins/str.rs"
+name = "iecho"
+path = "crates/nu-test-support/src/bins/iecho.rs"
+required-features = ["test-bins"]
+
+# Core plugins that ship with `cargo install nu` by default
+# Currently, Cargo limits us to installing only one binary
+# unless we use [[bin]], so we use this as a workaround
+[[bin]]
+name = "nu_plugin_core_textview"
+path = "src/plugins/nu_plugin_core_textview.rs"
+required-features = ["textview"]
 
 [[bin]]
-name = "nu_plugin_skip"
-path = "src/plugins/skip.rs"
+name = "nu_plugin_core_inc"
+path = "src/plugins/nu_plugin_core_inc.rs"
+required-features = ["inc"]
 
 [[bin]]
-name = "nu_plugin_sys"
-path = "src/plugins/sys.rs"
+name = "nu_plugin_core_ps"
+path = "src/plugins/nu_plugin_core_ps.rs"
+required-features = ["ps"]
 
 [[bin]]
-name = "nu_plugin_tree"
-path = "src/plugins/tree.rs"
+name = "nu_plugin_core_str"
+path = "src/plugins/nu_plugin_core_str.rs"
+required-features = ["str"]
 
 [[bin]]
-name = "nu_plugin_binaryview"
-path = "src/plugins/binaryview.rs"
+name = "nu_plugin_core_sys"
+path = "src/plugins/nu_plugin_core_sys.rs"
+required-features = ["sys"]
+
+# Stable plugins
+[[bin]]
+name = "nu_plugin_stable_average"
+path = "src/plugins/nu_plugin_stable_average.rs"
+required-features = ["average"]
 
 [[bin]]
-name = "nu_plugin_textview"
-path = "src/plugins/textview.rs"
+name = "nu_plugin_stable_fetch"
+path = "src/plugins/nu_plugin_stable_fetch.rs"
+required-features = ["fetch"]
 
+[[bin]]
+name = "nu_plugin_stable_binaryview"
+path = "src/plugins/nu_plugin_stable_binaryview.rs"
+required-features = ["binaryview"]
+
+[[bin]]
+name = "nu_plugin_stable_match"
+path = "src/plugins/nu_plugin_stable_match.rs"
+required-features = ["match"]
+
+[[bin]]
+name = "nu_plugin_stable_post"
+path = "src/plugins/nu_plugin_stable_post.rs"
+required-features = ["post"]
+
+[[bin]]
+name = "nu_plugin_stable_tree"
+path = "src/plugins/nu_plugin_stable_tree.rs"
+required-features = ["tree"]
+
+# Main nu binary
 [[bin]]
 name = "nu"
 path = "src/main.rs"

LICENSE

@@ -1,6 +1,6 @@
 MIT License
 
-Copyright (c) 2019 Yehuda Katz, Jonathan Turner
+Copyright (c) 2019 - 2020 Yehuda Katz, Jonathan Turner
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

Makefile.toml

@@ -4,21 +4,12 @@ command = "lalrpop"
 args = ["src/parser/parser.lalrpop"]
 
 [tasks.baseline]
-dependencies = ["lalrpop"]
-
-[tasks.build]
 command = "cargo"
-args = ["build"]
-dependencies = ["lalrpop"]
+args = ["build", "--bins"]
 
 [tasks.run]
 command = "cargo"
-args = ["run", "--release"]
-dependencies = ["baseline"]
-
-[tasks.release]
-command = "cargo"
-args = ["build", "--release"]
+args = ["run"]
 dependencies = ["baseline"]
 
 [tasks.test]

README.md

@@ -1,148 +1,262 @@
-[![Build Status](https://dev.azure.com/nushell/nushell/_apis/build/status/nushell.nushell?branchName=master)](https://dev.azure.com/nushell/nushell/_build/latest?definitionId=2&branchName=master) [![Discord](https://img.shields.io/discord/601130461678272522.svg?logo=discord)](https://discord.gg/NtAbbGn)
+[![Gitpod Ready-to-Code](https://img.shields.io/badge/Gitpod-Ready--to--Code-blue?logo=gitpod)](https://gitpod.io/#https://github.com/nushell/nushell)
+[![Crates.io](https://img.shields.io/crates/v/nu.svg)](https://crates.io/crates/nu)
+[![Build Status](https://dev.azure.com/nushell/nushell/_apis/build/status/nushell.nushell?branchName=master)](https://dev.azure.com/nushell/nushell/_build/latest?definitionId=2&branchName=master)
+[![Discord](https://img.shields.io/discord/601130461678272522.svg?logo=discord)](https://discord.gg/NtAbbGn)
+[![The Changelog #363](https://img.shields.io/badge/The%20Changelog-%23363-61c192.svg)](https://changelog.com/podcast/363)
+
 
 # Nu Shell
 
-A modern, GitHub-era shell written in Rust
+A new type of shell.
 
-![Example of nushell](images/nushell-autocomplete4.gif "Example of nushell")
+![Example of nushell](images/nushell-autocomplete.gif "Example of nushell")
 
 # Status
 
-This project has reached a minimum-viable product level of quality. While contributors dogfood it as their daily driver, it may be instable for some commands. Future releases will work fill out missing features and improve stability. Its design is also subject to change as it matures.
+This project has reached a minimum-viable product level of quality.
+While contributors dogfood it as their daily driver, it may be unstable for some commands.
+Future releases will work to fill out missing features and improve stability.
+Its design is also subject to change as it matures.
 
-Nu comes with a set of built-in commands (listed below). If a command is unknown, the command will shell-out and execute it (using cmd on Windows or bash on Linux and MacOS), correctly passing through stdin, stdout and stderr, so things like your daily git workflows and even `vim` will work just fine.
+Nu comes with a set of built-in commands (listed below).
+If a command is unknown, the command will shell-out and execute it (using cmd on Windows or bash on Linux and macOS), correctly passing through stdin, stdout, and stderr, so things like your daily git workflows and even `vim` will work just fine.
 
-There is also a [book](https://book.nushell.sh) about Nu, currently in progress.
+# Learning more
+
+There are a few good resources to learn about Nu.
+There is a [book](https://www.nushell.sh/book/) about Nu that is currently in progress.
+The book focuses on using Nu and its core concepts.
+
+If you're a developer who would like to contribute to Nu, we're also working on a [book for developers](https://www.nushell.sh/contributor-book/) to help you get started.
+There are also [good first issues](https://github.com/nushell/nushell/issues?q=is%3Aopen+is%3Aissue+label%3A%22good+first+issue%22) to help you dive in.
+
+We also have an active [Discord](https://discord.gg/NtAbbGn) and [Twitter](https://twitter.com/nu_shell) if you'd like to come and chat with us.
+
+You can also find more learning resources in our [documentation](https://www.nushell.sh/documentation.html) site.
+
+Try it in Gitpod.
+
+[![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/#https://github.com/nushell/nushell)
 
 # Installation
 
-Up-to-date installation instructions can be found in the [installation chapter of the book](https://book.nushell.sh/en/installation).
+## Local
+
+Up-to-date installation instructions can be found in the [installation chapter of the book](https://www.nushell.sh/book/en/installation.html).  **Windows users**: please note that Nu works on Windows 10 and does not currently have Windows 7/8.1 support.
+
+To build Nu, you will need to use the **latest stable (1.39 or later)** version of the compiler.
 
 Required dependencies:
 
-* libssl
-  * on macOS (via homebrew): `brew install openssl`
-  * on Linux (on Debian/Ubuntu): `apt install libssl-dev`
+* pkg-config and libssl (only needed on Linux)
+  * on Debian/Ubuntu: `apt install pkg-config libssl-dev`
 
 Optional dependencies:
 
 * To use Nu with all possible optional features enabled, you'll also need the following:
   * on Linux (on Debian/Ubuntu): `apt install libxcb-composite0-dev libx11-dev`
 
-To install Nu via cargo:
+To install Nu via cargo (make sure you have installed [rustup](https://rustup.rs/) and the latest stable compiler via `rustup install stable`):
 
 ```
 cargo install nu
 ```
 
-You can also install Nu with all the bells and whistles:
+You can also build Nu yourself with all the bells and whistles (be sure to have installed the [dependencies](https://www.nushell.sh/book/en/installation.html#dependencies) for your platform), once you have checked out this repo with git:
 
 ```
-cargo install nu --features rawkey,clipboard
+cargo build --workspace --features=stable
 ```
 
-The following optional features are currently supported:
+## Docker
 
-* **rawkey** - direct keyboard input, which creates a smoother experience in viewing text and binaries
-* **clipboard** - integration with the native clipboard via the `clip` command
+### Quickstart
+
+Want to try Nu right away? Execute the following to get started.
+
+```bash
+docker run -it quay.io/nushell/nu:latest
+```
+
+### Guide
+
+If you want to pull a pre-built container, you can browse tags for the [nushell organization](https://quay.io/organization/nushell)
+on Quay.io. Pulling a container would come down to:
+
+```bash
+$ docker pull quay.io/nushell/nu
+$ docker pull quay.io/nushell/nu-base
+```
+
+Both "nu-base" and "nu" provide the nu binary, however nu-base also includes the source code at `/code`
+in the container and all dependencies.
+
+Optionally, you can also build the containers locally using the [dockerfiles provided](docker):
+To build the base image:
+
+```bash
+$ docker build -f docker/Dockerfile.nu-base -t nushell/nu-base .
+```
+
+And then to build the smaller container (using a Multistage build):
+
+```bash
+$ docker build -f docker/Dockerfile -t nushell/nu .
+```
+
+Either way, you can run either container as follows:
+
+```bash
+$ docker run -it nushell/nu-base
+$ docker run -it nushell/nu
+/> exit
+```
+
+The second container is a bit smaller if the size is important to you.
+
+## Packaging status
+
+[![Packaging status](https://repology.org/badge/vertical-allrepos/nushell.svg)](https://repology.org/project/nushell/versions)
+
+### Fedora
+
+[COPR repo](https://copr.fedorainfracloud.org/coprs/atim/nushell/): `sudo dnf copr enable atim/nushell -y && sudo dnf install nushell -y`
 
 # Philosophy
 
-Nu draws inspiration from projects like PowerShell, functional programming languages, and modern cli tools. Rather than thinking of files and services as raw streams of text, Nu looks at each input as something with structure. For example, when you list the contents of a directory, what you get back in a list of objects, where each object represents an item in that directory. These values can be piped through a series of steps, in a series of commands called a 'pipeline'.
+Nu draws inspiration from projects like PowerShell, functional programming languages, and modern CLI tools.
+Rather than thinking of files and services as raw streams of text, Nu looks at each input as something with structure.
+For example, when you list the contents of a directory, what you get back is a table of rows, where each row represents an item in that directory.
+These values can be piped through a series of steps, in a series of commands called a 'pipeline'.
 
 ## Pipelines
 
-In Unix, it's common to pipe between commands to split up a sophisticated command over multiple steps. Nu takes this a step further and builds heavily on the idea of _pipelines_. Just as the Unix philosophy, Nu allows commands to output from stdout and read from stdin. Additionally, commands can output structured data (you can think of this as a third kind of stream). Commands that work in the pipeline fit into one of three categories
+In Unix, it's common to pipe between commands to split up a sophisticated command over multiple steps.
+Nu takes this a step further and builds heavily on the idea of _pipelines_.
+Just as the Unix philosophy, Nu allows commands to output from stdout and read from stdin.
+Additionally, commands can output structured data (you can think of this as a third kind of stream).
+Commands that work in the pipeline fit into one of three categories:
 
 * Commands that produce a stream (eg, `ls`)
 * Commands that filter a stream (eg, `where type == "Directory"`)
-* Commands that consumes the output of the pipeline (eg, `autoview`)
+* Commands that consume the output of the pipeline (eg, `autoview`)
 
 Commands are separated by the pipe symbol (`|`) to denote a pipeline flowing left to right.
 
 ```
 /home/jonathan/Source/nushell(master)> ls | where type == "Directory" | autoview
---------+-----------+----------+--------+--------------+----------------
- name   | type      | readonly | size   | accessed     | modified
---------+-----------+----------+--------+--------------+----------------
- target | Directory |          | 4.1 KB | 19 hours ago | 19 hours ago
- images | Directory |          | 4.1 KB | 2 weeks ago  | a week ago
- tests  | Directory |          | 4.1 KB | 2 weeks ago  | 18 minutes ago
- docs   | Directory |          | 4.1 KB | a week ago   | a week ago
- .git   | Directory |          | 4.1 KB | 2 weeks ago  | 25 minutes ago
- src    | Directory |          | 4.1 KB | 2 weeks ago  | 25 minutes ago
- .cargo | Directory |          | 4.1 KB | 2 weeks ago  | 2 weeks ago
------------+-----------+----------+--------+--------------+----------------
+────┬───────────┬───────────┬──────────┬────────┬──────────────┬────────────────
+ #  │ name      │ type      │ readonly │ size   │ accessed     │ modified
+────┼───────────┼───────────┼──────────┼────────┼──────────────┼────────────────
+  0 │ .azure    │ Directory │          │ 4.1 KB │ 2 months ago │ a day ago
+  1 │ target    │ Directory │          │ 4.1 KB │ 3 days ago   │ 3 days ago
+  2 │ images    │ Directory │          │ 4.1 KB │ 2 months ago │ 2 weeks ago
+  3 │ tests     │ Directory │          │ 4.1 KB │ 2 months ago │ 37 minutes ago
+  4 │ tmp       │ Directory │          │ 4.1 KB │ 2 weeks ago  │ 2 weeks ago
+  5 │ src       │ Directory │          │ 4.1 KB │ 2 months ago │ 37 minutes ago
+  6 │ assets    │ Directory │          │ 4.1 KB │ a month ago  │ a month ago
+  7 │ docs      │ Directory │          │ 4.1 KB │ 2 months ago │ 2 months ago
+────┴───────────┴───────────┴──────────┴────────┴──────────────┴────────────────
 ```
 
-Because most of the time you'll want to see the output of a pipeline, `autoview` is assumed. We could have also written the above:
+Because most of the time you'll want to see the output of a pipeline, `autoview` is assumed.
+We could have also written the above:
 
 ```
 /home/jonathan/Source/nushell(master)> ls | where type == Directory
 ```
 
-Being able to use the same commands and compose them differently is an important philosophy in Nu. For example, we could use the built-in `ps` command as well to get a list of the running processes, using the same `where` as above.
+Being able to use the same commands and compose them differently is an important philosophy in Nu.
+For example, we could use the built-in `ps` command as well to get a list of the running processes, using the same `where` as above.
 
 ```text
-C:\Code\nushell(master)> ps | where cpu > 0
------------------- +-----+-------+-------+----------
- name              | cmd | cpu   | pid   | status
------------------- +-----+-------+-------+----------
- msedge.exe        |  -  | 0.77  | 26472 | Runnable
- nu.exe            |  -  | 7.83  | 15473 | Runnable
- SearchIndexer.exe |  -  | 82.17 | 23476 | Runnable
- BlueJeans.exe     |  -  | 4.54  | 10000 | Runnable
--------------------+-----+-------+-------+----------
+/home/jonathan/Source/nushell(master)> ps | where cpu > 0
+───┬───────┬─────────────────┬──────────┬──────────
+ # │ pid   │ name            │ status   │ cpu
+───┼───────┼─────────────────┼──────────┼──────────
+ 0 │   992 │ chrome          │ Sleeping │ 6.988768
+ 1 │  4240 │ chrome          │ Sleeping │ 5.645982
+ 2 │ 13973 │ qemu-system-x86 │ Sleeping │ 4.996551
+ 3 │ 15746 │ nu              │ Sleeping │ 84.59905
+───┴───────┴─────────────────┴──────────┴──────────
 ```
 
 ## Opening files
 
-Nu can load file and URL contents as raw text or as structured data (if it recognizes the format). For example, you can load a .toml file as structured data and explore it:
+Nu can load file and URL contents as raw text or as structured data (if it recognizes the format).
+For example, you can load a .toml file as structured data and explore it:
 
 ```
 /home/jonathan/Source/nushell(master)> open Cargo.toml
------------------+------------------+-----------------
- dependencies    | dev-dependencies | package
------------------+------------------+-----------------
- [object Object] | [object Object]  | [object Object]
------------------+------------------+-----------------
+──────────────────┬────────────────┬──────────────────
+ bin              │ dependencies   │ dev-dependencies
+──────────────────┼────────────────┼──────────────────
+ [table: 12 rows] │ [table: 1 row] │ [table: 1 row]
+──────────────────┴────────────────┴──────────────────
 ```
 
 We can pipeline this into a command that gets the contents of one of the columns:
 
 ```
 /home/jonathan/Source/nushell(master)> open Cargo.toml | get package
--------------+----------------------------+---------+---------+------+---------
- authors     | description                | edition | license | name | version
--------------+----------------------------+---------+---------+------+---------
- [list List] | A shell for the GitHub era | 2018    | MIT     | nu   | 0.2.0
--------------+----------------------------+---------+---------+------+---------
+─────────────────┬────────────────────────────┬─────────┬─────────┬──────┬─────────
+ authors         │ description                │ edition │ license │ name │ version
+─────────────────┼────────────────────────────┼─────────┼─────────┼──────┼─────────
+ [table: 3 rows] │ A shell for the GitHub era │ 2018    │ MIT     │ nu   │ 0.9.0
+─────────────────┴────────────────────────────┴─────────┴─────────┴──────┴─────────
 ```
 
 Finally, we can use commands outside of Nu once we have the data we want:
 
 ```
 /home/jonathan/Source/nushell(master)> open Cargo.toml | get package.version | echo $it
-0.2.0
+0.9.0
 ```
 
 Here we use the variable `$it` to refer to the value being piped to the external command.
 
+## Configuration
+
+Nu has early support for configuring the shell. It currently supports the following settings:
+
+| Variable        | Type                 | Description                                                    |
+| --------------- | -------------------- | -------------------------------------------------------------- |
+| path            | table of strings     | PATH to use to find binaries                                   |
+| env             | row                  | the environment variables to pass to external commands         |
+| ctrlc_exit      | boolean              | whether or not to exit Nu after multiple ctrl-c presses        |
+| table_mode      | "light" or other     | enable lightweight or normal tables                            |
+| edit_mode       | "vi" or "emacs"      | changes line editing to "vi" or "emacs" mode                   |
+| completion_mode | "circular" or "list" | changes completion type to "circular" (default) or "list" mode |
+
+To set one of these variables, you can use `config --set`. For example:
+
+```
+> config --set [edit_mode "vi"]
+> config --set [path $nu.path]
+```
+
 ## Shells
 
-By default, Nu will work inside of a single directory and allow you to navigate around your filesystem. Sometimes, you'll want to work in multiple directories at the same time. For this, Nu offers a way of adding additional working directories that you can jump between. 
+Nu will work inside of a single directory and allow you to navigate around your filesystem by default.
+Nu also offers a way of adding additional working directories that you can jump between, allowing you to work in multiple directories at the same time.
 
-To do so, use the `enter` command, which will allow you create a new "shell" and enter it at the specified path. You can toggle between this new shell and the original shell with the `p` (for previous) and `n` (for next), allowing you to navigate around a ring buffer of shells. Once you're done with a shell, you can `exit` it and remove it from the ring buffer.
+To do so, use the `enter` command, which will allow you create a new "shell" and enter it at the specified path.
+You can toggle between this new shell and the original shell with the `p` (for previous) and `n` (for next), allowing you to navigate around a ring buffer of shells.
+Once you're done with a shell, you can `exit` it and remove it from the ring buffer.
 
 Finally, to get a list of all the current shells, you can use the `shells` command.
 
 ## Plugins
 
-Nu supports plugins that offer additional functionality to the shell and follow the same object model that built-in commands use. This allows you to extend nu for your needs.
+Nu supports plugins that offer additional functionality to the shell and follow the same structured data model that built-in commands use.
+This allows you to extend nu for your needs.
 
 There are a few examples in the `plugins` directory.
 
-Plugins are binaries that are available in your path and follow a "nu_plugin_*" naming convention. These binaries interact with nu via a simple JSON-RPC protocol where the command identifies itself and passes along its configuration, which then makes it available for use. If the plugin is a filter, data streams to it one element at a time, and it can stream data back in return via stdin/stdout. If the plugin is a sink, it is given the full vector of final data and is given free reign over stdin/stdout to use as it pleases.
+Plugins are binaries that are available in your path and follow a `nu_plugin_*` naming convention.
+These binaries interact with nu via a simple JSON-RPC protocol where the command identifies itself and passes along its configuration, which then makes it available for use.
+If the plugin is a filter, data streams to it one element at a time, and it can stream data back in return via stdin/stdout.
+If the plugin is a sink, it is given the full vector of final data and is given free reign over stdin/stdout to use as it pleases.
 
 # Goals
 
@@ -154,83 +268,15 @@ Nu adheres closely to a set of goals that make up its design philosophy. As feat
 
 * Nu's workflow and tools should have the usability in day-to-day experience of using a shell in 2019 (and beyond).
 
-* Nu views data as both structured and unstructured. It is an object shell like PowerShell.
+* Nu views data as both structured and unstructured. It is a structured shell like PowerShell.
 
-* Finally, Nu views data functionally. Rather than using mutation, pipelines act as a mean to load, change, and save data without mutable state.
+* Finally, Nu views data functionally. Rather than using mutation, pipelines act as a means to load, change, and save data without mutable state.
 
 # Commands
-## Initial commands
-| command | description |
-| ------------- | ------------- |
-| cd path | Change to a new path |
-| cp source path | Copy files |
-| ls (path) | View the contents of the current or given path |
-| mkdir path | Make directories, creates intermediary directories as required. |
-| mv source target | Move files or directories. |
-| date (--utc) | Get the current datetime |
-| ps | View current processes |
-| sys | View information about the current system |
-| open {filename or url} | Load a file into a cell, convert to table if possible (avoid by appending '--raw') |
-| rm   {file or directory} | Remove a file, (for removing directory append '--recursive') |
-| exit (--now) | Exit the current shell (or all shells) |
-| enter (path) | Create a new shell and begin at this path |
-| p | Go to previous shell |
-| n | Go to next shell |
-| shells | Display the list of current shells |
 
-## Filters on tables (structured data)
-| command | description |
-| ------------- | ------------- |
-| pick ...columns | Down-select table to only these columns |
-| reject ...columns | Remove the given columns from the table |
-| get column-or-column-path | Open given cells as text |
-| sort-by ...columns | Sort by the given columns |
-| where condition | Filter table to match the condition |
-| inc (field) | Increment a value or version. Optional use the field of a table |
-| add field value | Add a new field to the table |
-| sum | Sum a column of values |
-| edit field value | Edit an existing field to have a new value |
-| skip amount | Skip a number of rows |
-| first amount | Show only the first number of rows |
-| nth row-number | Return only the selected row |
-| str (field) | Apply string function. Optional use the field of a table |
-| tags | Read the tags (metadata) for values |
-| from-array | Expand an array/list into rows |
-| to-array | Collapse rows into a single list |
-| to-json | Convert table into .json text |
-| to-toml | Convert table into .toml text |
-| to-yaml | Convert table into .yaml text |
-| to-csv  | Convert table into .csv text  |
-
-## Filters on text (unstructured data)
-| command | description |
-| ------------- | ------------- |
-| from-csv | Parse text as .csv and create table |
-| from-ini | Parse text as .ini and create table |
-| from-json | Parse text as .json and create table |
-| from-toml | Parse text as .toml and create table |
-| from-xml | Parse text as .xml and create a table |
-| from-yaml | Parse text as a .yaml/.yml and create a table |
-| lines | Split single string into rows, one per line |
-| size | Gather word count statistics on the text |
-| split-column sep ...fields | Split row contents across multiple columns via the separator |
-| split-row sep | Split row contents over multiple rows via the separator |
-| trim | Trim leading and following whitespace from text data |
-| {external-command} $it | Run external command with given arguments, replacing $it with each row text |
-
-## Consuming commands
-| command | description |
-| ------------- | ------------- |
-| autoview | View the contents of the pipeline as a table or list |
-| binaryview | Autoview of binary data |
-| clip | Copy the contents of the pipeline to the copy/paste buffer |
-| save filename | Save the contents of the pipeline to a file |
-| table | View the contents of the pipeline as a table |
-| textview | Autoview of text data |
-| tree | View the contents of the pipeline as a tree |
-| vtable | View the contents of the pipeline as a vertical (rotated) table |
+You can find a list of Nu commands, complete with documentation, in [quick command references](https://www.nushell.sh/documentation.html#quick-command-references).
 
 # License
 
-The project is made available under the MIT license. See "LICENSE" for more information.
+The project is made available under the MIT license. See the `LICENSE` file for more information.
 

TODO.md

@@ -0,0 +1,60 @@
+This pattern is extremely repetitive and can be abstracted:
+
+```rs
+    let args = args.evaluate_once(registry)?;
+    let tag = args.name_tag();
+    let input = args.input;
+
+    let stream = async_stream! {
+        let values: Vec<Value> = input.values.collect().await;
+
+        let mut concat_string = String::new();
+        let mut latest_tag: Option<Tag> = None;
+
+        for value in values {
+            latest_tag = Some(value_tag.clone());
+            let value_span = value.tag.span;
+
+            match &value.value {
+                UntaggedValue::Primitive(Primitive::String(s)) => {
+                    concat_string.push_str(&s);
+                    concat_string.push_str("\n");
+                }
+                _ => yield Err(ShellError::labeled_error_with_secondary(
+                    "Expected a string from pipeline",
+                    "requires string input",
+                    name_span,
+                    "value originates from here",
+                    value_span,
+                )),
+
+            }
+        }
+
+```
+
+Mandatory and Optional in parse_command
+
+trace_remaining?
+
+select_fields and select_fields take unnecessary Tag
+
+Value#value should be Value#untagged
+
+Unify dictionary building, probably around a macro
+
+sys plugin in own crate
+
+textview in own crate
+
+Combine atomic and atomic_parse in parser
+
+at_end_possible_ws needs to be comment and separator sensitive
+
+Eliminate unnecessary `nodes` parser
+
+#[derive(HasSpan)]
+
+Figure out a solution for the duplication in stuff like NumberShape vs. NumberExpressionShape
+
+use `struct Expander` from signature.rs

build.rs

@@ -0,0 +1,3 @@
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    nu_build::build()
+}

crates/nu-build/Cargo.toml

@@ -0,0 +1,16 @@
+[package]
+name = "nu-build"
+version = "0.12.0"
+authors = ["Yehuda Katz <wycats@gmail.com>", "Jonathan Turner <jonathan.d.turner@gmail.com>", "Andrés N. Robalino <andres@androbtech.com>"]
+edition = "2018"
+description = "Core build system for nushell"
+license = "MIT"
+
+[lib]
+doctest = false
+
+[dependencies]
+serde = { version = "1.0.103", features = ["derive"] }
+lazy_static = "1.4.0"
+serde_json = "1.0.44"
+toml = "0.5.5"

crates/nu-build/src/lib.rs

@@ -0,0 +1,80 @@
+use lazy_static::lazy_static;
+use serde::Deserialize;
+use std::collections::BTreeMap;
+use std::collections::HashMap;
+use std::collections::HashSet;
+use std::env;
+use std::path::{Path, PathBuf};
+use std::sync::Mutex;
+
+lazy_static! {
+    static ref WORKSPACES: Mutex<BTreeMap<String, &'static Path>> = Mutex::new(BTreeMap::new());
+}
+
+// got from https://github.com/mitsuhiko/insta/blob/b113499249584cb650150d2d01ed96ee66db6b30/src/runtime.rs#L67-L88
+
+fn get_cargo_workspace(manifest_dir: &str) -> Result<Option<&Path>, Box<dyn std::error::Error>> {
+    let mut workspaces = WORKSPACES.lock()?;
+    if let Some(rv) = workspaces.get(manifest_dir) {
+        Ok(Some(rv))
+    } else {
+        #[derive(Deserialize)]
+        struct Manifest {
+            workspace_root: String,
+        }
+        let output = std::process::Command::new(env!("CARGO"))
+            .arg("metadata")
+            .arg("--format-version=1")
+            .current_dir(manifest_dir)
+            .output()?;
+        let manifest: Manifest = serde_json::from_slice(&output.stdout)?;
+        let path = Box::leak(Box::new(PathBuf::from(manifest.workspace_root)));
+        workspaces.insert(manifest_dir.to_string(), path.as_path());
+        Ok(workspaces.get(manifest_dir).cloned())
+    }
+}
+
+#[derive(Deserialize)]
+struct Feature {
+    #[allow(unused)]
+    description: String,
+    enabled: bool,
+}
+
+pub fn build() -> Result<(), Box<dyn std::error::Error>> {
+    let input = env::var("CARGO_MANIFEST_DIR")?;
+
+    let all_on = env::var("NUSHELL_ENABLE_ALL_FLAGS").is_ok();
+    let flags: HashSet<String> = env::var("NUSHELL_ENABLE_FLAGS")
+        .map(|s| s.split(',').map(|s| s.to_string()).collect())
+        .unwrap_or_else(|_| HashSet::new());
+
+    if all_on && !flags.is_empty() {
+        println!(
+            "cargo:warning=Both NUSHELL_ENABLE_ALL_FLAGS and NUSHELL_ENABLE_FLAGS were set. You don't need both."
+        );
+    }
+
+    let workspace = match get_cargo_workspace(&input)? {
+        // If the crate is being downloaded from crates.io, it won't have a workspace root, and that's ok
+        None => return Ok(()),
+        Some(workspace) => workspace,
+    };
+
+    let path = Path::new(&workspace).join("features.toml");
+
+    // If the crate is being downloaded from crates.io, it won't have a features.toml, and that's ok
+    if !path.exists() {
+        return Ok(());
+    }
+
+    let toml: HashMap<String, Feature> = toml::from_str(&std::fs::read_to_string(path)?)?;
+
+    for (key, value) in toml.iter() {
+        if value.enabled || all_on || flags.contains(key) {
+            println!("cargo:rustc-cfg={}", key);
+        }
+    }
+
+    Ok(())
+}

crates/nu-cli/Cargo.toml

@@ -0,0 +1,110 @@
+[package]
+name = "nu-cli"
+version = "0.12.0"
+authors = ["Yehuda Katz <wycats@gmail.com>", "Jonathan Turner <jonathan.d.turner@gmail.com>", "Andrés N. Robalino <andres@androbtech.com>"]
+description = "CLI for nushell"
+edition = "2018"
+license = "MIT"
+
+[lib]
+doctest = false
+
+[dependencies]
+nu-source = { version = "0.12.0", path = "../nu-source" }
+nu-plugin = { version = "0.12.0", path = "../nu-plugin" }
+nu-protocol = { version = "0.12.0", path = "../nu-protocol" }
+nu-errors = { version = "0.12.0", path = "../nu-errors" }
+nu-parser = { version = "0.12.0", path = "../nu-parser" }
+nu-value-ext = { version = "0.12.0", path = "../nu-value-ext" }
+nu-macros = { version = "0.12.0", path = "../nu-macros" }
+nu-test-support = { version = "0.12.0", path = "../nu-test-support" }
+
+ansi_term = "0.12.1"
+app_dirs = "1.2.1"
+async-stream = "0.2"
+base64 = "0.12.0"
+bigdecimal = { version = "0.1.0", features = ["serde"] }
+bson = { version = "0.14.1", features = ["decimal128"] }
+byte-unit = "3.0.3"
+bytes = "0.5.4"
+calamine = "0.16"
+cfg-if = "0.1"
+chrono = { version = "0.4.11", features = ["serde"] }
+clap = "2.33.0"
+csv = "1.1"
+ctrlc = "3.1.4"
+derive-new = "0.5.8"
+dirs = "2.0.2"
+dunce = "1.0.0"
+filesize = "0.1.0"
+futures = { version = "0.3", features = ["compat", "io-compat"] }
+futures-util = "0.3.4"
+futures_codec = "0.4"
+getset = "0.1.0"
+git2 = { version = "0.13.0", default_features = false }
+glob = "0.3.0"
+hex = "0.4"
+htmlescape = "0.3.1"
+ical = "0.6.*"
+ichwh = "0.3"
+indexmap = { version = "1.3.2", features = ["serde-1"] }
+itertools = "0.9.0"
+language-reporting = "0.4.0"
+log = "0.4.8"
+meval = "0.2"
+natural = "0.5.0"
+nom = "5.0.1"
+nom-tracable = "0.4.1"
+nom_locate = "1.0.0"
+num-bigint = { version = "0.2.6", features = ["serde"] }
+num-traits = "0.2.11"
+parking_lot = "0.10.0"
+pin-utils = "0.1.0-alpha.4"
+pretty-hex = "0.1.1"
+pretty_env_logger = "0.4.0"
+prettytable-rs = "0.8.0"
+ptree = {version = "0.2" }
+query_interface = "0.3.5"
+rand = "0.7"
+regex = "1"
+roxmltree = "0.10.0"
+rustyline = "6.0.0"
+serde = { version = "1.0.105", features = ["derive"] }
+serde-hjson = "0.9.1"
+serde_bytes = "0.11.3"
+serde_ini = "0.2.0"
+serde_json = "1.0.48"
+serde_urlencoded = "0.6.1"
+serde_yaml = "0.8"
+shellexpand = "2.0.0"
+strip-ansi-escapes = "0.1.0"
+tempfile = "3.1.0"
+term = "0.5.2"
+termcolor = "1.1.0"
+textwrap = {version = "0.11.0", features = ["term_size"]}
+toml = "0.5.6"
+trash = "1.0.0"
+typetag = "0.1.4"
+umask = "0.1"
+unicode-xid = "0.2.0"
+
+clipboard = { version = "0.5", optional = true }
+starship = { version = "0.38.0", optional = true }
+
+[target.'cfg(unix)'.dependencies]
+users = "0.9"
+
+[dependencies.rusqlite]
+version = "0.21.0"
+features = ["bundled", "blob"]
+
+[dev-dependencies]
+pretty_assertions = "0.6.1"
+
+[build-dependencies]
+nu-build = { version = "0.12.0", path = "../nu-build" }
+
+[features]
+stable = []
+starship-prompt = ["starship"]
+clipboard-cli = ["clipboard"]

crates/nu-cli/src/cli.rs

@@ -0,0 +1,800 @@
+use crate::commands::classified::external::{MaybeTextCodec, StringOrBinary};
+use crate::commands::classified::pipeline::run_pipeline;
+use crate::commands::plugin::JsonRpc;
+use crate::commands::plugin::{PluginCommand, PluginSink};
+use crate::commands::whole_stream_command;
+use crate::context::Context;
+#[cfg(not(feature = "starship-prompt"))]
+use crate::git::current_branch;
+use crate::prelude::*;
+use futures_codec::FramedRead;
+
+use nu_errors::ShellError;
+use nu_parser::{
+    ClassifiedCommand, ClassifiedPipeline, ExternalCommand, PipelineShape, SpannedToken,
+    TokensIterator,
+};
+use nu_protocol::{Primitive, ReturnSuccess, Signature, UntaggedValue, Value};
+
+use log::{debug, log_enabled, trace};
+use rustyline::error::ReadlineError;
+use rustyline::{
+    self, config::Configurer, config::EditMode, At, Cmd, ColorMode, CompletionType, Config, Editor,
+    KeyPress, Movement, Word,
+};
+use std::error::Error;
+use std::io::{BufRead, BufReader, Write};
+use std::iter::Iterator;
+use std::path::PathBuf;
+use std::sync::atomic::Ordering;
+
+fn load_plugin(path: &std::path::Path, context: &mut Context) -> Result<(), ShellError> {
+    let mut child = std::process::Command::new(path)
+        .stdin(std::process::Stdio::piped())
+        .stdout(std::process::Stdio::piped())
+        .spawn()
+        .expect("Failed to spawn child process");
+
+    let stdin = child.stdin.as_mut().expect("Failed to open stdin");
+    let stdout = child.stdout.as_mut().expect("Failed to open stdout");
+
+    let mut reader = BufReader::new(stdout);
+
+    let request = JsonRpc::new("config", Vec::<Value>::new());
+    let request_raw = serde_json::to_string(&request)?;
+    stdin.write_all(format!("{}\n", request_raw).as_bytes())?;
+    let path = dunce::canonicalize(path)?;
+
+    let mut input = String::new();
+    let result = match reader.read_line(&mut input) {
+        Ok(count) => {
+            trace!("processing response ({} bytes)", count);
+            trace!("response: {}", input);
+
+            let response = serde_json::from_str::<JsonRpc<Result<Signature, ShellError>>>(&input);
+            match response {
+                Ok(jrpc) => match jrpc.params {
+                    Ok(params) => {
+                        let fname = path.to_string_lossy();
+
+                        trace!("processing {:?}", params);
+
+                        let name = params.name.clone();
+                        let fname = fname.to_string();
+
+                        if context.get_command(&name).is_some() {
+                            trace!("plugin {:?} already loaded.", &name);
+                        } else if params.is_filter {
+                            context.add_commands(vec![whole_stream_command(PluginCommand::new(
+                                name, fname, params,
+                            ))]);
+                        } else {
+                            context.add_commands(vec![whole_stream_command(PluginSink::new(
+                                name, fname, params,
+                            ))]);
+                        }
+                        Ok(())
+                    }
+                    Err(e) => Err(e),
+                },
+                Err(e) => {
+                    trace!("incompatible plugin {:?}", input);
+                    Err(ShellError::untagged_runtime_error(format!(
+                        "Error: {:?}",
+                        e
+                    )))
+                }
+            }
+        }
+        Err(e) => Err(ShellError::untagged_runtime_error(format!(
+            "Error: {:?}",
+            e
+        ))),
+    };
+
+    let _ = child.wait();
+
+    result
+}
+
+fn search_paths() -> Vec<std::path::PathBuf> {
+    use std::env;
+
+    let mut search_paths = Vec::new();
+
+    // Automatically add path `nu` is in as a search path
+    if let Ok(exe_path) = env::current_exe() {
+        if let Some(exe_dir) = exe_path.parent() {
+            search_paths.push(exe_dir.to_path_buf());
+        }
+    }
+
+    #[cfg(not(debug_assertions))]
+    {
+        match env::var_os("PATH") {
+            Some(paths) => {
+                search_paths.extend(env::split_paths(&paths).collect::<Vec<_>>());
+            }
+            None => println!("PATH is not defined in the environment."),
+        }
+    }
+
+    search_paths
+}
+
+pub fn load_plugins(context: &mut Context) -> Result<(), ShellError> {
+    let opts = glob::MatchOptions {
+        case_sensitive: false,
+        require_literal_separator: false,
+        require_literal_leading_dot: false,
+    };
+
+    for path in search_paths() {
+        let mut pattern = path.to_path_buf();
+
+        pattern.push(std::path::Path::new("nu_plugin_[a-z0-9][a-z0-9]*"));
+
+        match glob::glob_with(&pattern.to_string_lossy(), opts) {
+            Err(_) => {}
+            Ok(binaries) => {
+                for bin in binaries.filter_map(Result::ok) {
+                    if !bin.is_file() {
+                        continue;
+                    }
+
+                    let bin_name = {
+                        if let Some(name) = bin.file_name() {
+                            match name.to_str() {
+                                Some(raw) => raw,
+                                None => continue,
+                            }
+                        } else {
+                            continue;
+                        }
+                    };
+
+                    let is_valid_name = {
+                        #[cfg(windows)]
+                        {
+                            bin_name
+                                .chars()
+                                .all(|c| c.is_ascii_alphanumeric() || c == '_' || c == '.')
+                        }
+
+                        #[cfg(not(windows))]
+                        {
+                            bin_name
+                                .chars()
+                                .all(|c| c.is_ascii_alphanumeric() || c == '_')
+                        }
+                    };
+
+                    let is_executable = {
+                        #[cfg(windows)]
+                        {
+                            bin_name.ends_with(".exe") || bin_name.ends_with(".bat")
+                        }
+
+                        #[cfg(not(windows))]
+                        {
+                            true
+                        }
+                    };
+
+                    if is_valid_name && is_executable {
+                        trace!("Trying {:?}", bin.display());
+
+                        // we are ok if this plugin load fails
+                        let _ = load_plugin(&bin, context);
+                    }
+                }
+            }
+        }
+    }
+
+    Ok(())
+}
+
+pub struct History;
+
+impl History {
+    pub fn path() -> PathBuf {
+        const FNAME: &str = "history.txt";
+        config::user_data()
+            .map(|mut p| {
+                p.push(FNAME);
+                p
+            })
+            .unwrap_or_else(|_| PathBuf::from(FNAME))
+    }
+}
+
+#[allow(dead_code)]
+fn create_default_starship_config() -> Option<toml::Value> {
+    let mut map = toml::value::Table::new();
+    map.insert("add_newline".into(), toml::Value::Boolean(false));
+
+    let mut git_branch = toml::value::Table::new();
+    git_branch.insert("symbol".into(), toml::Value::String("📙 ".into()));
+    map.insert("git_branch".into(), toml::Value::Table(git_branch));
+
+    let mut git_status = toml::value::Table::new();
+    git_status.insert("disabled".into(), toml::Value::Boolean(true));
+    map.insert("git_status".into(), toml::Value::Table(git_status));
+
+    Some(toml::Value::Table(map))
+}
+
+pub fn create_default_context(
+    syncer: &mut crate::env::environment_syncer::EnvironmentSyncer,
+) -> Result<Context, Box<dyn Error>> {
+    syncer.load_environment();
+
+    let mut context = Context::basic()?;
+    syncer.sync_env_vars(&mut context);
+    syncer.sync_path_vars(&mut context);
+
+    {
+        use crate::commands::*;
+
+        context.add_commands(vec![
+            // System/file operations
+            whole_stream_command(Pwd),
+            per_item_command(Ls),
+            per_item_command(Du),
+            whole_stream_command(Cd),
+            per_item_command(Remove),
+            per_item_command(Open),
+            whole_stream_command(Config),
+            per_item_command(Help),
+            per_item_command(History),
+            whole_stream_command(Save),
+            per_item_command(Touch),
+            per_item_command(Cpy),
+            whole_stream_command(Date),
+            per_item_command(Calc),
+            per_item_command(Mkdir),
+            per_item_command(Move),
+            per_item_command(Kill),
+            whole_stream_command(Version),
+            whole_stream_command(Clear),
+            whole_stream_command(What),
+            whole_stream_command(Which),
+            whole_stream_command(Debug),
+            // Statistics
+            whole_stream_command(Size),
+            whole_stream_command(Count),
+            // Metadata
+            whole_stream_command(Tags),
+            // Shells
+            whole_stream_command(Next),
+            whole_stream_command(Previous),
+            whole_stream_command(Shells),
+            per_item_command(Enter),
+            whole_stream_command(Exit),
+            // Viewers
+            whole_stream_command(Autoview),
+            whole_stream_command(Table),
+            // Text manipulation
+            whole_stream_command(SplitColumn),
+            whole_stream_command(SplitRow),
+            whole_stream_command(Lines),
+            whole_stream_command(Trim),
+            per_item_command(Echo),
+            per_item_command(Parse),
+            // Column manipulation
+            whole_stream_command(Reject),
+            whole_stream_command(Pick),
+            whole_stream_command(Get),
+            per_item_command(Edit),
+            per_item_command(Insert),
+            whole_stream_command(SplitBy),
+            // Row manipulation
+            whole_stream_command(Reverse),
+            whole_stream_command(Append),
+            whole_stream_command(Prepend),
+            whole_stream_command(SortBy),
+            whole_stream_command(GroupBy),
+            whole_stream_command(First),
+            whole_stream_command(Last),
+            whole_stream_command(Skip),
+            whole_stream_command(Nth),
+            per_item_command(Format),
+            per_item_command(Where),
+            whole_stream_command(Compact),
+            whole_stream_command(Default),
+            whole_stream_command(SkipWhile),
+            whole_stream_command(Range),
+            whole_stream_command(Rename),
+            whole_stream_command(Uniq),
+            // Table manipulation
+            whole_stream_command(Shuffle),
+            whole_stream_command(Wrap),
+            whole_stream_command(Pivot),
+            whole_stream_command(Headers),
+            // Data processing
+            whole_stream_command(Histogram),
+            whole_stream_command(Sum),
+            // File format output
+            whole_stream_command(ToBSON),
+            whole_stream_command(ToCSV),
+            whole_stream_command(ToHTML),
+            whole_stream_command(ToJSON),
+            whole_stream_command(ToSQLite),
+            whole_stream_command(ToDB),
+            whole_stream_command(ToMarkdown),
+            whole_stream_command(ToTOML),
+            whole_stream_command(ToTSV),
+            whole_stream_command(ToURL),
+            whole_stream_command(ToYAML),
+            // File format input
+            whole_stream_command(FromCSV),
+            whole_stream_command(FromTSV),
+            whole_stream_command(FromSSV),
+            whole_stream_command(FromINI),
+            whole_stream_command(FromBSON),
+            whole_stream_command(FromJSON),
+            whole_stream_command(FromODS),
+            whole_stream_command(FromDB),
+            whole_stream_command(FromSQLite),
+            whole_stream_command(FromTOML),
+            whole_stream_command(FromURL),
+            whole_stream_command(FromXLSX),
+            whole_stream_command(FromXML),
+            whole_stream_command(FromYAML),
+            whole_stream_command(FromYML),
+            whole_stream_command(FromIcs),
+            whole_stream_command(FromVcf),
+        ]);
+
+        cfg_if::cfg_if! {
+            if #[cfg(data_processing_primitives)] {
+                context.add_commands(vec![
+                whole_stream_command(ReduceBy),
+                whole_stream_command(EvaluateBy),
+                whole_stream_command(TSortBy),
+                whole_stream_command(MapMaxBy),
+                ]);
+            }
+        }
+
+        #[cfg(feature = "clipboard")]
+        {
+            context.add_commands(vec![whole_stream_command(
+                crate::commands::clip::clipboard::Clip,
+            )]);
+        }
+    }
+
+    Ok(context)
+}
+
+pub async fn run_pipeline_standalone(
+    pipeline: String,
+    redirect_stdin: bool,
+    context: &mut Context,
+) -> Result<(), Box<dyn Error>> {
+    let line = process_line(Ok(pipeline), context, redirect_stdin, false).await;
+
+    match line {
+        LineResult::Success(line) => {
+            let error_code = {
+                let errors = context.current_errors.clone();
+                let errors = errors.lock();
+
+                if errors.len() > 0 {
+                    1
+                } else {
+                    0
+                }
+            };
+
+            context.maybe_print_errors(Text::from(line));
+            if error_code != 0 {
+                std::process::exit(error_code);
+            }
+        }
+
+        LineResult::Error(line, err) => {
+            context.with_host(|host| {
+                print_err(err, host, &Text::from(line.clone()));
+            });
+
+            context.maybe_print_errors(Text::from(line));
+            std::process::exit(1);
+        }
+
+        _ => {}
+    }
+
+    Ok(())
+}
+
+/// The entry point for the CLI. Will register all known internal commands, load experimental commands, load plugins, then prepare the prompt and line reader for input.
+pub async fn cli() -> Result<(), Box<dyn Error>> {
+    let mut syncer = crate::env::environment_syncer::EnvironmentSyncer::new();
+    let mut context = create_default_context(&mut syncer)?;
+
+    let _ = load_plugins(&mut context);
+
+    let config = Config::builder().color_mode(ColorMode::Forced).build();
+    let mut rl: Editor<_> = Editor::with_config(config);
+
+    // add key bindings to move over a whole word with Ctrl+ArrowLeft and Ctrl+ArrowRight
+    rl.bind_sequence(
+        KeyPress::ControlLeft,
+        Cmd::Move(Movement::BackwardWord(1, Word::Vi)),
+    );
+    rl.bind_sequence(
+        KeyPress::ControlRight,
+        Cmd::Move(Movement::ForwardWord(1, At::AfterEnd, Word::Vi)),
+    );
+
+    #[cfg(windows)]
+    {
+        let _ = ansi_term::enable_ansi_support();
+    }
+
+    // we are ok if history does not exist
+    let _ = rl.load_history(&History::path());
+
+    let cc = context.ctrl_c.clone();
+    ctrlc::set_handler(move || {
+        cc.store(true, Ordering::SeqCst);
+    })
+    .expect("Error setting Ctrl-C handler");
+    let mut ctrlcbreak = false;
+    loop {
+        if context.ctrl_c.load(Ordering::SeqCst) {
+            context.ctrl_c.store(false, Ordering::SeqCst);
+            continue;
+        }
+
+        let cwd = context.shell_manager.path();
+
+        rl.set_helper(Some(crate::shell::Helper::new(context.clone())));
+
+        let edit_mode = config::config(Tag::unknown())?
+            .get("edit_mode")
+            .map(|s| match s.value.expect_string() {
+                "vi" => EditMode::Vi,
+                "emacs" => EditMode::Emacs,
+                _ => EditMode::Emacs,
+            })
+            .unwrap_or(EditMode::Emacs);
+
+        rl.set_edit_mode(edit_mode);
+
+        let completion_mode = config::config(Tag::unknown())?
+            .get("completion_mode")
+            .map(|s| match s.value.expect_string() {
+                "list" => CompletionType::List,
+                "circular" => CompletionType::Circular,
+                _ => CompletionType::Circular,
+            })
+            .unwrap_or(CompletionType::Circular);
+
+        rl.set_completion_type(completion_mode);
+
+        let colored_prompt = {
+            #[cfg(feature = "starship-prompt")]
+            {
+                std::env::set_var("STARSHIP_SHELL", "");
+                let mut starship_context =
+                    starship::context::Context::new_with_dir(clap::ArgMatches::default(), cwd);
+
+                match starship_context.config.config {
+                    None => {
+                        starship_context.config.config = create_default_starship_config();
+                    }
+                    Some(toml::Value::Table(t)) if t.is_empty() => {
+                        starship_context.config.config = create_default_starship_config();
+                    }
+                    _ => {}
+                };
+                starship::print::get_prompt(starship_context)
+            }
+            #[cfg(not(feature = "starship-prompt"))]
+            {
+                format!(
+                    "\x1b[32m{}{}\x1b[m> ",
+                    cwd,
+                    match current_branch() {
+                        Some(s) => format!("({})", s),
+                        None => "".to_string(),
+                    }
+                )
+            }
+        };
+
+        let prompt = {
+            if let Ok(bytes) = strip_ansi_escapes::strip(&colored_prompt) {
+                String::from_utf8_lossy(&bytes).to_string()
+            } else {
+                "> ".to_string()
+            }
+        };
+
+        rl.helper_mut().expect("No helper").colored_prompt = colored_prompt;
+        let mut initial_command = Some(String::new());
+        let mut readline = Err(ReadlineError::Eof);
+        while let Some(ref cmd) = initial_command {
+            readline = rl.readline_with_initial(&prompt, (&cmd, ""));
+            initial_command = None;
+        }
+
+        let line = process_line(readline, &mut context, false, true).await;
+
+        // Check the config to see if we need to update the path
+        // TODO: make sure config is cached so we don't path this load every call
+        // FIXME: we probably want to be a bit more graceful if we can't set the environment
+        syncer.reload();
+        syncer.sync_env_vars(&mut context);
+        syncer.sync_path_vars(&mut context);
+
+        match line {
+            LineResult::Success(line) => {
+                rl.add_history_entry(line.clone());
+                let _ = rl.save_history(&History::path());
+                context.maybe_print_errors(Text::from(line));
+            }
+
+            LineResult::Error(line, err) => {
+                rl.add_history_entry(line.clone());
+                let _ = rl.save_history(&History::path());
+
+                context.with_host(|host| {
+                    print_err(err, host, &Text::from(line.clone()));
+                });
+
+                context.maybe_print_errors(Text::from(line.clone()));
+            }
+
+            LineResult::CtrlC => {
+                let config_ctrlc_exit = config::config(Tag::unknown())?
+                    .get("ctrlc_exit")
+                    .map(|s| match s.value.expect_string() {
+                        "true" => true,
+                        _ => false,
+                    })
+                    .unwrap_or(false); // default behavior is to allow CTRL-C spamming similar to other shells
+
+                if !config_ctrlc_exit {
+                    continue;
+                }
+
+                if ctrlcbreak {
+                    let _ = rl.save_history(&History::path());
+                    std::process::exit(0);
+                } else {
+                    context.with_host(|host| host.stdout("CTRL-C pressed (again to quit)"));
+                    ctrlcbreak = true;
+                    continue;
+                }
+            }
+
+            LineResult::Break => {
+                break;
+            }
+        }
+        ctrlcbreak = false;
+    }
+
+    // we are ok if we can not save history
+    let _ = rl.save_history(&History::path());
+
+    Ok(())
+}
+
+fn chomp_newline(s: &str) -> &str {
+    if s.ends_with('\n') {
+        &s[..s.len() - 1]
+    } else {
+        s
+    }
+}
+
+enum LineResult {
+    Success(String),
+    Error(String, ShellError),
+    CtrlC,
+    Break,
+}
+
+/// Process the line by parsing the text to turn it into commands, classify those commands so that we understand what is being called in the pipeline, and then run this pipeline
+async fn process_line(
+    readline: Result<String, ReadlineError>,
+    ctx: &mut Context,
+    redirect_stdin: bool,
+    cli_mode: bool,
+) -> LineResult {
+    match &readline {
+        Ok(line) if line.trim() == "" => LineResult::Success(line.clone()),
+
+        Ok(line) => {
+            let line = chomp_newline(line);
+
+            let result = match nu_parser::parse(&line) {
+                Err(err) => {
+                    return LineResult::Error(line.to_string(), err);
+                }
+
+                Ok(val) => val,
+            };
+
+            debug!("=== Parsed ===");
+            debug!("{:#?}", result);
+
+            let pipeline = classify_pipeline(&result, &ctx, &Text::from(line));
+
+            if let Some(failure) = pipeline.failed {
+                return LineResult::Error(line.to_string(), failure.into());
+            }
+
+            // There's a special case to check before we process the pipeline:
+            // If we're giving a path by itself
+            // ...and it's not a command in the path
+            // ...and it doesn't have any arguments
+            // ...and we're in the CLI
+            // ...then change to this directory
+            if cli_mode && pipeline.commands.list.len() == 1 {
+                if let ClassifiedCommand::External(ExternalCommand {
+                    ref name, ref args, ..
+                }) = pipeline.commands.list[0]
+                {
+                    if dunce::canonicalize(name).is_ok()
+                        && PathBuf::from(name).is_dir()
+                        && ichwh::which(name).await.unwrap_or(None).is_none()
+                        && args.list.is_empty()
+                    {
+                        // Here we work differently if we're in Windows because of the expected Windows behavior
+                        #[cfg(windows)]
+                        {
+                            if name.ends_with(':') {
+                                // This looks like a drive shortcut. We need to a) switch drives and b) go back to the previous directory we were viewing on that drive
+                                // But first, we need to save where we are now
+                                let current_path = ctx.shell_manager.path();
+
+                                let split_path: Vec<_> = current_path.split(':').collect();
+                                if split_path.len() > 1 {
+                                    ctx.windows_drives_previous_cwd
+                                        .lock()
+                                        .insert(split_path[0].to_string(), current_path);
+                                }
+
+                                let name = name.to_uppercase();
+                                let new_drive: Vec<_> = name.split(':').collect();
+
+                                if let Some(val) =
+                                    ctx.windows_drives_previous_cwd.lock().get(new_drive[0])
+                                {
+                                    ctx.shell_manager.set_path(val.to_string());
+                                    return LineResult::Success(line.to_string());
+                                } else {
+                                    ctx.shell_manager.set_path(name.to_string());
+                                    return LineResult::Success(line.to_string());
+                                }
+                            } else {
+                                ctx.shell_manager.set_path(name.to_string());
+                                return LineResult::Success(line.to_string());
+                            }
+                        }
+                        #[cfg(not(windows))]
+                        {
+                            ctx.shell_manager.set_path(name.to_string());
+                            return LineResult::Success(line.to_string());
+                        }
+                    }
+                }
+            }
+            let input_stream = if redirect_stdin {
+                let file = futures::io::AllowStdIo::new(std::io::stdin());
+                let stream = FramedRead::new(file, MaybeTextCodec).map(|line| {
+                    if let Ok(line) = line {
+                        match line {
+                            StringOrBinary::String(s) => Ok(Value {
+                                value: UntaggedValue::Primitive(Primitive::String(s)),
+                                tag: Tag::unknown(),
+                            }),
+                            StringOrBinary::Binary(b) => Ok(Value {
+                                value: UntaggedValue::Primitive(Primitive::Binary(
+                                    b.into_iter().collect(),
+                                )),
+                                tag: Tag::unknown(),
+                            }),
+                        }
+                    } else {
+                        panic!("Internal error: could not read lines of text from stdin")
+                    }
+                });
+                Some(stream.to_input_stream())
+            } else {
+                None
+            };
+
+            match run_pipeline(pipeline, ctx, input_stream, line).await {
+                Ok(Some(input)) => {
+                    // Running a pipeline gives us back a stream that we can then
+                    // work through. At the top level, we just want to pull on the
+                    // values to compute them.
+                    use futures::stream::TryStreamExt;
+
+                    let context = RunnableContext {
+                        input,
+                        shell_manager: ctx.shell_manager.clone(),
+                        host: ctx.host.clone(),
+                        ctrl_c: ctx.ctrl_c.clone(),
+                        commands: ctx.registry.clone(),
+                        name: Tag::unknown(),
+                        source: Text::from(String::new()),
+                    };
+
+                    if let Ok(mut output_stream) = crate::commands::autoview::autoview(context) {
+                        loop {
+                            match output_stream.try_next().await {
+                                Ok(Some(ReturnSuccess::Value(Value {
+                                    value: UntaggedValue::Error(e),
+                                    ..
+                                }))) => return LineResult::Error(line.to_string(), e),
+                                Ok(Some(_item)) => {
+                                    if ctx.ctrl_c.load(Ordering::SeqCst) {
+                                        break;
+                                    }
+                                }
+                                Ok(None) => break,
+                                Err(e) => return LineResult::Error(line.to_string(), e),
+                            }
+                        }
+                    }
+
+                    LineResult::Success(line.to_string())
+                }
+                Ok(None) => LineResult::Success(line.to_string()),
+                Err(err) => LineResult::Error(line.to_string(), err),
+            }
+        }
+        Err(ReadlineError::Interrupted) => LineResult::CtrlC,
+        Err(ReadlineError::Eof) => LineResult::Break,
+        Err(err) => {
+            outln!("Error: {:?}", err);
+            LineResult::Break
+        }
+    }
+}
+
+pub fn classify_pipeline(
+    pipeline: &SpannedToken,
+    context: &Context,
+    source: &Text,
+) -> ClassifiedPipeline {
+    let pipeline_list = vec![pipeline.clone()];
+    let expand_context = context.expand_context(source);
+    let mut iterator = TokensIterator::new(&pipeline_list, expand_context, pipeline.span());
+
+    let result = iterator.expand_infallible(PipelineShape);
+
+    if log_enabled!(target: "nu::expand_syntax", log::Level::Debug) {
+        outln!("");
+        let _ = ptree::print_tree(&iterator.expand_tracer().print(source.clone()));
+        outln!("");
+    }
+
+    result
+}
+
+pub fn print_err(err: ShellError, host: &dyn Host, source: &Text) {
+    let diag = err.into_diagnostic();
+
+    let writer = host.err_termcolor();
+    let mut source = source.to_string();
+    source.push_str(" ");
+    let files = nu_parser::Files::new(source);
+    let _ = std::panic::catch_unwind(move || {
+        let _ = language_reporting::emit(
+            &mut writer.lock(),
+            &files,
+            &diag,
+            &language_reporting::DefaultConfig,
+        );
+    });
+}

crates/nu-cli/src/commands.rs

@@ -0,0 +1,220 @@
+#[macro_use]
+pub(crate) mod macros;
+
+mod from_delimited_data;
+mod to_delimited_data;
+
+pub(crate) mod append;
+pub(crate) mod args;
+pub(crate) mod autoview;
+pub(crate) mod calc;
+pub(crate) mod cd;
+pub(crate) mod classified;
+pub(crate) mod clip;
+pub(crate) mod command;
+pub(crate) mod compact;
+pub(crate) mod config;
+pub(crate) mod count;
+pub(crate) mod cp;
+pub(crate) mod date;
+pub(crate) mod debug;
+pub(crate) mod default;
+pub(crate) mod du;
+pub(crate) mod echo;
+pub(crate) mod edit;
+pub(crate) mod enter;
+#[allow(unused)]
+pub(crate) mod evaluate_by;
+pub(crate) mod exit;
+pub(crate) mod first;
+pub(crate) mod format;
+pub(crate) mod from_bson;
+pub(crate) mod from_csv;
+pub(crate) mod from_ics;
+pub(crate) mod from_ini;
+pub(crate) mod from_json;
+pub(crate) mod from_ods;
+pub(crate) mod from_sqlite;
+pub(crate) mod from_ssv;
+pub(crate) mod from_toml;
+pub(crate) mod from_tsv;
+pub(crate) mod from_url;
+pub(crate) mod from_vcf;
+pub(crate) mod from_xlsx;
+pub(crate) mod from_xml;
+pub(crate) mod from_yaml;
+pub(crate) mod get;
+pub(crate) mod group_by;
+pub(crate) mod headers;
+pub(crate) mod help;
+pub(crate) mod histogram;
+pub(crate) mod history;
+pub(crate) mod insert;
+pub(crate) mod last;
+pub(crate) mod lines;
+pub(crate) mod ls;
+#[allow(unused)]
+pub(crate) mod map_max_by;
+pub(crate) mod mkdir;
+pub(crate) mod mv;
+pub(crate) mod next;
+pub(crate) mod nth;
+pub(crate) mod open;
+pub(crate) mod parse;
+pub(crate) mod pick;
+pub(crate) mod pivot;
+pub(crate) mod plugin;
+pub(crate) mod prepend;
+pub(crate) mod prev;
+pub(crate) mod pwd;
+pub(crate) mod range;
+#[allow(unused)]
+pub(crate) mod reduce_by;
+pub(crate) mod reject;
+pub(crate) mod rename;
+pub(crate) mod reverse;
+pub(crate) mod rm;
+pub(crate) mod save;
+pub(crate) mod shells;
+pub(crate) mod shuffle;
+pub(crate) mod size;
+pub(crate) mod skip;
+pub(crate) mod skip_while;
+pub(crate) mod sort_by;
+pub(crate) mod split_by;
+pub(crate) mod split_column;
+pub(crate) mod split_row;
+pub(crate) mod sum;
+#[allow(unused)]
+pub(crate) mod t_sort_by;
+pub(crate) mod table;
+pub(crate) mod tags;
+pub(crate) mod to_bson;
+pub(crate) mod to_csv;
+pub(crate) mod to_html;
+pub(crate) mod to_json;
+pub(crate) mod to_md;
+pub(crate) mod to_sqlite;
+pub(crate) mod to_toml;
+pub(crate) mod to_tsv;
+pub(crate) mod to_url;
+pub(crate) mod to_yaml;
+pub(crate) mod trim;
+pub(crate) mod uniq;
+pub(crate) mod version;
+pub(crate) mod what;
+pub(crate) mod where_;
+pub(crate) mod which_;
+pub(crate) mod wrap;
+
+pub(crate) use autoview::Autoview;
+pub(crate) use cd::Cd;
+pub(crate) use command::{
+    per_item_command, whole_stream_command, Command, PerItemCommand, UnevaluatedCallInfo,
+    WholeStreamCommand,
+};
+
+pub(crate) use append::Append;
+pub(crate) use calc::Calc;
+pub(crate) use compact::Compact;
+pub(crate) use config::Config;
+pub(crate) use count::Count;
+pub(crate) use cp::Cpy;
+pub(crate) use date::Date;
+pub(crate) use debug::Debug;
+pub(crate) use default::Default;
+pub(crate) use du::Du;
+pub(crate) use echo::Echo;
+pub(crate) use edit::Edit;
+pub(crate) mod kill;
+pub(crate) use kill::Kill;
+pub(crate) mod clear;
+pub(crate) use clear::Clear;
+pub(crate) mod touch;
+pub(crate) use enter::Enter;
+#[allow(unused_imports)]
+pub(crate) use evaluate_by::EvaluateBy;
+pub(crate) use exit::Exit;
+pub(crate) use first::First;
+pub(crate) use format::Format;
+pub(crate) use from_bson::FromBSON;
+pub(crate) use from_csv::FromCSV;
+pub(crate) use from_ics::FromIcs;
+pub(crate) use from_ini::FromINI;
+pub(crate) use from_json::FromJSON;
+pub(crate) use from_ods::FromODS;
+pub(crate) use from_sqlite::FromDB;
+pub(crate) use from_sqlite::FromSQLite;
+pub(crate) use from_ssv::FromSSV;
+pub(crate) use from_toml::FromTOML;
+pub(crate) use from_tsv::FromTSV;
+pub(crate) use from_url::FromURL;
+pub(crate) use from_vcf::FromVcf;
+pub(crate) use from_xlsx::FromXLSX;
+pub(crate) use from_xml::FromXML;
+pub(crate) use from_yaml::FromYAML;
+pub(crate) use from_yaml::FromYML;
+pub(crate) use get::Get;
+pub(crate) use group_by::GroupBy;
+pub(crate) use headers::Headers;
+pub(crate) use help::Help;
+pub(crate) use histogram::Histogram;
+pub(crate) use history::History;
+pub(crate) use insert::Insert;
+pub(crate) use last::Last;
+pub(crate) use lines::Lines;
+pub(crate) use ls::Ls;
+#[allow(unused_imports)]
+pub(crate) use map_max_by::MapMaxBy;
+pub(crate) use mkdir::Mkdir;
+pub(crate) use mv::Move;
+pub(crate) use next::Next;
+pub(crate) use nth::Nth;
+pub(crate) use open::Open;
+pub(crate) use parse::Parse;
+pub(crate) use pick::Pick;
+pub(crate) use pivot::Pivot;
+pub(crate) use prepend::Prepend;
+pub(crate) use prev::Previous;
+pub(crate) use pwd::Pwd;
+pub(crate) use range::Range;
+#[allow(unused_imports)]
+pub(crate) use reduce_by::ReduceBy;
+pub(crate) use reject::Reject;
+pub(crate) use rename::Rename;
+pub(crate) use reverse::Reverse;
+pub(crate) use rm::Remove;
+pub(crate) use save::Save;
+pub(crate) use shells::Shells;
+pub(crate) use shuffle::Shuffle;
+pub(crate) use size::Size;
+pub(crate) use skip::Skip;
+pub(crate) use skip_while::SkipWhile;
+pub(crate) use sort_by::SortBy;
+pub(crate) use split_by::SplitBy;
+pub(crate) use split_column::SplitColumn;
+pub(crate) use split_row::SplitRow;
+pub(crate) use sum::Sum;
+#[allow(unused_imports)]
+pub(crate) use t_sort_by::TSortBy;
+pub(crate) use table::Table;
+pub(crate) use tags::Tags;
+pub(crate) use to_bson::ToBSON;
+pub(crate) use to_csv::ToCSV;
+pub(crate) use to_html::ToHTML;
+pub(crate) use to_json::ToJSON;
+pub(crate) use to_md::ToMarkdown;
+pub(crate) use to_sqlite::ToDB;
+pub(crate) use to_sqlite::ToSQLite;
+pub(crate) use to_toml::ToTOML;
+pub(crate) use to_tsv::ToTSV;
+pub(crate) use to_url::ToURL;
+pub(crate) use to_yaml::ToYAML;
+pub(crate) use touch::Touch;
+pub(crate) use trim::Trim;
+pub(crate) use uniq::Uniq;
+pub(crate) use version::Version;
+pub(crate) use what::What;
+pub(crate) use where_::Where;
+pub(crate) use which_::Which;
+pub(crate) use wrap::Wrap;

crates/nu-cli/src/commands/append.rs

@@ -0,0 +1,49 @@
+use crate::commands::WholeStreamCommand;
+use crate::context::CommandRegistry;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{Signature, SyntaxShape, Value};
+
+#[derive(Deserialize)]
+struct AppendArgs {
+    row: Value,
+}
+
+pub struct Append;
+
+impl WholeStreamCommand for Append {
+    fn name(&self) -> &str {
+        "append"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("append").required(
+            "row value",
+            SyntaxShape::Any,
+            "the value of the row to append to the table",
+        )
+    }
+
+    fn usage(&self) -> &str {
+        "Append the given row to the table"
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        args.process(registry, append)?.run()
+    }
+}
+
+fn append(
+    AppendArgs { row }: AppendArgs,
+    RunnableContext { input, .. }: RunnableContext,
+) -> Result<OutputStream, ShellError> {
+    let mut after: VecDeque<Value> = VecDeque::new();
+    after.push_back(row);
+    let after = futures::stream::iter(after);
+
+    Ok(OutputStream::from_input(input.values.chain(after)))
+}

crates/nu-cli/src/commands/args.rs

@@ -0,0 +1,10 @@
+use nu_protocol::Value;
+
+#[derive(Debug)]
+pub enum LogLevel {}
+
+#[derive(Debug)]
+pub struct LogItem {
+    level: LogLevel,
+    value: Value,
+}

crates/nu-cli/src/commands/autoview.rs

@@ -0,0 +1,296 @@
+use crate::commands::UnevaluatedCallInfo;
+use crate::commands::WholeStreamCommand;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_parser::{hir, hir::Expression, hir::Literal, hir::SpannedExpression};
+use nu_protocol::{Primitive, ReturnSuccess, Signature, UntaggedValue, Value};
+use std::sync::atomic::AtomicBool;
+use std::sync::atomic::Ordering;
+
+pub struct Autoview;
+
+impl WholeStreamCommand for Autoview {
+    fn name(&self) -> &str {
+        "autoview"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("autoview")
+    }
+
+    fn usage(&self) -> &str {
+        "View the contents of the pipeline as a table or list."
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        autoview(RunnableContext {
+            input: args.input,
+            commands: registry.clone(),
+            shell_manager: args.shell_manager,
+            host: args.host,
+            source: args.call_info.source,
+            ctrl_c: args.ctrl_c,
+            name: args.call_info.name_tag,
+        })
+    }
+}
+
+pub struct RunnableContextWithoutInput {
+    pub shell_manager: ShellManager,
+    pub host: Arc<parking_lot::Mutex<Box<dyn Host>>>,
+    pub source: Text,
+    pub ctrl_c: Arc<AtomicBool>,
+    pub commands: CommandRegistry,
+    pub name: Tag,
+}
+
+impl RunnableContextWithoutInput {
+    pub fn convert(context: RunnableContext) -> (InputStream, RunnableContextWithoutInput) {
+        let new_context = RunnableContextWithoutInput {
+            shell_manager: context.shell_manager,
+            host: context.host,
+            source: context.source,
+            ctrl_c: context.ctrl_c,
+            commands: context.commands,
+            name: context.name,
+        };
+        (context.input, new_context)
+    }
+}
+
+pub fn autoview(context: RunnableContext) -> Result<OutputStream, ShellError> {
+    let binary = context.get_command("binaryview");
+    let text = context.get_command("textview");
+    let table = context.get_command("table");
+
+    Ok(OutputStream::new(async_stream! {
+        let (mut input_stream, context) = RunnableContextWithoutInput::convert(context);
+
+        match input_stream.next().await {
+            Some(x) => {
+                match input_stream.next().await {
+                    Some(y) => {
+                        let ctrl_c = context.ctrl_c.clone();
+                        let stream = async_stream! {
+                            yield Ok(x);
+                            yield Ok(y);
+
+                            loop {
+                                match input_stream.next().await {
+                                    Some(z) => {
+                                        if ctrl_c.load(Ordering::SeqCst) {
+                                            break;
+                                        }
+                                        yield Ok(z);
+                                    }
+                                    _ => break,
+                                }
+                            }
+                        };
+                        let stream = stream.to_input_stream();
+
+                        if let Some(table) = table {
+                            let command_args = create_default_command_args(&context).with_input(stream);
+                            let result = table.run(command_args, &context.commands);
+                            result.collect::<Vec<_>>().await;
+                        }
+                    }
+                    _ => {
+                        match x {
+                            Value {
+                                value: UntaggedValue::Primitive(Primitive::String(ref s)),
+                                tag: Tag { anchor, span },
+                            } if anchor.is_some() => {
+                                if let Some(text) = text {
+                                    let mut stream = VecDeque::new();
+                                    stream.push_back(UntaggedValue::string(s).into_value(Tag { anchor, span }));
+                                    let command_args = create_default_command_args(&context).with_input(stream);
+                                    let result = text.run(command_args, &context.commands);
+                                    result.collect::<Vec<_>>().await;
+                                } else {
+                                    out!("{}", s);
+                                }
+                            }
+                            Value {
+                                value: UntaggedValue::Primitive(Primitive::String(s)),
+                                ..
+                            } => {
+                                out!("{}", s);
+                            }
+                            Value {
+                                value: UntaggedValue::Primitive(Primitive::Line(ref s)),
+                                tag: Tag { anchor, span },
+                            } if anchor.is_some() => {
+                                if let Some(text) = text {
+                                    let mut stream = VecDeque::new();
+                                    stream.push_back(UntaggedValue::string(s).into_value(Tag { anchor, span }));
+                                    let command_args = create_default_command_args(&context).with_input(stream);
+                                    let result = text.run(command_args, &context.commands);
+                                    result.collect::<Vec<_>>().await;
+                                } else {
+                                    out!("{}\n", s);
+                                }
+                            }
+                            Value {
+                                value: UntaggedValue::Primitive(Primitive::Line(s)),
+                                ..
+                            } => {
+                                out!("{}\n", s);
+                            }
+                            Value {
+                                value: UntaggedValue::Primitive(Primitive::Path(s)),
+                                ..
+                            } => {
+                                out!("{}", s.display());
+                            }
+                            Value {
+                                value: UntaggedValue::Primitive(Primitive::Int(n)),
+                                ..
+                            } => {
+                                out!("{}", n);
+                            }
+                            Value {
+                                value: UntaggedValue::Primitive(Primitive::Decimal(n)),
+                                ..
+                            } => {
+                                out!("{}", n);
+                            }
+
+                            Value { value: UntaggedValue::Primitive(Primitive::Binary(ref b)), .. } => {
+                                if let Some(binary) = binary {
+                                    let mut stream = VecDeque::new();
+                                    stream.push_back(x);
+                                    let command_args = create_default_command_args(&context).with_input(stream);
+                                    let result = binary.run(command_args, &context.commands);
+                                    result.collect::<Vec<_>>().await;
+                                } else {
+                                    use pretty_hex::*;
+                                    out!("{:?}", b.hex_dump());
+                                }
+                            }
+
+                            Value { value: UntaggedValue::Error(e), .. } => {
+                                yield Err(e);
+                            }
+
+                            Value { value: UntaggedValue::Row(row), ..} => {
+                                use prettytable::format::{FormatBuilder, LinePosition, LineSeparator};
+                                use prettytable::{color, Attr, Cell, Row, Table};
+                                use crate::data::value::{format_leaf, style_leaf};
+                                use textwrap::fill;
+
+                                let termwidth = std::cmp::max(textwrap::termwidth(), 20);
+
+                                enum TableMode {
+                                    Light,
+                                    Normal,
+                                }
+
+                                let mut table = Table::new();
+                                let table_mode = crate::data::config::config(Tag::unknown());
+
+                                let table_mode = if let Some(s) = table_mode?.get("table_mode") {
+                                    match s.as_string() {
+                                        Ok(typ) if typ == "light" => TableMode::Light,
+                                        _ => TableMode::Normal,
+                                    }
+                                } else {
+                                    TableMode::Normal
+                                };
+
+                                match table_mode {
+                                    TableMode::Light => {
+                                        table.set_format(
+                                            FormatBuilder::new()
+                                                .separator(LinePosition::Title, LineSeparator::new('─', '─', ' ', ' '))
+                                                .padding(1, 1)
+                                                .build(),
+                                        );
+                                    }
+                                    _ => {
+                                        table.set_format(
+                                            FormatBuilder::new()
+                                                .column_separator('│')
+                                                .separator(LinePosition::Top, LineSeparator::new('─', '┬', ' ', ' '))
+                                                .separator(LinePosition::Title, LineSeparator::new('─', '┼', ' ', ' '))
+                                                .separator(LinePosition::Bottom, LineSeparator::new('─', '┴', ' ', ' '))
+                                                .padding(1, 1)
+                                                .build(),
+                                        );
+                                    }
+                                }
+
+                                let mut max_key_len = 0;
+                                for (key, _) in row.entries.iter() {
+                                    max_key_len = std::cmp::max(max_key_len, key.chars().count());
+                                }
+
+                                if max_key_len > (termwidth/2 - 1) {
+                                    max_key_len = termwidth/2 - 1;
+                                }
+
+                                let max_val_len = termwidth - max_key_len - 5;
+
+                                for (key, value) in row.entries.iter() {
+                                    table.add_row(Row::new(vec![Cell::new(&fill(&key, max_key_len)).with_style(Attr::ForegroundColor(color::GREEN)).with_style(Attr::Bold),
+                                        Cell::new(&fill(&format_leaf(value).plain_string(100_000), max_val_len))]));
+                                }
+
+                                table.printstd();
+
+                                // table.print_term(&mut *context.host.lock().out_terminal().ok_or_else(|| ShellError::untagged_runtime_error("Could not open terminal for output"))?)
+                                //     .map_err(|_| ShellError::untagged_runtime_error("Internal error: could not print to terminal (for unix systems check to make sure TERM is set)"))?;
+                            }
+
+                            Value { value: ref item, .. } => {
+                                if let Some(table) = table {
+                                    let mut stream = VecDeque::new();
+                                    stream.push_back(x);
+                                    let command_args = create_default_command_args(&context).with_input(stream);
+                                    let result = table.run(command_args, &context.commands);
+                                    result.collect::<Vec<_>>().await;
+                                } else {
+                                    out!("{:?}", item);
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+            _ => {
+                //out!("<no results>");
+            }
+        }
+
+        // Needed for async_stream to type check
+        if false {
+            yield ReturnSuccess::value(UntaggedValue::nothing().into_untagged_value());
+        }
+    }))
+}
+
+fn create_default_command_args(context: &RunnableContextWithoutInput) -> RawCommandArgs {
+    let span = context.name.span;
+    RawCommandArgs {
+        host: context.host.clone(),
+        ctrl_c: context.ctrl_c.clone(),
+        shell_manager: context.shell_manager.clone(),
+        call_info: UnevaluatedCallInfo {
+            args: hir::Call {
+                head: Box::new(SpannedExpression::new(
+                    Expression::Literal(Literal::String(span)),
+                    span,
+                )),
+                positional: None,
+                named: None,
+                span,
+            },
+            source: context.source.clone(),
+            name_tag: context.name.clone(),
+        },
+    }
+}

crates/nu-cli/src/commands/calc.rs

@@ -0,0 +1,63 @@
+use crate::commands::PerItemCommand;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{CallInfo, Primitive, ReturnSuccess, UntaggedValue, Value};
+
+pub struct Calc;
+
+impl PerItemCommand for Calc {
+    fn name(&self) -> &str {
+        "calc"
+    }
+
+    fn usage(&self) -> &str {
+        "Parse a math expression into a number"
+    }
+
+    fn run(
+        &self,
+        _call_info: &CallInfo,
+        _registry: &CommandRegistry,
+        raw_args: &RawCommandArgs,
+        input: Value,
+    ) -> Result<OutputStream, ShellError> {
+        calc(input, raw_args)
+    }
+}
+
+fn calc(input: Value, args: &RawCommandArgs) -> Result<OutputStream, ShellError> {
+    let name_span = &args.call_info.name_tag.span;
+
+    let output = if let Ok(string) = input.as_string() {
+        match parse(&string, &input.tag) {
+            Ok(value) => ReturnSuccess::value(value),
+            Err(err) => Err(ShellError::labeled_error(
+                "Calculation error",
+                err,
+                &input.tag.span,
+            )),
+        }
+    } else {
+        Err(ShellError::labeled_error(
+            "Expected a string from pipeline",
+            "requires string input",
+            name_span,
+        ))
+    };
+
+    Ok(vec![output].into())
+}
+
+pub fn parse(math_expression: &str, tag: impl Into<Tag>) -> Result<Value, String> {
+    use std::f64;
+    let num = meval::eval_str(math_expression);
+    match num {
+        Ok(num) => {
+            if num == f64::INFINITY || num == f64::NEG_INFINITY {
+                return Err(String::from("cannot represent result"));
+            }
+            Ok(UntaggedValue::from(Primitive::from(num)).into_value(tag))
+        }
+        Err(error) => Err(error.to_string()),
+    }
+}

crates/nu-cli/src/commands/cd.rs

@@ -0,0 +1,45 @@
+use crate::commands::WholeStreamCommand;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_macros::signature;
+use nu_protocol::{Signature, SyntaxShape};
+
+pub struct Cd;
+
+impl WholeStreamCommand for Cd {
+    fn name(&self) -> &str {
+        "cd"
+    }
+
+    fn signature(&self) -> Signature {
+        signature! {
+            def cd {
+                "the directory to change to"
+                directory(optional Path) - "the directory to change to"
+            }
+        }
+        // Signature::build("cd").optional(
+        //     "directory",
+        //     SyntaxShape::Path,
+        //     "the directory to change to",
+        // )
+    }
+
+    fn usage(&self) -> &str {
+        "Change to a new path."
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        cd(args, registry)
+    }
+}
+
+fn cd(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStream, ShellError> {
+    let shell_manager = args.shell_manager.clone();
+    let args = args.evaluate_once(registry)?;
+    shell_manager.cd(args)
+}

crates/nu-cli/src/commands/classified/dynamic.rs

@@ -0,0 +1,7 @@
+use derive_new::new;
+use nu_parser::hir;
+
+#[derive(new, Debug, Eq, PartialEq)]
+pub(crate) struct Command {
+    pub(crate) args: hir::Call,
+}

crates/nu-cli/src/commands/classified/external.rs

@@ -0,0 +1,853 @@
+use crate::futures::ThreadedReceiver;
+use crate::prelude::*;
+use bytes::{BufMut, Bytes, BytesMut};
+use futures::executor::block_on_stream;
+use futures::stream::StreamExt;
+use futures_codec::FramedRead;
+use log::trace;
+use nu_errors::ShellError;
+use nu_parser::commands::classified::external::ExternalArg;
+use nu_parser::ExternalCommand;
+use nu_protocol::{ColumnPath, Primitive, ShellTypeName, UntaggedValue, Value};
+use nu_source::{Tag, Tagged};
+use nu_value_ext::as_column_path;
+use std::io::Write;
+use std::ops::Deref;
+use std::process::{Command, Stdio};
+use std::sync::mpsc;
+
+pub enum StringOrBinary {
+    String(String),
+    Binary(Vec<u8>),
+}
+pub struct MaybeTextCodec;
+
+impl futures_codec::Encoder for MaybeTextCodec {
+    type Item = StringOrBinary;
+    type Error = std::io::Error;
+
+    fn encode(&mut self, item: Self::Item, dst: &mut BytesMut) -> Result<(), Self::Error> {
+        match item {
+            StringOrBinary::String(s) => {
+                dst.reserve(s.len());
+                dst.put(s.as_bytes());
+                Ok(())
+            }
+            StringOrBinary::Binary(b) => {
+                dst.reserve(b.len());
+                dst.put(Bytes::from(b));
+                Ok(())
+            }
+        }
+    }
+}
+
+impl futures_codec::Decoder for MaybeTextCodec {
+    type Item = StringOrBinary;
+    type Error = std::io::Error;
+
+    fn decode(&mut self, src: &mut BytesMut) -> Result<Option<Self::Item>, Self::Error> {
+        let v: Vec<u8> = src.to_vec();
+        match String::from_utf8(v) {
+            Ok(s) => {
+                src.clear();
+                if s.is_empty() {
+                    Ok(None)
+                } else {
+                    Ok(Some(StringOrBinary::String(s)))
+                }
+            }
+            Err(err) => {
+                // Note: the longest UTF-8 character per Unicode spec is currently 6 bytes. If we fail somewhere earlier than the last 6 bytes,
+                // we know that we're failing to understand the string encoding and not just seeing a partial character. When this happens, let's
+                // fall back to assuming it's a binary buffer.
+                if src.is_empty() {
+                    Ok(None)
+                } else if src.len() > 6 && (src.len() - err.utf8_error().valid_up_to() > 6) {
+                    // Fall back to assuming binary
+                    let buf = src.to_vec();
+                    src.clear();
+                    Ok(Some(StringOrBinary::Binary(buf)))
+                } else {
+                    // Looks like a utf-8 string, so let's assume that
+                    let buf = src.split_to(err.utf8_error().valid_up_to() + 1);
+                    String::from_utf8(buf.to_vec())
+                        .map(|x| Some(StringOrBinary::String(x)))
+                        .map_err(|e| std::io::Error::new(std::io::ErrorKind::InvalidData, e))
+                }
+            }
+        }
+    }
+}
+
+pub fn nu_value_to_string(command: &ExternalCommand, from: &Value) -> Result<String, ShellError> {
+    match &from.value {
+        UntaggedValue::Primitive(Primitive::Int(i)) => Ok(i.to_string()),
+        UntaggedValue::Primitive(Primitive::String(s))
+        | UntaggedValue::Primitive(Primitive::Line(s)) => Ok(s.clone()),
+        UntaggedValue::Primitive(Primitive::Path(p)) => Ok(p.to_string_lossy().to_string()),
+        unsupported => Err(ShellError::labeled_error(
+            format!("needs string data (given: {})", unsupported.type_name()),
+            "expected a string",
+            &command.name_tag,
+        )),
+    }
+}
+
+pub(crate) async fn run_external_command(
+    command: ExternalCommand,
+    context: &mut Context,
+    input: Option<InputStream>,
+    is_last: bool,
+) -> Result<Option<InputStream>, ShellError> {
+    trace!(target: "nu::run::external", "-> {}", command.name);
+
+    if !did_find_command(&command.name).await {
+        return Err(ShellError::labeled_error(
+            "Command not found",
+            "command not found",
+            &command.name_tag,
+        ));
+    }
+
+    if command.has_it_argument() || command.has_nu_argument() {
+        run_with_iterator_arg(command, context, input, is_last)
+    } else {
+        run_with_stdin(command, context, input, is_last)
+    }
+}
+
+fn prepare_column_path_for_fetching_it_variable(
+    argument: &ExternalArg,
+) -> Result<Tagged<ColumnPath>, ShellError> {
+    // We have "$it.[contents of interest]"
+    // and start slicing from "$it.[member+]"
+    //                             ^ here.
+    let key = nu_source::Text::from(argument.deref()).slice(4..argument.len());
+
+    to_column_path(&key, &argument.tag)
+}
+
+fn prepare_column_path_for_fetching_nu_variable(
+    argument: &ExternalArg,
+) -> Result<Tagged<ColumnPath>, ShellError> {
+    // We have "$nu.[contents of interest]"
+    // and start slicing from "$nu.[member+]"
+    //                             ^ here.
+    let key = nu_source::Text::from(argument.deref()).slice(4..argument.len());
+
+    to_column_path(&key, &argument.tag)
+}
+
+fn to_column_path(
+    path_members: &str,
+    tag: impl Into<Tag>,
+) -> Result<Tagged<ColumnPath>, ShellError> {
+    let tag = tag.into();
+
+    as_column_path(
+        &UntaggedValue::Table(
+            path_members
+                .split('.')
+                .map(|x| {
+                    let member = match x.parse::<u64>() {
+                        Ok(v) => UntaggedValue::int(v),
+                        Err(_) => UntaggedValue::string(x),
+                    };
+
+                    member.into_value(&tag)
+                })
+                .collect(),
+        )
+        .into_value(&tag),
+    )
+}
+
+fn run_with_iterator_arg(
+    command: ExternalCommand,
+    context: &mut Context,
+    input: Option<InputStream>,
+    is_last: bool,
+) -> Result<Option<InputStream>, ShellError> {
+    let path = context.shell_manager.path();
+
+    let mut inputs: InputStream = if let Some(input) = input {
+        trace_stream!(target: "nu::trace_stream::external::it", "input" = input)
+    } else {
+        InputStream::empty()
+    };
+
+    let stream = async_stream! {
+        while let Some(value) = inputs.next().await {
+            let name = command.name.clone();
+            let name_tag = command.name_tag.clone();
+            let home_dir = dirs::home_dir();
+            let path = &path;
+            let args = command.args.clone();
+
+            let it_replacement = {
+                if command.has_it_argument() {
+                    let empty_arg = ExternalArg {
+                        arg: "".to_string(),
+                        tag: name_tag.clone()
+                    };
+
+                    let key = args.iter()
+                        .find(|arg| arg.looks_like_it())
+                        .unwrap_or_else(|| &empty_arg);
+
+                    if args.iter().all(|arg| !arg.is_it()) {
+                        let key = match prepare_column_path_for_fetching_it_variable(&key) {
+                            Ok(keypath) => keypath,
+                            Err(reason) => {
+                                yield Ok(Value {
+                                    value: UntaggedValue::Error(reason),
+                                    tag: name_tag
+                                });
+                                return;
+                            }
+                        };
+
+                        match crate::commands::get::get_column_path(&key, &value) {
+                            Ok(field) => {
+                                match nu_value_to_string(&command, &field) {
+                                    Ok(val) => Some(val),
+                                    Err(reason) => {
+                                        yield Ok(Value {
+                                            value: UntaggedValue::Error(reason),
+                                            tag: name_tag
+                                        });
+                                        return;
+                                    },
+                                }
+                            },
+                            Err(reason) => {
+                                yield Ok(Value {
+                                    value: UntaggedValue::Error(reason),
+                                    tag: name_tag
+                                });
+                                return;
+                            }
+                        }
+                    } else {
+                        match nu_value_to_string(&command, &value) {
+                            Ok(val) => Some(val),
+                            Err(reason) => {
+                                yield Ok(Value {
+                                    value: UntaggedValue::Error(reason),
+                                    tag: name_tag
+                                });
+                                return;
+                            },
+                        }
+                    }
+                } else {
+                    None
+                }
+            };
+
+            let nu_replacement = {
+                if command.has_nu_argument() {
+                    let empty_arg = ExternalArg {
+                        arg: "".to_string(),
+                        tag: name_tag.clone()
+                    };
+
+                    let key = args.iter()
+                        .find(|arg| arg.looks_like_nu())
+                        .unwrap_or_else(|| &empty_arg);
+
+                    let nu_var = match crate::evaluate::variables::nu(&name_tag) {
+                        Ok(variables) => variables,
+                        Err(reason) => {
+                            yield Ok(Value {
+                                value: UntaggedValue::Error(reason),
+                                tag: name_tag
+                            });
+                            return;
+                        }
+                    };
+
+                    if args.iter().all(|arg| !arg.is_nu()) {
+                        let key = match prepare_column_path_for_fetching_nu_variable(&key) {
+                            Ok(keypath) => keypath,
+                            Err(reason) => {
+                                yield Ok(Value {
+                                    value: UntaggedValue::Error(reason),
+                                    tag: name_tag
+                                });
+                                return;
+                            }
+                        };
+
+                        match crate::commands::get::get_column_path(&key, &nu_var) {
+                            Ok(field) => {
+                                match nu_value_to_string(&command, &field) {
+                                    Ok(val) => Some(val),
+                                    Err(reason) => {
+                                        yield Ok(Value {
+                                            value: UntaggedValue::Error(reason),
+                                            tag: name_tag
+                                        });
+                                        return;
+                                    },
+                                }
+                            },
+                            Err(reason) => {
+                                yield Ok(Value {
+                                    value: UntaggedValue::Error(reason),
+                                    tag: name_tag
+                                });
+                                return;
+                            }
+                        }
+                    } else {
+                        match nu_value_to_string(&command, &nu_var) {
+                            Ok(val) => Some(val),
+                            Err(reason) => {
+                                yield Ok(Value {
+                                    value: UntaggedValue::Error(reason),
+                                    tag: name_tag
+                                });
+                                return;
+                            },
+                        }
+                    }
+                } else {
+                    None
+                }
+            };
+
+            let process_args = args.iter().filter_map(|arg| {
+                if arg.chars().all(|c| c.is_whitespace()) {
+                    None
+                } else {
+                    let arg = if arg.looks_like_it() {
+                        if let Some(mut value) = it_replacement.to_owned() {
+                            let mut value = expand_tilde(&value, || home_dir.as_ref()).as_ref().to_string();
+                            #[cfg(not(windows))]
+                            {
+                                value = {
+                                    if argument_contains_whitespace(&value) && !argument_is_quoted(&value) {
+                                        add_quotes(&value)
+                                    } else {
+                                        value
+                                    }
+                                };
+                            }
+                            Some(value)
+                        } else {
+                            None
+                        }
+                    } else if arg.looks_like_nu() {
+                        if let Some(mut value) = nu_replacement.to_owned() {
+                            #[cfg(not(windows))]
+                            {
+                                value = {
+                                    if argument_contains_whitespace(&value) && !argument_is_quoted(&value) {
+                                        add_quotes(&value)
+                                    } else {
+                                        value
+                                    }
+                                };
+                            }
+                            Some(value)
+                        } else {
+                            None
+                        }
+                    } else {
+                        Some(arg.to_string())
+                    };
+
+                    arg
+                }
+            }).collect::<Vec<String>>();
+
+            match spawn(&command, &path, &process_args[..], None, is_last) {
+                Ok(res) => {
+                    if let Some(mut res) = res {
+                        while let Some(item) = res.next().await {
+                            yield Ok(item)
+                        }
+                    }
+                }
+                Err(reason) => {
+                    yield Ok(Value {
+                        value: UntaggedValue::Error(reason),
+                        tag: name_tag
+                    });
+                    return;
+                }
+            }
+        }
+    };
+
+    Ok(Some(stream.to_input_stream()))
+}
+
+fn run_with_stdin(
+    command: ExternalCommand,
+    context: &mut Context,
+    input: Option<InputStream>,
+    is_last: bool,
+) -> Result<Option<InputStream>, ShellError> {
+    let path = context.shell_manager.path();
+
+    let input = input
+        .map(|input| trace_stream!(target: "nu::trace_stream::external::stdin", "input" = input));
+
+    let process_args = command
+        .args
+        .iter()
+        .map(|arg| {
+            let arg = expand_tilde(arg.deref(), dirs::home_dir);
+
+            #[cfg(not(windows))]
+            {
+                if argument_contains_whitespace(&arg) && argument_is_quoted(&arg) {
+                    if let Some(unquoted) = remove_quotes(&arg) {
+                        format!(r#""{}""#, unquoted)
+                    } else {
+                        arg.as_ref().to_string()
+                    }
+                } else {
+                    arg.as_ref().to_string()
+                }
+            }
+            #[cfg(windows)]
+            {
+                if let Some(unquoted) = remove_quotes(&arg) {
+                    unquoted.to_string()
+                } else {
+                    arg.as_ref().to_string()
+                }
+            }
+        })
+        .collect::<Vec<String>>();
+
+    spawn(&command, &path, &process_args[..], input, is_last)
+}
+
+fn spawn(
+    command: &ExternalCommand,
+    path: &str,
+    args: &[String],
+    input: Option<InputStream>,
+    is_last: bool,
+) -> Result<Option<InputStream>, ShellError> {
+    let command = command.clone();
+
+    let mut process = {
+        #[cfg(windows)]
+        {
+            let mut process = Command::new("cmd");
+            process.arg("/c");
+            process.arg(&command.name);
+            for arg in args {
+                process.arg(&arg);
+            }
+            process
+        }
+
+        #[cfg(not(windows))]
+        {
+            let cmd_with_args = vec![command.name.clone(), args.join(" ")].join(" ");
+            let mut process = Command::new("sh");
+            process.arg("-c").arg(cmd_with_args);
+            process
+        }
+    };
+
+    process.current_dir(path);
+    trace!(target: "nu::run::external", "cwd = {:?}", &path);
+
+    // We want stdout regardless of what
+    // we are doing ($it case or pipe stdin)
+    if !is_last {
+        process.stdout(Stdio::piped());
+        trace!(target: "nu::run::external", "set up stdout pipe");
+    }
+
+    // open since we have some contents for stdin
+    if input.is_some() {
+        process.stdin(Stdio::piped());
+        trace!(target: "nu::run::external", "set up stdin pipe");
+    }
+
+    trace!(target: "nu::run::external", "built command {:?}", process);
+
+    // TODO Switch to async_std::process once it's stabilized
+    if let Ok(mut child) = process.spawn() {
+        let (tx, rx) = mpsc::sync_channel(0);
+
+        let mut stdin = child.stdin.take();
+
+        let stdin_write_tx = tx.clone();
+        let stdout_read_tx = tx;
+        let stdin_name_tag = command.name_tag.clone();
+        let stdout_name_tag = command.name_tag;
+
+        std::thread::spawn(move || {
+            if let Some(input) = input {
+                let mut stdin_write = stdin
+                    .take()
+                    .expect("Internal error: could not get stdin pipe for external command");
+
+                for value in block_on_stream(input) {
+                    match &value.value {
+                        UntaggedValue::Primitive(Primitive::Nothing) => continue,
+                        UntaggedValue::Primitive(Primitive::String(s))
+                        | UntaggedValue::Primitive(Primitive::Line(s)) => {
+                            if let Err(e) = stdin_write.write(s.as_bytes()) {
+                                let message = format!("Unable to write to stdin (error = {})", e);
+
+                                let _ = stdin_write_tx.send(Ok(Value {
+                                    value: UntaggedValue::Error(ShellError::labeled_error(
+                                        message,
+                                        "application may have closed before completing pipeline",
+                                        &stdin_name_tag,
+                                    )),
+                                    tag: stdin_name_tag,
+                                }));
+                                return Err(());
+                            }
+                        }
+                        UntaggedValue::Primitive(Primitive::Binary(b)) => {
+                            if let Err(e) = stdin_write.write(b) {
+                                let message = format!("Unable to write to stdin (error = {})", e);
+
+                                let _ = stdin_write_tx.send(Ok(Value {
+                                    value: UntaggedValue::Error(ShellError::labeled_error(
+                                        message,
+                                        "application may have closed before completing pipeline",
+                                        &stdin_name_tag,
+                                    )),
+                                    tag: stdin_name_tag,
+                                }));
+                                return Err(());
+                            }
+                        }
+                        unsupported => {
+                            let _ = stdin_write_tx.send(Ok(Value {
+                                value: UntaggedValue::Error(ShellError::labeled_error(
+                                    format!(
+                                        "Received unexpected type from pipeline ({})",
+                                        unsupported.type_name()
+                                    ),
+                                    "expected a string",
+                                    stdin_name_tag.clone(),
+                                )),
+                                tag: stdin_name_tag,
+                            }));
+                            return Err(());
+                        }
+                    };
+                }
+            }
+
+            Ok(())
+        });
+
+        std::thread::spawn(move || {
+            if !is_last {
+                let stdout = if let Some(stdout) = child.stdout.take() {
+                    stdout
+                } else {
+                    let _ = stdout_read_tx.send(Ok(Value {
+                        value: UntaggedValue::Error(ShellError::labeled_error(
+                            "Can't redirect the stdout for external command",
+                            "can't redirect stdout",
+                            &stdout_name_tag,
+                        )),
+                        tag: stdout_name_tag,
+                    }));
+                    return Err(());
+                };
+
+                let file = futures::io::AllowStdIo::new(stdout);
+                let stream = FramedRead::new(file, MaybeTextCodec);
+
+                for line in block_on_stream(stream) {
+                    match line {
+                        Ok(line) => match line {
+                            StringOrBinary::String(s) => {
+                                let result = stdout_read_tx.send(Ok(Value {
+                                    value: UntaggedValue::Primitive(Primitive::String(s.clone())),
+                                    tag: stdout_name_tag.clone(),
+                                }));
+
+                                if result.is_err() {
+                                    break;
+                                }
+                            }
+                            StringOrBinary::Binary(b) => {
+                                let result = stdout_read_tx.send(Ok(Value {
+                                    value: UntaggedValue::Primitive(Primitive::Binary(
+                                        b.into_iter().collect(),
+                                    )),
+                                    tag: stdout_name_tag.clone(),
+                                }));
+
+                                if result.is_err() {
+                                    break;
+                                }
+                            }
+                        },
+                        Err(_) => {
+                            let _ = stdout_read_tx.send(Ok(Value {
+                                value: UntaggedValue::Error(ShellError::labeled_error(
+                                    "Unable to read from stdout.",
+                                    "unable to read from stdout",
+                                    &stdout_name_tag,
+                                )),
+                                tag: stdout_name_tag.clone(),
+                            }));
+                            break;
+                        }
+                    }
+                }
+            }
+
+            // We can give an error when we see a non-zero exit code, but this is different
+            // than what other shells will do.
+            if child.wait().is_err() {
+                let cfg = crate::data::config::config(Tag::unknown());
+                if let Ok(cfg) = cfg {
+                    if cfg.contains_key("nonzero_exit_errors") {
+                        let _ = stdout_read_tx.send(Ok(Value {
+                            value: UntaggedValue::Error(ShellError::labeled_error(
+                                "External command failed",
+                                "command failed",
+                                &stdout_name_tag,
+                            )),
+                            tag: stdout_name_tag,
+                        }));
+                    }
+                }
+            }
+
+            Ok(())
+        });
+
+        let stream = ThreadedReceiver::new(rx);
+        Ok(Some(stream.to_input_stream()))
+    } else {
+        Err(ShellError::labeled_error(
+            "Failed to spawn process",
+            "failed to spawn",
+            &command.name_tag,
+        ))
+    }
+}
+
+async fn did_find_command(name: &str) -> bool {
+    #[cfg(not(windows))]
+    {
+        ichwh::which(name).await.unwrap_or(None).is_some()
+    }
+
+    #[cfg(windows)]
+    {
+        if ichwh::which(name).await.unwrap_or(None).is_some() {
+            true
+        } else {
+            let cmd_builtins = [
+                "call", "cls", "color", "date", "dir", "echo", "find", "hostname", "pause",
+                "start", "time", "title", "ver", "copy", "mkdir", "rename", "rd", "rmdir", "type",
+            ];
+
+            cmd_builtins.contains(&name)
+        }
+    }
+}
+
+fn expand_tilde<SI: ?Sized, P, HD>(input: &SI, home_dir: HD) -> std::borrow::Cow<str>
+where
+    SI: AsRef<str>,
+    P: AsRef<std::path::Path>,
+    HD: FnOnce() -> Option<P>,
+{
+    shellexpand::tilde_with_context(input, home_dir)
+}
+
+#[allow(unused)]
+pub fn argument_contains_whitespace(argument: &str) -> bool {
+    argument.chars().any(|c| c.is_whitespace())
+}
+
+fn argument_is_quoted(argument: &str) -> bool {
+    if argument.len() < 2 {
+        return false;
+    }
+
+    (argument.starts_with('"') && argument.ends_with('"'))
+        || (argument.starts_with('\'') && argument.ends_with('\''))
+}
+
+#[allow(unused)]
+fn add_quotes(argument: &str) -> String {
+    format!("\"{}\"", argument)
+}
+
+fn remove_quotes(argument: &str) -> Option<&str> {
+    if !argument_is_quoted(argument) {
+        return None;
+    }
+
+    let size = argument.len();
+
+    Some(&argument[1..size - 1])
+}
+
+#[allow(unused)]
+fn shell_os_paths() -> Vec<std::path::PathBuf> {
+    let mut original_paths = vec![];
+
+    if let Some(paths) = std::env::var_os("PATH") {
+        original_paths = std::env::split_paths(&paths).collect::<Vec<_>>();
+    }
+
+    original_paths
+}
+
+#[cfg(test)]
+mod tests {
+    use super::{
+        add_quotes, argument_contains_whitespace, argument_is_quoted, expand_tilde, remove_quotes,
+        run_external_command, Context,
+    };
+    use futures::executor::block_on;
+    use nu_errors::ShellError;
+    use nu_test_support::commands::ExternalBuilder;
+
+    // async fn read(mut stream: OutputStream) -> Option<Value> {
+    //     match stream.try_next().await {
+    //         Ok(val) => {
+    //             if let Some(val) = val {
+    //                 val.raw_value()
+    //             } else {
+    //                 None
+    //             }
+    //         }
+    //         Err(_) => None,
+    //     }
+    // }
+
+    async fn non_existent_run() -> Result<(), ShellError> {
+        let cmd = ExternalBuilder::for_name("i_dont_exist.exe").build();
+
+        let mut ctx = Context::basic().expect("There was a problem creating a basic context.");
+
+        assert!(run_external_command(cmd, &mut ctx, None, false)
+            .await
+            .is_err());
+
+        Ok(())
+    }
+
+    // async fn failure_run() -> Result<(), ShellError> {
+    //     let cmd = ExternalBuilder::for_name("fail").build();
+
+    //     let mut ctx = Context::basic().expect("There was a problem creating a basic context.");
+    //     let stream = run_external_command(cmd, &mut ctx, None, false)
+    //         .await?
+    //         .expect("There was a problem running the external command.");
+
+    //     match read(stream.into()).await {
+    //         Some(Value {
+    //             value: UntaggedValue::Error(_),
+    //             ..
+    //         }) => {}
+    //         None | _ => panic!("Command didn't fail."),
+    //     }
+
+    //     Ok(())
+    // }
+
+    // #[test]
+    // fn identifies_command_failed() -> Result<(), ShellError> {
+    //     block_on(failure_run())
+    // }
+
+    #[test]
+    fn identifies_command_not_found() -> Result<(), ShellError> {
+        block_on(non_existent_run())
+    }
+
+    #[test]
+    fn checks_contains_whitespace_from_argument_to_be_passed_in() {
+        assert_eq!(argument_contains_whitespace("andrés"), false);
+        assert_eq!(argument_contains_whitespace("and rés"), true);
+        assert_eq!(argument_contains_whitespace(r#"and\ rés"#), true);
+    }
+
+    #[test]
+    fn checks_quotes_from_argument_to_be_passed_in() {
+        assert_eq!(argument_is_quoted(""), false);
+
+        assert_eq!(argument_is_quoted("'"), false);
+        assert_eq!(argument_is_quoted("'a"), false);
+        assert_eq!(argument_is_quoted("a"), false);
+        assert_eq!(argument_is_quoted("a'"), false);
+        assert_eq!(argument_is_quoted("''"), true);
+
+        assert_eq!(argument_is_quoted(r#"""#), false);
+        assert_eq!(argument_is_quoted(r#""a"#), false);
+        assert_eq!(argument_is_quoted(r#"a"#), false);
+        assert_eq!(argument_is_quoted(r#"a""#), false);
+        assert_eq!(argument_is_quoted(r#""""#), true);
+
+        assert_eq!(argument_is_quoted("'andrés"), false);
+        assert_eq!(argument_is_quoted("andrés'"), false);
+        assert_eq!(argument_is_quoted(r#""andrés"#), false);
+        assert_eq!(argument_is_quoted(r#"andrés""#), false);
+        assert_eq!(argument_is_quoted("'andrés'"), true);
+        assert_eq!(argument_is_quoted(r#""andrés""#), true);
+    }
+
+    #[test]
+    fn adds_quotes_to_argument_to_be_passed_in() {
+        assert_eq!(add_quotes("andrés"), "\"andrés\"");
+        //assert_eq!(add_quotes("\"andrés\""), "\"andrés\"");
+    }
+
+    #[test]
+    fn strips_quotes_from_argument_to_be_passed_in() {
+        assert_eq!(remove_quotes(""), None);
+
+        assert_eq!(remove_quotes("'"), None);
+        assert_eq!(remove_quotes("'a"), None);
+        assert_eq!(remove_quotes("a"), None);
+        assert_eq!(remove_quotes("a'"), None);
+        assert_eq!(remove_quotes("''"), Some(""));
+
+        assert_eq!(remove_quotes(r#"""#), None);
+        assert_eq!(remove_quotes(r#""a"#), None);
+        assert_eq!(remove_quotes(r#"a"#), None);
+        assert_eq!(remove_quotes(r#"a""#), None);
+        assert_eq!(remove_quotes(r#""""#), Some(""));
+
+        assert_eq!(remove_quotes("'andrés"), None);
+        assert_eq!(remove_quotes("andrés'"), None);
+        assert_eq!(remove_quotes(r#""andrés"#), None);
+        assert_eq!(remove_quotes(r#"andrés""#), None);
+        assert_eq!(remove_quotes("'andrés'"), Some("andrés"));
+        assert_eq!(remove_quotes(r#""andrés""#), Some("andrés"));
+    }
+
+    #[test]
+    fn expands_tilde_if_starts_with_tilde_character() {
+        assert_eq!(
+            expand_tilde("~", || Some(std::path::Path::new("the_path_to_nu_light"))),
+            "the_path_to_nu_light"
+        );
+    }
+
+    #[test]
+    fn does_not_expand_tilde_if_tilde_is_not_first_character() {
+        assert_eq!(
+            expand_tilde("1~1", || Some(std::path::Path::new("the_path_to_nu_light"))),
+            "1~1"
+        );
+    }
+}

crates/nu-cli/src/commands/classified/internal.rs

@@ -0,0 +1,179 @@
+use crate::commands::UnevaluatedCallInfo;
+use crate::prelude::*;
+use log::{log_enabled, trace};
+use nu_errors::ShellError;
+use nu_parser::InternalCommand;
+use nu_protocol::{CommandAction, Primitive, ReturnSuccess, UntaggedValue, Value};
+
+pub(crate) fn run_internal_command(
+    command: InternalCommand,
+    context: &mut Context,
+    input: Option<InputStream>,
+    source: Text,
+) -> Result<Option<InputStream>, ShellError> {
+    if log_enabled!(log::Level::Trace) {
+        trace!(target: "nu::run::internal", "->");
+        trace!(target: "nu::run::internal", "{}", command.name);
+        trace!(target: "nu::run::internal", "{}", command.args.debug(&source));
+    }
+
+    let objects: InputStream = if let Some(input) = input {
+        trace_stream!(target: "nu::trace_stream::internal", "input" = input)
+    } else {
+        InputStream::empty()
+    };
+
+    let internal_command = context.expect_command(&command.name);
+
+    let result = {
+        context.run_command(
+            internal_command?,
+            command.name_tag.clone(),
+            command.args.clone(),
+            &source,
+            objects,
+        )
+    };
+
+    let result = trace_out_stream!(target: "nu::trace_stream::internal", "output" = result);
+    let mut result = result.values;
+    let mut context = context.clone();
+
+    let stream = async_stream! {
+        let mut soft_errs: Vec<ShellError> = vec![];
+        let mut yielded = false;
+
+        while let Some(item) = result.next().await {
+            match item {
+                Ok(ReturnSuccess::Action(action)) => match action {
+                    CommandAction::ChangePath(path) => {
+                        context.shell_manager.set_path(path);
+                    }
+                    CommandAction::Exit => std::process::exit(0), // TODO: save history.txt
+                    CommandAction::Error(err) => {
+                        context.error(err);
+                        break;
+                    }
+                    CommandAction::AutoConvert(tagged_contents, extension) => {
+                        let contents_tag = tagged_contents.tag.clone();
+                        let command_name = format!("from-{}", extension);
+                        let command = command.clone();
+                        if let Some(converter) = context.registry.get_command(&command_name) {
+                            let new_args = RawCommandArgs {
+                                host: context.host.clone(),
+                                ctrl_c: context.ctrl_c.clone(),
+                                shell_manager: context.shell_manager.clone(),
+                                call_info: UnevaluatedCallInfo {
+                                    args: nu_parser::hir::Call {
+                                        head: command.args.head,
+                                        positional: None,
+                                        named: None,
+                                        span: Span::unknown()
+                                    },
+                                    source: source.clone(),
+                                    name_tag: command.name_tag,
+                                }
+                            };
+                            let mut result = converter.run(new_args.with_input(vec![tagged_contents]), &context.registry);
+                            let result_vec: Vec<Result<ReturnSuccess, ShellError>> = result.drain_vec().await;
+                            for res in result_vec {
+                                match res {
+                                    Ok(ReturnSuccess::Value(Value { value: UntaggedValue::Table(list), ..})) => {
+                                        for l in list {
+                                            yield Ok(l);
+                                        }
+                                    }
+                                    Ok(ReturnSuccess::Value(Value { value, .. })) => {
+                                        yield Ok(value.into_value(contents_tag.clone()));
+                                    }
+                                    Err(e) => yield Err(e),
+                                    _ => {}
+                                }
+                            }
+                        } else {
+                            yield Ok(tagged_contents)
+                        }
+                    }
+                    CommandAction::EnterHelpShell(value) => {
+                        match value {
+                            Value {
+                                value: UntaggedValue::Primitive(Primitive::String(cmd)),
+                                tag,
+                            } => {
+                                context.shell_manager.insert_at_current(Box::new(
+                                    HelpShell::for_command(
+                                        UntaggedValue::string(cmd).into_value(tag),
+                                        &context.registry(),
+                                    )?,
+                                ));
+                            }
+                            _ => {
+                                context.shell_manager.insert_at_current(Box::new(
+                                    HelpShell::index(&context.registry())?,
+                                ));
+                            }
+                        }
+                    }
+                    CommandAction::EnterValueShell(value) => {
+                        context
+                            .shell_manager
+                            .insert_at_current(Box::new(ValueShell::new(value)));
+                    }
+                    CommandAction::EnterShell(location) => {
+                        context.shell_manager.insert_at_current(Box::new(
+                            FilesystemShell::with_location(location, context.registry().clone()),
+                        ));
+                    }
+                    CommandAction::PreviousShell => {
+                        context.shell_manager.prev();
+                    }
+                    CommandAction::NextShell => {
+                        context.shell_manager.next();
+                    }
+                    CommandAction::LeaveShell => {
+                        context.shell_manager.remove_at_current();
+                        if context.shell_manager.is_empty() {
+                            std::process::exit(0); // TODO: save history.txt
+                        }
+                    }
+                },
+
+                Ok(ReturnSuccess::Value(Value {
+                    value: UntaggedValue::Error(err),
+                    ..
+                })) => {
+                    context.error(err);
+                    break;
+                }
+
+                Ok(ReturnSuccess::Value(v)) => {
+                    yielded = true;
+                    yield Ok(v);
+                }
+
+                Ok(ReturnSuccess::DebugValue(v)) => {
+                    yielded = true;
+
+                    let doc = PrettyDebug::pretty_doc(&v);
+                    let mut buffer = termcolor::Buffer::ansi();
+
+                    let _ = doc.render_raw(
+                        context.with_host(|host| host.width() - 5),
+                        &mut nu_source::TermColored::new(&mut buffer),
+                    );
+
+                    let value = String::from_utf8_lossy(buffer.as_slice());
+
+                    yield Ok(UntaggedValue::string(value).into_untagged_value())
+                }
+
+                Err(err) => {
+                    context.error(err);
+                    break;
+                }
+            }
+        }
+    };
+
+    Ok(Some(stream.to_input_stream()))
+}

crates/nu-cli/src/commands/classified/mod.rs

@@ -0,0 +1,7 @@
+mod dynamic;
+pub(crate) mod external;
+pub(crate) mod internal;
+pub(crate) mod pipeline;
+
+#[allow(unused_imports)]
+pub(crate) use dynamic::Command as DynamicCommand;

crates/nu-cli/src/commands/classified/pipeline.rs

@@ -0,0 +1,50 @@
+use crate::commands::classified::external::run_external_command;
+use crate::commands::classified::internal::run_internal_command;
+use crate::context::Context;
+use crate::stream::InputStream;
+use nu_errors::ShellError;
+use nu_parser::{ClassifiedCommand, ClassifiedPipeline};
+use nu_source::Text;
+
+pub(crate) async fn run_pipeline(
+    pipeline: ClassifiedPipeline,
+    ctx: &mut Context,
+    mut input: Option<InputStream>,
+    line: &str,
+) -> Result<Option<InputStream>, ShellError> {
+    let mut iter = pipeline.commands.list.into_iter().peekable();
+
+    loop {
+        let item: Option<ClassifiedCommand> = iter.next();
+        let next: Option<&ClassifiedCommand> = iter.peek();
+
+        input = match (item, next) {
+            (Some(ClassifiedCommand::Dynamic(_)), _) | (_, Some(ClassifiedCommand::Dynamic(_))) => {
+                return Err(ShellError::unimplemented("Dynamic commands"))
+            }
+
+            (Some(ClassifiedCommand::Expr(_)), _) | (_, Some(ClassifiedCommand::Expr(_))) => {
+                return Err(ShellError::unimplemented("Expression-only commands"))
+            }
+
+            (Some(ClassifiedCommand::Error(err)), _) => return Err(err.into()),
+            (_, Some(ClassifiedCommand::Error(err))) => return Err(err.clone().into()),
+
+            (Some(ClassifiedCommand::Internal(left)), _) => {
+                run_internal_command(left, ctx, input, Text::from(line))?
+            }
+
+            (Some(ClassifiedCommand::External(left)), None) => {
+                run_external_command(left, ctx, input, true).await?
+            }
+
+            (Some(ClassifiedCommand::External(left)), _) => {
+                run_external_command(left, ctx, input, false).await?
+            }
+
+            (None, _) => break,
+        };
+    }
+
+    Ok(input)
+}

crates/nu-cli/src/commands/clear.rs

@@ -0,0 +1,40 @@
+use crate::commands::WholeStreamCommand;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::Signature;
+use std::process::Command;
+
+pub struct Clear;
+
+impl WholeStreamCommand for Clear {
+    fn name(&self) -> &str {
+        "clear"
+    }
+    fn signature(&self) -> Signature {
+        Signature::build("clear")
+    }
+    fn usage(&self) -> &str {
+        "clears the terminal"
+    }
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        clear(args, registry)
+    }
+}
+fn clear(_args: CommandArgs, _registry: &CommandRegistry) -> Result<OutputStream, ShellError> {
+    if cfg!(windows) {
+        Command::new("cmd")
+            .args(&["/C", "cls"])
+            .status()
+            .expect("failed to execute process");
+    } else if cfg!(unix) {
+        Command::new("/bin/sh")
+            .args(&["-c", "clear"])
+            .status()
+            .expect("failed to execute process");
+    }
+    Ok(OutputStream::empty())
+}

crates/nu-cli/src/commands/clip.rs

@@ -0,0 +1,106 @@
+#[cfg(feature = "clipboard")]
+pub mod clipboard {
+    use crate::commands::WholeStreamCommand;
+    use crate::context::CommandRegistry;
+    use crate::prelude::*;
+    use futures::stream::StreamExt;
+    use nu_errors::ShellError;
+    use nu_protocol::{ReturnValue, Signature, Value};
+
+    use clipboard::{ClipboardContext, ClipboardProvider};
+
+    pub struct Clip;
+
+    #[derive(Deserialize)]
+    pub struct ClipArgs {}
+
+    impl WholeStreamCommand for Clip {
+        fn name(&self) -> &str {
+            "clip"
+        }
+
+        fn signature(&self) -> Signature {
+            Signature::build("clip")
+        }
+
+        fn usage(&self) -> &str {
+            "Copy the contents of the pipeline to the copy/paste buffer"
+        }
+
+        fn run(
+            &self,
+            args: CommandArgs,
+            registry: &CommandRegistry,
+        ) -> Result<OutputStream, ShellError> {
+            args.process(registry, clip)?.run()
+        }
+    }
+
+    pub fn clip(
+        ClipArgs {}: ClipArgs,
+        RunnableContext { input, name, .. }: RunnableContext,
+    ) -> Result<OutputStream, ShellError> {
+        let stream = async_stream! {
+            let values: Vec<Value> = input.values.collect().await;
+
+            let mut clip_stream = inner_clip(values, name).await;
+            while let Some(value) = clip_stream.next().await {
+                yield value;
+            }
+        };
+
+        let stream: BoxStream<'static, ReturnValue> = stream.boxed();
+
+        Ok(OutputStream::from(stream))
+    }
+
+    async fn inner_clip(input: Vec<Value>, name: Tag) -> OutputStream {
+        if let Ok(clip_context) = ClipboardProvider::new() {
+            let mut clip_context: ClipboardContext = clip_context;
+            let mut new_copy_data = String::new();
+
+            if !input.is_empty() {
+                let mut first = true;
+                for i in input.iter() {
+                    if !first {
+                        new_copy_data.push_str("\n");
+                    } else {
+                        first = false;
+                    }
+
+                    let string: String = match i.as_string() {
+                        Ok(string) => string.to_string(),
+                        Err(_) => {
+                            return OutputStream::one(Err(ShellError::labeled_error(
+                                "Given non-string data",
+                                "expected strings from pipeline",
+                                name,
+                            )))
+                        }
+                    };
+
+                    new_copy_data.push_str(&string);
+                }
+            }
+
+            match clip_context.set_contents(new_copy_data) {
+                Ok(_) => {}
+                Err(_) => {
+                    return OutputStream::one(Err(ShellError::labeled_error(
+                        "Could not set contents of clipboard",
+                        "could not set contents of clipboard",
+                        name,
+                    )));
+                }
+            }
+
+            OutputStream::empty()
+        } else {
+            OutputStream::one(Err(ShellError::labeled_error(
+                "Could not open clipboard",
+                "could not open clipboard",
+                name,
+            )))
+        }
+    }
+}

crates/nu-cli/src/commands/command.rs

@@ -1,87 +1,58 @@
-use crate::context::{SourceMap, SpanSource};
-use crate::errors::ShellError;
-use crate::evaluate::Scope;
-use crate::object::Value;
-use crate::parser::hir;
-use crate::parser::{registry, ConfigDeserializer};
+use crate::commands::help::get_help;
+use crate::context::CommandRegistry;
+use crate::deserializer::ConfigDeserializer;
+use crate::evaluate::evaluate_args::evaluate_args;
 use crate::prelude::*;
 use derive_new::new;
 use getset::Getters;
+use nu_errors::ShellError;
+use nu_parser::hir;
+use nu_protocol::{CallInfo, EvaluatedArgs, ReturnValue, Scope, Signature, Value};
 use serde::{Deserialize, Serialize};
-use std::fmt;
 use std::ops::Deref;
-use std::path::PathBuf;
-use uuid::Uuid;
+use std::sync::atomic::AtomicBool;
 
 #[derive(Deserialize, Serialize, Debug, Clone)]
 pub struct UnevaluatedCallInfo {
     pub args: hir::Call,
     pub source: Text,
-    pub source_map: SourceMap,
-    pub name_span: Span,
-}
-
-impl ToDebug for UnevaluatedCallInfo {
-    fn fmt_debug(&self, f: &mut fmt::Formatter, source: &str) -> fmt::Result {
-        self.args.fmt_debug(f, source)
-    }
+    pub name_tag: Tag,
 }
 
 impl UnevaluatedCallInfo {
     pub fn evaluate(
         self,
-        registry: &registry::CommandRegistry,
+        registry: &CommandRegistry,
         scope: &Scope,
     ) -> Result<CallInfo, ShellError> {
-        let args = self.args.evaluate(registry, scope, &self.source)?;
+        let args = evaluate_args(&self.args, registry, scope, &self.source)?;
 
         Ok(CallInfo {
             args,
-            source_map: self.source_map,
-            name_span: self.name_span,
+            name_tag: self.name_tag,
         })
     }
 
-    pub fn has_it_or_block(&self) -> bool {
-        use hir::RawExpression;
-        use hir::Variable;
-
-        if let Some(positional) = &self.args.positional() {
-            for pos in positional {
-                match pos {
-                    Tagged {
-                        item: RawExpression::Variable(Variable::It(_)),
-                        ..
-                    } => {
-                        return true;
-                    }
-                    Tagged {
-                        item: RawExpression::Block(_),
-                        ..
-                    } => {
-                        return true;
-                    }
-                    _ => {}
-                }
-            }
-        }
-
-        false
+    pub fn switch_present(&self, switch: &str) -> bool {
+        self.args.switch_preset(switch)
     }
 }
 
-#[derive(Deserialize, Serialize, Debug, Clone)]
-pub struct CallInfo {
-    pub args: registry::EvaluatedArgs,
-    pub source_map: SourceMap,
-    pub name_span: Span,
-}
-
-impl CallInfo {
-    pub fn process<'de, T: Deserialize<'de>>(
+pub trait CallInfoExt {
+    fn process<'de, T: Deserialize<'de>>(
         &self,
         shell_manager: &ShellManager,
-        callback: fn(T, &RunnablePerItemContext) -> Result<VecDeque<ReturnValue>, ShellError>,
+        ctrl_c: Arc<AtomicBool>,
+        callback: fn(T, &RunnablePerItemContext) -> Result<OutputStream, ShellError>,
+    ) -> Result<RunnablePerItemArgs<T>, ShellError>;
+}
+
+impl CallInfoExt for CallInfo {
+    fn process<'de, T: Deserialize<'de>>(
+        &self,
+        shell_manager: &ShellManager,
+        ctrl_c: Arc<AtomicBool>,
+        callback: fn(T, &RunnablePerItemContext) -> Result<OutputStream, ShellError>,
     ) -> Result<RunnablePerItemArgs<T>, ShellError> {
         let mut deserializer = ConfigDeserializer::from_call_info(self.clone());
 
@@ -89,7 +60,8 @@ impl CallInfo {
             args: T::deserialize(&mut deserializer)?,
             context: RunnablePerItemContext {
                 shell_manager: shell_manager.clone(),
-                name: self.name_span,
+                name: self.name_tag.clone(),
+                ctrl_c,
             },
             callback,
         })
@@ -97,26 +69,29 @@ impl CallInfo {
 }
 
 #[derive(Getters)]
-#[get = "crate"]
+#[get = "pub(crate)"]
 pub struct CommandArgs {
-    pub host: Arc<Mutex<dyn Host>>,
+    pub host: Arc<parking_lot::Mutex<Box<dyn Host>>>,
+    pub ctrl_c: Arc<AtomicBool>,
     pub shell_manager: ShellManager,
     pub call_info: UnevaluatedCallInfo,
     pub input: InputStream,
 }
 
 #[derive(Getters, Clone)]
-#[get = "crate"]
+#[get = "pub(crate)"]
 pub struct RawCommandArgs {
-    pub host: Arc<Mutex<dyn Host>>,
+    pub host: Arc<parking_lot::Mutex<Box<dyn Host>>>,
+    pub ctrl_c: Arc<AtomicBool>,
     pub shell_manager: ShellManager,
     pub call_info: UnevaluatedCallInfo,
 }
 
 impl RawCommandArgs {
-    pub fn with_input(self, input: Vec<Tagged<Value>>) -> CommandArgs {
+    pub fn with_input(self, input: impl Into<InputStream>) -> CommandArgs {
         CommandArgs {
             host: self.host,
+            ctrl_c: self.ctrl_c,
             shell_manager: self.shell_manager,
             call_info: self.call_info,
             input: input.into(),
@@ -124,56 +99,81 @@ impl RawCommandArgs {
     }
 }
 
-impl ToDebug for CommandArgs {
-    fn fmt_debug(&self, f: &mut fmt::Formatter, source: &str) -> fmt::Result {
-        self.call_info.fmt_debug(f, source)
+impl std::fmt::Debug for CommandArgs {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        self.call_info.fmt(f)
     }
 }
 
 impl CommandArgs {
     pub fn evaluate_once(
         self,
-        registry: &registry::CommandRegistry,
+        registry: &CommandRegistry,
     ) -> Result<EvaluatedWholeStreamCommandArgs, ShellError> {
         let host = self.host.clone();
+        let ctrl_c = self.ctrl_c.clone();
         let shell_manager = self.shell_manager.clone();
         let input = self.input;
         let call_info = self.call_info.evaluate(registry, &Scope::empty())?;
 
         Ok(EvaluatedWholeStreamCommandArgs::new(
             host,
+            ctrl_c,
             shell_manager,
             call_info,
             input,
         ))
     }
 
-    // pub fn name_span(&self) -> Span {
-    //     self.call_info.name_span
-    // }
-
-    pub fn process<'de, T: Deserialize<'de>>(
+    pub fn evaluate_once_with_scope(
         self,
         registry: &CommandRegistry,
-        callback: fn(T, RunnableContext) -> Result<OutputStream, ShellError>,
-    ) -> Result<RunnableArgs<T>, ShellError> {
-        let shell_manager = self.shell_manager.clone();
-        let source_map = self.call_info.source_map.clone();
+        scope: &Scope,
+    ) -> Result<EvaluatedWholeStreamCommandArgs, ShellError> {
         let host = self.host.clone();
+        let ctrl_c = self.ctrl_c.clone();
+        let shell_manager = self.shell_manager.clone();
+        let input = self.input;
+        let call_info = self.call_info.evaluate(registry, scope)?;
+
+        Ok(EvaluatedWholeStreamCommandArgs::new(
+            host,
+            ctrl_c,
+            shell_manager,
+            call_info,
+            input,
+        ))
+    }
+
+    pub fn source(&self) -> Text {
+        self.call_info.source.clone()
+    }
+
+    pub fn process<'de, T: Deserialize<'de>, O: ToOutputStream>(
+        self,
+        registry: &CommandRegistry,
+        callback: fn(T, RunnableContext) -> Result<O, ShellError>,
+    ) -> Result<RunnableArgs<T, O>, ShellError> {
+        let shell_manager = self.shell_manager.clone();
+        let host = self.host.clone();
+        let source = self.source();
+        let ctrl_c = self.ctrl_c.clone();
         let args = self.evaluate_once(registry)?;
+        let call_info = args.call_info.clone();
         let (input, args) = args.split();
-        let name_span = args.call_info.name_span;
-        let mut deserializer = ConfigDeserializer::from_call_info(args.call_info);
+        let name_tag = args.call_info.name_tag;
+        let mut deserializer = ConfigDeserializer::from_call_info(call_info);
 
         Ok(RunnableArgs {
             args: T::deserialize(&mut deserializer)?,
             context: RunnableContext {
-                input: input,
+                input,
                 commands: registry.clone(),
+                source,
                 shell_manager,
-                name: name_span,
-                source_map,
+                name: name_tag,
                 host,
+                ctrl_c,
             },
             callback,
         })
@@ -186,27 +186,32 @@ impl CommandArgs {
     ) -> Result<RunnableRawArgs<T>, ShellError> {
         let raw_args = RawCommandArgs {
             host: self.host.clone(),
+            ctrl_c: self.ctrl_c.clone(),
             shell_manager: self.shell_manager.clone(),
             call_info: self.call_info.clone(),
         };
 
         let shell_manager = self.shell_manager.clone();
-        let source_map = self.call_info.source_map.clone();
         let host = self.host.clone();
+        let source = self.source();
+        let ctrl_c = self.ctrl_c.clone();
         let args = self.evaluate_once(registry)?;
+        let call_info = args.call_info.clone();
+
         let (input, args) = args.split();
-        let name_span = args.call_info.name_span;
-        let mut deserializer = ConfigDeserializer::from_call_info(args.call_info);
+        let name_tag = args.call_info.name_tag;
+        let mut deserializer = ConfigDeserializer::from_call_info(call_info);
 
         Ok(RunnableRawArgs {
             args: T::deserialize(&mut deserializer)?,
             context: RunnableContext {
-                input: input,
+                input,
                 commands: registry.clone(),
+                source,
                 shell_manager,
-                name: name_span,
-                source_map,
+                name: name_tag,
                 host,
+                ctrl_c,
             },
             raw_args,
             callback,
@@ -216,58 +221,47 @@ impl CommandArgs {
 
 pub struct RunnablePerItemContext {
     pub shell_manager: ShellManager,
-    pub name: Span,
-}
-
-impl RunnablePerItemContext {
-    pub fn cwd(&self) -> PathBuf {
-        PathBuf::from(self.shell_manager.path())
-    }
+    pub name: Tag,
+    pub ctrl_c: Arc<AtomicBool>,
 }
 
 pub struct RunnableContext {
     pub input: InputStream,
     pub shell_manager: ShellManager,
-    pub host: Arc<Mutex<dyn Host>>,
+    pub host: Arc<parking_lot::Mutex<Box<dyn Host>>>,
+    pub source: Text,
+    pub ctrl_c: Arc<AtomicBool>,
     pub commands: CommandRegistry,
-    pub source_map: SourceMap,
-    pub name: Span,
+    pub name: Tag,
 }
 
 impl RunnableContext {
-    #[allow(unused)]
-    pub fn cwd(&self) -> PathBuf {
-        PathBuf::from(self.shell_manager.path())
-    }
-
-    pub fn expect_command(&self, name: &str) -> Arc<Command> {
-        self.commands
-            .get_command(name)
-            .expect(&format!("Expected command {}", name))
+    pub fn get_command(&self, name: &str) -> Option<Arc<Command>> {
+        self.commands.get_command(name)
     }
 }
 
 pub struct RunnablePerItemArgs<T> {
     args: T,
     context: RunnablePerItemContext,
-    callback: fn(T, &RunnablePerItemContext) -> Result<VecDeque<ReturnValue>, ShellError>,
+    callback: fn(T, &RunnablePerItemContext) -> Result<OutputStream, ShellError>,
 }
 
 impl<T> RunnablePerItemArgs<T> {
-    pub fn run(self) -> Result<VecDeque<ReturnValue>, ShellError> {
+    pub fn run(self) -> Result<OutputStream, ShellError> {
         (self.callback)(self.args, &self.context)
     }
 }
 
-pub struct RunnableArgs<T> {
+pub struct RunnableArgs<T, O: ToOutputStream> {
     args: T,
     context: RunnableContext,
-    callback: fn(T, RunnableContext) -> Result<OutputStream, ShellError>,
+    callback: fn(T, RunnableContext) -> Result<O, ShellError>,
 }
 
-impl<T> RunnableArgs<T> {
+impl<T, O: ToOutputStream> RunnableArgs<T, O> {
     pub fn run(self) -> Result<OutputStream, ShellError> {
-        (self.callback)(self.args, self.context)
+        (self.callback)(self.args, self.context).map(|v| v.to_output_stream())
     }
 }
 
@@ -301,7 +295,8 @@ impl Deref for EvaluatedWholeStreamCommandArgs {
 
 impl EvaluatedWholeStreamCommandArgs {
     pub fn new(
-        host: Arc<Mutex<dyn Host>>,
+        host: Arc<parking_lot::Mutex<dyn Host>>,
+        ctrl_c: Arc<AtomicBool>,
         shell_manager: ShellManager,
         call_info: CallInfo,
         input: impl Into<InputStream>,
@@ -309,6 +304,7 @@ impl EvaluatedWholeStreamCommandArgs {
         EvaluatedWholeStreamCommandArgs {
             args: EvaluatedCommandArgs {
                 host,
+                ctrl_c,
                 shell_manager,
                 call_info,
             },
@@ -316,11 +312,11 @@ impl EvaluatedWholeStreamCommandArgs {
         }
     }
 
-    pub fn name_span(&self) -> Span {
-        self.args.call_info.name_span
+    pub fn name_tag(&self) -> Tag {
+        self.args.call_info.name_tag.clone()
     }
 
-    pub fn parts(self) -> (InputStream, registry::EvaluatedArgs) {
+    pub fn parts(self) -> (InputStream, EvaluatedArgs) {
         let EvaluatedWholeStreamCommandArgs { args, input } = self;
 
         (input, args.call_info.args)
@@ -337,8 +333,6 @@ impl EvaluatedWholeStreamCommandArgs {
 #[get = "pub"]
 pub struct EvaluatedFilterCommandArgs {
     args: EvaluatedCommandArgs,
-    #[allow(unused)]
-    input: Tagged<Value>,
 }
 
 impl Deref for EvaluatedFilterCommandArgs {
@@ -350,151 +344,84 @@ impl Deref for EvaluatedFilterCommandArgs {
 
 impl EvaluatedFilterCommandArgs {
     pub fn new(
-        host: Arc<Mutex<dyn Host>>,
+        host: Arc<parking_lot::Mutex<dyn Host>>,
+        ctrl_c: Arc<AtomicBool>,
         shell_manager: ShellManager,
         call_info: CallInfo,
-        input: Tagged<Value>,
     ) -> EvaluatedFilterCommandArgs {
         EvaluatedFilterCommandArgs {
             args: EvaluatedCommandArgs {
                 host,
+                ctrl_c,
                 shell_manager,
                 call_info,
             },
-            input,
         }
     }
 }
 
 #[derive(Getters, new)]
-#[get = "crate"]
+#[get = "pub(crate)"]
 pub struct EvaluatedCommandArgs {
-    pub host: Arc<Mutex<dyn Host>>,
+    pub host: Arc<parking_lot::Mutex<dyn Host>>,
+    pub ctrl_c: Arc<AtomicBool>,
     pub shell_manager: ShellManager,
     pub call_info: CallInfo,
 }
 
 impl EvaluatedCommandArgs {
-    pub fn call_args(&self) -> &registry::EvaluatedArgs {
-        &self.call_info.args
-    }
-
-    pub fn nth(&self, pos: usize) -> Option<&Tagged<Value>> {
+    pub fn nth(&self, pos: usize) -> Option<&Value> {
         self.call_info.args.nth(pos)
     }
 
-    pub fn expect_nth(&self, pos: usize) -> Result<&Tagged<Value>, ShellError> {
-        self.call_info.args.expect_nth(pos)
-    }
-
-    pub fn len(&self) -> usize {
-        self.call_info.args.len()
-    }
-
-    pub fn get(&self, name: &str) -> Option<&Tagged<Value>> {
+    pub fn get(&self, name: &str) -> Option<&Value> {
         self.call_info.args.get(name)
     }
 
-    pub fn slice_from(&self, from: usize) -> Vec<Tagged<Value>> {
-        let positional = &self.call_info.args.positional;
-
-        match positional {
-            None => vec![],
-            Some(list) => list[from..].to_vec(),
-        }
-    }
-
-    #[allow(unused)]
     pub fn has(&self, name: &str) -> bool {
         self.call_info.args.has(name)
     }
 }
 
-#[derive(Debug, Serialize, Deserialize)]
-pub enum CommandAction {
-    ChangePath(String),
-    AddSpanSource(Uuid, SpanSource),
-    Exit,
-    EnterShell(String),
-    EnterValueShell(Tagged<Value>),
-    PreviousShell,
-    NextShell,
-    LeaveShell,
-}
-
-#[derive(Debug, Serialize, Deserialize)]
-pub enum ReturnSuccess {
-    Value(Tagged<Value>),
-    Action(CommandAction),
-}
-
-pub type ReturnValue = Result<ReturnSuccess, ShellError>;
-
-impl From<Tagged<Value>> for ReturnValue {
-    fn from(input: Tagged<Value>) -> ReturnValue {
-        Ok(ReturnSuccess::Value(input))
-    }
-}
-
-impl ReturnSuccess {
-    pub fn change_cwd(path: String) -> ReturnValue {
-        Ok(ReturnSuccess::Action(CommandAction::ChangePath(path)))
-    }
-
-    pub fn value(input: impl Into<Tagged<Value>>) -> ReturnValue {
-        Ok(ReturnSuccess::Value(input.into()))
-    }
-
-    pub fn action(input: CommandAction) -> ReturnValue {
-        Ok(ReturnSuccess::Action(input))
-    }
-
-    pub fn spanned_value(input: Value, span: Span) -> ReturnValue {
-        Ok(ReturnSuccess::Value(Tagged::from_simple_spanned_item(
-            input, span,
-        )))
-    }
-}
-
 pub trait WholeStreamCommand: Send + Sync {
     fn name(&self) -> &str;
 
+    fn signature(&self) -> Signature {
+        Signature::new(self.name()).desc(self.usage()).filter()
+    }
+
+    fn usage(&self) -> &str;
+
     fn run(
         &self,
         args: CommandArgs,
-        registry: &registry::CommandRegistry,
+        registry: &CommandRegistry,
     ) -> Result<OutputStream, ShellError>;
 
-    fn signature(&self) -> Signature {
-        Signature {
-            name: self.name().to_string(),
-            positional: vec![],
-            rest_positional: true,
-            named: indexmap::IndexMap::new(),
-            is_filter: true,
-        }
+    fn is_binary(&self) -> bool {
+        false
     }
 }
 
 pub trait PerItemCommand: Send + Sync {
     fn name(&self) -> &str;
 
+    fn signature(&self) -> Signature {
+        Signature::new(self.name()).desc(self.usage()).filter()
+    }
+
+    fn usage(&self) -> &str;
+
     fn run(
         &self,
         call_info: &CallInfo,
         registry: &CommandRegistry,
-        shell_manager: &ShellManager,
-        input: Tagged<Value>,
-    ) -> Result<VecDeque<ReturnValue>, ShellError>;
+        raw_args: &RawCommandArgs,
+        input: Value,
+    ) -> Result<OutputStream, ShellError>;
 
-    fn signature(&self) -> Signature {
-        Signature {
-            name: self.name().to_string(),
-            positional: vec![],
-            rest_positional: true,
-            named: indexmap::IndexMap::new(),
-            is_filter: true,
-        }
+    fn is_binary(&self) -> bool {
+        false
     }
 }
 
@@ -503,6 +430,38 @@ pub enum Command {
     PerItem(Arc<dyn PerItemCommand>),
 }
 
+impl PrettyDebugWithSource for Command {
+    fn pretty_debug(&self, source: &str) -> DebugDocBuilder {
+        match self {
+            Command::WholeStream(command) => b::typed(
+                "whole stream command",
+                b::description(command.name())
+                    + b::space()
+                    + b::equals()
+                    + b::space()
+                    + command.signature().pretty_debug(source),
+            ),
+            Command::PerItem(command) => b::typed(
+                "per item command",
+                b::description(command.name())
+                    + b::space()
+                    + b::equals()
+                    + b::space()
+                    + command.signature().pretty_debug(source),
+            ),
+        }
+    }
+}
+
+impl std::fmt::Debug for Command {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Command::WholeStream(command) => write!(f, "WholeStream({})", command.name()),
+            Command::PerItem(command) => write!(f, "PerItem({})", command.name()),
+        }
+    }
+}
+
 impl Command {
     pub fn name(&self) -> &str {
         match self {
@@ -518,13 +477,26 @@ impl Command {
         }
     }
 
-    pub fn run(&self, args: CommandArgs, registry: &registry::CommandRegistry) -> OutputStream {
+    pub fn usage(&self) -> &str {
+        match self {
+            Command::WholeStream(command) => command.usage(),
+            Command::PerItem(command) => command.usage(),
+        }
+    }
+
+    pub fn run(&self, args: CommandArgs, registry: &CommandRegistry) -> OutputStream {
+        if args.call_info.switch_present("help") {
+            get_help(self.name(), self.usage(), self.signature()).into()
+        } else {
             match self {
                 Command::WholeStream(command) => match command.run(args, registry) {
                     Ok(stream) => stream,
                     Err(err) => OutputStream::one(Err(err)),
                 },
-            Command::PerItem(command) => self.run_helper(command.clone(), args, registry.clone()),
+                Command::PerItem(command) => {
+                    self.run_helper(command.clone(), args, registry.clone())
+                }
+            }
         }
     }
 
@@ -536,11 +508,11 @@ impl Command {
     ) -> OutputStream {
         let raw_args = RawCommandArgs {
             host: args.host,
+            ctrl_c: args.ctrl_c,
             shell_manager: args.shell_manager,
             call_info: args.call_info,
         };
 
-        if raw_args.call_info.has_it_or_block() {
         let out = args
             .input
             .values
@@ -548,38 +520,31 @@ impl Command {
                 let call_info = raw_args
                     .clone()
                     .call_info
-                        .evaluate(&registry, &Scope::it_value(x.clone()))
-                        .unwrap();
-                    match command.run(&call_info, &registry, &raw_args.shell_manager, x) {
+                    .evaluate(&registry, &Scope::it_value(x.clone()));
+
+                match call_info {
+                    Ok(call_info) => match command.run(&call_info, &registry, &raw_args, x) {
                         Ok(o) => o,
-                        Err(e) => VecDeque::from(vec![ReturnValue::Err(e)]),
+                        Err(e) => {
+                            futures::stream::iter(vec![ReturnValue::Err(e)]).to_output_stream()
+                        }
+                    },
+                    Err(e) => futures::stream::iter(vec![ReturnValue::Err(e)]).to_output_stream(),
                 }
             })
             .flatten();
 
         out.to_output_stream()
-        } else {
-            let nothing = Value::nothing().tagged(Tag::unknown());
-            let call_info = raw_args
-                .clone()
-                .call_info
-                .evaluate(&registry, &Scope::it_value(nothing.clone()))
-                .unwrap();
-            // We don't have an $it or block, so just execute what we have
+    }
 
-            command
-                .run(&call_info, &registry, &raw_args.shell_manager, nothing)?
-                .into()
-            // let out = match command.run(&call_info, &registry, &raw_args.shell_manager, nothing) {
-            //     Ok(o) => o,
-            //     Err(e) => VecDeque::from(vec![ReturnValue::Err(e)]),
-            // };
-            // Ok(out.to_output_stream())
+    pub fn is_binary(&self) -> bool {
+        match self {
+            Command::WholeStream(command) => command.is_binary(),
+            Command::PerItem(command) => command.is_binary(),
         }
     }
 }
 
-#[allow(unused)]
 pub struct FnFilterCommand {
     name: String,
     func: fn(EvaluatedFilterCommandArgs) -> Result<OutputStream, ShellError>,
@@ -590,38 +555,43 @@ impl WholeStreamCommand for FnFilterCommand {
         &self.name
     }
 
+    fn usage(&self) -> &str {
+        "usage"
+    }
+
     fn run(
         &self,
         args: CommandArgs,
-        registry: &registry::CommandRegistry,
+        registry: &CommandRegistry,
     ) -> Result<OutputStream, ShellError> {
         let CommandArgs {
             host,
+            ctrl_c,
             shell_manager,
             call_info,
             input,
         } = args;
 
-        let host: Arc<Mutex<dyn Host>> = host.clone();
-        let shell_manager = shell_manager.clone();
-        let registry: registry::CommandRegistry = registry.clone();
+        let host: Arc<parking_lot::Mutex<dyn Host>> = host.clone();
+        let registry: CommandRegistry = registry.clone();
         let func = self.func;
 
         let result = input.values.map(move |it| {
             let registry = registry.clone();
-            let call_info = match call_info
-                .clone()
-                .evaluate(&registry, &Scope::it_value(it.clone()))
-            {
+            let call_info = match call_info.clone().evaluate(&registry, &Scope::it_value(it)) {
                 Err(err) => return OutputStream::from(vec![Err(err)]).values,
                 Ok(args) => args,
             };
 
-            let args =
-                EvaluatedFilterCommandArgs::new(host.clone(), shell_manager.clone(), call_info, it);
+            let args = EvaluatedFilterCommandArgs::new(
+                host.clone(),
+                ctrl_c.clone(),
+                shell_manager.clone(),
+                call_info,
+            );
 
             match func(args) {
-                Err(err) => return OutputStream::from(vec![Err(err)]).values,
+                Err(err) => OutputStream::from(vec![Err(err)]).values,
                 Ok(stream) => stream.values,
             }
         });
@@ -640,14 +610,3 @@ pub fn whole_stream_command(command: impl WholeStreamCommand + 'static) -> Arc<C
 pub fn per_item_command(command: impl PerItemCommand + 'static) -> Arc<Command> {
     Arc::new(Command::PerItem(Arc::new(command)))
 }
-
-#[allow(unused)]
-pub fn filter(
-    name: &str,
-    func: fn(EvaluatedFilterCommandArgs) -> Result<OutputStream, ShellError>,
-) -> Arc<Command> {
-    Arc::new(Command::WholeStream(Arc::new(FnFilterCommand {
-        name: name.to_string(),
-        func,
-    })))
-}

crates/nu-cli/src/commands/compact.rs

@@ -0,0 +1,61 @@
+use crate::commands::WholeStreamCommand;
+use crate::context::CommandRegistry;
+use crate::prelude::*;
+use futures::stream::StreamExt;
+use nu_errors::ShellError;
+use nu_protocol::{Signature, SyntaxShape, UntaggedValue, Value};
+use nu_source::Tagged;
+
+pub struct Compact;
+
+#[derive(Deserialize)]
+pub struct CompactArgs {
+    rest: Vec<Tagged<String>>,
+}
+
+impl WholeStreamCommand for Compact {
+    fn name(&self) -> &str {
+        "compact"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("compact").rest(SyntaxShape::Any, "the columns to compact from the table")
+    }
+
+    fn usage(&self) -> &str {
+        "Creates a table with non-empty rows"
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        args.process(registry, compact)?.run()
+    }
+}
+
+pub fn compact(
+    CompactArgs { rest: columns }: CompactArgs,
+    RunnableContext { input, .. }: RunnableContext,
+) -> Result<OutputStream, ShellError> {
+    let objects = input.values.filter(move |item| {
+        let keep = if columns.is_empty() {
+            item.is_some()
+        } else {
+            match item {
+                Value {
+                    value: UntaggedValue::Row(ref r),
+                    ..
+                } => columns
+                    .iter()
+                    .all(|field| r.get_data(field).borrow().is_some()),
+                _ => false,
+            }
+        };
+
+        futures::future::ready(keep)
+    });
+
+    Ok(objects.from_input_stream())
+}

crates/nu-cli/src/commands/config.rs

@@ -0,0 +1,188 @@
+use crate::commands::WholeStreamCommand;
+use crate::context::CommandRegistry;
+use crate::data::config;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{Primitive, ReturnSuccess, Signature, SyntaxShape, UntaggedValue, Value};
+use nu_source::Tagged;
+use std::path::PathBuf;
+
+pub struct Config;
+
+#[derive(Deserialize)]
+pub struct ConfigArgs {
+    load: Option<Tagged<PathBuf>>,
+    set: Option<(Tagged<String>, Value)>,
+    set_into: Option<Tagged<String>>,
+    get: Option<Tagged<String>>,
+    clear: Tagged<bool>,
+    remove: Option<Tagged<String>>,
+    path: Tagged<bool>,
+}
+
+impl WholeStreamCommand for Config {
+    fn name(&self) -> &str {
+        "config"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("config")
+            .named(
+                "load",
+                SyntaxShape::Path,
+                "load the config from the path give",
+                Some('l'),
+            )
+            .named(
+                "set",
+                SyntaxShape::Any,
+                "set a value in the config, eg) --set [key value]",
+                Some('s'),
+            )
+            .named(
+                "set_into",
+                SyntaxShape::Member,
+                "sets a variable from values in the pipeline",
+                Some('i'),
+            )
+            .named(
+                "get",
+                SyntaxShape::Any,
+                "get a value from the config",
+                Some('g'),
+            )
+            .named(
+                "remove",
+                SyntaxShape::Any,
+                "remove a value from the config",
+                Some('r'),
+            )
+            .switch("clear", "clear the config", Some('c'))
+            .switch("path", "return the path to the config file", Some('p'))
+    }
+
+    fn usage(&self) -> &str {
+        "Configuration management."
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        args.process(registry, config)?.run()
+    }
+}
+
+pub fn config(
+    ConfigArgs {
+        load,
+        set,
+        set_into,
+        get,
+        clear,
+        remove,
+        path,
+    }: ConfigArgs,
+    RunnableContext { name, input, .. }: RunnableContext,
+) -> Result<OutputStream, ShellError> {
+    let name_span = name.clone();
+
+    let stream = async_stream! {
+        let configuration = if let Some(supplied) = load {
+            Some(supplied.item().clone())
+        } else {
+            None
+        };
+
+        let mut result = crate::data::config::read(name_span, &configuration)?;
+
+        if let Some(v) = get {
+            let key = v.to_string();
+            let value = result
+                .get(&key)
+                .ok_or_else(|| ShellError::labeled_error("Missing key in config", "key", v.tag()))?;
+
+            match value {
+                Value {
+                    value: UntaggedValue::Table(list),
+                    ..
+                } => {
+                    for l in list {
+                        let value = l.clone();
+                        yield ReturnSuccess::value(l.clone());
+                    }
+                }
+                x => yield ReturnSuccess::value(x.clone()),
+            }
+        }
+        else if let Some((key, value)) = set {
+            result.insert(key.to_string(), value.clone());
+
+            config::write(&result, &configuration)?;
+
+            yield ReturnSuccess::value(UntaggedValue::Row(result.into()).into_value(&value.tag));
+        }
+        else if let Some(v) = set_into {
+            let rows: Vec<Value> = input.values.collect().await;
+            let key = v.to_string();
+
+            if rows.len() == 0 {
+                yield Err(ShellError::labeled_error("No values given for set_into", "needs value(s) from pipeline", v.tag()));
+            } else if rows.len() == 1 {
+                // A single value
+                let value = &rows[0];
+
+                result.insert(key.to_string(), value.clone());
+
+                config::write(&result, &configuration)?;
+
+                yield ReturnSuccess::value(UntaggedValue::Row(result.into()).into_value(name));
+            } else {
+                // Take in the pipeline as a table
+                let value = UntaggedValue::Table(rows).into_value(name.clone());
+
+                result.insert(key.to_string(), value.clone());
+
+                config::write(&result, &configuration)?;
+
+                yield ReturnSuccess::value(UntaggedValue::Row(result.into()).into_value(name));
+            }
+        }
+        else if let Tagged { item: true, tag } = clear {
+            result.clear();
+
+            config::write(&result, &configuration)?;
+
+            yield ReturnSuccess::value(UntaggedValue::Row(result.into()).into_value(tag));
+
+            return;
+        }
+        else if let Tagged { item: true, tag } = path {
+            let path = config::default_path_for(&configuration)?;
+
+            yield ReturnSuccess::value(UntaggedValue::Primitive(Primitive::Path(path)).into_value(tag));
+        }
+        else if let Some(v) = remove {
+            let key = v.to_string();
+
+            if result.contains_key(&key) {
+                result.swap_remove(&key);
+                config::write(&result, &configuration)?
+            } else {
+                yield Err(ShellError::labeled_error(
+                    "Key does not exist in config",
+                    "key",
+                    v.tag(),
+                ));
+            }
+
+            yield ReturnSuccess::value(UntaggedValue::Row(result.into()).into_value(v.tag()));
+        }
+        else {
+            yield ReturnSuccess::value(UntaggedValue::Row(result.into()).into_value(name));
+        }
+    };
+
+    Ok(stream.to_output_stream())
+}

crates/nu-cli/src/commands/count.rs

@@ -0,0 +1,46 @@
+use crate::commands::WholeStreamCommand;
+use crate::context::CommandRegistry;
+use crate::prelude::*;
+use futures::stream::StreamExt;
+use nu_errors::ShellError;
+use nu_protocol::{ReturnSuccess, Signature, UntaggedValue, Value};
+
+pub struct Count;
+
+#[derive(Deserialize)]
+pub struct CountArgs {}
+
+impl WholeStreamCommand for Count {
+    fn name(&self) -> &str {
+        "count"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("count")
+    }
+
+    fn usage(&self) -> &str {
+        "Show the total number of rows."
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        args.process(registry, count)?.run()
+    }
+}
+
+pub fn count(
+    CountArgs {}: CountArgs,
+    RunnableContext { input, name, .. }: RunnableContext,
+) -> Result<OutputStream, ShellError> {
+    let stream = async_stream! {
+        let rows: Vec<Value> = input.values.collect().await;
+
+        yield ReturnSuccess::value(UntaggedValue::int(rows.len()).into_value(name))
+    };
+
+    Ok(stream.to_output_stream())
+}

crates/nu-cli/src/commands/cp.rs

@@ -0,0 +1,54 @@
+use crate::commands::command::RunnablePerItemContext;
+use crate::context::CommandRegistry;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{CallInfo, Signature, SyntaxShape, Value};
+use nu_source::Tagged;
+use std::path::PathBuf;
+
+pub struct Cpy;
+
+#[derive(Deserialize)]
+pub struct CopyArgs {
+    pub src: Tagged<PathBuf>,
+    pub dst: Tagged<PathBuf>,
+    pub recursive: Tagged<bool>,
+}
+
+impl PerItemCommand for Cpy {
+    fn name(&self) -> &str {
+        "cp"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("cp")
+            .required("src", SyntaxShape::Pattern, "the place to copy from")
+            .required("dst", SyntaxShape::Path, "the place to copy to")
+            .switch(
+                "recursive",
+                "copy recursively through subdirectories",
+                Some('r'),
+            )
+    }
+
+    fn usage(&self) -> &str {
+        "Copy files."
+    }
+
+    fn run(
+        &self,
+        call_info: &CallInfo,
+        _registry: &CommandRegistry,
+        raw_args: &RawCommandArgs,
+        _input: Value,
+    ) -> Result<OutputStream, ShellError> {
+        call_info
+            .process(&raw_args.shell_manager, raw_args.ctrl_c.clone(), cp)?
+            .run()
+    }
+}
+
+fn cp(args: CopyArgs, context: &RunnablePerItemContext) -> Result<OutputStream, ShellError> {
+    let shell_manager = context.shell_manager.clone();
+    shell_manager.cp(args, context)
+}

crates/nu-cli/src/commands/date.rs

@@ -1,17 +1,31 @@
-use crate::errors::ShellError;
-use crate::object::{Dictionary, Value};
 use crate::prelude::*;
 use chrono::{DateTime, Local, Utc};
+use nu_errors::ShellError;
+use nu_protocol::{Dictionary, Value};
 
 use crate::commands::WholeStreamCommand;
-use crate::parser::registry::Signature;
 use chrono::{Datelike, TimeZone, Timelike};
 use core::fmt::Display;
 use indexmap::IndexMap;
+use nu_protocol::{Signature, UntaggedValue};
 
 pub struct Date;
 
 impl WholeStreamCommand for Date {
+    fn name(&self) -> &str {
+        "date"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("date")
+            .switch("utc", "use universal time (UTC)", Some('u'))
+            .switch("local", "use the local time", Some('l'))
+    }
+
+    fn usage(&self) -> &str {
+        "Get the current datetime."
+    }
+
     fn run(
         &self,
         args: CommandArgs,
@@ -19,16 +33,9 @@ impl WholeStreamCommand for Date {
     ) -> Result<OutputStream, ShellError> {
         date(args, registry)
     }
-    fn name(&self) -> &str {
-        "date"
 }
 
-    fn signature(&self) -> Signature {
-        Signature::build("date").switch("utc").switch("local")
-    }
-}
-
-pub fn date_to_value<T: TimeZone>(dt: DateTime<T>, span: Span) -> Tagged<Value>
+pub fn date_to_value<T: TimeZone>(dt: DateTime<T>, tag: Tag) -> Value
 where
     T::Offset: Display,
 {
@@ -36,53 +43,53 @@ where
 
     indexmap.insert(
         "year".to_string(),
-        Tagged::from_simple_spanned_item(Value::int(dt.year()), span),
+        UntaggedValue::int(dt.year()).into_value(&tag),
     );
     indexmap.insert(
         "month".to_string(),
-        Tagged::from_simple_spanned_item(Value::int(dt.month()), span),
+        UntaggedValue::int(dt.month()).into_value(&tag),
     );
     indexmap.insert(
         "day".to_string(),
-        Tagged::from_simple_spanned_item(Value::int(dt.day()), span),
+        UntaggedValue::int(dt.day()).into_value(&tag),
     );
     indexmap.insert(
         "hour".to_string(),
-        Tagged::from_simple_spanned_item(Value::int(dt.hour()), span),
+        UntaggedValue::int(dt.hour()).into_value(&tag),
     );
     indexmap.insert(
         "minute".to_string(),
-        Tagged::from_simple_spanned_item(Value::int(dt.minute()), span),
+        UntaggedValue::int(dt.minute()).into_value(&tag),
     );
     indexmap.insert(
         "second".to_string(),
-        Tagged::from_simple_spanned_item(Value::int(dt.second()), span),
+        UntaggedValue::int(dt.second()).into_value(&tag),
     );
 
     let tz = dt.offset();
     indexmap.insert(
         "timezone".to_string(),
-        Tagged::from_simple_spanned_item(Value::string(format!("{}", tz)), span),
+        UntaggedValue::string(format!("{}", tz)).into_value(&tag),
     );
 
-    Tagged::from_simple_spanned_item(Value::Object(Dictionary::from(indexmap)), span)
+    UntaggedValue::Row(Dictionary::from(indexmap)).into_value(&tag)
 }
 
 pub fn date(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStream, ShellError> {
     let args = args.evaluate_once(registry)?;
 
     let mut date_out = VecDeque::new();
-    let span = args.call_info.name_span;
+    let tag = args.call_info.name_tag.clone();
 
     let value = if args.has("utc") {
         let utc: DateTime<Utc> = Utc::now();
-        date_to_value(utc, span)
+        date_to_value(utc, tag)
     } else {
         let local: DateTime<Local> = Local::now();
-        date_to_value(local, span)
+        date_to_value(local, tag)
     };
 
     date_out.push_back(value);
 
-    Ok(date_out.to_output_stream())
+    Ok(futures::stream::iter(date_out).to_output_stream())
 }

crates/nu-cli/src/commands/debug.rs

@@ -0,0 +1,51 @@
+use crate::commands::WholeStreamCommand;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{ReturnSuccess, Signature, UntaggedValue};
+
+pub struct Debug;
+
+#[derive(Deserialize)]
+pub struct DebugArgs {
+    raw: bool,
+}
+
+impl WholeStreamCommand for Debug {
+    fn name(&self) -> &str {
+        "debug"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("debug").switch("raw", "Prints the raw value representation.", Some('r'))
+    }
+
+    fn usage(&self) -> &str {
+        "Print the Rust debug representation of the values"
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        args.process(registry, debug_value)?.run()
+    }
+}
+
+fn debug_value(
+    DebugArgs { raw }: DebugArgs,
+    RunnableContext { input, .. }: RunnableContext,
+) -> Result<impl ToOutputStream, ShellError> {
+    Ok(input
+        .values
+        .map(move |v| {
+            if raw {
+                ReturnSuccess::value(
+                    UntaggedValue::string(format!("{:#?}", v)).into_untagged_value(),
+                )
+            } else {
+                ReturnSuccess::debug_value(v)
+            }
+        })
+        .to_output_stream())
+}

crates/nu-cli/src/commands/default.rs

@@ -0,0 +1,76 @@
+use crate::commands::WholeStreamCommand;
+use crate::context::CommandRegistry;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{ReturnSuccess, Signature, SyntaxShape, UntaggedValue, Value};
+use nu_source::Tagged;
+use nu_value_ext::ValueExt;
+
+#[derive(Deserialize)]
+struct DefaultArgs {
+    column: Tagged<String>,
+    value: Value,
+}
+
+pub struct Default;
+
+impl WholeStreamCommand for Default {
+    fn name(&self) -> &str {
+        "default"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("default")
+            .required("column name", SyntaxShape::String, "the name of the column")
+            .required(
+                "column value",
+                SyntaxShape::Any,
+                "the value of the column to default",
+            )
+    }
+
+    fn usage(&self) -> &str {
+        "Sets a default row's column if missing."
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        args.process(registry, default)?.run()
+    }
+}
+
+fn default(
+    DefaultArgs { column, value }: DefaultArgs,
+    RunnableContext { input, .. }: RunnableContext,
+) -> Result<OutputStream, ShellError> {
+    let stream = input
+        .values
+        .map(move |item| {
+            let mut result = VecDeque::new();
+
+            let should_add = match item {
+                Value {
+                    value: UntaggedValue::Row(ref r),
+                    ..
+                } => r.get_data(&column.item).borrow().is_none(),
+                _ => false,
+            };
+
+            if should_add {
+                match item.insert_data_at_path(&column.item, value.clone()) {
+                    Some(new_value) => result.push_back(ReturnSuccess::value(new_value)),
+                    None => result.push_back(ReturnSuccess::value(item)),
+                }
+            } else {
+                result.push_back(ReturnSuccess::value(item));
+            }
+
+            futures::stream::iter(result)
+        })
+        .flatten();
+
+    Ok(stream.to_output_stream())
+}

crates/nu-cli/src/commands/du.rs

@@ -0,0 +1,376 @@
+extern crate filesize;
+
+use crate::commands::command::RunnablePerItemContext;
+use crate::prelude::*;
+use filesize::file_real_size_fast;
+use glob::*;
+use indexmap::map::IndexMap;
+use nu_errors::ShellError;
+use nu_protocol::{CallInfo, ReturnSuccess, Signature, SyntaxShape, UntaggedValue, Value};
+use nu_source::Tagged;
+use std::path::PathBuf;
+
+const NAME: &str = "du";
+const GLOB_PARAMS: MatchOptions = MatchOptions {
+    case_sensitive: true,
+    require_literal_separator: true,
+    require_literal_leading_dot: false,
+};
+
+pub struct Du;
+
+#[derive(Deserialize, Clone)]
+pub struct DuArgs {
+    path: Option<Tagged<PathBuf>>,
+    all: bool,
+    deref: bool,
+    exclude: Option<Tagged<String>>,
+    #[serde(rename = "max-depth")]
+    max_depth: Option<Tagged<u64>>,
+    #[serde(rename = "min-size")]
+    min_size: Option<Tagged<u64>>,
+}
+
+impl PerItemCommand for Du {
+    fn name(&self) -> &str {
+        NAME
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build(NAME)
+            .optional("path", SyntaxShape::Pattern, "starting directory")
+            .switch(
+                "all",
+                "Output file sizes as well as directory sizes",
+                Some('a'),
+            )
+            .switch(
+                "deref",
+                "Dereference symlinks to their targets for size",
+                Some('r'),
+            )
+            .named(
+                "exclude",
+                SyntaxShape::Pattern,
+                "Exclude these file names",
+                Some('x'),
+            )
+            .named(
+                "max-depth",
+                SyntaxShape::Int,
+                "Directory recursion limit",
+                Some('d'),
+            )
+            .named(
+                "min-size",
+                SyntaxShape::Int,
+                "Exclude files below this size",
+                Some('m'),
+            )
+    }
+
+    fn usage(&self) -> &str {
+        "Find disk usage sizes of specified items"
+    }
+
+    fn run(
+        &self,
+        call_info: &CallInfo,
+        _registry: &CommandRegistry,
+        raw_args: &RawCommandArgs,
+        _input: Value,
+    ) -> Result<OutputStream, ShellError> {
+        call_info
+            .process(&raw_args.shell_manager, raw_args.ctrl_c.clone(), du)?
+            .run()
+    }
+}
+
+fn du(args: DuArgs, ctx: &RunnablePerItemContext) -> Result<OutputStream, ShellError> {
+    let tag = ctx.name.clone();
+
+    let exclude = args.exclude.map_or(Ok(None), move |x| {
+        Pattern::new(&x.item)
+            .map(Option::Some)
+            .map_err(|e| ShellError::labeled_error(e.msg, "glob error", x.tag.clone()))
+    })?;
+
+    let include_files = args.all;
+    let paths = match args.path {
+        Some(p) => {
+            let p = p.item.to_str().expect("Why isn't this encoded properly?");
+            glob::glob_with(p, GLOB_PARAMS)
+        }
+        None => glob::glob_with("*", GLOB_PARAMS),
+    }
+    .map_err(|e| ShellError::labeled_error(e.msg, "glob error", tag.clone()))?
+    .filter(move |p| {
+        if include_files {
+            true
+        } else {
+            match p {
+                Ok(f) if f.is_dir() => true,
+                Err(e) if e.path().is_dir() => true,
+                _ => false,
+            }
+        }
+    })
+    .map(|v| v.map_err(glob_err_into));
+
+    let ctrl_c = ctx.ctrl_c.clone();
+    let all = args.all;
+    let deref = args.deref;
+    let max_depth = args.max_depth.map(|f| f.item);
+    let min_size = args.min_size.map(|f| f.item);
+
+    let params = DirBuilder {
+        tag: tag.clone(),
+        min: min_size,
+        deref,
+        exclude,
+        all,
+    };
+
+    let stream = futures::stream::iter(paths)
+        .interruptible(ctrl_c)
+        .map(move |path| match path {
+            Ok(p) => {
+                if p.is_dir() {
+                    Ok(ReturnSuccess::Value(
+                        DirInfo::new(p, &params, max_depth).into(),
+                    ))
+                } else {
+                    FileInfo::new(p, deref, tag.clone()).map(|v| ReturnSuccess::Value(v.into()))
+                }
+            }
+            Err(e) => Err(e),
+        });
+
+    Ok(stream.to_output_stream())
+}
+
+struct DirBuilder {
+    tag: Tag,
+    min: Option<u64>,
+    deref: bool,
+    exclude: Option<Pattern>,
+    all: bool,
+}
+
+struct DirInfo {
+    dirs: Vec<DirInfo>,
+    files: Vec<FileInfo>,
+    errors: Vec<ShellError>,
+    size: u64,
+    blocks: u64,
+    path: PathBuf,
+    tag: Tag,
+}
+
+struct FileInfo {
+    path: PathBuf,
+    size: u64,
+    blocks: Option<u64>,
+    tag: Tag,
+}
+
+impl FileInfo {
+    fn new(path: impl Into<PathBuf>, deref: bool, tag: Tag) -> Result<Self, ShellError> {
+        let path = path.into();
+        let m = if deref {
+            std::fs::metadata(&path)
+        } else {
+            std::fs::symlink_metadata(&path)
+        };
+
+        match m {
+            Ok(d) => {
+                let block_size = file_real_size_fast(&path, &d).ok();
+
+                Ok(FileInfo {
+                    path,
+                    blocks: block_size,
+                    size: d.len(),
+                    tag,
+                })
+            }
+            Err(e) => Err(e.into()),
+        }
+    }
+}
+
+impl DirInfo {
+    fn new(path: impl Into<PathBuf>, params: &DirBuilder, depth: Option<u64>) -> Self {
+        let path = path.into();
+
+        let mut s = Self {
+            dirs: Vec::new(),
+            errors: Vec::new(),
+            files: Vec::new(),
+            size: 0,
+            blocks: 0,
+            tag: params.tag.clone(),
+            path,
+        };
+
+        match std::fs::read_dir(&s.path) {
+            Ok(d) => {
+                for f in d {
+                    match f {
+                        Ok(i) => match i.file_type() {
+                            Ok(t) if t.is_dir() => s = s.add_dir(i.path(), depth, &params),
+                            Ok(_t) => s = s.add_file(i.path(), &params),
+                            Err(e) => s = s.add_error(e.into()),
+                        },
+                        Err(e) => s = s.add_error(e.into()),
+                    }
+                }
+            }
+            Err(e) => s = s.add_error(e.into()),
+        }
+        s
+    }
+
+    fn add_dir(
+        mut self,
+        path: impl Into<PathBuf>,
+        mut depth: Option<u64>,
+        params: &DirBuilder,
+    ) -> Self {
+        if let Some(current) = depth {
+            if let Some(new) = current.checked_sub(1) {
+                depth = Some(new);
+            } else {
+                return self;
+            }
+        }
+
+        let d = DirInfo::new(path, &params, depth);
+        self.size += d.size;
+        self.blocks += d.blocks;
+        self.dirs.push(d);
+        self
+    }
+
+    fn add_file(mut self, f: impl Into<PathBuf>, params: &DirBuilder) -> Self {
+        let f = f.into();
+        let include = params
+            .exclude
+            .as_ref()
+            .map_or(true, |x| !x.matches_path(&f));
+        if include {
+            match FileInfo::new(f, params.deref, self.tag.clone()) {
+                Ok(file) => {
+                    let inc = params.min.map_or(true, |s| file.size >= s);
+                    if inc {
+                        self.size += file.size;
+                        self.blocks += file.blocks.unwrap_or(0);
+                        if params.all {
+                            self.files.push(file);
+                        }
+                    }
+                }
+                Err(e) => self = self.add_error(e),
+            }
+        }
+        self
+    }
+
+    fn add_error(mut self, e: ShellError) -> Self {
+        self.errors.push(e);
+        self
+    }
+}
+
+fn glob_err_into(e: GlobError) -> ShellError {
+    let e = e.into_error();
+    ShellError::from(e)
+}
+
+fn value_from_vec<V>(vec: Vec<V>, tag: &Tag) -> Value
+where
+    V: Into<Value>,
+{
+    if vec.is_empty() {
+        UntaggedValue::nothing()
+    } else {
+        let values = vec.into_iter().map(Into::into).collect::<Vec<Value>>();
+        UntaggedValue::Table(values)
+    }
+    .retag(tag)
+}
+
+impl From<DirInfo> for Value {
+    fn from(d: DirInfo) -> Self {
+        let mut r: IndexMap<String, Value> = IndexMap::new();
+
+        r.insert(
+            "path".to_string(),
+            UntaggedValue::path(d.path).retag(&d.tag),
+        );
+
+        r.insert(
+            "apparent".to_string(),
+            UntaggedValue::bytes(d.size).retag(&d.tag),
+        );
+
+        r.insert(
+            "physical".to_string(),
+            UntaggedValue::bytes(d.blocks).retag(&d.tag),
+        );
+
+        r.insert("directories".to_string(), value_from_vec(d.dirs, &d.tag));
+
+        r.insert("files".to_string(), value_from_vec(d.files, &d.tag));
+
+        if !d.errors.is_empty() {
+            let v = UntaggedValue::Table(
+                d.errors
+                    .into_iter()
+                    .map(move |e| UntaggedValue::Error(e).into_untagged_value())
+                    .collect::<Vec<Value>>(),
+            )
+            .retag(&d.tag);
+
+            r.insert("errors".to_string(), v);
+        }
+
+        Value {
+            value: UntaggedValue::row(r),
+            tag: d.tag,
+        }
+    }
+}
+
+impl From<FileInfo> for Value {
+    fn from(f: FileInfo) -> Self {
+        let mut r: IndexMap<String, Value> = IndexMap::new();
+
+        r.insert(
+            "path".to_string(),
+            UntaggedValue::path(f.path).retag(&f.tag),
+        );
+
+        r.insert(
+            "apparent".to_string(),
+            UntaggedValue::bytes(f.size).retag(&f.tag),
+        );
+
+        let b = f
+            .blocks
+            .map(UntaggedValue::bytes)
+            .unwrap_or_else(UntaggedValue::nothing)
+            .retag(&f.tag);
+
+        r.insert("physical".to_string(), b);
+
+        r.insert(
+            "directories".to_string(),
+            UntaggedValue::nothing().retag(&f.tag),
+        );
+
+        r.insert("files".to_string(), UntaggedValue::nothing().retag(&f.tag));
+
+        UntaggedValue::row(r).retag(&f.tag)
+    }
+}

crates/nu-cli/src/commands/echo.rs

@@ -0,0 +1,67 @@
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{CallInfo, ReturnSuccess, Signature, SyntaxShape, UntaggedValue, Value};
+
+pub struct Echo;
+
+impl PerItemCommand for Echo {
+    fn name(&self) -> &str {
+        "echo"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("echo").rest(SyntaxShape::Any, "the values to echo")
+    }
+
+    fn usage(&self) -> &str {
+        "Echo the arguments back to the user."
+    }
+
+    fn run(
+        &self,
+        call_info: &CallInfo,
+        registry: &CommandRegistry,
+        raw_args: &RawCommandArgs,
+        _input: Value,
+    ) -> Result<OutputStream, ShellError> {
+        run(call_info, registry, raw_args)
+    }
+}
+
+fn run(
+    call_info: &CallInfo,
+    _registry: &CommandRegistry,
+    _raw_args: &RawCommandArgs,
+) -> Result<OutputStream, ShellError> {
+    let mut output = vec![];
+
+    if let Some(ref positional) = call_info.args.positional {
+        for i in positional {
+            match i.as_string() {
+                Ok(s) => {
+                    output.push(Ok(ReturnSuccess::Value(
+                        UntaggedValue::string(s).into_value(i.tag.clone()),
+                    )));
+                }
+                _ => match i {
+                    Value {
+                        value: UntaggedValue::Table(table),
+                        ..
+                    } => {
+                        for value in table {
+                            output.push(Ok(ReturnSuccess::Value(value.clone())));
+                        }
+                    }
+                    _ => {
+                        output.push(Ok(ReturnSuccess::Value(i.clone())));
+                    }
+                },
+            }
+        }
+    }
+
+    // TODO: This whole block can probably be replaced with `.map()`
+    let stream = futures::stream::iter(output);
+
+    Ok(stream.to_output_stream())
+}

crates/nu-cli/src/commands/edit.rs

@@ -0,0 +1,72 @@
+use crate::commands::PerItemCommand;
+use crate::context::CommandRegistry;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{CallInfo, ReturnSuccess, Signature, SyntaxShape, UntaggedValue, Value};
+use nu_value_ext::ValueExt;
+
+pub struct Edit;
+
+impl PerItemCommand for Edit {
+    fn name(&self) -> &str {
+        "edit"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("edit")
+            .required(
+                "Field",
+                SyntaxShape::ColumnPath,
+                "the name of the column to edit",
+            )
+            .required(
+                "Value",
+                SyntaxShape::String,
+                "the new value to give the cell(s)",
+            )
+    }
+
+    fn usage(&self) -> &str {
+        "Edit an existing column to have a new value."
+    }
+
+    fn run(
+        &self,
+        call_info: &CallInfo,
+        _registry: &CommandRegistry,
+        _raw_args: &RawCommandArgs,
+        value: Value,
+    ) -> Result<OutputStream, ShellError> {
+        let value_tag = value.tag();
+        let field = call_info.args.expect_nth(0)?.as_column_path()?;
+        let replacement = call_info.args.expect_nth(1)?.tagged_unknown();
+
+        let stream = match value {
+            obj
+            @
+            Value {
+                value: UntaggedValue::Row(_),
+                ..
+            } => match obj.replace_data_at_column_path(&field, replacement.item.clone()) {
+                Some(v) => futures::stream::iter(vec![Ok(ReturnSuccess::Value(v))]),
+                None => {
+                    return Err(ShellError::labeled_error(
+                        "edit could not find place to insert column",
+                        "column name",
+                        &field.tag,
+                    ))
+                }
+            },
+
+            _ => {
+                return Err(ShellError::labeled_error(
+                    "Unrecognized type in stream",
+                    "original value",
+                    value_tag,
+                ))
+            }
+        };
+
+        Ok(stream.to_output_stream())
+    }
+}

crates/nu-cli/src/commands/enter.rs

@@ -0,0 +1,156 @@
+use crate::commands::PerItemCommand;
+use crate::commands::UnevaluatedCallInfo;
+use crate::context::CommandRegistry;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{
+    CallInfo, CommandAction, Primitive, ReturnSuccess, Signature, SyntaxShape, UntaggedValue, Value,
+};
+
+pub struct Enter;
+
+impl PerItemCommand for Enter {
+    fn name(&self) -> &str {
+        "enter"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("enter").required(
+            "location",
+            SyntaxShape::Path,
+            "the location to create a new shell from",
+        )
+    }
+
+    fn usage(&self) -> &str {
+        "Create a new shell and begin at this path."
+    }
+
+    fn run(
+        &self,
+        call_info: &CallInfo,
+        registry: &CommandRegistry,
+        raw_args: &RawCommandArgs,
+        _input: Value,
+    ) -> Result<OutputStream, ShellError> {
+        let registry = registry.clone();
+        let raw_args = raw_args.clone();
+        match call_info.args.expect_nth(0)? {
+            Value {
+                value: UntaggedValue::Primitive(Primitive::Path(location)),
+                tag,
+                ..
+            } => {
+                let location_string = location.display().to_string();
+                let location_clone = location_string.clone();
+                let tag_clone = tag.clone();
+
+                if location_string.starts_with("help") {
+                    let spec = location_string.split(':').collect::<Vec<&str>>();
+
+                    if spec.len() == 2 {
+                        let (_, command) = (spec[0], spec[1]);
+
+                        if registry.has(command) {
+                            return Ok(vec![Ok(ReturnSuccess::Action(
+                                CommandAction::EnterHelpShell(
+                                    UntaggedValue::string(command).into_value(Tag::unknown()),
+                                ),
+                            ))]
+                            .into());
+                        }
+                    }
+                    Ok(vec![Ok(ReturnSuccess::Action(CommandAction::EnterHelpShell(
+                        UntaggedValue::nothing().into_value(Tag::unknown()),
+                    )))]
+                    .into())
+                } else if location.is_dir() {
+                    Ok(vec![Ok(ReturnSuccess::Action(CommandAction::EnterShell(
+                        location_clone,
+                    )))]
+                    .into())
+                } else {
+                    let stream = async_stream! {
+                        // If it's a file, attempt to open the file as a value and enter it
+                        let cwd = raw_args.shell_manager.path();
+
+                        let full_path = std::path::PathBuf::from(cwd);
+
+                        let (file_extension, contents, contents_tag) =
+                            crate::commands::open::fetch(
+                                &full_path,
+                                &location_clone,
+                                tag_clone.span,
+                            ).await?;
+
+                        match contents {
+                            UntaggedValue::Primitive(Primitive::String(_)) => {
+                                let tagged_contents = contents.into_value(&contents_tag);
+
+                                if let Some(extension) = file_extension {
+                                    let command_name = format!("from-{}", extension);
+                                    if let Some(converter) =
+                                        registry.get_command(&command_name)
+                                    {
+                                        let new_args = RawCommandArgs {
+                                            host: raw_args.host,
+                                            ctrl_c: raw_args.ctrl_c,
+                                            shell_manager: raw_args.shell_manager,
+                                            call_info: UnevaluatedCallInfo {
+                                                args: nu_parser::hir::Call {
+                                                    head: raw_args.call_info.args.head,
+                                                    positional: None,
+                                                    named: None,
+                                                    span: Span::unknown()
+                                                },
+                                                source: raw_args.call_info.source,
+                                                name_tag: raw_args.call_info.name_tag,
+                                            },
+                                        };
+                                        let mut result = converter.run(
+                                            new_args.with_input(vec![tagged_contents]),
+                                            &registry,
+                                        );
+                                        let result_vec: Vec<Result<ReturnSuccess, ShellError>> =
+                                            result.drain_vec().await;
+                                        for res in result_vec {
+                                            match res {
+                                                Ok(ReturnSuccess::Value(Value {
+                                                    value,
+                                                    ..
+                                                })) => {
+                                                    yield Ok(ReturnSuccess::Action(CommandAction::EnterValueShell(
+                                                        Value {
+                                                            value,
+                                                            tag: contents_tag.clone(),
+                                                        })));
+                                                }
+                                                x => yield x,
+                                            }
+                                        }
+                                    } else {
+                                        yield Ok(ReturnSuccess::Action(CommandAction::EnterValueShell(tagged_contents)));
+                                    }
+                                } else {
+                                    yield Ok(ReturnSuccess::Action(CommandAction::EnterValueShell(tagged_contents)));
+                                }
+                            }
+                            _ => {
+                                let tagged_contents = contents.into_value(contents_tag);
+
+                                yield Ok(ReturnSuccess::Action(CommandAction::EnterValueShell(tagged_contents)));
+                            }
+                        }
+                    };
+                    Ok(stream.to_output_stream())
+                }
+            }
+            x => Ok(
+                vec![Ok(ReturnSuccess::Action(CommandAction::EnterValueShell(
+                    x.clone(),
+                )))]
+                .into(),
+            ),
+        }
+    }
+}

crates/nu-cli/src/commands/evaluate_by.rs

@@ -0,0 +1,72 @@
+use crate::commands::WholeStreamCommand;
+use crate::prelude::*;
+use crate::utils::data_processing::{evaluate, fetch};
+use nu_errors::ShellError;
+use nu_protocol::{ReturnSuccess, Signature, SyntaxShape, UntaggedValue, Value};
+use nu_source::{SpannedItem, Tagged};
+use nu_value_ext::ValueExt;
+
+pub struct EvaluateBy;
+
+#[derive(Deserialize)]
+pub struct EvaluateByArgs {
+    evaluate_with: Option<Tagged<String>>,
+}
+
+impl WholeStreamCommand for EvaluateBy {
+    fn name(&self) -> &str {
+        "evaluate-by"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("evaluate-by").named(
+            "evaluate_with",
+            SyntaxShape::String,
+            "the name of the column to evaluate by",
+            Some('w'),
+        )
+    }
+
+    fn usage(&self) -> &str {
+        "Creates a new table with the data from the tables rows evaluated by the column given."
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        args.process(registry, evaluate_by)?.run()
+    }
+}
+
+pub fn evaluate_by(
+    EvaluateByArgs { evaluate_with }: EvaluateByArgs,
+    RunnableContext { input, name, .. }: RunnableContext,
+) -> Result<OutputStream, ShellError> {
+    let stream = async_stream! {
+        let values: Vec<Value> = input.values.collect().await;
+
+        if values.is_empty() {
+            yield Err(ShellError::labeled_error(
+                    "Expected table from pipeline",
+                    "requires a table input",
+                    name
+                ))
+        } else {
+
+            let evaluate_with = if let Some(evaluator) = evaluate_with {
+                Some(evaluator.item().clone())
+            } else {
+                None
+            };
+
+            match evaluate(&values[0], evaluate_with, name) {
+                Ok(evaluated) => yield ReturnSuccess::value(evaluated),
+                Err(err) => yield Err(err)
+            }
+        }
+    };
+
+    Ok(stream.to_output_stream())
+}

crates/nu-cli/src/commands/exit.rs

@@ -1,11 +1,24 @@
-use crate::commands::command::{CommandAction, WholeStreamCommand};
-use crate::errors::ShellError;
-use crate::parser::registry::{CommandRegistry, Signature};
+use crate::commands::command::WholeStreamCommand;
+use crate::context::CommandRegistry;
 use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{CommandAction, ReturnSuccess, Signature};
 
 pub struct Exit;
 
 impl WholeStreamCommand for Exit {
+    fn name(&self) -> &str {
+        "exit"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("exit").switch("now", "exit out of the shell immediately", Some('n'))
+    }
+
+    fn usage(&self) -> &str {
+        "Exit the current shell (or all shells)"
+    }
+
     fn run(
         &self,
         args: CommandArgs,
@@ -13,14 +26,6 @@ impl WholeStreamCommand for Exit {
     ) -> Result<OutputStream, ShellError> {
         exit(args, registry)
     }
-
-    fn name(&self) -> &str {
-        "exit"
-    }
-
-    fn signature(&self) -> Signature {
-        Signature::build("exit").switch("now")
-    }
 }
 
 pub fn exit(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStream, ShellError> {

crates/nu-cli/src/commands/first.rs

@@ -0,0 +1,54 @@
+use crate::commands::WholeStreamCommand;
+use crate::context::CommandRegistry;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{Signature, SyntaxShape};
+use nu_source::Tagged;
+
+pub struct First;
+
+#[derive(Deserialize)]
+pub struct FirstArgs {
+    rows: Option<Tagged<usize>>,
+}
+
+impl WholeStreamCommand for First {
+    fn name(&self) -> &str {
+        "first"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("first").optional(
+            "rows",
+            SyntaxShape::Int,
+            "starting from the front, the number of rows to return",
+        )
+    }
+
+    fn usage(&self) -> &str {
+        "Show only the first number of rows."
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        args.process(registry, first)?.run()
+    }
+}
+
+fn first(
+    FirstArgs { rows }: FirstArgs,
+    context: RunnableContext,
+) -> Result<OutputStream, ShellError> {
+    let rows_desired = if let Some(quantity) = rows {
+        *quantity
+    } else {
+        1
+    };
+
+    Ok(OutputStream::from_input(
+        context.input.values.take(rows_desired),
+    ))
+}

crates/nu-cli/src/commands/format.rs

@@ -0,0 +1,157 @@
+use crate::commands::PerItemCommand;
+use crate::context::CommandRegistry;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{
+    CallInfo, ColumnPath, ReturnSuccess, Signature, SyntaxShape, UntaggedValue, Value,
+};
+use nu_source::Tagged;
+use nu_value_ext::{as_column_path, get_data_by_column_path};
+use std::borrow::Borrow;
+
+use nom::{
+    bytes::complete::{tag, take_while},
+    IResult,
+};
+
+pub struct Format;
+
+impl PerItemCommand for Format {
+    fn name(&self) -> &str {
+        "format"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("format").required(
+            "pattern",
+            SyntaxShape::Any,
+            "the pattern to output. Eg) \"{foo}: {bar}\"",
+        )
+    }
+
+    fn usage(&self) -> &str {
+        "Format columns into a string using a simple pattern."
+    }
+
+    fn run(
+        &self,
+        call_info: &CallInfo,
+        _registry: &CommandRegistry,
+        _raw_args: &RawCommandArgs,
+        value: Value,
+    ) -> Result<OutputStream, ShellError> {
+        //let value_tag = value.tag();
+        let pattern = call_info.args.expect_nth(0)?;
+        let pattern_tag = pattern.tag.clone();
+        let pattern = pattern.as_string()?;
+
+        let format_pattern = format(&pattern).map_err(|_| {
+            ShellError::labeled_error(
+                "Could not create format pattern",
+                "could not create format pattern",
+                &pattern_tag,
+            )
+        })?;
+        let commands = format_pattern.1;
+
+        let output = match value {
+            value
+            @
+            Value {
+                value: UntaggedValue::Row(_),
+                ..
+            } => {
+                let mut output = String::new();
+
+                for command in &commands {
+                    match command {
+                        FormatCommand::Text(s) => {
+                            output.push_str(s);
+                        }
+                        FormatCommand::Column(c) => {
+                            let key = to_column_path(&c, &pattern_tag)?;
+
+                            let fetcher = get_data_by_column_path(
+                                &value,
+                                &key,
+                                Box::new(move |(_, _, error)| error),
+                            );
+
+                            if let Ok(c) = fetcher {
+                                output
+                                    .push_str(&value::format_leaf(c.borrow()).plain_string(100_000))
+                            }
+                            // That column doesn't match, so don't emit anything
+                        }
+                    }
+                }
+
+                output
+            }
+            _ => String::new(),
+        };
+
+        Ok(futures::stream::iter(vec![ReturnSuccess::value(
+            UntaggedValue::string(output).into_untagged_value(),
+        )])
+        .to_output_stream())
+    }
+}
+
+#[derive(Debug)]
+enum FormatCommand {
+    Text(String),
+    Column(String),
+}
+
+fn format(input: &str) -> IResult<&str, Vec<FormatCommand>> {
+    let mut output = vec![];
+
+    let mut loop_input = input;
+    loop {
+        let (input, before) = take_while(|c| c != '{')(loop_input)?;
+        if !before.is_empty() {
+            output.push(FormatCommand::Text(before.to_string()));
+        }
+        if input != "" {
+            // Look for column as we're now at one
+            let (input, _) = tag("{")(input)?;
+            let (input, column) = take_while(|c| c != '}')(input)?;
+            let (input, _) = tag("}")(input)?;
+
+            output.push(FormatCommand::Column(column.to_string()));
+            loop_input = input;
+        } else {
+            loop_input = input;
+        }
+        if loop_input == "" {
+            break;
+        }
+    }
+
+    Ok((loop_input, output))
+}
+
+fn to_column_path(
+    path_members: &str,
+    tag: impl Into<Tag>,
+) -> Result<Tagged<ColumnPath>, ShellError> {
+    let tag = tag.into();
+
+    as_column_path(
+        &UntaggedValue::Table(
+            path_members
+                .split('.')
+                .map(|x| {
+                    let member = match x.parse::<u64>() {
+                        Ok(v) => UntaggedValue::int(v),
+                        Err(_) => UntaggedValue::string(x),
+                    };
+
+                    member.into_value(&tag)
+                })
+                .collect(),
+        )
+        .into_value(&tag),
+    )
+}

crates/nu-cli/src/commands/from_bson.rs

@@ -0,0 +1,225 @@
+use crate::commands::WholeStreamCommand;
+use crate::prelude::*;
+use bson::{decode_document, spec::BinarySubtype, Bson};
+use nu_errors::{ExpectedRange, ShellError};
+use nu_protocol::{Primitive, ReturnSuccess, Signature, TaggedDictBuilder, UntaggedValue, Value};
+use nu_source::SpannedItem;
+use std::str::FromStr;
+
+pub struct FromBSON;
+
+impl WholeStreamCommand for FromBSON {
+    fn name(&self) -> &str {
+        "from-bson"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("from-bson")
+    }
+
+    fn usage(&self) -> &str {
+        "Parse text as .bson and create table."
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        from_bson(args, registry)
+    }
+}
+
+fn bson_array(input: &[Bson], tag: Tag) -> Result<Vec<Value>, ShellError> {
+    let mut out = vec![];
+
+    for value in input {
+        out.push(convert_bson_value_to_nu_value(value, &tag)?);
+    }
+
+    Ok(out)
+}
+
+fn convert_bson_value_to_nu_value(v: &Bson, tag: impl Into<Tag>) -> Result<Value, ShellError> {
+    let tag = tag.into();
+    let span = tag.span;
+
+    Ok(match v {
+        Bson::FloatingPoint(n) => UntaggedValue::Primitive(Primitive::from(*n)).into_value(&tag),
+        Bson::String(s) => {
+            UntaggedValue::Primitive(Primitive::String(String::from(s))).into_value(&tag)
+        }
+        Bson::Array(a) => UntaggedValue::Table(bson_array(a, tag.clone())?).into_value(&tag),
+        Bson::Document(doc) => {
+            let mut collected = TaggedDictBuilder::new(tag.clone());
+            for (k, v) in doc.iter() {
+                collected.insert_value(k.clone(), convert_bson_value_to_nu_value(v, &tag)?);
+            }
+
+            collected.into_value()
+        }
+        Bson::Boolean(b) => UntaggedValue::Primitive(Primitive::Boolean(*b)).into_value(&tag),
+        Bson::Null => UntaggedValue::Primitive(Primitive::Nothing).into_value(&tag),
+        Bson::RegExp(r, opts) => {
+            let mut collected = TaggedDictBuilder::new(tag.clone());
+            collected.insert_value(
+                "$regex".to_string(),
+                UntaggedValue::Primitive(Primitive::String(String::from(r))).into_value(&tag),
+            );
+            collected.insert_value(
+                "$options".to_string(),
+                UntaggedValue::Primitive(Primitive::String(String::from(opts))).into_value(&tag),
+            );
+            collected.into_value()
+        }
+        Bson::I32(n) => UntaggedValue::int(*n).into_value(&tag),
+        Bson::I64(n) => UntaggedValue::int(*n).into_value(&tag),
+        Bson::Decimal128(n) => {
+            // TODO: this really isn't great, and we should update this to do a higher
+            // fidelity translation
+            let decimal = BigDecimal::from_str(&format!("{}", n)).map_err(|_| {
+                ShellError::range_error(
+                    ExpectedRange::BigDecimal,
+                    &n.spanned(span),
+                    "converting BSON Decimal128 to BigDecimal".to_owned(),
+                )
+            })?;
+            UntaggedValue::Primitive(Primitive::Decimal(decimal)).into_value(&tag)
+        }
+        Bson::JavaScriptCode(js) => {
+            let mut collected = TaggedDictBuilder::new(tag.clone());
+            collected.insert_value(
+                "$javascript".to_string(),
+                UntaggedValue::Primitive(Primitive::String(String::from(js))).into_value(&tag),
+            );
+            collected.into_value()
+        }
+        Bson::JavaScriptCodeWithScope(js, doc) => {
+            let mut collected = TaggedDictBuilder::new(tag.clone());
+            collected.insert_value(
+                "$javascript".to_string(),
+                UntaggedValue::Primitive(Primitive::String(String::from(js))).into_value(&tag),
+            );
+            collected.insert_value(
+                "$scope".to_string(),
+                convert_bson_value_to_nu_value(&Bson::Document(doc.to_owned()), tag)?,
+            );
+            collected.into_value()
+        }
+        Bson::TimeStamp(ts) => {
+            let mut collected = TaggedDictBuilder::new(tag.clone());
+            collected.insert_value(
+                "$timestamp".to_string(),
+                UntaggedValue::int(*ts).into_value(&tag),
+            );
+            collected.into_value()
+        }
+        Bson::Binary(bst, bytes) => {
+            let mut collected = TaggedDictBuilder::new(tag.clone());
+            collected.insert_value(
+                "$binary_subtype".to_string(),
+                match bst {
+                    BinarySubtype::UserDefined(u) => UntaggedValue::int(*u),
+                    _ => {
+                        UntaggedValue::Primitive(Primitive::String(binary_subtype_to_string(*bst)))
+                    }
+                }
+                .into_value(&tag),
+            );
+            collected.insert_value(
+                "$binary".to_string(),
+                UntaggedValue::Primitive(Primitive::Binary(bytes.to_owned())).into_value(&tag),
+            );
+            collected.into_value()
+        }
+        Bson::ObjectId(obj_id) => {
+            let mut collected = TaggedDictBuilder::new(tag.clone());
+            collected.insert_value(
+                "$object_id".to_string(),
+                UntaggedValue::Primitive(Primitive::String(obj_id.to_hex())).into_value(&tag),
+            );
+            collected.into_value()
+        }
+        Bson::UtcDatetime(dt) => UntaggedValue::Primitive(Primitive::Date(*dt)).into_value(&tag),
+        Bson::Symbol(s) => {
+            let mut collected = TaggedDictBuilder::new(tag.clone());
+            collected.insert_value(
+                "$symbol".to_string(),
+                UntaggedValue::Primitive(Primitive::String(String::from(s))).into_value(&tag),
+            );
+            collected.into_value()
+        }
+    })
+}
+
+fn binary_subtype_to_string(bst: BinarySubtype) -> String {
+    match bst {
+        BinarySubtype::Generic => "generic",
+        BinarySubtype::Function => "function",
+        BinarySubtype::BinaryOld => "binary_old",
+        BinarySubtype::UuidOld => "uuid_old",
+        BinarySubtype::Uuid => "uuid",
+        BinarySubtype::Md5 => "md5",
+        _ => unreachable!(),
+    }
+    .to_string()
+}
+
+#[derive(Debug)]
+struct BytesReader {
+    pos: usize,
+    inner: Vec<u8>,
+}
+
+impl BytesReader {
+    fn new(bytes: Vec<u8>) -> BytesReader {
+        BytesReader {
+            pos: 0,
+            inner: bytes,
+        }
+    }
+}
+
+impl std::io::Read for BytesReader {
+    fn read(&mut self, buf: &mut [u8]) -> std::io::Result<usize> {
+        let src: &mut &[u8] = &mut self.inner[self.pos..].as_ref();
+        let diff = src.read(buf)?;
+        self.pos += diff;
+        Ok(diff)
+    }
+}
+
+pub fn from_bson_bytes_to_value(bytes: Vec<u8>, tag: impl Into<Tag>) -> Result<Value, ShellError> {
+    let mut docs = Vec::new();
+    let mut b_reader = BytesReader::new(bytes);
+    while let Ok(v) = decode_document(&mut b_reader) {
+        docs.push(Bson::Document(v));
+    }
+
+    convert_bson_value_to_nu_value(&Bson::Array(docs), tag)
+}
+
+fn from_bson(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStream, ShellError> {
+    let args = args.evaluate_once(registry)?;
+    let tag = args.name_tag();
+    let input = args.input;
+
+    let stream = async_stream! {
+        let bytes = input.collect_binary(tag.clone()).await?;
+
+        match from_bson_bytes_to_value(bytes.item, tag.clone()) {
+            Ok(x) => yield ReturnSuccess::value(x),
+            Err(_) => {
+                yield Err(ShellError::labeled_error_with_secondary(
+                    "Could not parse as BSON",
+                    "input cannot be parsed as BSON",
+                    tag.clone(),
+                    "value originates from here",
+                    bytes.tag,
+                ))
+            }
+        }
+    };
+
+    Ok(stream.to_output_stream())
+}

crates/nu-cli/src/commands/from_csv.rs

@@ -0,0 +1,79 @@
+use crate::commands::from_delimited_data::from_delimited_data;
+use crate::commands::WholeStreamCommand;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{Primitive, Signature, SyntaxShape, UntaggedValue, Value};
+
+pub struct FromCSV;
+
+#[derive(Deserialize)]
+pub struct FromCSVArgs {
+    headerless: bool,
+    separator: Option<Value>,
+}
+
+impl WholeStreamCommand for FromCSV {
+    fn name(&self) -> &str {
+        "from-csv"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("from-csv")
+            .named(
+                "separator",
+                SyntaxShape::String,
+                "a character to separate columns, defaults to ','",
+                Some('s'),
+            )
+            .switch(
+                "headerless",
+                "don't treat the first row as column names",
+                None,
+            )
+    }
+
+    fn usage(&self) -> &str {
+        "Parse text as .csv and create table."
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        args.process(registry, from_csv)?.run()
+    }
+}
+
+fn from_csv(
+    FromCSVArgs {
+        headerless,
+        separator,
+    }: FromCSVArgs,
+    runnable_context: RunnableContext,
+) -> Result<OutputStream, ShellError> {
+    let sep = match separator {
+        Some(Value {
+            value: UntaggedValue::Primitive(Primitive::String(s)),
+            tag,
+            ..
+        }) => {
+            if s == r"\t" {
+                '\t'
+            } else {
+                let vec_s: Vec<char> = s.chars().collect();
+                if vec_s.len() != 1 {
+                    return Err(ShellError::labeled_error(
+                        "Expected a single separator char from --separator",
+                        "requires a single character string input",
+                        tag,
+                    ));
+                };
+                vec_s[0]
+            }
+        }
+        _ => ',',
+    };
+
+    from_delimited_data(headerless, sep, "CSV", runnable_context)
+}

crates/nu-cli/src/commands/from_delimited_data.rs

@@ -0,0 +1,169 @@
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_parser::hir::syntax_shape::{ExpandContext, SignatureRegistry};
+use nu_parser::utils::{parse_line_with_separator as parse, LineSeparatedShape};
+use nu_parser::TokensIterator;
+use nu_protocol::{ReturnSuccess, Signature, TaggedDictBuilder, UntaggedValue, Value};
+use nu_source::nom_input;
+
+use derive_new::new;
+
+pub fn from_delimited_data(
+    headerless: bool,
+    sep: char,
+    format_name: &'static str,
+    RunnableContext { input, name, .. }: RunnableContext,
+) -> Result<OutputStream, ShellError> {
+    let name_tag = name;
+
+    let stream = async_stream! {
+        let concat_string = input.collect_string(name_tag.clone()).await?;
+
+        match from_delimited_string_to_value(concat_string.item, headerless, sep, name_tag.clone()) {
+            Ok(rows) => {
+                for row in rows {
+                    match row {
+                        Value { value: UntaggedValue::Table(list), .. } => {
+                            for l in list {
+                                yield ReturnSuccess::value(l);
+                            }
+                        }
+                        x => yield ReturnSuccess::value(x),
+                    }
+                }
+            },
+            Err(err) => {
+                let line_one = format!("Could not parse as {}", format_name);
+                let line_two = format!("input cannot be parsed as {}", format_name);
+                yield Err(ShellError::labeled_error_with_secondary(
+                    line_one,
+                    line_two,
+                    name_tag.clone(),
+                    "value originates from here",
+                    concat_string.tag,
+                ))
+            } ,
+        }
+    };
+
+    Ok(stream.to_output_stream())
+}
+
+#[derive(Debug, Clone, new)]
+pub struct EmptyRegistry {
+    #[new(default)]
+    signatures: indexmap::IndexMap<String, Signature>,
+}
+
+impl EmptyRegistry {}
+
+impl SignatureRegistry for EmptyRegistry {
+    fn has(&self, _name: &str) -> bool {
+        false
+    }
+    fn get(&self, _name: &str) -> Option<Signature> {
+        None
+    }
+    fn clone_box(&self) -> Box<dyn SignatureRegistry> {
+        Box::new(self.clone())
+    }
+}
+
+fn from_delimited_string_to_value(
+    s: String,
+    headerless: bool,
+    sep: char,
+    tag: impl Into<Tag>,
+) -> Result<Vec<Value>, ShellError> {
+    let tag = tag.into();
+
+    let mut entries = s.lines();
+
+    let mut fields = vec![];
+    let mut out = vec![];
+
+    if let Some(first_entry) = entries.next() {
+        let tokens = match parse(&sep.to_string(), nom_input(first_entry)) {
+            Ok((_, tokens)) => tokens,
+            Err(err) => return Err(ShellError::parse_error(err)),
+        };
+
+        let tokens_span = tokens.span;
+        let source: nu_source::Text = tokens_span.slice(&first_entry).into();
+
+        if !headerless {
+            fields = tokens
+                .item
+                .iter()
+                .filter(|token| !token.is_separator())
+                .map(|field| field.source(&source).to_string())
+                .collect::<Vec<_>>();
+        }
+
+        let registry = Box::new(EmptyRegistry::new());
+        let ctx = ExpandContext::new(registry, &source, None);
+
+        let mut iterator = TokensIterator::new(&tokens.item, ctx, tokens_span);
+        let (results, tokens_identified) = iterator.expand(LineSeparatedShape);
+        let results = results?;
+
+        let mut row = TaggedDictBuilder::new(&tag);
+
+        if headerless {
+            let fallback_columns = (1..=tokens_identified)
+                .map(|i| format!("Column{}", i))
+                .collect::<Vec<String>>();
+
+            for (idx, field) in results.into_iter().enumerate() {
+                let key = if headerless {
+                    &fallback_columns[idx]
+                } else {
+                    &fields[idx]
+                };
+
+                row.insert_value(key, field.into_value(&tag));
+            }
+
+            out.push(row.into_value())
+        }
+    }
+
+    for entry in entries {
+        let tokens = match parse(&sep.to_string(), nom_input(entry)) {
+            Ok((_, tokens)) => tokens,
+            Err(err) => return Err(ShellError::parse_error(err)),
+        };
+        let tokens_span = tokens.span;
+
+        let source: nu_source::Text = tokens_span.slice(&entry).into();
+        let registry = Box::new(EmptyRegistry::new());
+        let ctx = ExpandContext::new(registry, &source, None);
+
+        let mut iterator = TokensIterator::new(&tokens.item, ctx, tokens_span);
+        let (results, tokens_identified) = iterator.expand(LineSeparatedShape);
+        let results = results?;
+
+        let mut row = TaggedDictBuilder::new(&tag);
+
+        let fallback_columns = (1..=tokens_identified)
+            .map(|i| format!("Column{}", i))
+            .collect::<Vec<String>>();
+
+        for (idx, field) in results.into_iter().enumerate() {
+            let key = if headerless {
+                &fallback_columns[idx]
+            } else {
+                match fields.get(idx) {
+                    Some(key) => key,
+                    None => &fallback_columns[idx],
+                }
+            };
+
+            row.insert_value(key, field.into_value(&tag));
+        }
+
+        out.push(row.into_value())
+    }
+
+    Ok(out)
+}

crates/nu-cli/src/commands/from_ics.rs

@@ -0,0 +1,240 @@
+extern crate ical;
+use crate::commands::WholeStreamCommand;
+use crate::prelude::*;
+use ical::parser::ical::component::*;
+use ical::property::Property;
+use nu_errors::ShellError;
+use nu_protocol::{Primitive, ReturnSuccess, Signature, TaggedDictBuilder, UntaggedValue, Value};
+use std::io::BufReader;
+
+pub struct FromIcs;
+
+impl WholeStreamCommand for FromIcs {
+    fn name(&self) -> &str {
+        "from-ics"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("from-ics")
+    }
+
+    fn usage(&self) -> &str {
+        "Parse text as .ics and create table."
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        from_ics(args, registry)
+    }
+}
+
+fn from_ics(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStream, ShellError> {
+    let args = args.evaluate_once(registry)?;
+    let tag = args.name_tag();
+    let input = args.input;
+
+    let stream = async_stream! {
+        let input_string = input.collect_string(tag.clone()).await?.item;
+        let input_bytes = input_string.as_bytes();
+        let buf_reader = BufReader::new(input_bytes);
+        let parser = ical::IcalParser::new(buf_reader);
+
+        for calendar in parser {
+            match calendar {
+                Ok(c) => yield ReturnSuccess::value(calendar_to_value(c, tag.clone())),
+                Err(_) => yield Err(ShellError::labeled_error(
+                    "Could not parse as .ics",
+                    "input cannot be parsed as .ics",
+                    tag.clone()
+                )),
+            }
+        }
+    };
+
+    Ok(stream.to_output_stream())
+}
+
+fn calendar_to_value(calendar: IcalCalendar, tag: Tag) -> Value {
+    let mut row = TaggedDictBuilder::new(tag.clone());
+
+    row.insert_untagged(
+        "properties",
+        properties_to_value(calendar.properties, tag.clone()),
+    );
+    row.insert_untagged("events", events_to_value(calendar.events, tag.clone()));
+    row.insert_untagged("alarms", alarms_to_value(calendar.alarms, tag.clone()));
+    row.insert_untagged("to-Dos", todos_to_value(calendar.todos, tag.clone()));
+    row.insert_untagged(
+        "journals",
+        journals_to_value(calendar.journals, tag.clone()),
+    );
+    row.insert_untagged(
+        "free-busys",
+        free_busys_to_value(calendar.free_busys, tag.clone()),
+    );
+    row.insert_untagged("timezones", timezones_to_value(calendar.timezones, tag));
+
+    row.into_value()
+}
+
+fn events_to_value(events: Vec<IcalEvent>, tag: Tag) -> UntaggedValue {
+    UntaggedValue::table(
+        &events
+            .into_iter()
+            .map(|event| {
+                let mut row = TaggedDictBuilder::new(tag.clone());
+                row.insert_untagged(
+                    "properties",
+                    properties_to_value(event.properties, tag.clone()),
+                );
+                row.insert_untagged("alarms", alarms_to_value(event.alarms, tag.clone()));
+                row.into_value()
+            })
+            .collect::<Vec<Value>>(),
+    )
+}
+
+fn alarms_to_value(alarms: Vec<IcalAlarm>, tag: Tag) -> UntaggedValue {
+    UntaggedValue::table(
+        &alarms
+            .into_iter()
+            .map(|alarm| {
+                let mut row = TaggedDictBuilder::new(tag.clone());
+                row.insert_untagged(
+                    "properties",
+                    properties_to_value(alarm.properties, tag.clone()),
+                );
+                row.into_value()
+            })
+            .collect::<Vec<Value>>(),
+    )
+}
+
+fn todos_to_value(todos: Vec<IcalTodo>, tag: Tag) -> UntaggedValue {
+    UntaggedValue::table(
+        &todos
+            .into_iter()
+            .map(|todo| {
+                let mut row = TaggedDictBuilder::new(tag.clone());
+                row.insert_untagged(
+                    "properties",
+                    properties_to_value(todo.properties, tag.clone()),
+                );
+                row.insert_untagged("alarms", alarms_to_value(todo.alarms, tag.clone()));
+                row.into_value()
+            })
+            .collect::<Vec<Value>>(),
+    )
+}
+
+fn journals_to_value(journals: Vec<IcalJournal>, tag: Tag) -> UntaggedValue {
+    UntaggedValue::table(
+        &journals
+            .into_iter()
+            .map(|journal| {
+                let mut row = TaggedDictBuilder::new(tag.clone());
+                row.insert_untagged(
+                    "properties",
+                    properties_to_value(journal.properties, tag.clone()),
+                );
+                row.into_value()
+            })
+            .collect::<Vec<Value>>(),
+    )
+}
+
+fn free_busys_to_value(free_busys: Vec<IcalFreeBusy>, tag: Tag) -> UntaggedValue {
+    UntaggedValue::table(
+        &free_busys
+            .into_iter()
+            .map(|free_busy| {
+                let mut row = TaggedDictBuilder::new(tag.clone());
+                row.insert_untagged(
+                    "properties",
+                    properties_to_value(free_busy.properties, tag.clone()),
+                );
+                row.into_value()
+            })
+            .collect::<Vec<Value>>(),
+    )
+}
+
+fn timezones_to_value(timezones: Vec<IcalTimeZone>, tag: Tag) -> UntaggedValue {
+    UntaggedValue::table(
+        &timezones
+            .into_iter()
+            .map(|timezone| {
+                let mut row = TaggedDictBuilder::new(tag.clone());
+                row.insert_untagged(
+                    "properties",
+                    properties_to_value(timezone.properties, tag.clone()),
+                );
+                row.insert_untagged(
+                    "transitions",
+                    timezone_transitions_to_value(timezone.transitions, tag.clone()),
+                );
+                row.into_value()
+            })
+            .collect::<Vec<Value>>(),
+    )
+}
+
+fn timezone_transitions_to_value(
+    transitions: Vec<IcalTimeZoneTransition>,
+    tag: Tag,
+) -> UntaggedValue {
+    UntaggedValue::table(
+        &transitions
+            .into_iter()
+            .map(|transition| {
+                let mut row = TaggedDictBuilder::new(tag.clone());
+                row.insert_untagged(
+                    "properties",
+                    properties_to_value(transition.properties, tag.clone()),
+                );
+                row.into_value()
+            })
+            .collect::<Vec<Value>>(),
+    )
+}
+
+fn properties_to_value(properties: Vec<Property>, tag: Tag) -> UntaggedValue {
+    UntaggedValue::table(
+        &properties
+            .into_iter()
+            .map(|prop| {
+                let mut row = TaggedDictBuilder::new(tag.clone());
+
+                let name = UntaggedValue::string(prop.name);
+                let value = match prop.value {
+                    Some(val) => UntaggedValue::string(val),
+                    None => UntaggedValue::Primitive(Primitive::Nothing),
+                };
+                let params = match prop.params {
+                    Some(param_list) => params_to_value(param_list, tag.clone()).into(),
+                    None => UntaggedValue::Primitive(Primitive::Nothing),
+                };
+
+                row.insert_untagged("name", name);
+                row.insert_untagged("value", value);
+                row.insert_untagged("params", params);
+                row.into_value()
+            })
+            .collect::<Vec<Value>>(),
+    )
+}
+
+fn params_to_value(params: Vec<(String, Vec<String>)>, tag: Tag) -> Value {
+    let mut row = TaggedDictBuilder::new(tag);
+
+    for (param_name, param_values) in params {
+        let values: Vec<Value> = param_values.into_iter().map(|val| val.into()).collect();
+        let values = UntaggedValue::table(&values);
+        row.insert_untagged(param_name, values);
+    }
+
+    row.into_value()
+}

crates/nu-cli/src/commands/from_ini.rs

@@ -0,0 +1,96 @@
+use crate::commands::WholeStreamCommand;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{Primitive, ReturnSuccess, Signature, TaggedDictBuilder, UntaggedValue, Value};
+use std::collections::HashMap;
+
+pub struct FromINI;
+
+impl WholeStreamCommand for FromINI {
+    fn name(&self) -> &str {
+        "from-ini"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("from-ini")
+    }
+
+    fn usage(&self) -> &str {
+        "Parse text as .ini and create table"
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        from_ini(args, registry)
+    }
+}
+
+fn convert_ini_second_to_nu_value(v: &HashMap<String, String>, tag: impl Into<Tag>) -> Value {
+    let mut second = TaggedDictBuilder::new(tag);
+
+    for (key, value) in v.iter() {
+        second.insert_untagged(key.clone(), Primitive::String(value.clone()));
+    }
+
+    second.into_value()
+}
+
+fn convert_ini_top_to_nu_value(
+    v: &HashMap<String, HashMap<String, String>>,
+    tag: impl Into<Tag>,
+) -> Value {
+    let tag = tag.into();
+    let mut top_level = TaggedDictBuilder::new(tag.clone());
+
+    for (key, value) in v.iter() {
+        top_level.insert_value(
+            key.clone(),
+            convert_ini_second_to_nu_value(value, tag.clone()),
+        );
+    }
+
+    top_level.into_value()
+}
+
+pub fn from_ini_string_to_value(
+    s: String,
+    tag: impl Into<Tag>,
+) -> Result<Value, serde_ini::de::Error> {
+    let v: HashMap<String, HashMap<String, String>> = serde_ini::from_str(&s)?;
+    Ok(convert_ini_top_to_nu_value(&v, tag))
+}
+
+fn from_ini(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStream, ShellError> {
+    let args = args.evaluate_once(registry)?;
+    let tag = args.name_tag();
+    let input = args.input;
+
+    let stream = async_stream! {
+        let concat_string = input.collect_string(tag.clone()).await?;
+
+        match from_ini_string_to_value(concat_string.item, tag.clone()) {
+            Ok(x) => match x {
+                Value { value: UntaggedValue::Table(list), .. } => {
+                    for l in list {
+                        yield ReturnSuccess::value(l);
+                    }
+                }
+                x => yield ReturnSuccess::value(x),
+            },
+            Err(_) => {
+                yield Err(ShellError::labeled_error_with_secondary(
+                    "Could not parse as INI",
+                    "input cannot be parsed as INI",
+                    &tag,
+                    "value originates from here",
+                    concat_string.tag,
+                ))
+            }
+        }
+    };
+
+    Ok(stream.to_output_stream())
+}

crates/nu-cli/src/commands/from_json.rs

@@ -0,0 +1,133 @@
+use crate::commands::WholeStreamCommand;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{Primitive, ReturnSuccess, Signature, TaggedDictBuilder, UntaggedValue, Value};
+
+pub struct FromJSON;
+
+#[derive(Deserialize)]
+pub struct FromJSONArgs {
+    objects: bool,
+}
+
+impl WholeStreamCommand for FromJSON {
+    fn name(&self) -> &str {
+        "from-json"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("from-json").switch(
+            "objects",
+            "treat each line as a separate value",
+            Some('o'),
+        )
+    }
+
+    fn usage(&self) -> &str {
+        "Parse text as .json and create table."
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        args.process(registry, from_json)?.run()
+    }
+}
+
+fn convert_json_value_to_nu_value(v: &serde_hjson::Value, tag: impl Into<Tag>) -> Value {
+    let tag = tag.into();
+
+    match v {
+        serde_hjson::Value::Null => UntaggedValue::Primitive(Primitive::Nothing).into_value(&tag),
+        serde_hjson::Value::Bool(b) => UntaggedValue::boolean(*b).into_value(&tag),
+        serde_hjson::Value::F64(n) => UntaggedValue::decimal(*n).into_value(&tag),
+        serde_hjson::Value::U64(n) => UntaggedValue::int(*n).into_value(&tag),
+        serde_hjson::Value::I64(n) => UntaggedValue::int(*n).into_value(&tag),
+        serde_hjson::Value::String(s) => {
+            UntaggedValue::Primitive(Primitive::String(String::from(s))).into_value(&tag)
+        }
+        serde_hjson::Value::Array(a) => UntaggedValue::Table(
+            a.iter()
+                .map(|x| convert_json_value_to_nu_value(x, &tag))
+                .collect(),
+        )
+        .into_value(tag),
+        serde_hjson::Value::Object(o) => {
+            let mut collected = TaggedDictBuilder::new(&tag);
+            for (k, v) in o.iter() {
+                collected.insert_value(k.clone(), convert_json_value_to_nu_value(v, &tag));
+            }
+
+            collected.into_value()
+        }
+    }
+}
+
+pub fn from_json_string_to_value(s: String, tag: impl Into<Tag>) -> serde_hjson::Result<Value> {
+    let v: serde_hjson::Value = serde_hjson::from_str(&s)?;
+    Ok(convert_json_value_to_nu_value(&v, tag))
+}
+
+fn from_json(
+    FromJSONArgs { objects }: FromJSONArgs,
+    RunnableContext { input, name, .. }: RunnableContext,
+) -> Result<OutputStream, ShellError> {
+    let name_tag = name;
+
+    let stream = async_stream! {
+        let concat_string = input.collect_string(name_tag.clone()).await?;
+
+        if objects {
+            for json_str in concat_string.item.lines() {
+                if json_str.is_empty() {
+                    continue;
+                }
+
+                match from_json_string_to_value(json_str.to_string(), &name_tag) {
+                    Ok(x) =>
+                        yield ReturnSuccess::value(x),
+                    Err(e) => {
+                        let mut message = "Could not parse as JSON (".to_string();
+                        message.push_str(&e.to_string());
+                        message.push_str(")");
+
+                        yield Err(ShellError::labeled_error_with_secondary(
+                            message,
+                            "input cannot be parsed as JSON",
+                            &name_tag,
+                            "value originates from here",
+                            concat_string.tag.clone()))
+                    }
+                }
+            }
+        } else {
+            match from_json_string_to_value(concat_string.item, name_tag.clone()) {
+                Ok(x) =>
+                    match x {
+                        Value { value: UntaggedValue::Table(list), .. } => {
+                            for l in list {
+                                yield ReturnSuccess::value(l);
+                            }
+                        }
+                        x => yield ReturnSuccess::value(x),
+                    }
+                Err(e) => {
+                    let mut message = "Could not parse as JSON (".to_string();
+                    message.push_str(&e.to_string());
+                    message.push_str(")");
+
+                    yield Err(ShellError::labeled_error_with_secondary(
+                        message,
+                        "input cannot be parsed as JSON",
+                        name_tag,
+                        "value originates from here",
+                        concat_string.tag))
+                }
+            }
+        }
+    };
+
+    Ok(stream.to_output_stream())
+}

crates/nu-cli/src/commands/from_ods.rs

@@ -0,0 +1,98 @@
+use crate::commands::WholeStreamCommand;
+use crate::prelude::*;
+use crate::TaggedListBuilder;
+use calamine::*;
+use nu_errors::ShellError;
+use nu_protocol::{ReturnSuccess, Signature, TaggedDictBuilder, UntaggedValue};
+use std::io::Cursor;
+
+pub struct FromODS;
+
+#[derive(Deserialize)]
+pub struct FromODSArgs {
+    headerless: bool,
+}
+
+impl WholeStreamCommand for FromODS {
+    fn name(&self) -> &str {
+        "from-ods"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("from-ods").switch(
+            "headerless",
+            "don't treat the first row as column names",
+            None,
+        )
+    }
+
+    fn usage(&self) -> &str {
+        "Parse OpenDocument Spreadsheet(.ods) data and create table."
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        args.process(registry, from_ods)?.run()
+    }
+}
+
+fn from_ods(
+    FromODSArgs {
+        headerless: _headerless,
+    }: FromODSArgs,
+    runnable_context: RunnableContext,
+) -> Result<OutputStream, ShellError> {
+    let input = runnable_context.input;
+    let tag = runnable_context.name;
+
+    let stream = async_stream! {
+        let bytes = input.collect_binary(tag.clone()).await?;
+        let mut buf: Cursor<Vec<u8>> = Cursor::new(bytes.item);
+        let mut ods = Ods::<_>::new(buf).map_err(|_| ShellError::labeled_error(
+            "Could not load ods file",
+            "could not load ods file",
+            &tag))?;
+
+        let mut dict = TaggedDictBuilder::new(&tag);
+
+        let sheet_names = ods.sheet_names().to_owned();
+
+        for sheet_name in &sheet_names {
+            let mut sheet_output = TaggedListBuilder::new(&tag);
+
+            if let Some(Ok(current_sheet)) = ods.worksheet_range(sheet_name) {
+                for row in current_sheet.rows() {
+                    let mut row_output = TaggedDictBuilder::new(&tag);
+                    for (i, cell) in row.iter().enumerate() {
+                        let value = match cell {
+                            DataType::Empty => UntaggedValue::nothing(),
+                            DataType::String(s) => UntaggedValue::string(s),
+                            DataType::Float(f) => UntaggedValue::decimal(*f),
+                            DataType::Int(i) => UntaggedValue::int(*i),
+                            DataType::Bool(b) => UntaggedValue::boolean(*b),
+                            _ => UntaggedValue::nothing(),
+                        };
+
+                        row_output.insert_untagged(&format!("Column{}", i), value);
+                    }
+
+                    sheet_output.push_untagged(row_output.into_untagged_value());
+                }
+
+                dict.insert_untagged(sheet_name, sheet_output.into_untagged_value());
+            } else {
+                yield Err(ShellError::labeled_error(
+                    "Could not load sheet",
+                    "could not load sheet",
+                    &tag));
+            }
+        }
+
+        yield ReturnSuccess::value(dict.into_value());
+    };
+
+    Ok(stream.to_output_stream())
+}

crates/nu-cli/src/commands/from_sqlite.rs

@@ -0,0 +1,165 @@
+use crate::commands::WholeStreamCommand;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{Primitive, ReturnSuccess, Signature, TaggedDictBuilder, UntaggedValue, Value};
+use rusqlite::{types::ValueRef, Connection, Row, NO_PARAMS};
+use std::io::Write;
+use std::path::Path;
+
+pub struct FromSQLite;
+
+impl WholeStreamCommand for FromSQLite {
+    fn name(&self) -> &str {
+        "from-sqlite"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("from-sqlite")
+    }
+
+    fn usage(&self) -> &str {
+        "Parse binary data as sqlite .db and create table."
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        from_sqlite(args, registry)
+    }
+}
+
+pub struct FromDB;
+
+impl WholeStreamCommand for FromDB {
+    fn name(&self) -> &str {
+        "from-db"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("from-db")
+    }
+
+    fn usage(&self) -> &str {
+        "Parse binary data as db and create table."
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        from_sqlite(args, registry)
+    }
+}
+
+pub fn convert_sqlite_file_to_nu_value(
+    path: &Path,
+    tag: impl Into<Tag> + Clone,
+) -> Result<Value, rusqlite::Error> {
+    let conn = Connection::open(path)?;
+
+    let mut meta_out = Vec::new();
+    let mut meta_stmt = conn.prepare("select name from sqlite_master where type='table'")?;
+    let mut meta_rows = meta_stmt.query(NO_PARAMS)?;
+    while let Some(meta_row) = meta_rows.next()? {
+        let table_name: String = meta_row.get(0)?;
+        let mut meta_dict = TaggedDictBuilder::new(tag.clone());
+        let mut out = Vec::new();
+        let mut table_stmt = conn.prepare(&format!("select * from [{}]", table_name))?;
+        let mut table_rows = table_stmt.query(NO_PARAMS)?;
+        while let Some(table_row) = table_rows.next()? {
+            out.push(convert_sqlite_row_to_nu_value(table_row, tag.clone())?)
+        }
+        meta_dict.insert_value(
+            "table_name".to_string(),
+            UntaggedValue::Primitive(Primitive::String(table_name)).into_value(tag.clone()),
+        );
+        meta_dict.insert_value(
+            "table_values",
+            UntaggedValue::Table(out).into_value(tag.clone()),
+        );
+        meta_out.push(meta_dict.into_value());
+    }
+    let tag = tag.into();
+    Ok(UntaggedValue::Table(meta_out).into_value(tag))
+}
+
+fn convert_sqlite_row_to_nu_value(
+    row: &Row,
+    tag: impl Into<Tag> + Clone,
+) -> Result<Value, rusqlite::Error> {
+    let mut collected = TaggedDictBuilder::new(tag.clone());
+    for (i, c) in row.columns().iter().enumerate() {
+        collected.insert_value(
+            c.name().to_string(),
+            convert_sqlite_value_to_nu_value(row.get_raw(i), tag.clone()),
+        );
+    }
+    Ok(collected.into_value())
+}
+
+fn convert_sqlite_value_to_nu_value(value: ValueRef, tag: impl Into<Tag> + Clone) -> Value {
+    match value {
+        ValueRef::Null => {
+            UntaggedValue::Primitive(Primitive::String(String::from(""))).into_value(tag)
+        }
+        ValueRef::Integer(i) => UntaggedValue::int(i).into_value(tag),
+        ValueRef::Real(f) => UntaggedValue::decimal(f).into_value(tag),
+        ValueRef::Text(s) => {
+            // this unwrap is safe because we know the ValueRef is Text.
+            UntaggedValue::Primitive(Primitive::String(String::from_utf8_lossy(s).to_string()))
+                .into_value(tag)
+        }
+        ValueRef::Blob(u) => UntaggedValue::binary(u.to_owned()).into_value(tag),
+    }
+}
+
+pub fn from_sqlite_bytes_to_value(
+    mut bytes: Vec<u8>,
+    tag: impl Into<Tag> + Clone,
+) -> Result<Value, std::io::Error> {
+    // FIXME: should probably write a sqlite virtual filesystem
+    // that will allow us to use bytes as a file to avoid this
+    // write out, but this will require C code. Might be
+    // best done as a PR to rusqlite.
+    let mut tempfile = tempfile::NamedTempFile::new()?;
+    tempfile.write_all(bytes.as_mut_slice())?;
+    match convert_sqlite_file_to_nu_value(tempfile.path(), tag) {
+        Ok(value) => Ok(value),
+        Err(e) => Err(std::io::Error::new(std::io::ErrorKind::Other, e)),
+    }
+}
+
+fn from_sqlite(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStream, ShellError> {
+    let args = args.evaluate_once(registry)?;
+    let tag = args.name_tag();
+    let input = args.input;
+
+    let stream = async_stream! {
+        let bytes = input.collect_binary(tag.clone()).await?;
+        match from_sqlite_bytes_to_value(bytes.item, tag.clone()) {
+            Ok(x) => match x {
+                Value { value: UntaggedValue::Table(list), .. } => {
+                    for l in list {
+                        yield ReturnSuccess::value(l);
+                    }
+                }
+                _ => yield ReturnSuccess::value(x),
+            }
+            Err(err) => {
+                println!("{:?}", err);
+                yield Err(ShellError::labeled_error_with_secondary(
+                    "Could not parse as SQLite",
+                    "input cannot be parsed as SQLite",
+                    &tag,
+                    "value originates from here",
+                    bytes.tag,
+                ))
+            }
+        }
+    };
+
+    Ok(stream.to_output_stream())
+}

crates/nu-cli/src/commands/from_ssv.rs

@@ -0,0 +1,492 @@
+use crate::commands::WholeStreamCommand;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{
+    Primitive, ReturnSuccess, Signature, SyntaxShape, TaggedDictBuilder, UntaggedValue, Value,
+};
+use nu_source::Tagged;
+
+pub struct FromSSV;
+
+#[derive(Deserialize)]
+pub struct FromSSVArgs {
+    headerless: bool,
+    #[serde(rename(deserialize = "aligned-columns"))]
+    aligned_columns: bool,
+    #[serde(rename(deserialize = "minimum-spaces"))]
+    minimum_spaces: Option<Tagged<usize>>,
+}
+
+const STRING_REPRESENTATION: &str = "from-ssv";
+const DEFAULT_MINIMUM_SPACES: usize = 2;
+
+impl WholeStreamCommand for FromSSV {
+    fn name(&self) -> &str {
+        STRING_REPRESENTATION
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build(STRING_REPRESENTATION)
+            .switch(
+                "headerless",
+                "don't treat the first row as column names",
+                None,
+            )
+            .switch("aligned-columns", "assume columns are aligned", Some('a'))
+            .named(
+                "minimum-spaces",
+                SyntaxShape::Int,
+                "the minimum spaces to separate columns",
+                Some('m'),
+            )
+    }
+
+    fn usage(&self) -> &str {
+        "Parse text as space-separated values and create a table. The default minimum number of spaces counted as a separator is 2."
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        args.process(registry, from_ssv)?.run()
+    }
+}
+
+enum HeaderOptions<'a> {
+    WithHeaders(&'a str),
+    WithoutHeaders,
+}
+
+fn parse_aligned_columns<'a>(
+    lines: impl Iterator<Item = &'a str>,
+    headers: HeaderOptions,
+    separator: &str,
+) -> Vec<Vec<(String, String)>> {
+    fn construct<'a>(
+        lines: impl Iterator<Item = &'a str>,
+        headers: Vec<(String, usize)>,
+    ) -> Vec<Vec<(String, String)>> {
+        lines
+            .map(|l| {
+                headers
+                    .iter()
+                    .enumerate()
+                    .map(|(i, (header_name, start_position))| {
+                        let val = match headers.get(i + 1) {
+                            Some((_, end)) => {
+                                if *end < l.len() {
+                                    l.get(*start_position..*end)
+                                } else {
+                                    l.get(*start_position..)
+                                }
+                            }
+                            None => l.get(*start_position..),
+                        }
+                        .unwrap_or("")
+                        .trim()
+                        .into();
+                        (header_name.clone(), val)
+                    })
+                    .collect()
+            })
+            .collect()
+    }
+
+    let find_indices = |line: &str| {
+        let values = line
+            .split(&separator)
+            .map(str::trim)
+            .filter(|s| !s.is_empty());
+        values
+            .fold(
+                (0, vec![]),
+                |(current_pos, mut indices), value| match line[current_pos..].find(value) {
+                    None => (current_pos, indices),
+                    Some(index) => {
+                        let absolute_index = current_pos + index;
+                        indices.push(absolute_index);
+                        (absolute_index + value.len(), indices)
+                    }
+                },
+            )
+            .1
+    };
+
+    let parse_with_headers = |lines, headers_raw: &str| {
+        let indices = find_indices(headers_raw);
+        let headers = headers_raw
+            .split(&separator)
+            .map(str::trim)
+            .filter(|s| !s.is_empty())
+            .map(String::from)
+            .zip(indices);
+
+        let columns = headers.collect::<Vec<(String, usize)>>();
+
+        construct(lines, columns)
+    };
+
+    let parse_without_headers = |ls: Vec<&str>| {
+        let mut indices = ls
+            .iter()
+            .flat_map(|s| find_indices(*s))
+            .collect::<Vec<usize>>();
+
+        indices.sort();
+        indices.dedup();
+
+        let headers: Vec<(String, usize)> = indices
+            .iter()
+            .enumerate()
+            .map(|(i, position)| (format!("Column{}", i + 1), *position))
+            .collect();
+
+        construct(ls.iter().map(|s| s.to_owned()), headers)
+    };
+
+    match headers {
+        HeaderOptions::WithHeaders(headers_raw) => parse_with_headers(lines, headers_raw),
+        HeaderOptions::WithoutHeaders => parse_without_headers(lines.collect()),
+    }
+}
+
+fn parse_separated_columns<'a>(
+    lines: impl Iterator<Item = &'a str>,
+    headers: HeaderOptions,
+    separator: &str,
+) -> Vec<Vec<(String, String)>> {
+    fn collect<'a>(
+        headers: Vec<String>,
+        rows: impl Iterator<Item = &'a str>,
+        separator: &str,
+    ) -> Vec<Vec<(String, String)>> {
+        rows.map(|r| {
+            headers
+                .iter()
+                .zip(r.split(separator).map(str::trim).filter(|s| !s.is_empty()))
+                .map(|(a, b)| (a.to_owned(), b.to_owned()))
+                .collect()
+        })
+        .collect()
+    }
+
+    let parse_with_headers = |lines, headers_raw: &str| {
+        let headers = headers_raw
+            .split(&separator)
+            .map(str::trim)
+            .map(str::to_owned)
+            .filter(|s| !s.is_empty())
+            .collect();
+        collect(headers, lines, separator)
+    };
+
+    let parse_without_headers = |ls: Vec<&str>| {
+        let num_columns = ls.iter().map(|r| r.len()).max().unwrap_or(0);
+
+        let headers = (1..=num_columns)
+            .map(|i| format!("Column{}", i))
+            .collect::<Vec<String>>();
+        collect(headers, ls.into_iter(), separator)
+    };
+
+    match headers {
+        HeaderOptions::WithHeaders(headers_raw) => parse_with_headers(lines, headers_raw),
+        HeaderOptions::WithoutHeaders => parse_without_headers(lines.collect()),
+    }
+}
+
+fn string_to_table(
+    s: &str,
+    headerless: bool,
+    aligned_columns: bool,
+    split_at: usize,
+) -> Vec<Vec<(String, String)>> {
+    let mut lines = s.lines().filter(|l| !l.trim().is_empty());
+    let separator = " ".repeat(std::cmp::max(split_at, 1));
+
+    let (ls, header_options) = if headerless {
+        (lines, HeaderOptions::WithoutHeaders)
+    } else {
+        match lines.next() {
+            Some(header) => (lines, HeaderOptions::WithHeaders(header)),
+            None => return vec![],
+        }
+    };
+
+    let f = if aligned_columns {
+        parse_aligned_columns
+    } else {
+        parse_separated_columns
+    };
+
+    f(ls, header_options, &separator)
+}
+
+fn from_ssv_string_to_value(
+    s: &str,
+    headerless: bool,
+    aligned_columns: bool,
+    split_at: usize,
+    tag: impl Into<Tag>,
+) -> Option<Value> {
+    let tag = tag.into();
+    let rows = string_to_table(s, headerless, aligned_columns, split_at)
+        .iter()
+        .map(|row| {
+            let mut tagged_dict = TaggedDictBuilder::new(&tag);
+            for (col, entry) in row {
+                tagged_dict.insert_value(
+                    col,
+                    UntaggedValue::Primitive(Primitive::String(String::from(entry)))
+                        .into_value(&tag),
+                )
+            }
+            tagged_dict.into_value()
+        })
+        .collect();
+
+    Some(UntaggedValue::Table(rows).into_value(&tag))
+}
+
+fn from_ssv(
+    FromSSVArgs {
+        headerless,
+        aligned_columns,
+        minimum_spaces,
+    }: FromSSVArgs,
+    RunnableContext { input, name, .. }: RunnableContext,
+) -> Result<OutputStream, ShellError> {
+    let stream = async_stream! {
+        let concat_string = input.collect_string(name.clone()).await?;
+        let split_at = match minimum_spaces {
+            Some(number) => number.item,
+            None => DEFAULT_MINIMUM_SPACES
+        };
+
+        match from_ssv_string_to_value(&concat_string.item, headerless, aligned_columns, split_at, name.clone()) {
+            Some(x) => match x {
+                Value { value: UntaggedValue::Table(list), ..} => {
+                    for l in list { yield ReturnSuccess::value(l) }
+                }
+                x => yield ReturnSuccess::value(x)
+            },
+            None => {
+                yield Err(ShellError::labeled_error_with_secondary(
+                    "Could not parse as SSV",
+                    "input cannot be parsed ssv",
+                    &name,
+                    "value originates from here",
+                    &concat_string.tag,
+                ))
+            },
+        }
+    };
+
+    Ok(stream.to_output_stream())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    fn owned(x: &str, y: &str) -> (String, String) {
+        (String::from(x), String::from(y))
+    }
+
+    #[test]
+    fn it_trims_empty_and_whitespace_only_lines() {
+        let input = r#"
+
+            a       b
+
+            1       2
+
+            3       4
+        "#;
+        let result = string_to_table(input, false, true, 1);
+        assert_eq!(
+            result,
+            vec![
+                vec![owned("a", "1"), owned("b", "2")],
+                vec![owned("a", "3"), owned("b", "4")]
+            ]
+        );
+    }
+
+    #[test]
+    fn it_deals_with_single_column_input() {
+        let input = r#"
+            a
+            1
+            2
+        "#;
+        let result = string_to_table(input, false, true, 1);
+        assert_eq!(result, vec![vec![owned("a", "1")], vec![owned("a", "2")]]);
+    }
+
+    #[test]
+    fn it_uses_first_row_as_data_when_headerless() {
+        let input = r#"
+            a b
+            1 2
+            3 4
+        "#;
+        let result = string_to_table(input, true, true, 1);
+        assert_eq!(
+            result,
+            vec![
+                vec![owned("Column1", "a"), owned("Column2", "b")],
+                vec![owned("Column1", "1"), owned("Column2", "2")],
+                vec![owned("Column1", "3"), owned("Column2", "4")]
+            ]
+        );
+    }
+
+    #[test]
+    fn it_allows_a_predefined_number_of_spaces() {
+        let input = r#"
+            column a   column b
+            entry 1    entry number  2
+            3          four
+        "#;
+
+        let result = string_to_table(input, false, true, 3);
+        assert_eq!(
+            result,
+            vec![
+                vec![
+                    owned("column a", "entry 1"),
+                    owned("column b", "entry number  2")
+                ],
+                vec![owned("column a", "3"), owned("column b", "four")]
+            ]
+        );
+    }
+
+    #[test]
+    fn it_trims_remaining_separator_space() {
+        let input = r#"
+            colA   colB     colC
+            val1   val2     val3
+        "#;
+
+        let trimmed = |s: &str| s.trim() == s;
+
+        let result = string_to_table(input, false, true, 2);
+        assert!(result
+            .iter()
+            .all(|row| row.iter().all(|(a, b)| trimmed(a) && trimmed(b))));
+    }
+
+    #[test]
+    fn it_keeps_empty_columns() {
+        let input = r#"
+            colA   col B     col C
+                   val2      val3
+            val4   val 5     val 6
+            val7             val8
+        "#;
+
+        let result = string_to_table(input, false, true, 2);
+        assert_eq!(
+            result,
+            vec![
+                vec![
+                    owned("colA", ""),
+                    owned("col B", "val2"),
+                    owned("col C", "val3")
+                ],
+                vec![
+                    owned("colA", "val4"),
+                    owned("col B", "val 5"),
+                    owned("col C", "val 6")
+                ],
+                vec![
+                    owned("colA", "val7"),
+                    owned("col B", ""),
+                    owned("col C", "val8")
+                ],
+            ]
+        );
+    }
+
+    #[test]
+    fn it_can_produce_an_empty_stream_for_header_only_input() {
+        let input = "colA   col B";
+
+        let result = string_to_table(input, false, true, 2);
+        let expected: Vec<Vec<(String, String)>> = vec![];
+        assert_eq!(expected, result);
+    }
+
+    #[test]
+    fn it_uses_the_full_final_column() {
+        let input = r#"
+            colA   col B
+            val1   val2   trailing value that should be included
+        "#;
+
+        let result = string_to_table(input, false, true, 2);
+        assert_eq!(
+            result,
+            vec![vec![
+                owned("colA", "val1"),
+                owned("col B", "val2   trailing value that should be included"),
+            ]]
+        );
+    }
+
+    #[test]
+    fn it_handles_empty_values_when_headerless_and_aligned_columns() {
+        let input = r#"
+            a multi-word value  b           d
+            1                        3-3    4
+                                                       last
+        "#;
+
+        let result = string_to_table(input, true, true, 2);
+        assert_eq!(
+            result,
+            vec![
+                vec![
+                    owned("Column1", "a multi-word value"),
+                    owned("Column2", "b"),
+                    owned("Column3", ""),
+                    owned("Column4", "d"),
+                    owned("Column5", "")
+                ],
+                vec![
+                    owned("Column1", "1"),
+                    owned("Column2", ""),
+                    owned("Column3", "3-3"),
+                    owned("Column4", "4"),
+                    owned("Column5", "")
+                ],
+                vec![
+                    owned("Column1", ""),
+                    owned("Column2", ""),
+                    owned("Column3", ""),
+                    owned("Column4", ""),
+                    owned("Column5", "last")
+                ],
+            ]
+        );
+    }
+
+    #[test]
+    fn input_is_parsed_correctly_if_either_option_works() {
+        let input = r#"
+                docker-registry   docker-registry=default                   docker-registry=default   172.30.78.158   5000/TCP
+                kubernetes        component=apiserver,provider=kubernetes   <none>                    172.30.0.2      443/TCP
+                kubernetes-ro     component=apiserver,provider=kubernetes   <none>                    172.30.0.1      80/TCP
+            "#;
+
+        let aligned_columns_headerless = string_to_table(input, true, true, 2);
+        let separator_headerless = string_to_table(input, true, false, 2);
+        let aligned_columns_with_headers = string_to_table(input, false, true, 2);
+        let separator_with_headers = string_to_table(input, false, false, 2);
+        assert_eq!(aligned_columns_headerless, separator_headerless);
+        assert_eq!(aligned_columns_with_headers, separator_with_headers);
+    }
+}

crates/nu-cli/src/commands/from_toml.rs

@@ -0,0 +1,98 @@
+use crate::commands::WholeStreamCommand;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{Primitive, ReturnSuccess, Signature, TaggedDictBuilder, UntaggedValue, Value};
+
+pub struct FromTOML;
+
+impl WholeStreamCommand for FromTOML {
+    fn name(&self) -> &str {
+        "from-toml"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("from-toml")
+    }
+
+    fn usage(&self) -> &str {
+        "Parse text as .toml and create table."
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        from_toml(args, registry)
+    }
+}
+
+pub fn convert_toml_value_to_nu_value(v: &toml::Value, tag: impl Into<Tag>) -> Value {
+    let tag = tag.into();
+
+    match v {
+        toml::Value::Boolean(b) => UntaggedValue::boolean(*b).into_value(tag),
+        toml::Value::Integer(n) => UntaggedValue::int(*n).into_value(tag),
+        toml::Value::Float(n) => UntaggedValue::decimal(*n).into_value(tag),
+        toml::Value::String(s) => {
+            UntaggedValue::Primitive(Primitive::String(String::from(s))).into_value(tag)
+        }
+        toml::Value::Array(a) => UntaggedValue::Table(
+            a.iter()
+                .map(|x| convert_toml_value_to_nu_value(x, &tag))
+                .collect(),
+        )
+        .into_value(tag),
+        toml::Value::Datetime(dt) => {
+            UntaggedValue::Primitive(Primitive::String(dt.to_string())).into_value(tag)
+        }
+        toml::Value::Table(t) => {
+            let mut collected = TaggedDictBuilder::new(&tag);
+
+            for (k, v) in t.iter() {
+                collected.insert_value(k.clone(), convert_toml_value_to_nu_value(v, &tag));
+            }
+
+            collected.into_value()
+        }
+    }
+}
+
+pub fn from_toml_string_to_value(s: String, tag: impl Into<Tag>) -> Result<Value, toml::de::Error> {
+    let v: toml::Value = s.parse::<toml::Value>()?;
+    Ok(convert_toml_value_to_nu_value(&v, tag))
+}
+
+pub fn from_toml(
+    args: CommandArgs,
+    registry: &CommandRegistry,
+) -> Result<OutputStream, ShellError> {
+    let args = args.evaluate_once(registry)?;
+    let tag = args.name_tag();
+    let input = args.input;
+
+    let stream = async_stream! {
+        let concat_string = input.collect_string(tag.clone()).await?;
+        match from_toml_string_to_value(concat_string.item, tag.clone()) {
+            Ok(x) => match x {
+                Value { value: UntaggedValue::Table(list), .. } => {
+                    for l in list {
+                        yield ReturnSuccess::value(l);
+                    }
+                }
+                x => yield ReturnSuccess::value(x),
+            },
+            Err(_) => {
+                yield Err(ShellError::labeled_error_with_secondary(
+                    "Could not parse as TOML",
+                    "input cannot be parsed as TOML",
+                    &tag,
+                    "value originates from here",
+                    concat_string.tag,
+                ))
+            }
+        }
+    };
+
+    Ok(stream.to_output_stream())
+}

crates/nu-cli/src/commands/from_tsv.rs

@@ -0,0 +1,45 @@
+use crate::commands::from_delimited_data::from_delimited_data;
+use crate::commands::WholeStreamCommand;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::Signature;
+
+pub struct FromTSV;
+
+#[derive(Deserialize)]
+pub struct FromTSVArgs {
+    headerless: bool,
+}
+
+impl WholeStreamCommand for FromTSV {
+    fn name(&self) -> &str {
+        "from-tsv"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("from-tsv").switch(
+            "headerless",
+            "don't treat the first row as column names",
+            None,
+        )
+    }
+
+    fn usage(&self) -> &str {
+        "Parse text as .tsv and create table."
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        args.process(registry, from_tsv)?.run()
+    }
+}
+
+fn from_tsv(
+    FromTSVArgs { headerless }: FromTSVArgs,
+    runnable_context: RunnableContext,
+) -> Result<OutputStream, ShellError> {
+    from_delimited_data(headerless, '\t', "TSV", runnable_context)
+}

crates/nu-cli/src/commands/from_url.rs

@@ -0,0 +1,63 @@
+use crate::commands::WholeStreamCommand;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{ReturnSuccess, Signature, TaggedDictBuilder, UntaggedValue};
+
+pub struct FromURL;
+
+impl WholeStreamCommand for FromURL {
+    fn name(&self) -> &str {
+        "from-url"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("from-url")
+    }
+
+    fn usage(&self) -> &str {
+        "Parse url-encoded string as a table."
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        from_url(args, registry)
+    }
+}
+
+fn from_url(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStream, ShellError> {
+    let args = args.evaluate_once(registry)?;
+    let tag = args.name_tag();
+    let input = args.input;
+
+    let stream = async_stream! {
+        let concat_string = input.collect_string(tag.clone()).await?;
+
+        let result = serde_urlencoded::from_str::<Vec<(String, String)>>(&concat_string.item);
+
+        match result {
+            Ok(result) => {
+                let mut row = TaggedDictBuilder::new(tag);
+
+                for (k,v) in result {
+                    row.insert_untagged(k, UntaggedValue::string(v));
+                }
+
+                yield ReturnSuccess::value(row.into_value());
+            }
+            _ => {
+                yield Err(ShellError::labeled_error_with_secondary(
+                    "String not compatible with url-encoding",
+                    "input not url-encoded",
+                    tag,
+                    "value originates from here",
+                    concat_string.tag,
+                ));
+            }
+        }
+    };
+
+    Ok(stream.to_output_stream())
+}

crates/nu-cli/src/commands/from_vcf.rs

@@ -0,0 +1,102 @@
+extern crate ical;
+use crate::commands::WholeStreamCommand;
+use crate::prelude::*;
+use ical::parser::vcard::component::*;
+use ical::property::Property;
+use nu_errors::ShellError;
+use nu_protocol::{Primitive, ReturnSuccess, Signature, TaggedDictBuilder, UntaggedValue, Value};
+use std::io::BufReader;
+
+pub struct FromVcf;
+
+impl WholeStreamCommand for FromVcf {
+    fn name(&self) -> &str {
+        "from-vcf"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("from-vcf")
+    }
+
+    fn usage(&self) -> &str {
+        "Parse text as .vcf and create table."
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        from_vcf(args, registry)
+    }
+}
+
+fn from_vcf(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStream, ShellError> {
+    let args = args.evaluate_once(registry)?;
+    let tag = args.name_tag();
+    let input = args.input;
+
+    let stream = async_stream! {
+        let input_string = input.collect_string(tag.clone()).await?.item;
+        let input_bytes = input_string.as_bytes();
+        let buf_reader = BufReader::new(input_bytes);
+        let parser = ical::VcardParser::new(buf_reader);
+
+        for contact in parser {
+            match contact {
+                Ok(c) => yield ReturnSuccess::value(contact_to_value(c, tag.clone())),
+                Err(_) => yield Err(ShellError::labeled_error(
+                    "Could not parse as .vcf",
+                    "input cannot be parsed as .vcf",
+                    tag.clone()
+                )),
+            }
+        }
+    };
+
+    Ok(stream.to_output_stream())
+}
+
+fn contact_to_value(contact: VcardContact, tag: Tag) -> Value {
+    let mut row = TaggedDictBuilder::new(tag.clone());
+    row.insert_untagged("properties", properties_to_value(contact.properties, tag));
+    row.into_value()
+}
+
+fn properties_to_value(properties: Vec<Property>, tag: Tag) -> UntaggedValue {
+    UntaggedValue::table(
+        &properties
+            .into_iter()
+            .map(|prop| {
+                let mut row = TaggedDictBuilder::new(tag.clone());
+
+                let name = UntaggedValue::string(prop.name);
+                let value = match prop.value {
+                    Some(val) => UntaggedValue::string(val),
+                    None => UntaggedValue::Primitive(Primitive::Nothing),
+                };
+                let params = match prop.params {
+                    Some(param_list) => params_to_value(param_list, tag.clone()).into(),
+                    None => UntaggedValue::Primitive(Primitive::Nothing),
+                };
+
+                row.insert_untagged("name", name);
+                row.insert_untagged("value", value);
+                row.insert_untagged("params", params);
+                row.into_value()
+            })
+            .collect::<Vec<Value>>(),
+    )
+}
+
+fn params_to_value(params: Vec<(String, Vec<String>)>, tag: Tag) -> Value {
+    let mut row = TaggedDictBuilder::new(tag);
+
+    for (param_name, param_values) in params {
+        let values: Vec<Value> = param_values.into_iter().map(|val| val.into()).collect();
+        let values = UntaggedValue::table(&values);
+        row.insert_untagged(param_name, values);
+    }
+
+    row.into_value()
+}

crates/nu-cli/src/commands/from_xlsx.rs

@@ -0,0 +1,99 @@
+use crate::commands::WholeStreamCommand;
+use crate::prelude::*;
+use crate::TaggedListBuilder;
+use calamine::*;
+use nu_errors::ShellError;
+use nu_protocol::{ReturnSuccess, Signature, TaggedDictBuilder, UntaggedValue};
+use std::io::Cursor;
+
+pub struct FromXLSX;
+
+#[derive(Deserialize)]
+pub struct FromXLSXArgs {
+    headerless: bool,
+}
+
+impl WholeStreamCommand for FromXLSX {
+    fn name(&self) -> &str {
+        "from-xlsx"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("from-xlsx").switch(
+            "headerless",
+            "don't treat the first row as column names",
+            None,
+        )
+    }
+
+    fn usage(&self) -> &str {
+        "Parse binary Excel(.xlsx) data and create table."
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        args.process(registry, from_xlsx)?.run()
+    }
+}
+
+fn from_xlsx(
+    FromXLSXArgs {
+        headerless: _headerless,
+    }: FromXLSXArgs,
+    runnable_context: RunnableContext,
+) -> Result<OutputStream, ShellError> {
+    let input = runnable_context.input;
+    let tag = runnable_context.name;
+
+    let stream = async_stream! {
+        let value = input.collect_binary(tag.clone()).await?;
+
+        let mut buf: Cursor<Vec<u8>> = Cursor::new(value.item);
+        let mut xls = Xlsx::<_>::new(buf).map_err(|_| {
+            ShellError::labeled_error("Could not load xlsx file", "could not load xlsx file", &tag)
+        })?;
+
+        let mut dict = TaggedDictBuilder::new(&tag);
+
+        let sheet_names = xls.sheet_names().to_owned();
+
+        for sheet_name in &sheet_names {
+            let mut sheet_output = TaggedListBuilder::new(&tag);
+
+            if let Some(Ok(current_sheet)) = xls.worksheet_range(sheet_name) {
+                for row in current_sheet.rows() {
+                    let mut row_output = TaggedDictBuilder::new(&tag);
+                    for (i, cell) in row.iter().enumerate() {
+                        let value = match cell {
+                            DataType::Empty => UntaggedValue::nothing(),
+                            DataType::String(s) => UntaggedValue::string(s),
+                            DataType::Float(f) => UntaggedValue::decimal(*f),
+                            DataType::Int(i) => UntaggedValue::int(*i),
+                            DataType::Bool(b) => UntaggedValue::boolean(*b),
+                            _ => UntaggedValue::nothing(),
+                        };
+
+                        row_output.insert_untagged(&format!("Column{}", i), value);
+                    }
+
+                    sheet_output.push_untagged(row_output.into_untagged_value());
+                }
+
+                dict.insert_untagged(sheet_name, sheet_output.into_untagged_value());
+            } else {
+                yield Err(ShellError::labeled_error(
+                    "Could not load sheet",
+                    "could not load sheet",
+                    &tag,
+                ));
+            }
+        }
+
+        yield ReturnSuccess::value(dict.into_value());
+    };
+
+    Ok(stream.to_output_stream())
+}

crates/nu-cli/src/commands/from_xml.rs

@@ -0,0 +1,303 @@
+use crate::commands::WholeStreamCommand;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{Primitive, ReturnSuccess, Signature, TaggedDictBuilder, UntaggedValue, Value};
+
+pub struct FromXML;
+
+impl WholeStreamCommand for FromXML {
+    fn name(&self) -> &str {
+        "from-xml"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("from-xml")
+    }
+
+    fn usage(&self) -> &str {
+        "Parse text as .xml and create table."
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        from_xml(args, registry)
+    }
+}
+
+fn from_attributes_to_value(attributes: &[roxmltree::Attribute], tag: impl Into<Tag>) -> Value {
+    let tag = tag.into();
+
+    let mut collected = TaggedDictBuilder::new(tag);
+    for a in attributes {
+        collected.insert_untagged(String::from(a.name()), UntaggedValue::string(a.value()));
+    }
+
+    collected.into_value()
+}
+
+fn from_node_to_value<'a, 'd>(n: &roxmltree::Node<'a, 'd>, tag: impl Into<Tag>) -> Value {
+    let tag = tag.into();
+
+    if n.is_element() {
+        let name = n.tag_name().name().trim().to_string();
+
+        let mut children_values = vec![];
+        for c in n.children() {
+            children_values.push(from_node_to_value(&c, &tag));
+        }
+
+        let children_values: Vec<Value> = children_values
+            .into_iter()
+            .filter(|x| match x {
+                Value {
+                    value: UntaggedValue::Primitive(Primitive::String(f)),
+                    ..
+                } => {
+                    !f.trim().is_empty() // non-whitespace characters?
+                }
+                _ => true,
+            })
+            .collect();
+
+        let mut collected = TaggedDictBuilder::new(&tag);
+
+        let attribute_value: Value = from_attributes_to_value(&n.attributes(), &tag);
+
+        let mut row = TaggedDictBuilder::new(&tag);
+        row.insert_untagged(
+            String::from("children"),
+            UntaggedValue::Table(children_values),
+        );
+        row.insert_untagged(String::from("attributes"), attribute_value);
+        collected.insert_untagged(name, row.into_value());
+
+        collected.into_value()
+    } else if n.is_comment() {
+        UntaggedValue::string("<comment>").into_value(tag)
+    } else if n.is_pi() {
+        UntaggedValue::string("<processing_instruction>").into_value(tag)
+    } else if n.is_text() {
+        match n.text() {
+            Some(text) => UntaggedValue::string(text).into_value(tag),
+            None => UntaggedValue::string("<error>").into_value(tag),
+        }
+    } else {
+        UntaggedValue::string("<unknown>").into_value(tag)
+    }
+}
+
+fn from_document_to_value(d: &roxmltree::Document, tag: impl Into<Tag>) -> Value {
+    from_node_to_value(&d.root_element(), tag)
+}
+
+pub fn from_xml_string_to_value(s: String, tag: impl Into<Tag>) -> Result<Value, roxmltree::Error> {
+    let parsed = roxmltree::Document::parse(&s)?;
+    Ok(from_document_to_value(&parsed, tag))
+}
+
+fn from_xml(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStream, ShellError> {
+    let args = args.evaluate_once(registry)?;
+    let tag = args.name_tag();
+    let input = args.input;
+
+    let stream = async_stream! {
+        let concat_string = input.collect_string(tag.clone()).await?;
+
+        match from_xml_string_to_value(concat_string.item, tag.clone()) {
+            Ok(x) => match x {
+                Value { value: UntaggedValue::Table(list), .. } => {
+                    for l in list {
+                        yield ReturnSuccess::value(l);
+                    }
+                }
+                x => yield ReturnSuccess::value(x),
+            },
+            Err(_) => {
+                yield Err(ShellError::labeled_error_with_secondary(
+                    "Could not parse as XML",
+                    "input cannot be parsed as XML",
+                    &tag,
+                    "value originates from here",
+                    &concat_string.tag,
+                ))
+            } ,
+        }
+    };
+
+    Ok(stream.to_output_stream())
+}
+
+#[cfg(test)]
+mod tests {
+
+    use crate::commands::from_xml;
+    use indexmap::IndexMap;
+    use nu_protocol::{UntaggedValue, Value};
+    use nu_source::*;
+
+    fn string(input: impl Into<String>) -> Value {
+        UntaggedValue::string(input.into()).into_untagged_value()
+    }
+
+    fn row(entries: IndexMap<String, Value>) -> Value {
+        UntaggedValue::row(entries).into_untagged_value()
+    }
+
+    fn table(list: &[Value]) -> Value {
+        UntaggedValue::table(list).into_untagged_value()
+    }
+
+    fn parse(xml: &str) -> Result<Value, roxmltree::Error> {
+        from_xml::from_xml_string_to_value(xml.to_string(), Tag::unknown())
+    }
+
+    #[test]
+    fn parses_empty_element() -> Result<(), roxmltree::Error> {
+        let source = "<nu></nu>";
+
+        assert_eq!(
+            parse(source)?,
+            row(indexmap! {
+                "nu".into() => row(indexmap! {
+                    "children".into() => table(&[]),
+                    "attributes".into() => row(indexmap! {})
+                })
+            })
+        );
+
+        Ok(())
+    }
+
+    #[test]
+    fn parses_element_with_text() -> Result<(), roxmltree::Error> {
+        let source = "<nu>La era de los tres caballeros</nu>";
+
+        assert_eq!(
+            parse(source)?,
+            row(indexmap! {
+                "nu".into() => row(indexmap! {
+                    "children".into() => table(&[string("La era de los tres caballeros")]),
+                    "attributes".into() => row(indexmap! {})
+                })
+            })
+        );
+
+        Ok(())
+    }
+
+    #[test]
+    fn parses_element_with_elements() -> Result<(), roxmltree::Error> {
+        let source = "\
+<nu>
+    <dev>Andrés</dev>
+    <dev>Jonathan</dev>
+    <dev>Yehuda</dev>
+</nu>";
+
+        assert_eq!(
+            parse(source)?,
+            row(indexmap! {
+                "nu".into() => row(indexmap! {
+                    "children".into() => table(&[
+                        row(indexmap! {
+                            "dev".into() => row(indexmap! {
+                                "children".into() => table(&[string("Andrés")]),
+                                "attributes".into() => row(indexmap! {})
+                            })
+                        }),
+                        row(indexmap! {
+                            "dev".into() => row(indexmap! {
+                                "children".into() => table(&[string("Jonathan")]),
+                                "attributes".into() => row(indexmap! {})
+                            })
+                        }),
+                        row(indexmap! {
+                            "dev".into() => row(indexmap! {
+                                "children".into() => table(&[string("Yehuda")]),
+                                "attributes".into() => row(indexmap! {})
+                            })
+                        })
+                    ]),
+                    "attributes".into() => row(indexmap! {})
+                })
+            })
+        );
+
+        Ok(())
+    }
+
+    #[test]
+    fn parses_element_with_attribute() -> Result<(), roxmltree::Error> {
+        let source = "\
+<nu version=\"2.0\">
+</nu>";
+
+        assert_eq!(
+            parse(source)?,
+            row(indexmap! {
+                "nu".into() => row(indexmap! {
+                    "children".into() => table(&[]),
+                    "attributes".into() => row(indexmap! {
+                        "version".into() => string("2.0")
+                    })
+                })
+            })
+        );
+
+        Ok(())
+    }
+
+    #[test]
+    fn parses_element_with_attribute_and_element() -> Result<(), roxmltree::Error> {
+        let source = "\
+<nu version=\"2.0\">
+    <version>2.0</version>
+</nu>";
+
+        assert_eq!(
+            parse(source)?,
+            row(indexmap! {
+                "nu".into() => row(indexmap! {
+                    "children".into() => table(&[
+                           row(indexmap! {
+                                "version".into() => row(indexmap! {
+                                    "children".into() => table(&[string("2.0")]),
+                                    "attributes".into() => row(indexmap! {})
+                                })
+                          })
+                    ]),
+                    "attributes".into() => row(indexmap! {
+                        "version".into() => string("2.0")
+                    })
+                })
+            })
+        );
+
+        Ok(())
+    }
+
+    #[test]
+    fn parses_element_with_multiple_attributes() -> Result<(), roxmltree::Error> {
+        let source = "\
+<nu version=\"2.0\" age=\"25\">
+</nu>";
+
+        assert_eq!(
+            parse(source)?,
+            row(indexmap! {
+                "nu".into() => row(indexmap! {
+                    "children".into() => table(&[]),
+                    "attributes".into() => row(indexmap! {
+                        "version".into() => string("2.0"),
+                        "age".into() => string("25")
+                    })
+                })
+            })
+        );
+
+        Ok(())
+    }
+}

crates/nu-cli/src/commands/from_yaml.rs

@@ -0,0 +1,151 @@
+use crate::commands::WholeStreamCommand;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{Primitive, ReturnSuccess, Signature, TaggedDictBuilder, UntaggedValue, Value};
+
+pub struct FromYAML;
+
+impl WholeStreamCommand for FromYAML {
+    fn name(&self) -> &str {
+        "from-yaml"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("from-yaml")
+    }
+
+    fn usage(&self) -> &str {
+        "Parse text as .yaml/.yml and create table."
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        from_yaml(args, registry)
+    }
+}
+
+pub struct FromYML;
+
+impl WholeStreamCommand for FromYML {
+    fn name(&self) -> &str {
+        "from-yml"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("from-yml")
+    }
+
+    fn usage(&self) -> &str {
+        "Parse text as .yaml/.yml and create table."
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        from_yaml(args, registry)
+    }
+}
+
+fn convert_yaml_value_to_nu_value(
+    v: &serde_yaml::Value,
+    tag: impl Into<Tag>,
+) -> Result<Value, ShellError> {
+    let tag = tag.into();
+
+    Ok(match v {
+        serde_yaml::Value::Bool(b) => UntaggedValue::boolean(*b).into_value(tag),
+        serde_yaml::Value::Number(n) if n.is_i64() => {
+            UntaggedValue::int(n.as_i64().ok_or_else(|| {
+                ShellError::labeled_error(
+                    "Expected a compatible number",
+                    "expected a compatible number",
+                    &tag,
+                )
+            })?)
+            .into_value(tag)
+        }
+        serde_yaml::Value::Number(n) if n.is_f64() => {
+            UntaggedValue::decimal(n.as_f64().ok_or_else(|| {
+                ShellError::labeled_error(
+                    "Expected a compatible number",
+                    "expected a compatible number",
+                    &tag,
+                )
+            })?)
+            .into_value(tag)
+        }
+        serde_yaml::Value::String(s) => UntaggedValue::string(s).into_value(tag),
+        serde_yaml::Value::Sequence(a) => {
+            let result: Result<Vec<Value>, ShellError> = a
+                .iter()
+                .map(|x| convert_yaml_value_to_nu_value(x, &tag))
+                .collect();
+            UntaggedValue::Table(result?).into_value(tag)
+        }
+        serde_yaml::Value::Mapping(t) => {
+            let mut collected = TaggedDictBuilder::new(&tag);
+
+            for (k, v) in t.iter() {
+                match k {
+                    serde_yaml::Value::String(k) => {
+                        collected.insert_value(k.clone(), convert_yaml_value_to_nu_value(v, &tag)?);
+                    }
+                    _ => unimplemented!("Unknown key type"),
+                }
+            }
+
+            collected.into_value()
+        }
+        serde_yaml::Value::Null => UntaggedValue::Primitive(Primitive::Nothing).into_value(tag),
+        x => unimplemented!("Unsupported yaml case: {:?}", x),
+    })
+}
+
+pub fn from_yaml_string_to_value(s: String, tag: impl Into<Tag>) -> Result<Value, ShellError> {
+    let tag = tag.into();
+    let v: serde_yaml::Value = serde_yaml::from_str(&s).map_err(|x| {
+        ShellError::labeled_error(
+            format!("Could not load yaml: {}", x),
+            "could not load yaml from text",
+            &tag,
+        )
+    })?;
+    Ok(convert_yaml_value_to_nu_value(&v, tag)?)
+}
+
+fn from_yaml(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStream, ShellError> {
+    let args = args.evaluate_once(registry)?;
+    let tag = args.name_tag();
+    let input = args.input;
+
+    let stream = async_stream! {
+        let concat_string = input.collect_string(tag.clone()).await?;
+
+        match from_yaml_string_to_value(concat_string.item, tag.clone()) {
+            Ok(x) => match x {
+                Value { value: UntaggedValue::Table(list), .. } => {
+                    for l in list {
+                        yield ReturnSuccess::value(l);
+                    }
+                }
+                x => yield ReturnSuccess::value(x),
+            },
+            Err(_) => {
+                yield Err(ShellError::labeled_error_with_secondary(
+                    "Could not parse as YAML",
+                    "input cannot be parsed as YAML",
+                    &tag,
+                    "value originates from here",
+                    &concat_string.tag,
+                ))
+            }
+        }
+    };
+
+    Ok(stream.to_output_stream())
+}

crates/nu-cli/src/commands/get.rs

@@ -0,0 +1,242 @@
+use crate::commands::WholeStreamCommand;
+use crate::prelude::*;
+use indexmap::set::IndexSet;
+use log::trace;
+use nu_errors::ShellError;
+use nu_protocol::{
+    did_you_mean, ColumnPath, PathMember, Primitive, ReturnSuccess, ReturnValue, Signature,
+    SyntaxShape, UnspannedPathMember, UntaggedValue, Value,
+};
+use nu_source::span_for_spanned_list;
+use nu_value_ext::get_data_by_column_path;
+
+pub struct Get;
+
+#[derive(Deserialize)]
+pub struct GetArgs {
+    rest: Vec<ColumnPath>,
+}
+
+impl WholeStreamCommand for Get {
+    fn name(&self) -> &str {
+        "get"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("get").rest(
+            SyntaxShape::ColumnPath,
+            "optionally return additional data by path",
+        )
+    }
+
+    fn usage(&self) -> &str {
+        "Open given cells as text."
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        args.process(registry, get)?.run()
+    }
+}
+
+pub fn get_column_path(path: &ColumnPath, obj: &Value) -> Result<Value, ShellError> {
+    let fields = path.clone();
+
+    get_data_by_column_path(
+        obj,
+        path,
+        Box::new(move |(obj_source, column_path_tried, error)| {
+            let path_members_span = span_for_spanned_list(fields.members().iter().map(|p| p.span));
+
+            match &obj_source.value {
+                UntaggedValue::Table(rows) => match column_path_tried {
+                    PathMember {
+                        unspanned: UnspannedPathMember::String(column),
+                        ..
+                    } => {
+                        let primary_label = format!("There isn't a column named '{}'", &column);
+
+                        let suggestions: IndexSet<_> = rows
+                            .iter()
+                            .filter_map(|r| did_you_mean(&r, &column_path_tried))
+                            .map(|s| s[0].1.to_owned())
+                            .collect();
+                        let mut existing_columns: IndexSet<_> = IndexSet::default();
+                        let mut names: Vec<String> = vec![];
+
+                        for row in rows {
+                            for field in row.data_descriptors() {
+                                if !existing_columns.contains(&field[..]) {
+                                    existing_columns.insert(field.clone());
+                                    names.push(field);
+                                }
+                            }
+                        }
+
+                        if names.is_empty() {
+                            return ShellError::labeled_error_with_secondary(
+                                "Unknown column",
+                                primary_label,
+                                column_path_tried.span,
+                                "Appears to contain rows. Try indexing instead.",
+                                column_path_tried.span.since(path_members_span),
+                            );
+                        } else {
+                            return ShellError::labeled_error_with_secondary(
+                                "Unknown column",
+                                primary_label,
+                                column_path_tried.span,
+                                format!(
+                                    "Perhaps you meant '{}'? Columns available: {}",
+                                    suggestions
+                                        .iter()
+                                        .map(|x| x.to_owned())
+                                        .collect::<Vec<String>>()
+                                        .join(","),
+                                    names.join(",")
+                                ),
+                                column_path_tried.span.since(path_members_span),
+                            );
+                        };
+                    }
+                    PathMember {
+                        unspanned: UnspannedPathMember::Int(idx),
+                        ..
+                    } => {
+                        let total = rows.len();
+
+                        let secondary_label = if total == 1 {
+                            "The table only has 1 row".to_owned()
+                        } else {
+                            format!("The table only has {} rows (0 to {})", total, total - 1)
+                        };
+
+                        return ShellError::labeled_error_with_secondary(
+                            "Row not found",
+                            format!("There isn't a row indexed at {}", idx),
+                            column_path_tried.span,
+                            secondary_label,
+                            column_path_tried.span.since(path_members_span),
+                        );
+                    }
+                },
+                UntaggedValue::Row(columns) => match column_path_tried {
+                    PathMember {
+                        unspanned: UnspannedPathMember::String(column),
+                        ..
+                    } => {
+                        let primary_label = format!("There isn't a column named '{}'", &column);
+
+                        if let Some(suggestions) = did_you_mean(&obj_source, column_path_tried) {
+                            return ShellError::labeled_error_with_secondary(
+                                "Unknown column",
+                                primary_label,
+                                column_path_tried.span,
+                                format!(
+                                    "Perhaps you meant '{}'? Columns available: {}",
+                                    suggestions[0].1,
+                                    &obj_source.data_descriptors().join(",")
+                                ),
+                                column_path_tried.span.since(path_members_span),
+                            );
+                        }
+                    }
+                    PathMember {
+                        unspanned: UnspannedPathMember::Int(idx),
+                        ..
+                    } => {
+                        return ShellError::labeled_error_with_secondary(
+                            "No rows available",
+                            format!("A row at '{}' can't be indexed.", &idx),
+                            column_path_tried.span,
+                            format!(
+                                "Appears to contain columns. Columns available: {}",
+                                columns.keys().join(",")
+                            ),
+                            column_path_tried.span.since(path_members_span),
+                        )
+                    }
+                },
+                _ => {}
+            }
+
+            if let Some(suggestions) = did_you_mean(&obj_source, column_path_tried) {
+                return ShellError::labeled_error(
+                    "Unknown column",
+                    format!("did you mean '{}'?", suggestions[0].1),
+                    column_path_tried.span.since(path_members_span),
+                );
+            }
+
+            error
+        }),
+    )
+}
+
+pub fn get(
+    GetArgs { rest: mut fields }: GetArgs,
+    RunnableContext { mut input, .. }: RunnableContext,
+) -> Result<OutputStream, ShellError> {
+    if fields.is_empty() {
+        let stream = async_stream! {
+            let mut vec = input.drain_vec().await;
+
+            let descs = nu_protocol::merge_descriptors(&vec);
+            for desc in descs {
+                yield ReturnSuccess::value(desc);
+            }
+        };
+
+        let stream: BoxStream<'static, ReturnValue> = stream.boxed();
+
+        Ok(stream.to_output_stream())
+    } else {
+        let member = fields.remove(0);
+        trace!("get {:?} {:?}", member, fields);
+        let stream = input
+            .values
+            .map(move |item| {
+                let mut result = VecDeque::new();
+
+                let member = vec![member.clone()];
+
+                let column_paths = vec![&member, &fields]
+                    .into_iter()
+                    .flatten()
+                    .collect::<Vec<&ColumnPath>>();
+
+                for path in column_paths {
+                    let res = get_column_path(&path, &item);
+
+                    match res {
+                        Ok(got) => match got {
+                            Value {
+                                value: UntaggedValue::Table(rows),
+                                ..
+                            } => {
+                                for item in rows {
+                                    result.push_back(ReturnSuccess::value(item.clone()));
+                                }
+                            }
+                            Value {
+                                value: UntaggedValue::Primitive(Primitive::Nothing),
+                                ..
+                            } => {}
+                            other => result.push_back(ReturnSuccess::value(other.clone())),
+                        },
+                        Err(reason) => result.push_back(ReturnSuccess::value(
+                            UntaggedValue::Error(reason).into_untagged_value(),
+                        )),
+                    }
+                }
+
+                futures::stream::iter(result)
+            })
+            .flatten();
+
+        Ok(stream.to_output_stream())
+    }
+}

crates/nu-cli/src/commands/group_by.rs

@@ -0,0 +1,223 @@
+use crate::commands::WholeStreamCommand;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{ReturnSuccess, Signature, SyntaxShape, TaggedDictBuilder, UntaggedValue, Value};
+use nu_source::Tagged;
+use nu_value_ext::get_data_by_key;
+
+pub struct GroupBy;
+
+#[derive(Deserialize)]
+pub struct GroupByArgs {
+    column_name: Tagged<String>,
+}
+
+impl WholeStreamCommand for GroupBy {
+    fn name(&self) -> &str {
+        "group-by"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("group-by").required(
+            "column_name",
+            SyntaxShape::String,
+            "the name of the column to group by",
+        )
+    }
+
+    fn usage(&self) -> &str {
+        "Creates a new table with the data from the table rows grouped by the column given."
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        args.process(registry, group_by)?.run()
+    }
+}
+
+pub fn group_by(
+    GroupByArgs { column_name }: GroupByArgs,
+    RunnableContext { input, name, .. }: RunnableContext,
+) -> Result<OutputStream, ShellError> {
+    let stream = async_stream! {
+        let values: Vec<Value> = input.values.collect().await;
+
+        if values.is_empty() {
+            yield Err(ShellError::labeled_error(
+                    "Expected table from pipeline",
+                    "requires a table input",
+                    column_name.span()
+                ))
+        } else {
+            match group(&column_name, values, name) {
+                Ok(grouped) => yield ReturnSuccess::value(grouped),
+                Err(err) => yield Err(err)
+            }
+        }
+    };
+
+    Ok(stream.to_output_stream())
+}
+
+pub fn group(
+    column_name: &Tagged<String>,
+    values: Vec<Value>,
+    tag: impl Into<Tag>,
+) -> Result<Value, ShellError> {
+    let tag = tag.into();
+
+    let mut groups: indexmap::IndexMap<String, Vec<Value>> = indexmap::IndexMap::new();
+
+    for value in values {
+        let group_key = get_data_by_key(&value, column_name.borrow_spanned());
+
+        if let Some(group_key) = group_key {
+            let group_key = group_key.as_string()?.to_string();
+            let group = groups.entry(group_key).or_insert(vec![]);
+            group.push(value);
+        } else {
+            let possibilities = value.data_descriptors();
+
+            let mut possible_matches: Vec<_> = possibilities
+                .iter()
+                .map(|x| (natural::distance::levenshtein_distance(x, column_name), x))
+                .collect();
+
+            possible_matches.sort();
+
+            if !possible_matches.is_empty() {
+                return Err(ShellError::labeled_error(
+                    "Unknown column",
+                    format!("did you mean '{}'?", possible_matches[0].1),
+                    column_name.tag(),
+                ));
+            } else {
+                return Err(ShellError::labeled_error(
+                    "Unknown column",
+                    "row does not contain this column",
+                    column_name.tag(),
+                ));
+            }
+        }
+    }
+
+    let mut out = TaggedDictBuilder::new(&tag);
+
+    for (k, v) in groups.iter() {
+        out.insert_untagged(k, UntaggedValue::table(v));
+    }
+
+    Ok(out.into_value())
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::commands::group_by::group;
+    use indexmap::IndexMap;
+    use nu_errors::ShellError;
+    use nu_protocol::{UntaggedValue, Value};
+    use nu_source::*;
+
+    fn string(input: impl Into<String>) -> Value {
+        UntaggedValue::string(input.into()).into_untagged_value()
+    }
+
+    fn row(entries: IndexMap<String, Value>) -> Value {
+        UntaggedValue::row(entries).into_untagged_value()
+    }
+
+    fn table(list: &[Value]) -> Value {
+        UntaggedValue::table(list).into_untagged_value()
+    }
+
+    fn nu_releases_commiters() -> Vec<Value> {
+        vec![
+            row(
+                indexmap! {"name".into() => string("AR"), "country".into() => string("EC"), "date".into() => string("August 23-2019")},
+            ),
+            row(
+                indexmap! {"name".into() => string("JT"), "country".into() => string("NZ"), "date".into() => string("August 23-2019")},
+            ),
+            row(
+                indexmap! {"name".into() => string("YK"), "country".into() => string("US"), "date".into() => string("October 10-2019")},
+            ),
+            row(
+                indexmap! {"name".into() => string("AR"), "country".into() => string("EC"), "date".into() => string("Sept 24-2019")},
+            ),
+            row(
+                indexmap! {"name".into() => string("JT"), "country".into() => string("NZ"), "date".into() => string("October 10-2019")},
+            ),
+            row(
+                indexmap! {"name".into() => string("YK"), "country".into() => string("US"), "date".into() => string("Sept 24-2019")},
+            ),
+            row(
+                indexmap! {"name".into() => string("AR"), "country".into() => string("EC"), "date".into() => string("October 10-2019")},
+            ),
+            row(
+                indexmap! {"name".into() => string("JT"), "country".into() => string("NZ"), "date".into() => string("Sept 24-2019")},
+            ),
+            row(
+                indexmap! {"name".into() => string("YK"), "country".into() => string("US"), "date".into() => string("August 23-2019")},
+            ),
+        ]
+    }
+
+    #[test]
+    fn groups_table_by_date_column() -> Result<(), ShellError> {
+        let for_key = String::from("date").tagged_unknown();
+
+        assert_eq!(
+            group(&for_key, nu_releases_commiters(), Tag::unknown())?,
+            row(indexmap! {
+                "August 23-2019".into() =>  table(&[
+                    row(indexmap!{"name".into() => string("AR"), "country".into() => string("EC"), "date".into() => string("August 23-2019")}),
+                    row(indexmap!{"name".into() => string("JT"), "country".into() => string("NZ"), "date".into() => string("August 23-2019")}),
+                    row(indexmap!{"name".into() => string("YK"), "country".into() => string("US"), "date".into() => string("August 23-2019")})
+                ]),
+                "October 10-2019".into() =>  table(&[
+                    row(indexmap!{"name".into() => string("YK"), "country".into() => string("US"), "date".into() => string("October 10-2019")}),
+                    row(indexmap!{"name".into() => string("JT"), "country".into() => string("NZ"), "date".into() => string("October 10-2019")}),
+                    row(indexmap!{"name".into() => string("AR"), "country".into() => string("EC"), "date".into() => string("October 10-2019")})
+                ]),
+                "Sept 24-2019".into() =>  table(&[
+                    row(indexmap!{"name".into() => string("AR"), "country".into() => string("EC"), "date".into() => string("Sept 24-2019")}),
+                    row(indexmap!{"name".into() => string("YK"), "country".into() => string("US"), "date".into() => string("Sept 24-2019")}),
+                    row(indexmap!{"name".into() => string("JT"), "country".into() => string("NZ"), "date".into() => string("Sept 24-2019")})
+                ]),
+            })
+        );
+
+        Ok(())
+    }
+
+    #[test]
+    fn groups_table_by_country_column() -> Result<(), ShellError> {
+        let for_key = String::from("country").tagged_unknown();
+
+        assert_eq!(
+            group(&for_key, nu_releases_commiters(), Tag::unknown())?,
+            row(indexmap! {
+                "EC".into() =>  table(&[
+                    row(indexmap!{"name".into() => string("AR"), "country".into() => string("EC"), "date".into() => string("August 23-2019")}),
+                    row(indexmap!{"name".into() => string("AR"), "country".into() => string("EC"), "date".into() => string("Sept 24-2019")}),
+                    row(indexmap!{"name".into() => string("AR"), "country".into() => string("EC"), "date".into() => string("October 10-2019")})
+                ]),
+                "NZ".into() =>  table(&[
+                    row(indexmap!{"name".into() => string("JT"), "country".into() => string("NZ"), "date".into() => string("August 23-2019")}),
+                    row(indexmap!{"name".into() => string("JT"), "country".into() => string("NZ"), "date".into() => string("October 10-2019")}),
+                    row(indexmap!{"name".into() => string("JT"), "country".into() => string("NZ"), "date".into() => string("Sept 24-2019")})
+                ]),
+                "US".into() =>  table(&[
+                    row(indexmap!{"name".into() => string("YK"), "country".into() => string("US"), "date".into() => string("October 10-2019")}),
+                    row(indexmap!{"name".into() => string("YK"), "country".into() => string("US"), "date".into() => string("Sept 24-2019")}),
+                    row(indexmap!{"name".into() => string("YK"), "country".into() => string("US"), "date".into() => string("August 23-2019")}),
+                ]),
+            })
+        );
+
+        Ok(())
+    }
+}

crates/nu-cli/src/commands/headers.rs

@@ -0,0 +1,80 @@
+use crate::commands::WholeStreamCommand;
+use crate::context::CommandRegistry;
+use crate::prelude::*;
+use futures::stream::StreamExt;
+use indexmap::IndexMap;
+use nu_errors::ShellError;
+use nu_protocol::Dictionary;
+use nu_protocol::{ReturnSuccess, Signature, UntaggedValue, Value};
+
+pub struct Headers;
+#[derive(Deserialize)]
+pub struct HeadersArgs {}
+
+impl WholeStreamCommand for Headers {
+    fn name(&self) -> &str {
+        "headers"
+    }
+    fn signature(&self) -> Signature {
+        Signature::build("headers")
+    }
+    fn usage(&self) -> &str {
+        "Use the first row of the table as column names"
+    }
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        args.process(registry, headers)?.run()
+    }
+}
+
+pub fn headers(
+    HeadersArgs {}: HeadersArgs,
+    RunnableContext { input, .. }: RunnableContext,
+) -> Result<OutputStream, ShellError> {
+    let stream = async_stream! {
+        let rows: Vec<Value> = input.values.collect().await;
+
+        if rows.len() < 1 {
+            yield Err(ShellError::untagged_runtime_error("Couldn't find headers, was the input a properly formatted, non-empty table?"));
+        }
+
+        //the headers are the first row in the table
+        let headers: Vec<String> = match &rows[0].value {
+            UntaggedValue::Row(d) => {
+                Ok(d.entries.iter().map(|(k, v)| {
+                    match v.as_string() {
+                        Ok(s) => s,
+                        Err(_) => { //If a cell that should contain a header name is empty, we name the column Column[index]
+                            match d.entries.get_full(k) {
+                                Some((index, _, _)) => format!("Column{}", index),
+                                None => "unknownColumn".to_string()
+                            }
+                        }
+                    }
+                }).collect())
+            }
+            _ => Err(ShellError::unexpected_eof("Could not get headers, is the table empty?", rows[0].tag.span))
+        }?;
+
+        //Each row is a dictionary with the headers as keys
+        for r in rows.iter().skip(1) {
+            match &r.value {
+                UntaggedValue::Row(d) => {
+                    let mut i = 0;
+                    let mut entries = IndexMap::new();
+                    for (_, v) in d.entries.iter() {
+                        entries.insert(headers[i].clone(), v.clone());
+                        i += 1;
+                    }
+                    yield Ok(ReturnSuccess::Value(UntaggedValue::Row(Dictionary{entries}).into_value(r.tag.clone())))
+                }
+                _ => yield Err(ShellError::unexpected_eof("Couldn't iterate through rows, was the input a properly formatted table?", r.tag.span))
+            }
+        }
+    };
+
+    Ok(stream.to_output_stream())
+}

crates/nu-cli/src/commands/help.rs

@@ -0,0 +1,242 @@
+use crate::commands::PerItemCommand;
+use crate::data::command_dict;
+
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{
+    CallInfo, NamedType, PositionalType, Primitive, ReturnSuccess, Signature, SyntaxShape,
+    TaggedDictBuilder, UntaggedValue, Value,
+};
+use nu_source::SpannedItem;
+use nu_value_ext::get_data_by_key;
+
+pub struct Help;
+
+impl PerItemCommand for Help {
+    fn name(&self) -> &str {
+        "help"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("help").rest(SyntaxShape::Any, "the name of command(s) to get help on")
+    }
+
+    fn usage(&self) -> &str {
+        "Display help information about commands."
+    }
+
+    fn run(
+        &self,
+        call_info: &CallInfo,
+        registry: &CommandRegistry,
+        _raw_args: &RawCommandArgs,
+        _input: Value,
+    ) -> Result<OutputStream, ShellError> {
+        let tag = &call_info.name_tag;
+
+        match call_info.args.nth(0) {
+            Some(Value {
+                value: UntaggedValue::Primitive(Primitive::String(document)),
+                tag,
+            }) => {
+                let mut help = VecDeque::new();
+                if document == "commands" {
+                    let mut sorted_names = registry.names();
+                    sorted_names.sort();
+                    for cmd in sorted_names {
+                        let mut short_desc = TaggedDictBuilder::new(tag.clone());
+                        let value = command_dict(
+                            registry.get_command(&cmd).ok_or_else(|| {
+                                ShellError::labeled_error(
+                                    format!("Could not load {}", cmd),
+                                    "could not load command",
+                                    tag,
+                                )
+                            })?,
+                            tag.clone(),
+                        );
+
+                        short_desc.insert_untagged("name", cmd);
+                        short_desc.insert_untagged(
+                            "description",
+                            get_data_by_key(&value, "usage".spanned_unknown())
+                                .ok_or_else(|| {
+                                    ShellError::labeled_error(
+                                        "Expected a usage key",
+                                        "expected a 'usage' key",
+                                        &value.tag,
+                                    )
+                                })?
+                                .as_string()?,
+                        );
+
+                        help.push_back(ReturnSuccess::value(short_desc.into_value()));
+                    }
+                } else if let Some(command) = registry.get_command(document) {
+                    return Ok(
+                        get_help(&command.name(), &command.usage(), command.signature()).into(),
+                    );
+                }
+                let help = futures::stream::iter(help);
+                Ok(help.to_output_stream())
+            }
+            _ => {
+                let msg = r#"Welcome to Nushell.
+
+Here are some tips to help you get started.
+  * help commands - list all available commands
+  * help <command name> - display help about a particular command
+
+Nushell works on the idea of a "pipeline". Pipelines are commands connected with the '|' character.
+Each stage in the pipeline works together to load, parse, and display information to you.
+
+[Examples]
+
+List the files in the current directory, sorted by size:
+    ls | sort-by size
+
+Get information about the current system:
+    sys | get host
+
+Get the processes on your system actively using CPU:
+    ps | where cpu > 0
+
+You can also learn more at https://www.nushell.sh/book/"#;
+
+                let output_stream = futures::stream::iter(vec![ReturnSuccess::value(
+                    UntaggedValue::string(msg).into_value(tag),
+                )]);
+
+                Ok(output_stream.to_output_stream())
+            }
+        }
+    }
+}
+
+pub(crate) fn get_help(
+    cmd_name: &str,
+    cmd_usage: &str,
+    cmd_sig: Signature,
+) -> impl Into<OutputStream> {
+    let mut help = VecDeque::new();
+    let mut long_desc = String::new();
+
+    long_desc.push_str(&cmd_usage);
+    long_desc.push_str("\n");
+
+    let signature = cmd_sig;
+
+    let mut one_liner = String::new();
+    one_liner.push_str(&signature.name);
+    one_liner.push_str(" ");
+
+    for positional in &signature.positional {
+        match &positional.0 {
+            PositionalType::Mandatory(name, _m) => {
+                one_liner.push_str(&format!("<{}> ", name));
+            }
+            PositionalType::Optional(name, _o) => {
+                one_liner.push_str(&format!("({}) ", name));
+            }
+        }
+    }
+
+    if signature.rest_positional.is_some() {
+        one_liner.push_str(" ...args");
+    }
+
+    if !signature.named.is_empty() {
+        one_liner.push_str("{flags} ");
+    }
+
+    long_desc.push_str(&format!("\nUsage:\n  > {}\n", one_liner));
+
+    if !signature.positional.is_empty() || signature.rest_positional.is_some() {
+        long_desc.push_str("\nparameters:\n");
+        for positional in signature.positional {
+            match positional.0 {
+                PositionalType::Mandatory(name, _m) => {
+                    long_desc.push_str(&format!("  <{}> {}\n", name, positional.1));
+                }
+                PositionalType::Optional(name, _o) => {
+                    long_desc.push_str(&format!("  ({}) {}\n", name, positional.1));
+                }
+            }
+        }
+
+        if let Some(rest_positional) = signature.rest_positional {
+            long_desc.push_str(&format!("  ...args: {}\n", rest_positional.1));
+        }
+    }
+    if !signature.named.is_empty() {
+        long_desc.push_str("\nflags:\n");
+        for (flag, ty) in signature.named {
+            let msg = match ty.0 {
+                NamedType::Switch(s) => {
+                    if let Some(c) = s {
+                        format!(
+                            "  -{}, --{}{} {}\n",
+                            c,
+                            flag,
+                            if !ty.1.is_empty() { ":" } else { "" },
+                            ty.1
+                        )
+                    } else {
+                        format!(
+                            "  --{}{} {}\n",
+                            flag,
+                            if !ty.1.is_empty() { ":" } else { "" },
+                            ty.1
+                        )
+                    }
+                }
+                NamedType::Mandatory(s, m) => {
+                    if let Some(c) = s {
+                        format!(
+                            "  -{}, --{} <{}> (required parameter){} {}\n",
+                            c,
+                            flag,
+                            m.display(),
+                            if !ty.1.is_empty() { ":" } else { "" },
+                            ty.1
+                        )
+                    } else {
+                        format!(
+                            "  --{} <{}> (required parameter){} {}\n",
+                            flag,
+                            m.display(),
+                            if !ty.1.is_empty() { ":" } else { "" },
+                            ty.1
+                        )
+                    }
+                }
+                NamedType::Optional(s, o) => {
+                    if let Some(c) = s {
+                        format!(
+                            "  -{}, --{} <{}>{} {}\n",
+                            c,
+                            flag,
+                            o.display(),
+                            if !ty.1.is_empty() { ":" } else { "" },
+                            ty.1
+                        )
+                    } else {
+                        format!(
+                            "  --{} <{}>{} {}\n",
+                            flag,
+                            o.display(),
+                            if !ty.1.is_empty() { ":" } else { "" },
+                            ty.1
+                        )
+                    }
+                }
+            };
+            long_desc.push_str(&msg);
+        }
+    }
+
+    help.push_back(ReturnSuccess::value(
+        UntaggedValue::string(long_desc).into_value(Tag::from((0, cmd_name.len(), None))),
+    ));
+    help
+}

crates/nu-cli/src/commands/histogram.rs

@@ -0,0 +1,160 @@
+use crate::commands::group_by::group;
+use crate::commands::WholeStreamCommand;
+use crate::prelude::*;
+use crate::utils::data_processing::{columns_sorted, evaluate, map_max, reduce, t_sort};
+use nu_errors::ShellError;
+use nu_protocol::{
+    Primitive, ReturnSuccess, Signature, SyntaxShape, TaggedDictBuilder, UntaggedValue, Value,
+};
+use nu_source::Tagged;
+use num_traits::{ToPrimitive, Zero};
+
+pub struct Histogram;
+
+#[derive(Deserialize)]
+pub struct HistogramArgs {
+    column_name: Tagged<String>,
+    rest: Vec<Tagged<String>>,
+}
+
+impl WholeStreamCommand for Histogram {
+    fn name(&self) -> &str {
+        "histogram"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("histogram")
+            .required(
+                "column_name",
+                SyntaxShape::String,
+                "the name of the column to graph by",
+            )
+            .rest(
+                SyntaxShape::Member,
+                "column name to give the histogram's frequency column",
+            )
+    }
+
+    fn usage(&self) -> &str {
+        "Creates a new table with a histogram based on the column name passed in."
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        args.process(registry, histogram)?.run()
+    }
+}
+
+pub fn histogram(
+    HistogramArgs { column_name, rest }: HistogramArgs,
+    RunnableContext { input, name, .. }: RunnableContext,
+) -> Result<OutputStream, ShellError> {
+    let stream = async_stream! {
+        let values: Vec<Value> = input.values.collect().await;
+
+        let Tagged { item: group_by, .. } = column_name.clone();
+
+        let groups = group(&column_name, values, &name)?;
+        let group_labels = columns_sorted(Some(group_by.clone()), &groups, &name);
+        let sorted = t_sort(Some(group_by.clone()), None, &groups, &name)?;
+        let evaled = evaluate(&sorted, None, &name)?;
+        let reduced = reduce(&evaled, None, &name)?;
+        let maxima = map_max(&reduced, None, &name)?;
+        let percents = percentages(&reduced, maxima, &name)?;
+
+        match percents {
+            Value {
+                value: UntaggedValue::Table(datasets),
+                ..
+            } => {
+
+                let mut idx = 0;
+
+                let column_names_supplied: Vec<_> = rest.iter().map(|f| f.item.clone()).collect();
+
+                let frequency_column_name = if column_names_supplied.is_empty() {
+                    "frequency".to_string()
+                } else {
+                    column_names_supplied[0].clone()
+                };
+
+                let column = (*column_name).clone();
+
+                if let Value { value: UntaggedValue::Table(start), .. } = datasets.get(0).ok_or_else(|| ShellError::labeled_error("Unable to load dataset", "unabled to load dataset", &name))? {
+                    for percentage in start.iter() {
+
+                        let mut fact = TaggedDictBuilder::new(&name);
+                        let value: Tagged<String> = group_labels.get(idx).ok_or_else(|| ShellError::labeled_error("Unable to load group labels", "unabled to load group labels", &name))?.clone();
+                        fact.insert_value(&column, UntaggedValue::string(value.item).into_value(value.tag));
+
+                        if let Value { value: UntaggedValue::Primitive(Primitive::Int(ref num)), ref tag } = percentage.clone() {
+                            let string = std::iter::repeat("*").take(num.to_i32().ok_or_else(|| ShellError::labeled_error("Expected a number", "expected a number", tag))? as usize).collect::<String>();
+                            fact.insert_untagged(&frequency_column_name, UntaggedValue::string(string));
+                        }
+
+                        idx += 1;
+
+                        yield ReturnSuccess::value(fact.into_value());
+                    }
+                }
+            }
+            _ => {}
+        }
+    };
+
+    Ok(stream.to_output_stream())
+}
+
+fn percentages(values: &Value, max: Value, tag: impl Into<Tag>) -> Result<Value, ShellError> {
+    let tag = tag.into();
+
+    let results: Value = match values {
+        Value {
+            value: UntaggedValue::Table(datasets),
+            ..
+        } => {
+            let datasets: Vec<_> = datasets
+                .iter()
+                .map(|subsets| match subsets {
+                    Value {
+                        value: UntaggedValue::Table(data),
+                        ..
+                    } => {
+                        let data = data
+                            .iter()
+                            .map(|d| match d {
+                                Value {
+                                    value: UntaggedValue::Primitive(Primitive::Int(n)),
+                                    ..
+                                } => {
+                                    let max = match &max {
+                                        Value {
+                                            value: UntaggedValue::Primitive(Primitive::Int(maxima)),
+                                            ..
+                                        } => maxima.clone(),
+                                        _ => Zero::zero(),
+                                    };
+
+                                    let n = (n * 100) / max;
+
+                                    UntaggedValue::int(n).into_value(&tag)
+                                }
+                                _ => UntaggedValue::int(0).into_value(&tag),
+                            })
+                            .collect::<Vec<_>>();
+                        UntaggedValue::Table(data).into_value(&tag)
+                    }
+                    _ => UntaggedValue::Table(vec![]).into_value(&tag),
+                })
+                .collect();
+
+            UntaggedValue::Table(datasets).into_value(&tag)
+        }
+        other => other.clone(),
+    };
+
+    Ok(results)
+}

crates/nu-cli/src/commands/history.rs

@@ -0,0 +1,49 @@
+use crate::cli::History as HistoryFile;
+use crate::commands::PerItemCommand;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{CallInfo, ReturnSuccess, Signature, UntaggedValue, Value};
+use std::fs::File;
+use std::io::{BufRead, BufReader};
+
+pub struct History;
+
+impl PerItemCommand for History {
+    fn name(&self) -> &str {
+        "history"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("history")
+    }
+
+    fn usage(&self) -> &str {
+        "Display command history."
+    }
+
+    fn run(
+        &self,
+        call_info: &CallInfo,
+        _registry: &CommandRegistry,
+        _raw_args: &RawCommandArgs,
+        _input: Value,
+    ) -> Result<OutputStream, ShellError> {
+        let tag = call_info.name_tag.clone();
+
+        let stream = async_stream! {
+            let history_path = HistoryFile::path();
+            let file = File::open(history_path);
+            if let Ok(file) = file {
+                let reader = BufReader::new(file);
+                for line in reader.lines() {
+                    if let Ok(line) = line {
+                        yield ReturnSuccess::value(UntaggedValue::string(line).into_value(tag.clone()));
+                    }
+                }
+            } else {
+                yield Err(ShellError::labeled_error("Could not open history", "history file could not be opened", tag.clone()));
+            }
+        };
+        Ok(stream.to_output_stream())
+    }
+}

crates/nu-cli/src/commands/insert.rs

@@ -0,0 +1,66 @@
+use crate::commands::PerItemCommand;
+use crate::context::CommandRegistry;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{CallInfo, ReturnSuccess, Signature, SyntaxShape, UntaggedValue, Value};
+use nu_value_ext::ValueExt;
+
+pub struct Insert;
+
+impl PerItemCommand for Insert {
+    fn name(&self) -> &str {
+        "insert"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("insert")
+            .required(
+                "column",
+                SyntaxShape::ColumnPath,
+                "the column name to insert",
+            )
+            .required(
+                "value",
+                SyntaxShape::String,
+                "the value to give the cell(s)",
+            )
+    }
+
+    fn usage(&self) -> &str {
+        "Edit an existing column to have a new value."
+    }
+
+    fn run(
+        &self,
+        call_info: &CallInfo,
+        _registry: &CommandRegistry,
+        _raw_args: &RawCommandArgs,
+        value: Value,
+    ) -> Result<OutputStream, ShellError> {
+        let value_tag = value.tag();
+        let field = call_info.args.expect_nth(0)?.as_column_path()?;
+        let replacement = call_info.args.expect_nth(1)?.tagged_unknown();
+
+        let stream = match value {
+            obj
+            @
+            Value {
+                value: UntaggedValue::Row(_),
+                ..
+            } => match obj.insert_data_at_column_path(&field, replacement.item.clone()) {
+                Ok(v) => futures::stream::iter(vec![Ok(ReturnSuccess::Value(v))]),
+                Err(err) => return Err(err),
+            },
+
+            _ => {
+                return Err(ShellError::labeled_error(
+                    "Unrecognized type in stream",
+                    "original value",
+                    value_tag,
+                ))
+            }
+        };
+
+        Ok(stream.to_output_stream())
+    }
+}

crates/nu-cli/src/commands/kill.rs

@@ -0,0 +1,104 @@
+use crate::commands::command::RunnablePerItemContext;
+use crate::context::CommandRegistry;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{CallInfo, Signature, SyntaxShape, Value};
+use nu_source::Tagged;
+use std::process::{Command, Stdio};
+
+pub struct Kill;
+
+#[derive(Deserialize)]
+pub struct KillArgs {
+    pub pid: Tagged<u64>,
+    pub rest: Vec<Tagged<u64>>,
+    pub force: Tagged<bool>,
+    pub quiet: Tagged<bool>,
+}
+
+impl PerItemCommand for Kill {
+    fn name(&self) -> &str {
+        "kill"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("kill")
+            .required(
+                "pid",
+                SyntaxShape::Int,
+                "process id of process that is to be killed",
+            )
+            .rest(SyntaxShape::Int, "rest of processes to kill")
+            .switch("force", "forcefully kill the process", Some('f'))
+            .switch("quiet", "won't print anything to the console", Some('q'))
+    }
+
+    fn usage(&self) -> &str {
+        "Kill a process using the process id."
+    }
+
+    fn run(
+        &self,
+        call_info: &CallInfo,
+        _registry: &CommandRegistry,
+        raw_args: &RawCommandArgs,
+        _input: Value,
+    ) -> Result<OutputStream, ShellError> {
+        call_info
+            .process(&raw_args.shell_manager, raw_args.ctrl_c.clone(), kill)?
+            .run()
+    }
+}
+
+fn kill(
+    KillArgs {
+        pid,
+        rest,
+        force,
+        quiet,
+    }: KillArgs,
+    _context: &RunnablePerItemContext,
+) -> Result<OutputStream, ShellError> {
+    let mut cmd = if cfg!(windows) {
+        let mut cmd = Command::new("taskkill");
+
+        if *force {
+            cmd.arg("/F");
+        }
+
+        cmd.arg("/PID");
+        cmd.arg(pid.item().to_string());
+
+        // each pid must written as `/PID 0` otherwise
+        // taskkill will act as `killall` unix command
+        for id in &rest {
+            cmd.arg("/PID");
+            cmd.arg(id.item().to_string());
+        }
+
+        cmd
+    } else {
+        let mut cmd = Command::new("kill");
+
+        if *force {
+            cmd.arg("-9");
+        }
+
+        cmd.arg(pid.item().to_string());
+
+        cmd.args(rest.iter().map(move |id| id.item().to_string()));
+
+        cmd
+    };
+
+    // pipe everything to null
+    if *quiet {
+        cmd.stdin(Stdio::null())
+            .stdout(Stdio::null())
+            .stderr(Stdio::null());
+    }
+
+    cmd.status().expect("failed to execute shell command");
+
+    Ok(OutputStream::empty())
+}

crates/nu-cli/src/commands/last.rs

@@ -0,0 +1,61 @@
+use crate::commands::WholeStreamCommand;
+use crate::context::CommandRegistry;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{ReturnSuccess, Signature, SyntaxShape, Value};
+use nu_source::Tagged;
+
+pub struct Last;
+
+#[derive(Deserialize)]
+pub struct LastArgs {
+    rows: Option<Tagged<u64>>,
+}
+
+impl WholeStreamCommand for Last {
+    fn name(&self) -> &str {
+        "last"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("last").optional(
+            "rows",
+            SyntaxShape::Number,
+            "starting from the back, the number of rows to return",
+        )
+    }
+
+    fn usage(&self) -> &str {
+        "Show only the last number of rows."
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        args.process(registry, last)?.run()
+    }
+}
+
+fn last(LastArgs { rows }: LastArgs, context: RunnableContext) -> Result<OutputStream, ShellError> {
+    let stream = async_stream! {
+        let v: Vec<_> = context.input.into_vec().await;
+
+        let rows_desired = if let Some(quantity) = rows {
+            *quantity
+        } else {
+         1
+        };
+
+        let count = (rows_desired as usize);
+        if count < v.len() {
+            let k = v.len() - count;
+            for x in v[k..].iter() {
+                let y: Value = x.clone();
+                yield ReturnSuccess::value(y)
+            }
+        }
+    };
+    Ok(stream.to_output_stream())
+}

crates/nu-cli/src/commands/lines.rs

@@ -0,0 +1,116 @@
+use crate::commands::WholeStreamCommand;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{Primitive, ReturnSuccess, Signature, UntaggedValue, Value};
+
+pub struct Lines;
+
+impl WholeStreamCommand for Lines {
+    fn name(&self) -> &str {
+        "lines"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("lines")
+    }
+
+    fn usage(&self) -> &str {
+        "Split single string into rows, one per line."
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        lines(args, registry)
+    }
+}
+
+fn ends_with_line_ending(st: &str) -> bool {
+    let mut temp = st.to_string();
+    let last = temp.pop();
+    if let Some(c) = last {
+        c == '\n'
+    } else {
+        false
+    }
+}
+
+fn lines(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStream, ShellError> {
+    let args = args.evaluate_once(registry)?;
+    let tag = args.name_tag();
+    let name_span = tag.span;
+    let mut input = args.input;
+
+    let mut leftover = vec![];
+    let mut leftover_string = String::new();
+    let stream = async_stream! {
+        loop {
+            match input.values.next().await {
+                Some(Value { value: UntaggedValue::Primitive(Primitive::String(st)), ..}) => {
+                    let mut st = leftover_string.clone() + &st;
+                    leftover.clear();
+
+                    let mut lines: Vec<String> = st.lines().map(|x| x.to_string()).collect();
+
+                    if !ends_with_line_ending(&st) {
+                        if let Some(last) = lines.pop() {
+                            leftover_string = last;
+                        } else {
+                            leftover_string.clear();
+                        }
+                    } else {
+                        leftover_string.clear();
+                    }
+
+                    let success_lines: Vec<_> = lines.iter().map(|x| ReturnSuccess::value(UntaggedValue::line(x).into_untagged_value())).collect();
+                    yield futures::stream::iter(success_lines)
+                }
+                Some(Value { value: UntaggedValue::Primitive(Primitive::Line(st)), ..}) => {
+                    let mut st = leftover_string.clone() + &st;
+                    leftover.clear();
+
+                    let mut lines: Vec<String> = st.lines().map(|x| x.to_string()).collect();
+                    if !ends_with_line_ending(&st) {
+                        if let Some(last) = lines.pop() {
+                            leftover_string = last;
+                        } else {
+                            leftover_string.clear();
+                        }
+                    } else {
+                        leftover_string.clear();
+                    }
+
+                    let success_lines: Vec<_> = lines.iter().map(|x| ReturnSuccess::value(UntaggedValue::line(x).into_untagged_value())).collect();
+                    yield futures::stream::iter(success_lines)
+                }
+                Some( Value { tag: value_span, ..}) => {
+                    yield futures::stream::iter(vec![Err(ShellError::labeled_error_with_secondary(
+                        "Expected a string from pipeline",
+                        "requires string input",
+                        name_span,
+                        "value originates from here",
+                        value_span,
+                    ))]);
+                }
+                None => {
+                    if !leftover.is_empty() {
+                        let mut st = leftover_string.clone();
+                        if let Ok(extra) = String::from_utf8(leftover) {
+                            st.push_str(&extra);
+                        }
+                        yield futures::stream::iter(vec![ReturnSuccess::value(UntaggedValue::string(st).into_untagged_value())])
+                    }
+                    break;
+                }
+            }
+        }
+        if !leftover_string.is_empty() {
+            yield futures::stream::iter(vec![ReturnSuccess::value(UntaggedValue::string(leftover_string).into_untagged_value())]);
+        }
+    }
+    .flatten();
+
+    Ok(stream.to_output_stream())
+}

crates/nu-cli/src/commands/ls.rs

@@ -0,0 +1,70 @@
+use crate::commands::command::RunnablePerItemContext;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{CallInfo, Signature, SyntaxShape, Value};
+use nu_source::Tagged;
+use std::path::PathBuf;
+
+pub struct Ls;
+
+#[derive(Deserialize)]
+pub struct LsArgs {
+    pub path: Option<Tagged<PathBuf>>,
+    pub all: bool,
+    pub full: bool,
+    #[serde(rename = "short-names")]
+    pub short_names: bool,
+    #[serde(rename = "with-symlink-targets")]
+    pub with_symlink_targets: bool,
+}
+
+impl PerItemCommand for Ls {
+    fn name(&self) -> &str {
+        "ls"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("ls")
+            .optional(
+                "path",
+                SyntaxShape::Pattern,
+                "a path to get the directory contents from",
+            )
+            .switch("all", "also show hidden files", Some('a'))
+            .switch(
+                "full",
+                "list all available columns for each entry",
+                Some('f'),
+            )
+            .switch(
+                "short-names",
+                "only print the file names and not the path",
+                Some('s'),
+            )
+            .switch(
+                "with-symlink-targets",
+                "display the paths to the target files that symlinks point to",
+                Some('w'),
+            )
+    }
+
+    fn usage(&self) -> &str {
+        "View the contents of the current or given path."
+    }
+
+    fn run(
+        &self,
+        call_info: &CallInfo,
+        _registry: &CommandRegistry,
+        raw_args: &RawCommandArgs,
+        _input: Value,
+    ) -> Result<OutputStream, ShellError> {
+        call_info
+            .process(&raw_args.shell_manager, raw_args.ctrl_c.clone(), ls)?
+            .run()
+    }
+}
+
+fn ls(args: LsArgs, context: &RunnablePerItemContext) -> Result<OutputStream, ShellError> {
+    context.shell_manager.ls(args, context)
+}

crates/nu-cli/src/commands/macros.rs

@@ -1,11 +1,4 @@
 #[doc(hidden)]
-#[allow(unused)]
-macro_rules! named_type {
-    ($name:ident) => {
-        $crate::parser::registry::NamedType::$($name)*
-    }
-}
-
 #[macro_export]
 macro_rules! command {
     (
@@ -52,8 +45,8 @@ macro_rules! command {
                 stringify!($config_name)
             }
 
-            fn config(&self) -> $crate::parser::registry::Signature {
-                $crate::parser::registry::Signature {
+            fn config(&self) -> $nu_parser::registry::Signature {
+                $nu_parser::registry::Signature {
                     name: self.name().to_string(),
                     positional: vec![$($mandatory_positional)*],
                     rest_positional: false,
@@ -61,13 +54,13 @@ macro_rules! command {
                     is_sink: false,
 
                     named: {
-                        use $crate::parser::registry::NamedType;
+                        use $nu_parser::registry::NamedType;
 
                         #[allow(unused_mut)]
                         let mut named: indexmap::IndexMap<String, NamedType> = indexmap::IndexMap::new();
 
                         $(
-                            named.insert(stringify!($named_param).to_string(), $crate::parser::registry::NamedType::$named_kind);
+                            named.insert(stringify!($named_param).to_string(), $nu_parser::registry::NamedType::$named_kind);
                         )*
 
                         named
@@ -121,7 +114,7 @@ macro_rules! command {
                 $($extract)* {
                     use std::convert::TryInto;
 
-                    $args.get(stringify!($param_name)).clone().try_into()?
+                    $args.get(stringify!($param_name)).try_into()?
                 }
             }
         );
@@ -171,7 +164,7 @@ macro_rules! command {
                 $($extract)* {
                     use std::convert::TryInto;
 
-                    $args.get(stringify!($param_name)).clone().try_into()?
+                    $args.get(stringify!($param_name)).try_into()?
                 }
             }
         );
@@ -221,7 +214,7 @@ macro_rules! command {
                 $($extract)* {
                     use std::convert::TryInto;
 
-                    $args.get(stringify!($param_name)).clone().try_into()?
+                    $args.get(stringify!($param_name)).try_into()?
                 }
             }
         );
@@ -257,7 +250,7 @@ macro_rules! command {
             Rest { $($rest)* }
             Signature {
                 name: $config_name,
-                mandatory_positional: vec![ $($mandatory_positional)* $crate::parser::registry::PositionalType::mandatory_block(
+                mandatory_positional: vec![ $($mandatory_positional)* $nu_parser::registry::PositionalType::mandatory_block(
                     stringify!($param_name)
                 ), ],
                 optional_positional: vec![ $($optional_positional)* ],
@@ -273,7 +266,7 @@ macro_rules! command {
 
             Extract {
                 $($extract:tt)* {
-                    use $crate::object::types::ExtractType;
+                    use $crate::data::types::ExtractType;
                     let value = $args.expect_nth($($positional_count)*)?;
                     Block::extract(value)?
                 }
@@ -312,7 +305,7 @@ macro_rules! command {
             Rest { $($rest)* }
             Signature {
                 name: $config_name,
-                mandatory_positional: vec![ $($mandatory_positional)* $crate::parser::registry::PositionalType::mandatory(
+                mandatory_positional: vec![ $($mandatory_positional)* $nu_parser::registry::PositionalType::mandatory(
                     stringify!($param_name), <$param_kind>::syntax_type()
                 ), ],
                 optional_positional: vec![ $($optional_positional)* ],
@@ -328,7 +321,7 @@ macro_rules! command {
 
             Extract {
                 $($extract:tt)* {
-                    use $crate::object::types::ExtractType;
+                    use $crate::data::types::ExtractType;
                     let value = $args.expect_nth($($positional_count)*)?;
                     <$param_kind>::extract(&value)?
                 }
@@ -356,39 +349,4 @@ macro_rules! command {
             }
         );
     };
-
-    // ($export:ident as $name:tt ( $args:ident, -- $param:ident : $kind:ident ) $body:block) => {
-    //     #[allow(non_camel_case_types)]
-    //     pub struct $export;
-
-    //     impl Command for $export {
-    //         fn run(&self, $args: CommandArgs) -> Result<OutputStream, ShellError> {
-    //             fn command($args: CommandArgs, $param: $kind) -> Result<OutputStream, ShellError> {
-    //                 $body
-    //             }
-
-    //             use std::convert::TryInto;
-
-    //             let param = $args.get(stringify!($param)).try_into()?;
-    //             command($args, param)
-    //         }
-
-    //         fn name(&self) -> &str {
-    //             stringify!($name)
-    //         }
-
-    //         fn config(&self) -> Signature {
-    //             let mut named: IndexMap<String, NamedType> = IndexMap::new();
-    //             named.insert(stringify!($param).to_string(), NamedType::$kind);
-
-    //             Signature {
-    //                 name: self.name().to_string(),
-    //                 mandatory_positional: vec![],
-    //                 optional_positional: vec![],
-    //                 rest_positional: false,
-    //                 named,
-    //             }
-    //         }
-    //     }
-    // };
 }

crates/nu-cli/src/commands/map_max_by.rs

@@ -0,0 +1,74 @@
+use crate::commands::WholeStreamCommand;
+use crate::data::value;
+use crate::prelude::*;
+use crate::utils::data_processing::map_max;
+use nu_errors::ShellError;
+use nu_protocol::{Primitive, ReturnSuccess, Signature, SyntaxShape, UntaggedValue, Value};
+use nu_source::Tagged;
+use num_traits::cast::ToPrimitive;
+
+pub struct MapMaxBy;
+
+#[derive(Deserialize)]
+pub struct MapMaxByArgs {
+    column_name: Option<Tagged<String>>,
+}
+
+impl WholeStreamCommand for MapMaxBy {
+    fn name(&self) -> &str {
+        "map-max-by"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("map-max-by").named(
+            "column_name",
+            SyntaxShape::String,
+            "the name of the column to map-max the table's rows",
+            Some('c'),
+        )
+    }
+
+    fn usage(&self) -> &str {
+        "Creates a new table with the data from the tables rows maxed by the column given."
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        args.process(registry, map_max_by)?.run()
+    }
+}
+
+pub fn map_max_by(
+    MapMaxByArgs { column_name }: MapMaxByArgs,
+    RunnableContext { input, name, .. }: RunnableContext,
+) -> Result<OutputStream, ShellError> {
+    let stream = async_stream! {
+        let values: Vec<Value> = input.values.collect().await;
+
+
+        if values.is_empty() {
+            yield Err(ShellError::labeled_error(
+                    "Expected table from pipeline",
+                    "requires a table input",
+                    name
+                ))
+        } else {
+
+            let map_by_column = if let Some(column_to_map) = column_name {
+                Some(column_to_map.item().clone())
+            } else {
+                None
+            };
+
+            match map_max(&values[0], map_by_column, name) {
+                Ok(table_maxed) => yield ReturnSuccess::value(table_maxed),
+                Err(err) => yield Err(err)
+            }
+        }
+    };
+
+    Ok(stream.to_output_stream())
+}

crates/nu-cli/src/commands/mkdir.rs

@@ -0,0 +1,45 @@
+use crate::commands::command::RunnablePerItemContext;
+use crate::context::CommandRegistry;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{CallInfo, Signature, SyntaxShape, Value};
+use nu_source::Tagged;
+use std::path::PathBuf;
+
+pub struct Mkdir;
+
+#[derive(Deserialize)]
+pub struct MkdirArgs {
+    pub rest: Vec<Tagged<PathBuf>>,
+}
+
+impl PerItemCommand for Mkdir {
+    fn name(&self) -> &str {
+        "mkdir"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("mkdir").rest(SyntaxShape::Path, "the name(s) of the path(s) to create")
+    }
+
+    fn usage(&self) -> &str {
+        "Make directories, creates intermediary directories as required."
+    }
+
+    fn run(
+        &self,
+        call_info: &CallInfo,
+        _registry: &CommandRegistry,
+        raw_args: &RawCommandArgs,
+        _input: Value,
+    ) -> Result<OutputStream, ShellError> {
+        call_info
+            .process(&raw_args.shell_manager, raw_args.ctrl_c.clone(), mkdir)?
+            .run()
+    }
+}
+
+fn mkdir(args: MkdirArgs, context: &RunnablePerItemContext) -> Result<OutputStream, ShellError> {
+    let shell_manager = context.shell_manager.clone();
+    shell_manager.mkdir(args, context)
+}

crates/nu-cli/src/commands/mv.rs

@@ -0,0 +1,56 @@
+use crate::commands::command::RunnablePerItemContext;
+use crate::context::CommandRegistry;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{CallInfo, Signature, SyntaxShape, Value};
+use nu_source::Tagged;
+use std::path::PathBuf;
+
+pub struct Move;
+
+#[derive(Deserialize)]
+pub struct MoveArgs {
+    pub src: Tagged<PathBuf>,
+    pub dst: Tagged<PathBuf>,
+}
+
+impl PerItemCommand for Move {
+    fn name(&self) -> &str {
+        "mv"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("mv")
+            .required(
+                "source",
+                SyntaxShape::Pattern,
+                "the location to move files/directories from",
+            )
+            .required(
+                "destination",
+                SyntaxShape::Path,
+                "the location to move files/directories to",
+            )
+    }
+
+    fn usage(&self) -> &str {
+        "Move files or directories."
+    }
+
+    fn run(
+        &self,
+        call_info: &CallInfo,
+        _registry: &CommandRegistry,
+        raw_args: &RawCommandArgs,
+        _input: Value,
+    ) -> Result<OutputStream, ShellError> {
+        call_info
+            .process(&raw_args.shell_manager, raw_args.ctrl_c.clone(), mv)?
+            .run()
+    }
+}
+
+fn mv(args: MoveArgs, context: &RunnablePerItemContext) -> Result<OutputStream, ShellError> {
+    let shell_manager = context.shell_manager.clone();
+    shell_manager.mv(args, context)
+}

crates/nu-cli/src/commands/next.rs

@@ -1,19 +1,11 @@
-use crate::commands::command::CommandAction;
 use crate::commands::WholeStreamCommand;
-use crate::errors::ShellError;
 use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{CommandAction, ReturnSuccess, Signature};
 
 pub struct Next;
 
 impl WholeStreamCommand for Next {
-    fn run(
-        &self,
-        args: CommandArgs,
-        registry: &CommandRegistry,
-    ) -> Result<OutputStream, ShellError> {
-        next(args, registry)
-    }
-
     fn name(&self) -> &str {
         "n"
     }
@@ -21,6 +13,18 @@ impl WholeStreamCommand for Next {
     fn signature(&self) -> Signature {
         Signature::build("n")
     }
+
+    fn usage(&self) -> &str {
+        "Go to next shell."
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        next(args, registry)
+    }
 }
 
 fn next(_args: CommandArgs, _registry: &CommandRegistry) -> Result<OutputStream, ShellError> {

crates/nu-cli/src/commands/nth.rs

@@ -0,0 +1,76 @@
+use crate::commands::WholeStreamCommand;
+use crate::context::CommandRegistry;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{ReturnSuccess, Signature, SyntaxShape};
+use nu_source::Tagged;
+
+#[derive(Deserialize)]
+struct NthArgs {
+    row_number: Tagged<u64>,
+    rest: Vec<Tagged<u64>>,
+}
+
+pub struct Nth;
+
+impl WholeStreamCommand for Nth {
+    fn name(&self) -> &str {
+        "nth"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("nth")
+            .required(
+                "row number",
+                SyntaxShape::Any,
+                "the number of the row to return",
+            )
+            .rest(SyntaxShape::Any, "Optionally return more rows")
+    }
+
+    fn usage(&self) -> &str {
+        "Return only the selected rows"
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        args.process(registry, nth)?.run()
+    }
+}
+
+fn nth(
+    NthArgs {
+        row_number,
+        rest: and_rows,
+    }: NthArgs,
+    RunnableContext { input, .. }: RunnableContext,
+) -> Result<OutputStream, ShellError> {
+    let stream = input
+        .values
+        .enumerate()
+        .map(move |(idx, item)| {
+            let row_number = vec![row_number.clone()];
+
+            let row_numbers = vec![&row_number, &and_rows]
+                .into_iter()
+                .flatten()
+                .collect::<Vec<&Tagged<u64>>>();
+
+            let mut result = VecDeque::new();
+
+            if row_numbers
+                .iter()
+                .any(|requested| requested.item == idx as u64)
+            {
+                result.push_back(ReturnSuccess::value(item));
+            }
+
+            futures::stream::iter(result)
+        })
+        .flatten();
+
+    Ok(stream.to_output_stream())
+}

crates/nu-cli/src/commands/open.rs

@@ -0,0 +1,254 @@
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{
+    CallInfo, CommandAction, ReturnSuccess, Signature, SyntaxShape, UntaggedValue, Value,
+};
+use nu_source::{AnchorLocation, Span};
+use std::path::{Path, PathBuf};
+
+pub struct Open;
+
+impl PerItemCommand for Open {
+    fn name(&self) -> &str {
+        "open"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build(self.name())
+            .required(
+                "path",
+                SyntaxShape::Path,
+                "the file path to load values from",
+            )
+            .switch(
+                "raw",
+                "load content as a string instead of a table",
+                Some('r'),
+            )
+    }
+
+    fn usage(&self) -> &str {
+        "Load a file into a cell, convert to table if possible (avoid by appending '--raw')"
+    }
+
+    fn run(
+        &self,
+        call_info: &CallInfo,
+        _registry: &CommandRegistry,
+        raw_args: &RawCommandArgs,
+        _input: Value,
+    ) -> Result<OutputStream, ShellError> {
+        run(call_info, raw_args)
+    }
+}
+
+fn run(call_info: &CallInfo, raw_args: &RawCommandArgs) -> Result<OutputStream, ShellError> {
+    let shell_manager = &raw_args.shell_manager;
+    let cwd = PathBuf::from(shell_manager.path());
+    let full_path = cwd;
+
+    let path = call_info.args.nth(0).ok_or_else(|| {
+        ShellError::labeled_error(
+            "No file or directory specified",
+            "for command",
+            &call_info.name_tag,
+        )
+    })?;
+
+    let path_buf = path.as_path()?;
+    let path_str = path_buf.display().to_string();
+    let path_span = path.tag.span;
+    let has_raw = call_info.args.has("raw");
+
+    let stream = async_stream! {
+
+        let result = fetch(&full_path, &path_str, path_span).await;
+
+        if let Err(e) = result {
+            yield Err(e);
+            return;
+        }
+        let (file_extension, contents, contents_tag) = result?;
+
+        let file_extension = if has_raw {
+            None
+        } else {
+            // If the extension could not be determined via mimetype, try to use the path
+            // extension. Some file types do not declare their mimetypes (such as bson files).
+            file_extension.or(path_str.split('.').last().map(String::from))
+        };
+
+        let tagged_contents = contents.into_value(&contents_tag);
+
+        if let Some(extension) = file_extension {
+            yield Ok(ReturnSuccess::Action(CommandAction::AutoConvert(tagged_contents, extension)))
+        } else {
+            yield ReturnSuccess::value(tagged_contents);
+        }
+    };
+
+    Ok(stream.to_output_stream())
+}
+
+pub async fn fetch(
+    cwd: &PathBuf,
+    location: &str,
+    span: Span,
+) -> Result<(Option<String>, UntaggedValue, Tag), ShellError> {
+    let mut cwd = cwd.clone();
+
+    cwd.push(Path::new(location));
+    if let Ok(cwd) = dunce::canonicalize(cwd) {
+        match std::fs::read(&cwd) {
+            Ok(bytes) => match std::str::from_utf8(&bytes) {
+                Ok(s) => Ok((
+                    cwd.extension()
+                        .map(|name| name.to_string_lossy().to_string()),
+                    UntaggedValue::string(s),
+                    Tag {
+                        span,
+                        anchor: Some(AnchorLocation::File(cwd.to_string_lossy().to_string())),
+                    },
+                )),
+                Err(_) => {
+                    //Non utf8 data.
+                    match (bytes.get(0), bytes.get(1)) {
+                        (Some(x), Some(y)) if *x == 0xff && *y == 0xfe => {
+                            // Possibly UTF-16 little endian
+                            let utf16 = read_le_u16(&bytes[2..]);
+
+                            if let Some(utf16) = utf16 {
+                                match std::string::String::from_utf16(&utf16) {
+                                    Ok(s) => Ok((
+                                        cwd.extension()
+                                            .map(|name| name.to_string_lossy().to_string()),
+                                        UntaggedValue::string(s),
+                                        Tag {
+                                            span,
+                                            anchor: Some(AnchorLocation::File(
+                                                cwd.to_string_lossy().to_string(),
+                                            )),
+                                        },
+                                    )),
+                                    Err(_) => Ok((
+                                        None,
+                                        UntaggedValue::binary(bytes),
+                                        Tag {
+                                            span,
+                                            anchor: Some(AnchorLocation::File(
+                                                cwd.to_string_lossy().to_string(),
+                                            )),
+                                        },
+                                    )),
+                                }
+                            } else {
+                                Ok((
+                                    None,
+                                    UntaggedValue::binary(bytes),
+                                    Tag {
+                                        span,
+                                        anchor: Some(AnchorLocation::File(
+                                            cwd.to_string_lossy().to_string(),
+                                        )),
+                                    },
+                                ))
+                            }
+                        }
+                        (Some(x), Some(y)) if *x == 0xfe && *y == 0xff => {
+                            // Possibly UTF-16 big endian
+                            let utf16 = read_be_u16(&bytes[2..]);
+
+                            if let Some(utf16) = utf16 {
+                                match std::string::String::from_utf16(&utf16) {
+                                    Ok(s) => Ok((
+                                        cwd.extension()
+                                            .map(|name| name.to_string_lossy().to_string()),
+                                        UntaggedValue::string(s),
+                                        Tag {
+                                            span,
+                                            anchor: Some(AnchorLocation::File(
+                                                cwd.to_string_lossy().to_string(),
+                                            )),
+                                        },
+                                    )),
+                                    Err(_) => Ok((
+                                        None,
+                                        UntaggedValue::binary(bytes),
+                                        Tag {
+                                            span,
+                                            anchor: Some(AnchorLocation::File(
+                                                cwd.to_string_lossy().to_string(),
+                                            )),
+                                        },
+                                    )),
+                                }
+                            } else {
+                                Ok((
+                                    None,
+                                    UntaggedValue::binary(bytes),
+                                    Tag {
+                                        span,
+                                        anchor: Some(AnchorLocation::File(
+                                            cwd.to_string_lossy().to_string(),
+                                        )),
+                                    },
+                                ))
+                            }
+                        }
+                        _ => Ok((
+                            None,
+                            UntaggedValue::binary(bytes),
+                            Tag {
+                                span,
+                                anchor: Some(AnchorLocation::File(
+                                    cwd.to_string_lossy().to_string(),
+                                )),
+                            },
+                        )),
+                    }
+                }
+            },
+            Err(_) => Err(ShellError::labeled_error(
+                "File could not be opened",
+                "file not found",
+                span,
+            )),
+        }
+    } else {
+        Err(ShellError::labeled_error(
+            "File could not be opened",
+            "file not found",
+            span,
+        ))
+    }
+}
+
+fn read_le_u16(input: &[u8]) -> Option<Vec<u16>> {
+    if input.len() % 2 != 0 || input.len() < 2 {
+        None
+    } else {
+        let mut result = vec![];
+        let mut pos = 0;
+        while pos < input.len() {
+            result.push(u16::from_le_bytes([input[pos], input[pos + 1]]));
+            pos += 2;
+        }
+
+        Some(result)
+    }
+}
+
+fn read_be_u16(input: &[u8]) -> Option<Vec<u16>> {
+    if input.len() % 2 != 0 || input.len() < 2 {
+        None
+    } else {
+        let mut result = vec![];
+        let mut pos = 0;
+        while pos < input.len() {
+            result.push(u16::from_be_bytes([input[pos], input[pos + 1]]));
+            pos += 2;
+        }
+
+        Some(result)
+    }
+}

crates/nu-cli/src/commands/parse.rs

@@ -0,0 +1,141 @@
+use crate::commands::PerItemCommand;
+use crate::context::CommandRegistry;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{
+    CallInfo, ReturnSuccess, Signature, SyntaxShape, TaggedDictBuilder, UntaggedValue, Value,
+};
+
+use nom::{
+    bytes::complete::{tag, take_while},
+    IResult,
+};
+use regex::Regex;
+
+#[derive(Debug)]
+enum ParseCommand {
+    Text(String),
+    Column(String),
+}
+
+fn parse(input: &str) -> IResult<&str, Vec<ParseCommand>> {
+    let mut output = vec![];
+
+    let mut loop_input = input;
+    loop {
+        let (input, before) = take_while(|c| c != '{')(loop_input)?;
+        if !before.is_empty() {
+            output.push(ParseCommand::Text(before.to_string()));
+        }
+        if input != "" {
+            // Look for column as we're now at one
+            let (input, _) = tag("{")(input)?;
+            let (input, column) = take_while(|c| c != '}')(input)?;
+            let (input, _) = tag("}")(input)?;
+
+            output.push(ParseCommand::Column(column.to_string()));
+            loop_input = input;
+        } else {
+            loop_input = input;
+        }
+        if loop_input == "" {
+            break;
+        }
+    }
+
+    Ok((loop_input, output))
+}
+
+fn column_names(commands: &[ParseCommand]) -> Vec<String> {
+    let mut output = vec![];
+
+    for command in commands {
+        if let ParseCommand::Column(c) = command {
+            output.push(c.clone());
+        }
+    }
+
+    output
+}
+
+fn build_regex(commands: &[ParseCommand]) -> String {
+    let mut output = String::new();
+
+    for command in commands {
+        match command {
+            ParseCommand::Text(s) => {
+                output.push_str(&s.replace("(", "\\("));
+            }
+            ParseCommand::Column(_) => {
+                output.push_str("(.*)");
+            }
+        }
+    }
+
+    output
+}
+pub struct Parse;
+
+impl PerItemCommand for Parse {
+    fn name(&self) -> &str {
+        "parse"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("parse").required(
+            "pattern",
+            SyntaxShape::Any,
+            "the pattern to match. Eg) \"{foo}: {bar}\"",
+        )
+    }
+
+    fn usage(&self) -> &str {
+        "Parse columns from string data using a simple pattern."
+    }
+
+    fn run(
+        &self,
+        call_info: &CallInfo,
+        _registry: &CommandRegistry,
+        _raw_args: &RawCommandArgs,
+        value: Value,
+    ) -> Result<OutputStream, ShellError> {
+        //let value_tag = value.tag();
+        let pattern = call_info.args.expect_nth(0)?.as_string()?;
+
+        let parse_pattern = parse(&pattern).map_err(|_| {
+            ShellError::labeled_error(
+                "Could not create parse pattern",
+                "could not create parse pattern",
+                &value.tag,
+            )
+        })?;
+        let parse_regex = build_regex(&parse_pattern.1);
+
+        let column_names = column_names(&parse_pattern.1);
+        let regex = Regex::new(&parse_regex).map_err(|_| {
+            ShellError::labeled_error("Could not parse regex", "could not parse regex", &value.tag)
+        })?;
+
+        let output = if let Ok(s) = value.as_string() {
+            let mut results = vec![];
+            for cap in regex.captures_iter(&s) {
+                let mut dict = TaggedDictBuilder::new(value.tag());
+
+                for (idx, column_name) in column_names.iter().enumerate() {
+                    dict.insert_untagged(
+                        column_name,
+                        UntaggedValue::string(&cap[idx + 1].to_string()),
+                    );
+                }
+
+                results.push(ReturnSuccess::value(dict.into_value()));
+            }
+
+            VecDeque::from(results)
+        } else {
+            VecDeque::new()
+        };
+        Ok(output.into())
+    }
+}

crates/nu-cli/src/commands/pick.rs

@@ -0,0 +1,167 @@
+use crate::commands::WholeStreamCommand;
+use crate::context::CommandRegistry;
+use crate::prelude::*;
+use futures_util::pin_mut;
+use nu_errors::ShellError;
+use nu_protocol::{
+    ColumnPath, PathMember, Primitive, ReturnSuccess, ReturnValue, Signature, SyntaxShape,
+    TaggedDictBuilder, UnspannedPathMember, UntaggedValue, Value,
+};
+use nu_source::span_for_spanned_list;
+use nu_value_ext::{as_string, get_data_by_column_path};
+
+#[derive(Deserialize)]
+struct PickArgs {
+    rest: Vec<ColumnPath>,
+}
+
+pub struct Pick;
+
+impl WholeStreamCommand for Pick {
+    fn name(&self) -> &str {
+        "pick"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("pick").rest(
+            SyntaxShape::ColumnPath,
+            "the columns to select from the table",
+        )
+    }
+
+    fn usage(&self) -> &str {
+        "Down-select table to only these columns."
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        args.process(registry, pick)?.run()
+    }
+}
+
+fn pick(
+    PickArgs { rest: mut fields }: PickArgs,
+    RunnableContext { input, name, .. }: RunnableContext,
+) -> Result<OutputStream, ShellError> {
+    if fields.is_empty() {
+        return Err(ShellError::labeled_error(
+            "Pick requires columns to pick",
+            "needs parameter",
+            name,
+        ));
+    }
+
+    let member = fields.remove(0);
+    let member = vec![member];
+
+    let column_paths = vec![&member, &fields]
+        .into_iter()
+        .flatten()
+        .cloned()
+        .collect::<Vec<ColumnPath>>();
+
+    let stream = async_stream! {
+        let values = input.values;
+        pin_mut!(values);
+
+        let mut empty = true;
+        let mut bring_back: indexmap::IndexMap<String, Vec<Value>> = indexmap::IndexMap::new();
+
+        while let Some(value) = values.next().await {
+            for path in &column_paths {
+                let path_members_span = span_for_spanned_list(path.members().iter().map(|p| p.span));
+
+                let fetcher = get_data_by_column_path(&value, &path, Box::new(move |(obj_source, path_member_tried, error)| {
+                    if let PathMember { unspanned: UnspannedPathMember::String(column), .. } = path_member_tried {
+                        return ShellError::labeled_error_with_secondary(
+                        "No data to fetch.",
+                        format!("Couldn't pick column \"{}\"", column),
+                        path_member_tried.span,
+                        format!("How about exploring it with \"get\"? Check the input is appropriate originating from here"),
+                        obj_source.tag.span)
+                    }
+
+                    error
+                }));
+
+
+                let field = path.clone();
+                let key = as_string(&UntaggedValue::Primitive(Primitive::ColumnPath(field.clone())).into_untagged_value())?;
+
+                match fetcher {
+                    Ok(results) => {
+                        match results.value {
+                            UntaggedValue::Table(records) => {
+                                for x in records {
+                                    let mut out = TaggedDictBuilder::new(name.clone());
+                                    out.insert_untagged(&key, x.value.clone());
+                                    let group = bring_back.entry(key.clone()).or_insert(vec![]);
+                                    group.push(out.into_value());
+                                }
+                            },
+                            x => {
+                                let mut out = TaggedDictBuilder::new(name.clone());
+                                out.insert_untagged(&key, x.clone());
+                                let group = bring_back.entry(key.clone()).or_insert(vec![]);
+                                group.push(out.into_value());
+                            }
+
+                        }
+                    }
+                    Err(reason) => {
+                        // At the moment, we can't add switches, named flags
+                        // and the like while already using .rest since it
+                        // breaks the parser.
+                        //
+                        // We allow flexibility for now and skip the error
+                        // if a given column isn't present.
+                        let strict: Option<bool> = None;
+
+                        if strict.is_some() {
+                            yield Err(reason);
+                            return;
+                        }
+
+                        bring_back.entry(key.clone()).or_insert(vec![]);
+                    }
+                }
+            }
+        }
+
+        let mut max = 0;
+
+        if let Some(max_column) = bring_back.values().max() {
+            max = max_column.len();
+        }
+
+        let keys = bring_back.keys().map(|x| x.clone()).collect::<Vec<String>>();
+
+        for mut current in 0..max  {
+            let mut out = TaggedDictBuilder::new(name.clone());
+
+            for k in &keys {
+                let nothing = UntaggedValue::Primitive(Primitive::Nothing).into_untagged_value();
+                let subsets = bring_back.get(k);
+
+                match subsets {
+                    Some(set) => {
+                        match set.get(current) {
+                            Some(row) => out.insert_untagged(k, row.get_data(k).borrow().clone()),
+                            None => out.insert_untagged(k, nothing.clone()),
+                        }
+                    }
+                    None => out.insert_untagged(k, nothing.clone()),
+                }
+            }
+
+            yield ReturnSuccess::value(out.into_value());
+        }
+    };
+
+    let stream: BoxStream<'static, ReturnValue> = stream.boxed();
+
+    Ok(stream.to_output_stream())
+}

crates/nu-cli/src/commands/pivot.rs

@@ -0,0 +1,136 @@
+use crate::commands::WholeStreamCommand;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{
+    merge_descriptors, ReturnSuccess, Signature, SyntaxShape, TaggedDictBuilder, UntaggedValue,
+};
+use nu_source::{SpannedItem, Tagged};
+use nu_value_ext::get_data_by_key;
+
+pub struct Pivot;
+
+#[derive(Deserialize)]
+pub struct PivotArgs {
+    rest: Vec<Tagged<String>>,
+    #[serde(rename(deserialize = "header-row"))]
+    header_row: bool,
+    #[serde(rename(deserialize = "ignore-titles"))]
+    ignore_titles: bool,
+}
+
+impl WholeStreamCommand for Pivot {
+    fn name(&self) -> &str {
+        "pivot"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("pivot")
+            .switch(
+                "header-row",
+                "treat the first row as column names",
+                Some('r'),
+            )
+            .switch(
+                "ignore-titles",
+                "don't pivot the column names into values",
+                Some('i'),
+            )
+            .rest(
+                SyntaxShape::String,
+                "the names to give columns once pivoted",
+            )
+    }
+
+    fn usage(&self) -> &str {
+        "Pivots the table contents so rows become columns and columns become rows."
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        args.process(registry, pivot)?.run()
+    }
+}
+
+pub fn pivot(args: PivotArgs, context: RunnableContext) -> Result<OutputStream, ShellError> {
+    let stream = async_stream! {
+        let input = context.input.into_vec().await;
+
+        let descs = merge_descriptors(&input);
+
+        let mut headers: Vec<String> = vec![];
+
+        if args.rest.len() > 0 && args.header_row {
+            yield Err(ShellError::labeled_error("Can not provide header names and use header row", "using header row", context.name));
+            return;
+        }
+
+        if args.header_row {
+            for i in input.clone() {
+                if let Some(desc) = descs.get(0) {
+                    match get_data_by_key(&i, desc[..].spanned_unknown()) {
+                        Some(x) => {
+                            if let Ok(s) = x.as_string() {
+                                headers.push(s.to_string());
+                            } else {
+                                yield Err(ShellError::labeled_error("Header row needs string headers", "used non-string headers", context.name));
+                                return;
+                            }
+                        }
+                        _ => {
+                            yield Err(ShellError::labeled_error("Header row is incomplete and can't be used", "using incomplete header row", context.name));
+                            return;
+                        }
+                    }
+                } else {
+                    yield Err(ShellError::labeled_error("Header row is incomplete and can't be used", "using incomplete header row", context.name));
+                    return;
+                }
+            }
+        } else {
+            for i in 0..=input.len() {
+                if let Some(name) = args.rest.get(i) {
+                    headers.push(name.to_string())
+                } else {
+                    headers.push(format!("Column{}", i));
+                }
+            }
+        }
+
+        let descs: Vec<_> = if args.header_row {
+            descs.iter().skip(1).collect()
+        } else {
+            descs.iter().collect()
+        };
+
+        for desc in descs {
+            let mut column_num: usize = 0;
+            let mut dict = TaggedDictBuilder::new(&context.name);
+
+            if !args.ignore_titles && !args.header_row {
+                dict.insert_untagged(headers[column_num].clone(), UntaggedValue::string(desc.clone()));
+                column_num += 1
+            }
+
+            for i in input.clone() {
+                match get_data_by_key(&i, desc[..].spanned_unknown()) {
+                    Some(x) => {
+                        dict.insert_value(headers[column_num].clone(), x.clone());
+                    }
+                    _ => {
+                        dict.insert_untagged(headers[column_num].clone(), UntaggedValue::nothing());
+                    }
+                }
+                column_num += 1;
+            }
+
+            yield ReturnSuccess::value(dict.into_value());
+        }
+
+
+    };
+
+    Ok(OutputStream::new(stream))
+}

crates/nu-cli/src/commands/plugin.rs

@@ -1,8 +1,9 @@
 use crate::commands::WholeStreamCommand;
-use crate::errors::ShellError;
-use crate::parser::registry;
 use crate::prelude::*;
 use derive_new::new;
+use log::trace;
+use nu_errors::ShellError;
+use nu_protocol::{Primitive, ReturnSuccess, ReturnValue, Scope, Signature, UntaggedValue, Value};
 use serde::{self, Deserialize, Serialize};
 use std::io::prelude::*;
 use std::io::BufReader;
@@ -38,7 +39,7 @@ pub enum NuResult {
 pub struct PluginCommand {
     name: String,
     path: String,
-    config: registry::Signature,
+    config: Signature,
 }
 
 impl WholeStreamCommand for PluginCommand {
@@ -46,10 +47,14 @@ impl WholeStreamCommand for PluginCommand {
         &self.name
     }
 
-    fn signature(&self) -> registry::Signature {
+    fn signature(&self) -> Signature {
         self.config.clone()
     }
 
+    fn usage(&self) -> &str {
+        &self.config.usage
+    }
+
     fn run(
         &self,
         args: CommandArgs,
@@ -64,7 +69,12 @@ pub fn filter_plugin(
     args: CommandArgs,
     registry: &CommandRegistry,
 ) -> Result<OutputStream, ShellError> {
-    let args = args.evaluate_once(registry)?;
+    trace!("filter_plugin :: {}", path);
+
+    let args = args.evaluate_once_with_scope(
+        registry,
+        &Scope::it_value(UntaggedValue::string("$it").into_untagged_value()),
+    )?;
 
     let mut child = std::process::Command::new(path)
         .stdin(std::process::Stdio::piped())
@@ -72,20 +82,24 @@ pub fn filter_plugin(
         .spawn()
         .expect("Failed to spawn child process");
 
-    let mut bos: VecDeque<Tagged<Value>> = VecDeque::new();
-    bos.push_back(Value::Primitive(Primitive::BeginningOfStream).tagged_unknown());
+    let mut bos: VecDeque<Value> = VecDeque::new();
+    bos.push_back(UntaggedValue::Primitive(Primitive::BeginningOfStream).into_untagged_value());
+    let bos = futures::stream::iter(bos);
 
-    let mut eos: VecDeque<Tagged<Value>> = VecDeque::new();
-    eos.push_back(Value::Primitive(Primitive::EndOfStream).tagged_unknown());
+    let mut eos: VecDeque<Value> = VecDeque::new();
+    eos.push_back(UntaggedValue::Primitive(Primitive::EndOfStream).into_untagged_value());
+    let eos = futures::stream::iter(eos);
 
     let call_info = args.call_info.clone();
 
+    trace!("filtering :: {:?}", call_info);
+
     let stream = bos
         .chain(args.input.values)
         .chain(eos)
         .map(move |v| match v {
-            Tagged {
-                item: Value::Primitive(Primitive::BeginningOfStream),
+            Value {
+                value: UntaggedValue::Primitive(Primitive::BeginningOfStream),
                 ..
             } => {
                 let stdin = child.stdin.as_mut().expect("Failed to open stdin");
@@ -94,8 +108,27 @@ pub fn filter_plugin(
                 let mut reader = BufReader::new(stdout);
 
                 let request = JsonRpc::new("begin_filter", call_info.clone());
-                let request_raw = serde_json::to_string(&request).unwrap();
-                let _ = stdin.write(format!("{}\n", request_raw).as_bytes()); // TODO: Handle error
+                let request_raw = serde_json::to_string(&request);
+
+                match request_raw {
+                    Err(_) => {
+                        let mut result = VecDeque::new();
+                        result.push_back(Err(ShellError::labeled_error(
+                            "Could not load json from plugin",
+                            "could not load json from plugin",
+                            &call_info.name_tag,
+                        )));
+                        return result;
+                    }
+                    Ok(request_raw) => match stdin.write(format!("{}\n", request_raw).as_bytes()) {
+                        Ok(_) => {}
+                        Err(err) => {
+                            let mut result = VecDeque::new();
+                            result.push_back(Err(ShellError::unexpected(format!("{}", err))));
+                            return result;
+                        }
+                    },
+                }
 
                 let mut input = String::new();
                 match reader.read_line(&mut input) {
@@ -112,7 +145,7 @@ pub fn filter_plugin(
                             },
                             Err(e) => {
                                 let mut result = VecDeque::new();
-                                result.push_back(Err(ShellError::string(format!(
+                                result.push_back(Err(ShellError::untagged_runtime_error(format!(
                                     "Error while processing begin_filter response: {:?} {}",
                                     e, input
                                 ))));
@@ -122,7 +155,7 @@ pub fn filter_plugin(
                     }
                     Err(e) => {
                         let mut result = VecDeque::new();
-                        result.push_back(Err(ShellError::string(format!(
+                        result.push_back(Err(ShellError::untagged_runtime_error(format!(
                             "Error while reading begin_filter response: {:?}",
                             e
                         ))));
@@ -130,8 +163,8 @@ pub fn filter_plugin(
                     }
                 }
             }
-            Tagged {
-                item: Value::Primitive(Primitive::EndOfStream),
+            Value {
+                value: UntaggedValue::Primitive(Primitive::EndOfStream),
                 ..
             } => {
                 let stdin = child.stdin.as_mut().expect("Failed to open stdin");
@@ -140,11 +173,19 @@ pub fn filter_plugin(
                 let mut reader = BufReader::new(stdout);
 
                 let request: JsonRpc<std::vec::Vec<Value>> = JsonRpc::new("end_filter", vec![]);
-                let request_raw = serde_json::to_string(&request).unwrap();
+                let request_raw = match serde_json::to_string(&request) {
+                    Ok(req) => req,
+                    Err(err) => {
+                        let mut result = VecDeque::new();
+                        result.push_back(Err(ShellError::unexpected(format!("{}", err))));
+                        return result;
+                    }
+                };
+
                 let _ = stdin.write(format!("{}\n", request_raw).as_bytes()); // TODO: Handle error
 
                 let mut input = String::new();
-                match reader.read_line(&mut input) {
+                let result = match reader.read_line(&mut input) {
                     Ok(_) => {
                         let response = serde_json::from_str::<NuResult>(&input);
                         match response {
@@ -152,8 +193,20 @@ pub fn filter_plugin(
                                 Ok(params) => {
                                     let request: JsonRpc<std::vec::Vec<Value>> =
                                         JsonRpc::new("quit", vec![]);
-                                    let request_raw = serde_json::to_string(&request).unwrap();
+                                    let request_raw = serde_json::to_string(&request);
+                                    match request_raw {
+                                        Ok(request_raw) => {
                                             let _ = stdin.write(format!("{}\n", request_raw).as_bytes()); // TODO: Handle error
+                                        }
+                                        Err(e) => {
+                                            let mut result = VecDeque::new();
+                                            result.push_back(Err(ShellError::untagged_runtime_error(format!(
+                                                "Error while processing begin_filter response: {:?} {}",
+                                                e, input
+                                            ))));
+                                            return result;
+                                        }
+                                    }
 
                                     params
                                 }
@@ -165,7 +218,7 @@ pub fn filter_plugin(
                             },
                             Err(e) => {
                                 let mut result = VecDeque::new();
-                                result.push_back(Err(ShellError::string(format!(
+                                result.push_back(Err(ShellError::untagged_runtime_error(format!(
                                     "Error while processing end_filter response: {:?} {}",
                                     e, input
                                 ))));
@@ -175,13 +228,17 @@ pub fn filter_plugin(
                     }
                     Err(e) => {
                         let mut result = VecDeque::new();
-                        result.push_back(Err(ShellError::string(format!(
+                        result.push_back(Err(ShellError::untagged_runtime_error(format!(
                             "Error while reading end_filter: {:?}",
                             e
                         ))));
                         result
                     }
-                }
+                };
+
+                let _ = child.wait();
+
+                result
             }
             _ => {
                 let stdin = child.stdin.as_mut().expect("Failed to open stdin");
@@ -190,8 +247,20 @@ pub fn filter_plugin(
                 let mut reader = BufReader::new(stdout);
 
                 let request = JsonRpc::new("filter", v);
-                let request_raw = serde_json::to_string(&request).unwrap();
+                let request_raw = serde_json::to_string(&request);
+                match request_raw {
+                    Ok(request_raw) => {
                         let _ = stdin.write(format!("{}\n", request_raw).as_bytes()); // TODO: Handle error
+                    }
+                    Err(e) => {
+                        let mut result = VecDeque::new();
+                        result.push_back(Err(ShellError::untagged_runtime_error(format!(
+                            "Error while processing filter response: {:?}",
+                            e
+                        ))));
+                        return result;
+                    }
+                }
 
                 let mut input = String::new();
                 match reader.read_line(&mut input) {
@@ -208,8 +277,8 @@ pub fn filter_plugin(
                             },
                             Err(e) => {
                                 let mut result = VecDeque::new();
-                                result.push_back(Err(ShellError::string(format!(
-                                    "Error while processing filter response: {:?} {}",
+                                result.push_back(Err(ShellError::untagged_runtime_error(format!(
+                                    "Error while processing filter response: {:?}\n== input ==\n{}",
                                     e, input
                                 ))));
                                 result
@@ -218,7 +287,7 @@ pub fn filter_plugin(
                     }
                     Err(e) => {
                         let mut result = VecDeque::new();
-                        result.push_back(Err(ShellError::string(format!(
+                        result.push_back(Err(ShellError::untagged_runtime_error(format!(
                             "Error while reading filter response: {:?}",
                             e
                         ))));
@@ -227,6 +296,7 @@ pub fn filter_plugin(
                 }
             }
         })
+        .map(futures::stream::iter) // convert to a stream
         .flatten();
 
     Ok(stream.to_output_stream())
@@ -236,7 +306,7 @@ pub fn filter_plugin(
 pub struct PluginSink {
     name: String,
     path: String,
-    config: registry::Signature,
+    config: Signature,
 }
 
 impl WholeStreamCommand for PluginSink {
@@ -244,10 +314,14 @@ impl WholeStreamCommand for PluginSink {
         &self.name
     }
 
-    fn signature(&self) -> registry::Signature {
+    fn signature(&self) -> Signature {
         self.config.clone()
     }
 
+    fn usage(&self) -> &str {
+        &self.config.usage
+    }
+
     fn run(
         &self,
         args: CommandArgs,
@@ -262,25 +336,39 @@ pub fn sink_plugin(
     args: CommandArgs,
     registry: &CommandRegistry,
 ) -> Result<OutputStream, ShellError> {
-    //use subprocess::Exec;
     let args = args.evaluate_once(registry)?;
     let call_info = args.call_info.clone();
 
-    let stream = async_stream_block! {
-        let input: Vec<Tagged<Value>> = args.input.values.collect().await;
+    let stream = async_stream! {
+        let input: Vec<Value> = args.input.values.collect().await;
 
         let request = JsonRpc::new("sink", (call_info.clone(), input));
-        let request_raw = serde_json::to_string(&request).unwrap();
-        let mut tmpfile = tempfile::NamedTempFile::new().unwrap();
+        let request_raw = serde_json::to_string(&request);
+        if let Ok(request_raw) = request_raw {
+            if let Ok(mut tmpfile) = tempfile::NamedTempFile::new() {
                 let _ = writeln!(tmpfile, "{}", request_raw);
                 let _ = tmpfile.flush();
 
                 let mut child = std::process::Command::new(path)
                     .arg(tmpfile.path())
-            .spawn()
-            .expect("Failed to spawn child process");
+                    .spawn();
 
+                if let Ok(mut child) = child {
                     let _ = child.wait();
+
+                    // Needed for async_stream to type check
+                    if false {
+                        yield ReturnSuccess::value(UntaggedValue::nothing().into_untagged_value());
+                    }
+                } else {
+                    yield Err(ShellError::untagged_runtime_error("Could not create process for sink command"));
+                }
+            } else {
+                yield Err(ShellError::untagged_runtime_error("Could not open file to send sink command message"));
+            }
+        } else {
+            yield Err(ShellError::untagged_runtime_error("Could not create message to sink command"));
+        }
     };
     Ok(OutputStream::new(stream))
 }

crates/nu-cli/src/commands/prepend.rs

@@ -0,0 +1,47 @@
+use crate::commands::WholeStreamCommand;
+use crate::context::CommandRegistry;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{Signature, SyntaxShape, Value};
+
+#[derive(Deserialize)]
+struct PrependArgs {
+    row: Value,
+}
+
+pub struct Prepend;
+
+impl WholeStreamCommand for Prepend {
+    fn name(&self) -> &str {
+        "prepend"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("prepend").required(
+            "row value",
+            SyntaxShape::Any,
+            "the value of the row to prepend to the table",
+        )
+    }
+
+    fn usage(&self) -> &str {
+        "Prepend the given row to the front of the table"
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        args.process(registry, prepend)?.run()
+    }
+}
+
+fn prepend(
+    PrependArgs { row }: PrependArgs,
+    RunnableContext { input, .. }: RunnableContext,
+) -> Result<OutputStream, ShellError> {
+    let prepend = futures::stream::iter(vec![row]);
+
+    Ok(OutputStream::from_input(prepend.chain(input.values)))
+}

crates/nu-cli/src/commands/prev.rs

@@ -1,20 +1,12 @@
-use crate::commands::command::CommandAction;
-use crate::errors::ShellError;
 use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{CommandAction, ReturnSuccess, Signature};
 
 use crate::commands::WholeStreamCommand;
 
 pub struct Previous;
 
 impl WholeStreamCommand for Previous {
-    fn run(
-        &self,
-        args: CommandArgs,
-        registry: &CommandRegistry,
-    ) -> Result<OutputStream, ShellError> {
-        previous(args, registry)
-    }
-
     fn name(&self) -> &str {
         "p"
     }
@@ -22,6 +14,18 @@ impl WholeStreamCommand for Previous {
     fn signature(&self) -> Signature {
         Signature::build("p")
     }
+
+    fn usage(&self) -> &str {
+        "Go to previous shell."
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        previous(args, registry)
+    }
 }
 
 fn previous(_args: CommandArgs, _registry: &CommandRegistry) -> Result<OutputStream, ShellError> {

crates/nu-cli/src/commands/pwd.rs

@@ -1,29 +1,34 @@
 use crate::commands::WholeStreamCommand;
-use crate::errors::ShellError;
 use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::Signature;
 
-pub struct CD;
+pub struct Pwd;
+
+impl WholeStreamCommand for Pwd {
+    fn name(&self) -> &str {
+        "pwd"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("pwd")
+    }
+
+    fn usage(&self) -> &str {
+        "Output the current working directory."
+    }
 
-impl WholeStreamCommand for CD {
     fn run(
         &self,
         args: CommandArgs,
         registry: &CommandRegistry,
     ) -> Result<OutputStream, ShellError> {
-        cd(args, registry)
-    }
-
-    fn name(&self) -> &str {
-        "cd"
-    }
-
-    fn signature(&self) -> Signature {
-        Signature::build("cd").optional("directory", SyntaxType::Path)
+        pwd(args, registry)
     }
 }
 
-fn cd(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStream, ShellError> {
+pub fn pwd(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStream, ShellError> {
     let shell_manager = args.shell_manager.clone();
     let args = args.evaluate_once(registry)?;
-    shell_manager.cd(args)
+    shell_manager.pwd(args)
 }

crates/nu-cli/src/commands/range.rs

@@ -0,0 +1,56 @@
+use crate::commands::WholeStreamCommand;
+use crate::context::CommandRegistry;
+use crate::deserializer::NumericRange;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{Signature, SyntaxShape};
+use nu_source::Tagged;
+
+#[derive(Deserialize)]
+struct RangeArgs {
+    area: Tagged<NumericRange>,
+}
+
+pub struct Range;
+
+impl WholeStreamCommand for Range {
+    fn name(&self) -> &str {
+        "range"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("range").required(
+            "rows ",
+            SyntaxShape::Range,
+            "range of rows to return: Eg) 4..7 (=> from 4 to 7)",
+        )
+    }
+
+    fn usage(&self) -> &str {
+        "Return only the selected rows"
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        args.process(registry, range)?.run()
+    }
+}
+
+fn range(
+    RangeArgs { area }: RangeArgs,
+    RunnableContext { input, .. }: RunnableContext,
+) -> Result<OutputStream, ShellError> {
+    let range = area.item;
+    let (from, _) = range.from;
+    let (to, _) = range.to;
+
+    let from = *from as usize;
+    let to = *to as usize;
+
+    Ok(OutputStream::from_input(
+        input.values.skip(from).take(to - from + 1),
+    ))
+}

crates/nu-cli/src/commands/reduce_by.rs

@@ -0,0 +1,72 @@
+use crate::commands::WholeStreamCommand;
+use crate::prelude::*;
+use crate::utils::data_processing::reduce;
+use nu_errors::ShellError;
+use nu_protocol::{Primitive, ReturnSuccess, Signature, SyntaxShape, UntaggedValue, Value};
+use nu_source::Tagged;
+use num_traits::cast::ToPrimitive;
+
+pub struct ReduceBy;
+
+#[derive(Deserialize)]
+pub struct ReduceByArgs {
+    reduce_with: Option<Tagged<String>>,
+}
+
+impl WholeStreamCommand for ReduceBy {
+    fn name(&self) -> &str {
+        "reduce-by"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("reduce-by").named(
+            "reduce_with",
+            SyntaxShape::String,
+            "the command to reduce by with",
+            Some('w'),
+        )
+    }
+
+    fn usage(&self) -> &str {
+        "Creates a new table with the data from the tables rows reduced by the command given."
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        args.process(registry, reduce_by)?.run()
+    }
+}
+
+pub fn reduce_by(
+    ReduceByArgs { reduce_with }: ReduceByArgs,
+    RunnableContext { input, name, .. }: RunnableContext,
+) -> Result<OutputStream, ShellError> {
+    let stream = async_stream! {
+        let values: Vec<Value> = input.values.collect().await;
+
+        if values.is_empty() {
+            yield Err(ShellError::labeled_error(
+                    "Expected table from pipeline",
+                    "requires a table input",
+                    name
+                ))
+        } else {
+
+            let reduce_with = if let Some(reducer) = reduce_with {
+                Some(reducer.item().clone())
+            } else {
+                None
+            };
+
+            match reduce(&values[0], reduce_with, name) {
+                Ok(reduced) => yield ReturnSuccess::value(reduced),
+                Err(err) => yield Err(err)
+            }
+        }
+    };
+
+    Ok(stream.to_output_stream())
+}

crates/nu-cli/src/commands/reject.rs

@@ -1,7 +1,9 @@
 use crate::commands::WholeStreamCommand;
-use crate::errors::ShellError;
-use crate::object::base::reject_fields;
+use crate::data::base::reject_fields;
 use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{Signature, SyntaxShape};
+use nu_source::Tagged;
 
 #[derive(Deserialize)]
 pub struct RejectArgs {
@@ -11,6 +13,18 @@ pub struct RejectArgs {
 pub struct Reject;
 
 impl WholeStreamCommand for Reject {
+    fn name(&self) -> &str {
+        "reject"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("reject").rest(SyntaxShape::Member, "the names of columns to remove")
+    }
+
+    fn usage(&self) -> &str {
+        "Remove the given columns from the table."
+    }
+
     fn run(
         &self,
         args: CommandArgs,
@@ -18,21 +32,13 @@ impl WholeStreamCommand for Reject {
     ) -> Result<OutputStream, ShellError> {
         args.process(registry, reject)?.run()
     }
-
-    fn name(&self) -> &str {
-        "reject"
-    }
-
-    fn signature(&self) -> Signature {
-        Signature::build("reject").rest()
-    }
 }
 
 fn reject(
     RejectArgs { rest: fields }: RejectArgs,
     RunnableContext { input, name, .. }: RunnableContext,
 ) -> Result<OutputStream, ShellError> {
-    if fields.len() == 0 {
+    if fields.is_empty() {
         return Err(ShellError::labeled_error(
             "Reject requires fields",
             "needs parameter",
@@ -44,7 +50,7 @@ fn reject(
 
     let stream = input
         .values
-        .map(move |item| reject_fields(&item, &fields, item.tag()).into_tagged_value());
+        .map(move |item| reject_fields(&item, &fields, &item.tag));
 
     Ok(stream.from_input_stream())
 }

crates/nu-cli/src/commands/rename.rs

@@ -0,0 +1,97 @@
+use crate::commands::WholeStreamCommand;
+use crate::prelude::*;
+use indexmap::IndexMap;
+use nu_errors::ShellError;
+use nu_protocol::{ReturnSuccess, Signature, SyntaxShape, UntaggedValue, Value};
+use nu_source::Tagged;
+
+pub struct Rename;
+
+#[derive(Deserialize)]
+pub struct Arguments {
+    column_name: Tagged<String>,
+    rest: Vec<Tagged<String>>,
+}
+
+impl WholeStreamCommand for Rename {
+    fn name(&self) -> &str {
+        "rename"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("rename")
+            .required(
+                "column_name",
+                SyntaxShape::String,
+                "the name of the column to rename for",
+            )
+            .rest(
+                SyntaxShape::Member,
+                "Additional column name(s) to rename for",
+            )
+    }
+
+    fn usage(&self) -> &str {
+        "Creates a new table with columns renamed."
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        args.process(registry, rename)?.run()
+    }
+}
+
+pub fn rename(
+    Arguments { column_name, rest }: Arguments,
+    RunnableContext { input, name, .. }: RunnableContext,
+) -> Result<OutputStream, ShellError> {
+    let mut new_column_names = vec![vec![column_name]];
+    new_column_names.push(rest);
+
+    let new_column_names = new_column_names.into_iter().flatten().collect::<Vec<_>>();
+
+    let stream = input
+        .values
+        .map(move |item| {
+            let mut result = VecDeque::new();
+
+            if let Value {
+                value: UntaggedValue::Row(row),
+                tag,
+            } = item
+            {
+                let mut renamed_row = IndexMap::new();
+
+                for (idx, (key, value)) in row.entries.iter().enumerate() {
+                    let key = if idx < new_column_names.len() {
+                        &new_column_names[idx].item
+                    } else {
+                        key
+                    };
+
+                    renamed_row.insert(key.clone(), value.clone());
+                }
+
+                let out = UntaggedValue::Row(renamed_row.into()).into_value(tag);
+
+                result.push_back(ReturnSuccess::value(out));
+            } else {
+                result.push_back(ReturnSuccess::value(
+                    UntaggedValue::Error(ShellError::labeled_error(
+                        "no column names available",
+                        "can't rename",
+                        &name,
+                    ))
+                    .into_untagged_value(),
+                ));
+            }
+
+            futures::stream::iter(result)
+        })
+        .flatten();
+
+    Ok(stream.to_output_stream())
+}

crates/nu-cli/src/commands/reverse.rs

@@ -0,0 +1,43 @@
+use crate::commands::WholeStreamCommand;
+use crate::context::CommandRegistry;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::Signature;
+
+pub struct Reverse;
+
+impl WholeStreamCommand for Reverse {
+    fn name(&self) -> &str {
+        "reverse"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("reverse")
+    }
+
+    fn usage(&self) -> &str {
+        "Reverses the table."
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        reverse(args, registry)
+    }
+}
+
+fn reverse(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStream, ShellError> {
+    let args = args.evaluate_once(registry)?;
+    let (input, _args) = args.parts();
+
+    let input = input.values.collect::<Vec<_>>();
+
+    let output = input.map(move |mut vec| {
+        vec.reverse();
+        futures::stream::iter(vec)
+    });
+
+    Ok(output.flatten_stream().from_input_stream())
+}

crates/nu-cli/src/commands/rm.rs

@@ -0,0 +1,54 @@
+use crate::commands::command::RunnablePerItemContext;
+use crate::context::CommandRegistry;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{CallInfo, Signature, SyntaxShape, Value};
+use nu_source::Tagged;
+use std::path::PathBuf;
+
+pub struct Remove;
+
+#[derive(Deserialize)]
+pub struct RemoveArgs {
+    pub rest: Vec<Tagged<PathBuf>>,
+    pub recursive: Tagged<bool>,
+    pub trash: Tagged<bool>,
+}
+
+impl PerItemCommand for Remove {
+    fn name(&self) -> &str {
+        "rm"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("rm")
+            .switch(
+                "trash",
+                "use the platform's recycle bin instead of permanently deleting",
+                Some('t'),
+            )
+            .switch("recursive", "delete subdirectories recursively", Some('r'))
+            .rest(SyntaxShape::Pattern, "the file path(s) to remove")
+    }
+
+    fn usage(&self) -> &str {
+        "Remove file(s)"
+    }
+
+    fn run(
+        &self,
+        call_info: &CallInfo,
+        _registry: &CommandRegistry,
+        raw_args: &RawCommandArgs,
+        _input: Value,
+    ) -> Result<OutputStream, ShellError> {
+        call_info
+            .process(&raw_args.shell_manager, raw_args.ctrl_c.clone(), rm)?
+            .run()
+    }
+}
+
+fn rm(args: RemoveArgs, context: &RunnablePerItemContext) -> Result<OutputStream, ShellError> {
+    let shell_manager = context.shell_manager.clone();
+    shell_manager.rm(args, context)
+}

crates/nu-cli/src/commands/save.rs

@@ -0,0 +1,290 @@
+use crate::commands::{UnevaluatedCallInfo, WholeStreamCommand};
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{Primitive, ReturnSuccess, Signature, SyntaxShape, UntaggedValue, Value};
+use nu_source::Tagged;
+use std::path::{Path, PathBuf};
+
+pub struct Save;
+
+macro_rules! process_unknown {
+    ($scope:tt, $input:ident, $name_tag:ident) => {{
+        if $input.len() > 0 {
+            match $input[0] {
+                Value {
+                    value: UntaggedValue::Primitive(Primitive::Binary(_)),
+                    ..
+                } => process_binary!($scope, $input, $name_tag),
+                _ => process_string!($scope, $input, $name_tag),
+            }
+        } else {
+            process_string!($scope, $input, $name_tag)
+        }
+    }};
+}
+
+macro_rules! process_string {
+    ($scope:tt, $input:ident, $name_tag:ident) => {{
+        let mut result_string = String::new();
+        for res in $input {
+            match res {
+                Value {
+                    value: UntaggedValue::Primitive(Primitive::String(s)),
+                    ..
+                } => {
+                    result_string.push_str(&s);
+                }
+                _ => {
+                    break $scope Err(ShellError::labeled_error(
+                        "Save requires string data",
+                        "consider converting data to string (see `help commands`)",
+                        $name_tag,
+                    ));
+                }
+            }
+        }
+        Ok(result_string.into_bytes())
+    }};
+}
+
+macro_rules! process_binary {
+    ($scope:tt, $input:ident, $name_tag:ident) => {{
+        let mut result_binary: Vec<u8> = Vec::new();
+        for res in $input {
+            match res {
+                Value {
+                    value: UntaggedValue::Primitive(Primitive::Binary(b)),
+                    ..
+                } => {
+                    for u in b.into_iter() {
+                        result_binary.push(u);
+                    }
+                }
+                _ => {
+                    break $scope Err(ShellError::labeled_error(
+                        "Save could not successfully save",
+                        "unexpected data during binary save",
+                        $name_tag,
+                    ));
+                }
+            }
+        }
+        Ok(result_binary)
+    }};
+}
+
+macro_rules! process_string_return_success {
+    ($scope:tt, $result_vec:ident, $name_tag:ident) => {{
+        let mut result_string = String::new();
+        for res in $result_vec {
+            match res {
+                Ok(ReturnSuccess::Value(Value {
+                    value: UntaggedValue::Primitive(Primitive::String(s)),
+                    ..
+                })) => {
+                    result_string.push_str(&s);
+                }
+                _ => {
+                    break $scope Err(ShellError::labeled_error(
+                        "Save could not successfully save",
+                        "unexpected data during text save",
+                        $name_tag,
+                    ));
+                }
+            }
+        }
+        Ok(result_string.into_bytes())
+    }};
+}
+
+macro_rules! process_binary_return_success {
+    ($scope:tt, $result_vec:ident, $name_tag:ident) => {{
+        let mut result_binary: Vec<u8> = Vec::new();
+        for res in $result_vec {
+            match res {
+                Ok(ReturnSuccess::Value(Value {
+                    value: UntaggedValue::Primitive(Primitive::Binary(b)),
+                    ..
+                })) => {
+                    for u in b.into_iter() {
+                        result_binary.push(u);
+                    }
+                }
+                _ => {
+                    break $scope Err(ShellError::labeled_error(
+                        "Save could not successfully save",
+                        "unexpected data during binary save",
+                        $name_tag,
+                    ));
+                }
+            }
+        }
+        Ok(result_binary)
+    }};
+}
+
+#[derive(Deserialize)]
+pub struct SaveArgs {
+    path: Option<Tagged<PathBuf>>,
+    raw: bool,
+}
+
+impl WholeStreamCommand for Save {
+    fn name(&self) -> &str {
+        "save"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("save")
+            .optional("path", SyntaxShape::Path, "the path to save contents to")
+            .switch(
+                "raw",
+                "treat values as-is rather than auto-converting based on file extension",
+                Some('r'),
+            )
+    }
+
+    fn usage(&self) -> &str {
+        "Save the contents of the pipeline to a file."
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        Ok(args.process_raw(registry, save)?.run())
+    }
+}
+
+fn save(
+    SaveArgs {
+        path,
+        raw: save_raw,
+    }: SaveArgs,
+    RunnableContext {
+        input,
+        name,
+        shell_manager,
+        host,
+        ctrl_c,
+        commands: registry,
+        ..
+    }: RunnableContext,
+    raw_args: RawCommandArgs,
+) -> Result<OutputStream, ShellError> {
+    let mut full_path = PathBuf::from(shell_manager.path());
+    let name_tag = name.clone();
+
+    let stream = async_stream! {
+        let input: Vec<Value> = input.values.collect().await;
+        if path.is_none() {
+            // If there is no filename, check the metadata for the anchor filename
+            if input.len() > 0 {
+                let anchor = input[0].tag.anchor();
+                match anchor {
+                    Some(path) => match path {
+                        AnchorLocation::File(file) => {
+                            full_path.push(Path::new(&file));
+                        }
+                        _ => {
+                            yield Err(ShellError::labeled_error(
+                                "Save requires a filepath",
+                                "needs path",
+                                name_tag.clone(),
+                            ));
+                        }
+                    },
+                    None => {
+                        yield Err(ShellError::labeled_error(
+                            "Save requires a filepath",
+                            "needs path",
+                            name_tag.clone(),
+                        ));
+                    }
+                }
+            } else {
+                yield Err(ShellError::labeled_error(
+                    "Save requires a filepath",
+                    "needs path",
+                    name_tag.clone(),
+                ));
+            }
+        } else {
+            if let Some(file) = path {
+                full_path.push(file.item());
+            }
+        }
+
+        // TODO use label_break_value once it is stable:
+        // https://github.com/rust-lang/rust/issues/48594
+        let content : Result<Vec<u8>, ShellError> = 'scope: loop {
+            break if !save_raw {
+                if let Some(extension) = full_path.extension() {
+                    let command_name = format!("to-{}", extension.to_string_lossy());
+                    if let Some(converter) = registry.get_command(&command_name) {
+                        let new_args = RawCommandArgs {
+                            host,
+                            ctrl_c,
+                            shell_manager,
+                            call_info: UnevaluatedCallInfo {
+                                args: nu_parser::hir::Call {
+                                    head: raw_args.call_info.args.head,
+                                    positional: None,
+                                    named: None,
+                                    span: Span::unknown()
+                                },
+                                source: raw_args.call_info.source,
+                                name_tag: raw_args.call_info.name_tag,
+                            }
+                        };
+                        let mut result = converter.run(new_args.with_input(input), &registry);
+                        let result_vec: Vec<Result<ReturnSuccess, ShellError>> = result.drain_vec().await;
+                        if converter.is_binary() {
+                            process_binary_return_success!('scope, result_vec, name_tag)
+                        } else {
+                            process_string_return_success!('scope, result_vec, name_tag)
+                        }
+                    } else {
+                        process_unknown!('scope, input, name_tag)
+                    }
+                } else {
+                    process_unknown!('scope, input, name_tag)
+                }
+            } else {
+                Ok(string_from(&input).into_bytes())
+            };
+        };
+
+        match content {
+            Ok(save_data) => match std::fs::write(full_path, save_data) {
+                Ok(o) => o,
+                Err(e) => yield Err(ShellError::labeled_error(e.to_string(), "IO error while saving", name)),
+            },
+            Err(e) => yield Err(e),
+        }
+
+    };
+
+    Ok(OutputStream::new(stream))
+}
+
+fn string_from(input: &[Value]) -> String {
+    let mut save_data = String::new();
+
+    if !input.is_empty() {
+        let mut first = true;
+        for i in input.iter() {
+            if !first {
+                save_data.push_str("\n");
+            } else {
+                first = false;
+            }
+            if let Ok(data) = &i.as_string() {
+                save_data.push_str(data);
+            }
+        }
+    }
+
+    save_data
+}