Bump to 0.14 (#1766)

It seems that the description was copy-pasted by mistake from the
append command.

.azure/azure-pipelines.yml

@@ -3,12 +3,27 @@ trigger:
 
 strategy:
   matrix:
-    linux-nightly:
-      image: ubuntu-16.04
-    macos-nightly:
+    linux-stable:
+      image: ubuntu-18.04
+      style: 'unflagged'
+    macos-stable:
       image: macos-10.14
-    windows-nightly:
-      image: vs2017-win2016
+      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: $(image)
@@ -16,13 +31,33 @@ pool:
 steps:
   - bash: |
       set -e
-      curl https://sh.rustup.rs -sSf | sh -s -- -y --no-modify-path --default-toolchain `cat rust-toolchain`
-      export PATH=$HOME/.cargo/bin:$PATH
+      if [ -e /etc/debian_version ]
+      then
+        sudo apt-get -y install libxcb-composite0-dev libx11-dev
+      fi
+      if [ "$(uname)" == "Darwin" ]; then
+        curl https://sh.rustup.rs -sSf | sh -s -- -y --no-modify-path --default-toolchain "stable"
+        echo "Installing clippy"
+        rustup component add clippy --toolchain stable-x86_64-apple-darwin
+        export PATH=$HOME/.cargo/bin:$PATH
+      fi
+      rustup update
       rustc -Vv
       echo "##vso[task.prependpath]$HOME/.cargo/bin"
-      rustup component add rustfmt --toolchain `cat rust-toolchain`
+      rustup component add rustfmt
     displayName: Install Rust
-  - bash: RUSTFLAGS="-D warnings" cargo test --all-features
+  - 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"]

.dockerignore

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

.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

@@ -2,7 +2,7 @@ name: Publish consumable Docker images
 
 on:
   push:
-    tags: ['*.*.*']
+    tags: ['v?[0-9]+.[0-9]+.[0-9]+*']
 
 jobs:
   compile:
@@ -14,13 +14,17 @@ jobs:
         - x86_64-unknown-linux-gnu
     steps:
     - uses: actions/checkout@v1
-    - run: cargo install cross
+    - 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}
+        rm -frd target/${{ matrix.arch }}/release/{*/*,*.d,*.rlib,.fingerprint}
         find . -empty -delete
     - uses: actions/upload-artifact@master
       with:
@@ -31,6 +35,10 @@ jobs:
     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:
@@ -44,55 +52,67 @@ jobs:
         - glibc
         - musl
         include:
-        - { tag: alpine,           base-image: alpine,                     arch: x86_64-unknown-linux-musl, plugin: true    }
-        - { tag: slim,             base-image: 'debian:stable-slim',       arch: x86_64-unknown-linux-gnu,  plugin: true    }
-        - { tag: debian,           base-image: debian,                     arch: x86_64-unknown-linux-gnu,  plugin: true    }
-        - { tag: glibc-busybox,    base-image: 'busybox:glibc',            arch: x86_64-unknown-linux-gnu,  use-patch: true }
-        - { tag: musl-busybox,     base-image: 'busybox:musl',             arch: x86_64-unknown-linux-musl,                 }
-        - { tag: musl-distroless,  base-image: 'gcr.io/distroless/static', arch: x86_64-unknown-linux-musl,                 }
-        - { tag: glibc-distroless, base-image: 'gcr.io/distroless/cc',     arch: x86_64-unknown-linux-gnu,  use-patch: true }
-        - { tag: glibc,            base-image: scratch,                    arch: x86_64-unknown-linux-gnu,                  }
-        - { tag: musl,             base-image: scratch,                    arch: x86_64-unknown-linux-musl,                 }
+        - { 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: |
-        REGISTRY=${REGISTRY,,}; export TAG=${GITHUB_REF##*/}-${{ matrix.tag }};
+      run: |-
+        export DOCKER_TAG=${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 ${{ secrets.DOCKER_REGISTRY }} | docker login docker.pkg.github.com -u ${{ github.actor }} --password-stdin
+        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: ${{ matrix.base-image }}
-        REGISTRY: docker.pkg.github.com/${{ github.repository }}
 
     #region semantics tagging
-    - name: Retag and push without suffixing version
-      run: |
+    - name: Retag and push with suffixed version
+      run: |-
         VERSION=${GITHUB_REF##*/}
-        docker tag ${REGISTRY,,}/nu:${VERSION}-${{ matrix.tag }} ${REGISTRY,,}/nu:${{ matrix.tag }}
-        docker tag ${REGISTRY,,}/nu:${VERSION}-${{ matrix.tag }} ${REGISTRY,,}/nu:${VERSION%%.*}-${{ matrix.tag }}
-        docker tag ${REGISTRY,,}/nu:${VERSION}-${{ matrix.tag }} ${REGISTRY,,}/nu:${VERSION%.*}-${{ matrix.tag }}
-        docker push ${REGISTRY,,}/nu:${VERSION%.*}-${{ matrix.tag }}              # latest patch
-        docker push ${REGISTRY,,}/nu:${VERSION%%.*}-${{ matrix.tag }}             # latest features
-        docker push ${REGISTRY,,}/nu:${{ matrix.tag }}                            # latest version
-      env: { REGISTRY: 'docker.pkg.github.com/${{ github.repository }}' }
+
+        latest_version=${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: |
+      run: |-
         VERSION=${GITHUB_REF##*/}
-        docker tag ${REGISTRY,,}/nu:${{ matrix.tag }} ${REGISTRY,,}/nu:latest
-        docker tag ${REGISTRY,,}/nu:${VERSION}-${{ matrix.tag }} ${REGISTRY,,}/nu:${VERSION%.*}
-        docker tag ${REGISTRY,,}/nu:${VERSION}-${{ matrix.tag }} ${REGISTRY,,}/nu:${VERSION%%.*}
-        docker tag ${REGISTRY,,}/nu:${VERSION}-${{ matrix.tag }} ${REGISTRY,,}/nu:${VERSION}
-        docker push ${REGISTRY,,}/nu:${VERSION}       # exact version
-        docker push ${REGISTRY,,}/nu:${VERSION%%.*}   # latest features
-        docker push ${REGISTRY,,}/nu:${VERSION%.*}    # latest patch
-        docker push ${REGISTRY,,}/nu:latest           # latest version
-      env: { REGISTRY: 'docker.pkg.github.com/${{ github.repository }}' }
+
+        # ${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

@@ -3,6 +3,7 @@
 **/*.rs.bk
 history.txt
 tests/fixtures/nuplayground
+crates/*/target
 
 # Debian/Ubuntu
 debian/.debhelper/
@@ -10,3 +11,12 @@ debian/debhelper-build-stamp
 debian/files
 debian/nu.substvars
 debian/nu/
+
+# macOS junk
+.DS_Store
+
+# JetBrains' IDE items
+.idea/*
+
+# VSCode's IDE items
+.vscode/*

.gitpod.Dockerfile

@@ -0,0 +1,14 @@
+FROM gitpod/workspace-full
+
+USER gitpod
+
+RUN sudo apt-get update && \
+    sudo apt-get install -y \
+        libssl-dev \
+        libxcb-composite0-dev \
+        pkg-config \
+        libpython3.6 \
+        rust-lldb \
+    && sudo rm -rf /var/lib/apt/lists/*
+
+ENV RUST_LLDB=/usr/bin/lldb-8

.gitpod.yml

@@ -0,0 +1,25 @@
+image:
+  file: .gitpod.Dockerfile
+tasks:
+  - name: Clippy
+    init: cargo clippy --all --features=stable -- -D clippy::result_unwrap_used -D clippy::option_unwrap_used
+  - name: Testing
+    init: cargo test --all --features=stable,test-bins
+  - name: Build
+    init: cargo build --features=stable
+  - name: Nu
+    init: cargo install --path . --features=stable
+    command: nu
+github:
+  prebuilds:
+    branches: true
+    pullRequestsFromForks: true
+    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==
+    - bungcip.better-toml@0.3.2:3QfgGxxYtGHfJKQU7H0nEw==
+    - webfreak.debug@0.24.0:1zVcRsAhewYEX3/A9xjMNw==

.theia/launch.json

@@ -0,0 +1,14 @@
+{
+  "version": "0.2.0",
+  "configurations": [
+      {
+          "type": "gdb",
+          "request": "launch",
+          "name": "Debug Rust Code",
+          "preLaunchTask": "cargo",
+          "target": "${workspaceFolder}/target/debug/nu",
+          "cwd": "${workspaceFolder}",
+          "valuesFormatting": "parseText"
+      }
+  ]
+}

.theia/tasks.json

@@ -0,0 +1,12 @@
+{
+    "tasks": [
+        {
+            "command": "cargo",
+            "args": [
+                "build"
+            ],
+            "type": "process",
+            "label": "cargo",
+        }
+    ],
+}

CONTRIBUTING.md

@@ -0,0 +1,28 @@
+Welcome to nushell!
+
+*Note: for a more complete guide see [The nu contributor book](https://github.com/nushell/contributor-book)*
+
+For speedy contributions open it in Gitpod, nu will be pre-installed with the latest build in a VSCode like editor all from your browser.
+
+[![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/#https://github.com/nushell/nushell)
+
+To get live support from the community see our [Discord](https://discordapp.com/invite/NtAbbGn), [Twitter](https://twitter.com/nu_shell) or file an issue or feature request here on [GitHub](https://github.com/nushell/nushell/issues/new/choose)!
+<!--WIP-->
+
+# Developing
+## Set up
+This is no different than other Rust projects.
+
+```shell
+git clone https://github.com/nushell/nushell
+cd nushell
+cargo build
+```
+
+## Tests
+
+Run tests with:
+
+```shell
+cargo test --all --features=stable,test-bins
+```

Cargo.toml

@@ -1,163 +1,181 @@
 [package]
 name = "nu"
-version = "0.3.0"
-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 = "0.14.0"
+authors = ["The Nu Project Contributors"]
+description = "A new type 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 = "5.0.3"
-chrono = { version = "0.4.9", features = ["serde"] }
-derive-new = "0.5.8"
-prettytable-rs = "0.8.0"
-itertools = "0.8.0"
-ansi_term = "0.12.1"
-nom = "5.0.0"
-dunce = "1.0.0"
-indexmap = { version = "1.2.0", features = ["serde-1"] }
-chrono-humanize = "0.0.11"
-byte-unit = "3.0.1"
-base64 = "0.10.1"
-futures-preview = { version = "=0.3.0-alpha.18", features = ["compat", "io-compat"] }
-futures-async-stream = "=0.1.0-alpha.5"
-futures_codec = "0.2.5"
-num-traits = "0.2.8"
-term = "0.5.2"
-bytes = "0.4.12"
-log = "0.4.8"
-pretty_env_logger = "0.3.1"
-serde = { version = "1.0.100", features = ["derive"] }
-bson = { version = "0.14.0", features = ["decimal128"] }
-serde_json = "1.0.40"
-serde-hjson = "0.9.1"
-serde_yaml = "0.8"
-serde_bytes = "0.11.2"
-getset = "0.0.8"
-language-reporting = "0.3.1"
-app_dirs = "1.2.1"
-csv = "1.1"
-toml = "0.5.3"
+nu-cli = { version = "0.14.0", path = "./crates/nu-cli" }
+nu-source = { version = "0.14.0", path = "./crates/nu-source" }
+nu-plugin = { version = "0.14.0", path = "./crates/nu-plugin" }
+nu-protocol = { version = "0.14.0", path = "./crates/nu-protocol" }
+nu-errors = { version = "0.14.0", path = "./crates/nu-errors" }
+nu-parser = { version = "0.14.0", path = "./crates/nu-parser" }
+nu-value-ext = { version = "0.14.0", path = "./crates/nu-value-ext" }
+nu_plugin_average = { version = "0.14.0", path = "./crates/nu_plugin_average", optional=true }
+nu_plugin_binaryview = { version = "0.14.0", path = "./crates/nu_plugin_binaryview", optional=true }
+nu_plugin_fetch = { version = "0.14.0", path = "./crates/nu_plugin_fetch", optional=true }
+nu_plugin_inc = { version = "0.14.0", path = "./crates/nu_plugin_inc", optional=true }
+nu_plugin_match = { version = "0.14.0", path = "./crates/nu_plugin_match", optional=true }
+nu_plugin_post = { version = "0.14.0", path = "./crates/nu_plugin_post", optional=true }
+nu_plugin_ps = { version = "0.14.0", path = "./crates/nu_plugin_ps", optional=true }
+nu_plugin_start = { version = "0.1.0", path = "./crates/nu_plugin_start", optional=true }
+nu_plugin_str = { version = "0.14.0", path = "./crates/nu_plugin_str", optional=true }
+nu_plugin_sys = { version = "0.14.0", path = "./crates/nu_plugin_sys", optional=true }
+nu_plugin_textview = { version = "0.14.0", path = "./crates/nu_plugin_textview", optional=true }
+nu_plugin_tree = { version = "0.14.0", path = "./crates/nu_plugin_tree", optional=true }
+
+crossterm = { version = "0.17.2", optional = true }
+semver = { version = "0.9.0", optional = true }
+syntect = { version = "4.1", default-features = false, features = ["default-fancy"], optional = true}
+url = { version = "2.1.1", optional = true }
+
 clap = "2.33.0"
-git2 = { version = "0.10.1", default_features = false }
-dirs = "2.0.2"
-glob = "0.3.0"
-ctrlc = "3.1.3"
-surf = "1.0.2"
-url = "2.1.0"
-roxmltree = "0.7.0"
-nom_locate = "1.0.0"
-enum-utils = "0.1.1"
-unicode-xid = "0.2.0"
-serde_ini = "0.2.0"
-subprocess = "0.1.18"
-mime = "0.3.14"
-pretty-hex = "0.1.0"
-hex = "0.3.2"
-tempfile = "3.1.0"
-semver = "0.9.0"
-which = "2.0.1"
-uuid = {version = "0.7.4", features = [ "v4", "serde" ]}
-textwrap = {version = "0.11.0", features = ["term_size"]}
-shellexpand = "1.0.0"
-futures-timer = "0.4.0"
-pin-utils = "0.1.0-alpha.4"
-num-bigint = { version = "0.2.3", features = ["serde"] }
-bigdecimal = { version = "0.1.0", features = ["serde"] }
-natural = "0.3.0"
-serde_urlencoded = "0.6.1"
-sublime_fuzzy = "0.5"
-
-neso = { version = "0.5.0", optional = true }
-crossterm = { version = "0.10.2", optional = true }
-syntect = {version = "3.2.0", optional = true }
-onig_sys = {version = "=69.1.0", optional = true }
-heim = {version = "0.0.8-alpha.1", optional = true }
-battery = {version = "0.7.4", optional = true }
-rawkey = {version = "0.1.2", optional = true }
-clipboard = {version = "0.5", optional = true }
-ptree = {version = "0.2", optional = true }
-image = { version = "0.22.2", default_features = false, features = ["png_codec", "jpeg"], optional = true }
-
-[features]
-default = ["textview", "sys", "ps"]
-raw-key = ["rawkey", "neso"]
-textview = ["syntect", "onig_sys", "crossterm"]
-binaryview = ["image", "crossterm"]
-sys = ["heim", "battery"]
-ps = ["heim"]
-
-[dependencies.rusqlite]
-version = "0.20.0"
-features = ["bundled", "blob"]
+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"
+nu-test-support = { version = "0.14.0", path = "./crates/nu-test-support" }
 
-[lib]
-name = "nu"
-path = "src/lib.rs"
+[build-dependencies]
+toml = "0.5.6"
+serde = { version = "1.0.106", features = ["derive"] }
+nu-build = { version = "0.14.0", 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", "trash-support", "start"]
+
+# Default
+textview = ["crossterm", "syntect", "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"]
+start = ["nu_plugin_start"]
+
+clipboard-cli = ["nu-cli/clipboard-cli"]
+starship-prompt = ["nu-cli/starship-prompt"]
+trash-support = ["nu-cli/trash-support"]
 
 [[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_embed"
-path = "src/plugins/embed.rs"
+name = "cococo"
+path = "crates/nu-test-support/src/bins/cococo.rs"
+required-features = ["test-bins"]
 
 [[bin]]
-name = "nu_plugin_add"
-path = "src/plugins/add.rs"
+name = "nonu"
+path = "crates/nu-test-support/src/bins/nonu.rs"
+required-features = ["test-bins"]
 
 [[bin]]
-name = "nu_plugin_edit"
-path = "src/plugins/edit.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_str"
-path = "src/plugins/str.rs"
-
-[[bin]]
-name = "nu_plugin_skip"
-path = "src/plugins/skip.rs"
-
-[[bin]]
-name = "nu_plugin_sys"
-path = "src/plugins/sys.rs"
-required-features = ["sys"]
-
-[[bin]]
-name = "nu_plugin_ps"
-path = "src/plugins/ps.rs"
-required-features = ["ps"]
-
-[[bin]]
-name = "nu_plugin_tree"
-path = "src/plugins/tree.rs"
-required-features = ["tree"]
-
-[[bin]]
-name = "nu_plugin_binaryview"
-path = "src/plugins/binaryview.rs"
-required-features = ["binaryview"]
-
-[[bin]]
-name = "nu_plugin_textview"
-path = "src/plugins/textview.rs"
+name = "nu_plugin_core_textview"
+path = "src/plugins/nu_plugin_core_textview.rs"
 required-features = ["textview"]
 
+[[bin]]
+name = "nu_plugin_core_inc"
+path = "src/plugins/nu_plugin_core_inc.rs"
+required-features = ["inc"]
+
+[[bin]]
+name = "nu_plugin_core_ps"
+path = "src/plugins/nu_plugin_core_ps.rs"
+required-features = ["ps"]
+
+[[bin]]
+name = "nu_plugin_core_str"
+path = "src/plugins/nu_plugin_core_str.rs"
+required-features = ["str"]
+
+[[bin]]
+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_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"]
+
+[[bin]]
+name = "nu_plugin_stable_start"
+path = "src/plugins/nu_plugin_stable_start.rs"
+required-features = ["start"]
+
+# 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

@@ -1,35 +1,50 @@
+[![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 shell for the GitHub era
+A new type of shell.
 
 ![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 unstable 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.
 
 # Learning more
 
-There are a few good resources to learn about Nu. First, there is a [book](https://book.nushell.sh) about Nu, currently in progress. The book focuses on using Nu and its core concepts.
+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://github.com/nushell/contributor-book/tree/master/en) to help 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.
+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 chat with us.
+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
 
 ## Local
 
-Up-to-date installation instructions can be found in the [installation chapter of the book](https://book.nushell.sh/en/installation).
+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 **nightly** version of the compiler.
+To build Nu, you will need to use the **latest stable (1.39 or later)** version of the compiler.
 
 Required dependencies:
 
@@ -41,20 +56,30 @@ 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 +nightly install nu
+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 +nightly install nu --all-features
+cargo build --workspace --features=stable
 ```
 
 ## Docker
 
+### 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:
 
@@ -87,31 +112,40 @@ $ docker run -it nushell/nu
 /> exit
 ```
 
-The second container is a bit smaller, if size is important to you.
+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 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'.
+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
 ────┼───────────┼───────────┼──────────┼────────┼──────────────┼────────────────
   0 │ .azure    │ Directory │          │ 4.1 KB │ 2 months ago │ a day ago
@@ -122,78 +156,107 @@ Commands are separated by the pipe symbol (`|`) to denote a pipeline flowing lef
   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
 /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
-━━━━━━━━━━━━━━━━━━┯━━━━━━━━━━━━━━━━┯━━━━━━━━━━━━━━━━━━
+──────────────────┬────────────────┬──────────────────
  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
 ─────────────────┼────────────────────────────┼─────────┼─────────┼──────┼─────────
- [table: 3 rows] │ A shell for the GitHub era │ 2018    │ ISC     │ nu   │ 0.3.0
-━━━━━━━━━━━━━━━━━┷━━━━━━━━━━━━━━━━━━━━━━━━━━━━┷━━━━━━━━━┷━━━━━━━━━┷━━━━━━┷━━━━━━━━━
+ [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
-0.3.0
+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 structured data 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
 
@@ -210,95 +273,14 @@ Nu adheres closely to a set of goals that make up its design philosophy. As feat
 * 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 |
-| date (--utc) | Get the current datetime |
-| fetch url | Fetch contents from a url and retrieve data as a table if possible |
-| help | Display help information about commands |
-| 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. |
-| open filename | Load a file into a cell, convert to table if possible (avoid by appending '--raw') |
-| post url body (--user <user>) (--password <password>) | Post content to a url and retrieve data as a table if possible |
-| ps | View current processes |
-| sys | View information about the current system |
-| which filename | Finds a program file. |
-| rm   {file or directory} | Remove a file, (for removing directory append '--recursive') |
-| version | Display Nu version |
 
-## Shell commands
-| 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 |
+You can find a list of Nu commands, complete with documentation, in [quick command references](https://www.nushell.sh/documentation.html#quick-command-references).
 
-## Filters on tables (structured data)
-| command | description |
-| ------------- | ------------- |
-| add column-or-column-path value | Add a new column to the table |
-| edit column-or-column-path value | Edit an existing column to have a new value |
-| embed column | Creates a new table of one column with the given name, and places the current table inside of it |
-| first amount | Show only the first number of rows |
-| get column-or-column-path | Open column and get data from the corresponding cells |
-| inc (column-or-column-path) | Increment a value or version. Optionally use the column of a table |
-| last amount | Show only the last number of rows |
-| nth row-number | Return only the selected row |
-| pick ...columns | Down-select table to only these columns |
-| pivot --header-row <headers> | Pivot the tables, making columns into rows and vice versa |
-| reject ...columns | Remove the given columns from the table |
-| reverse | Reverses the table. |
-| skip amount | Skip a number of rows |
-| skip-while condition | Skips rows while the condition matches. |
-| sort-by ...columns | Sort by the given columns |
-| str (column) | Apply string function. Optionally use the column of a table |
-| sum | Sum a column of values |
-| tags | Read the tags (metadata) for values |
-| to-bson | Convert table into .bson binary data |
-| to-csv | Convert table into .csv text |
-| to-json | Convert table into .json text |
-| to-sqlite | Convert table to sqlite .db binary data |
-| to-toml | Convert table into .toml text |
-| to-tsv | Convert table into .tsv text |
-| to-url | Convert table to a urlencoded string |
-| to-yaml | Convert table into .yaml text |
-| where condition | Filter table to match the condition |
+# Contributing
 
-## Filters on text (unstructured data)
-| command | description |
-| ------------- | ------------- |
-| from-bson | Parse binary data as .bson and create table |
-| 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-sqlite | Parse binary data as sqlite .db and create table |
-| from-toml | Parse text as .toml and create table |
-| from-tsv  | Parse text as .tsv and create table  |
-| from-url | Parse urlencoded string and create a 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 ...column-names | Split row contents across multiple columns via the separator, optionally give the columns names |
-| 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 (optional feature) |
-| clip | Copy the contents of the pipeline to the copy/paste buffer (optional feature) |
-| 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 (optional feature) |
+See [Contributing](CONTRIBUTING.md) for details.
 
 # 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 = "0.14.0"
+authors = ["The Nu Project Contributors"]
+edition = "2018"
+description = "Core build system for nushell"
+license = "MIT"
+
+[lib]
+doctest = false
+
+[dependencies]
+serde = { version = "1.0.106", features = ["derive"] }
+lazy_static = "1.4.0"
+serde_json = "1.0.51"
+toml = "0.5.6"

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 +1,112 @@
+[package]
+name = "nu-cli"
+version = "0.14.0"
+authors = ["The Nu Project Contributors"]
+description = "CLI for nushell"
+edition = "2018"
+license = "MIT"
+
+[lib]
+doctest = false
+
+[dependencies]
+nu-source = { version = "0.14.0", path = "../nu-source" }
+nu-plugin = { version = "0.14.0", path = "../nu-plugin" }
+nu-protocol = { version = "0.14.0", path = "../nu-protocol" }
+nu-errors = { version = "0.14.0", path = "../nu-errors" }
+nu-parser = { version = "0.14.0", path = "../nu-parser" }
+nu-value-ext = { version = "0.14.0", path = "../nu-value-ext" }
+nu-test-support = { version = "0.14.0", 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"
+eml-parser = "0.1.0"
+filesize = "0.2.0"
+futures = { version = "0.3", features = ["compat", "io-compat"] }
+futures-util = "0.3.4"
+futures_codec = "0.4"
+getset = "0.1.0"
+git2 = { version = "0.13.1", default_features = false }
+glob = "0.3.0"
+hex = "0.4"
+htmlescape = "0.3.1"
+ical = "0.6.*"
+ichwh = "0.3.4"
+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"
+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 = "0.10.1"
+rustyline = "6.1.2"
+serde = { version = "1.0.106", features = ["derive"] }
+serde-hjson = "0.9.1"
+serde_bytes = "0.11.3"
+serde_ini = "0.2.0"
+serde_json = "1.0.51"
+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"
+typetag = "0.1.4"
+umask = "0.1"
+unicode-xid = "0.2.0"
+which = "3"
+
+trash = { version = "1.0.0", optional = true }
+clipboard = { version = "0.5", optional = true }
+starship = { version = "0.39.0", optional = true }
+rayon = "1.3.0"
+
+[target.'cfg(unix)'.dependencies]
+users = "0.10.0"
+
+[dependencies.rusqlite]
+version = "0.22.0"
+features = ["bundled", "blob"]
+
+[build-dependencies]
+nu-build = { version = "0.14.0", path = "../nu-build" }
+
+[dev-dependencies]
+quickcheck = "0.9"
+quickcheck_macros = "0.9"
+
+[features]
+stable = []
+starship-prompt = ["starship"]
+clipboard-cli = ["clipboard"]
+trash-support = ["trash"]

crates/nu-cli/src/cli.rs

@@ -0,0 +1,938 @@
+use crate::commands::classified::block::run_block;
+use crate::commands::classified::external::{MaybeTextCodec, StringOrBinary};
+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::path::canonicalize;
+use crate::prelude::*;
+use futures_codec::FramedRead;
+
+use nu_errors::ShellError;
+use nu_protocol::hir::{ClassifiedCommand, Expression, InternalCommand, Literal, NamedArguments};
+use nu_protocol::{Primitive, ReturnSuccess, Scope, Signature, UntaggedValue, Value};
+
+use log::{debug, 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::{Path, PathBuf};
+use std::sync::atomic::Ordering;
+
+use rayon::prelude::*;
+
+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]*"));
+
+        let plugs: Vec<_> = glob::glob_with(&pattern.to_string_lossy(), opts)?
+            .filter_map(|x| x.ok())
+            .collect();
+
+        let _failures: Vec<_> = plugs
+            .par_iter()
+            .map(|path| {
+                let bin_name = {
+                    if let Some(name) = path.file_name() {
+                        match name.to_str() {
+                            Some(raw) => raw,
+                            None => "",
+                        }
+                    } else {
+                        ""
+                    }
+                };
+
+                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 {:?}", path.display());
+
+                    // we are ok if this plugin load fails
+                    let _ = load_plugin(&path, &mut context.clone());
+                }
+            })
+            .collect();
+    }
+
+    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::EnvironmentSyncer,
+    interactive: bool,
+) -> 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),
+            whole_stream_command(Ls),
+            whole_stream_command(Du),
+            whole_stream_command(Cd),
+            whole_stream_command(Remove),
+            whole_stream_command(Open),
+            whole_stream_command(Config),
+            whole_stream_command(Help),
+            whole_stream_command(History),
+            whole_stream_command(Save),
+            whole_stream_command(Touch),
+            whole_stream_command(Cpy),
+            whole_stream_command(Date),
+            whole_stream_command(Cal),
+            whole_stream_command(Calc),
+            whole_stream_command(Mkdir),
+            whole_stream_command(Move),
+            whole_stream_command(Kill),
+            whole_stream_command(Version),
+            whole_stream_command(Clear),
+            whole_stream_command(What),
+            whole_stream_command(Which),
+            whole_stream_command(Debug),
+            whole_stream_command(Alias),
+            whole_stream_command(WithEnv),
+            // 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),
+            whole_stream_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),
+            whole_stream_command(Echo),
+            whole_stream_command(Parse),
+            // Column manipulation
+            whole_stream_command(Reject),
+            whole_stream_command(Select),
+            whole_stream_command(Get),
+            whole_stream_command(Update),
+            whole_stream_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(Nth),
+            whole_stream_command(Drop),
+            whole_stream_command(Format),
+            whole_stream_command(Where),
+            whole_stream_command(Compact),
+            whole_stream_command(Default),
+            whole_stream_command(Skip),
+            whole_stream_command(SkipUntil),
+            whole_stream_command(SkipWhile),
+            whole_stream_command(Keep),
+            whole_stream_command(KeepUntil),
+            whole_stream_command(KeepWhile),
+            whole_stream_command(Range),
+            whole_stream_command(Rename),
+            whole_stream_command(Uniq),
+            whole_stream_command(Each),
+            whole_stream_command(IsEmpty),
+            // Table manipulation
+            whole_stream_command(Merge),
+            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(To),
+            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(From),
+            whole_stream_command(FromCSV),
+            whole_stream_command(FromEML),
+            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),
+            // "Private" commands (not intended to be accessed directly)
+            whole_stream_command(RunExternalCommand { interactive }),
+        ]);
+
+        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_vec_of_pipelines(
+    pipelines: Vec<String>,
+    redirect_stdin: bool,
+) -> Result<(), Box<dyn Error>> {
+    let mut syncer = crate::EnvironmentSyncer::new();
+    let mut context = create_default_context(&mut syncer, false)?;
+
+    let _ = crate::load_plugins(&mut context);
+
+    let cc = context.ctrl_c.clone();
+
+    ctrlc::set_handler(move || {
+        cc.store(true, Ordering::SeqCst);
+    })
+    .expect("Error setting Ctrl-C handler");
+
+    if context.ctrl_c.load(Ordering::SeqCst) {
+        context.ctrl_c.store(false, Ordering::SeqCst);
+    }
+
+    // before we start up, let's run our startup commands
+    if let Ok(config) = crate::data::config::config(Tag::unknown()) {
+        if let Some(commands) = config.get("startup") {
+            match commands {
+                Value {
+                    value: UntaggedValue::Table(pipelines),
+                    ..
+                } => {
+                    for pipeline in pipelines {
+                        if let Ok(pipeline_string) = pipeline.as_string() {
+                            let _ = run_pipeline_standalone(
+                                pipeline_string,
+                                false,
+                                &mut context,
+                                false,
+                            )
+                            .await;
+                        }
+                    }
+                }
+                _ => {
+                    println!("warning: expected a table of pipeline strings as startup commands");
+                }
+            }
+        }
+    }
+
+    for pipeline in pipelines {
+        run_pipeline_standalone(pipeline, redirect_stdin, &mut context, true).await?;
+    }
+    Ok(())
+}
+
+pub async fn run_pipeline_standalone(
+    pipeline: String,
+    redirect_stdin: bool,
+    context: &mut Context,
+    exit_on_error: bool,
+) -> 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 && exit_on_error {
+                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));
+            if exit_on_error {
+                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>> {
+    #[cfg(windows)]
+    const DEFAULT_COMPLETION_MODE: CompletionType = CompletionType::Circular;
+    #[cfg(not(windows))]
+    const DEFAULT_COMPLETION_MODE: CompletionType = CompletionType::List;
+
+    let mut syncer = crate::EnvironmentSyncer::new();
+    let mut context = create_default_context(&mut syncer, true)?;
+
+    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;
+
+    // before we start up, let's run our startup commands
+    if let Ok(config) = crate::data::config::config(Tag::unknown()) {
+        if let Some(commands) = config.get("startup") {
+            match commands {
+                Value {
+                    value: UntaggedValue::Table(pipelines),
+                    ..
+                } => {
+                    for pipeline in pipelines {
+                        if let Ok(pipeline_string) = pipeline.as_string() {
+                            let _ = run_pipeline_standalone(
+                                pipeline_string,
+                                false,
+                                &mut context,
+                                false,
+                            )
+                            .await;
+                        }
+                    }
+                }
+                _ => {
+                    println!("warning: expected a table of pipeline strings as startup commands");
+                }
+            }
+        }
+    }
+
+    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 key_timeout = config::config(Tag::unknown())?
+            .get("key_timeout")
+            .map(|s| s.value.expect_int())
+            .unwrap_or(1);
+
+        rl.set_keyseq_timeout(key_timeout as i32);
+
+        let completion_mode = config::config(Tag::unknown())?
+            .get("completion_mode")
+            .map(|s| match s.value.expect_string() {
+                "list" => CompletionType::List,
+                "circular" => CompletionType::Circular,
+                _ => DEFAULT_COMPLETION_MODE,
+            })
+            .unwrap_or(DEFAULT_COMPLETION_MODE);
+
+        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::lite_parse(&line, 0) {
+                Err(err) => {
+                    return LineResult::Error(line.to_string(), err.into());
+                }
+
+                Ok(val) => val,
+            };
+
+            debug!("=== Parsed ===");
+            debug!("{:#?}", result);
+
+            let mut classified_block = nu_parser::classify_block(&result, ctx.registry());
+
+            debug!("{:#?}", classified_block);
+            //println!("{:#?}", pipeline);
+
+            if let Some(failure) = classified_block.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
+                && classified_block.block.block.len() == 1
+                && classified_block.block.block[0].list.len() == 1
+            {
+                if let ClassifiedCommand::Internal(InternalCommand {
+                    ref name, ref args, ..
+                }) = classified_block.block.block[0].list[0]
+                {
+                    let internal_name = name;
+                    let name = args
+                        .positional
+                        .as_ref()
+                        .and_then(|potionals| {
+                            potionals.get(0).map(|e| {
+                                if let Expression::Literal(Literal::String(ref s)) = e.expr {
+                                    &s
+                                } else {
+                                    ""
+                                }
+                            })
+                        })
+                        .unwrap_or("");
+
+                    if internal_name == "run_external"
+                        && args
+                            .positional
+                            .as_ref()
+                            .map(|ref v| v.len() == 1)
+                            .unwrap_or(true)
+                        && args
+                            .named
+                            .as_ref()
+                            .map(NamedArguments::is_empty)
+                            .unwrap_or(true)
+                        && canonicalize(ctx.shell_manager.path(), name).is_ok()
+                        && Path::new(&name).is_dir()
+                        && which::which(&name).is_err()
+                    {
+                        // 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(format!("{}\\", 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")
+                    }
+                });
+                stream.to_input_stream()
+            } else {
+                InputStream::empty()
+            };
+
+            classified_block.block.expand_it_usage();
+
+            trace!("{:#?}", classified_block);
+            let env = ctx.get_env();
+            match run_block(&classified_block.block, ctx, input_stream, &Scope::env(env)).await {
+                Ok(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(),
+                        registry: ctx.registry.clone(),
+                        name: Tag::unknown(),
+                    };
+
+                    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())
+                }
+                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 print_err(err: ShellError, host: &dyn Host, source: &Text) {
+    if let Some(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,
+            );
+        });
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    #[quickcheck]
+    fn quickcheck_parse(data: String) -> bool {
+        if let Ok(lite_block) = nu_parser::lite_parse(&data, 0) {
+            let context = crate::context::Context::basic().unwrap();
+            let _ = nu_parser::classify_block(&lite_block, context.registry());
+        }
+        true
+    }
+}

crates/nu-cli/src/commands.rs

@@ -0,0 +1,250 @@
+#[macro_use]
+pub(crate) mod macros;
+
+mod from_delimited_data;
+mod to_delimited_data;
+
+pub(crate) mod alias;
+pub(crate) mod append;
+pub(crate) mod args;
+pub(crate) mod autoview;
+pub(crate) mod cal;
+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 drop;
+pub(crate) mod du;
+pub(crate) mod each;
+pub(crate) mod echo;
+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;
+pub(crate) mod from_bson;
+pub(crate) mod from_csv;
+pub(crate) mod from_eml;
+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 is_empty;
+pub(crate) mod keep;
+pub(crate) mod keep_until;
+pub(crate) mod keep_while;
+pub(crate) mod last;
+pub(crate) mod lines;
+pub(crate) mod ls;
+#[allow(unused)]
+pub(crate) mod map_max_by;
+pub(crate) mod merge;
+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 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 run_alias;
+pub(crate) mod run_external;
+pub(crate) mod save;
+pub(crate) mod select;
+pub(crate) mod shells;
+pub(crate) mod shuffle;
+pub(crate) mod size;
+pub(crate) mod skip;
+pub(crate) mod skip_until;
+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;
+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 update;
+pub(crate) mod version;
+pub(crate) mod what;
+pub(crate) mod where_;
+pub(crate) mod which_;
+pub(crate) mod with_env;
+pub(crate) mod wrap;
+
+pub(crate) use autoview::Autoview;
+pub(crate) use cd::Cd;
+pub(crate) use command::{
+    whole_stream_command, Command, Example, UnevaluatedCallInfo, WholeStreamCommand,
+};
+
+pub(crate) use alias::Alias;
+pub(crate) use append::Append;
+pub(crate) use cal::Cal;
+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 drop::Drop;
+pub(crate) use du::Du;
+pub(crate) use each::Each;
+pub(crate) use echo::Echo;
+pub(crate) use is_empty::IsEmpty;
+pub(crate) use update::Update;
+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::From;
+pub(crate) use from_bson::FromBSON;
+pub(crate) use from_csv::FromCSV;
+pub(crate) use from_eml::FromEML;
+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 keep::Keep;
+pub(crate) use keep_until::KeepUntil;
+pub(crate) use keep_while::KeepWhile;
+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 merge::Merge;
+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 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 run_external::RunExternalCommand;
+pub(crate) use save::Save;
+pub(crate) use select::Select;
+pub(crate) use shells::Shells;
+pub(crate) use shuffle::Shuffle;
+pub(crate) use size::Size;
+pub(crate) use skip::Skip;
+pub(crate) use skip_until::SkipUntil;
+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::To;
+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 with_env::WithEnv;
+pub(crate) use wrap::Wrap;

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

@@ -0,0 +1,80 @@
+use crate::commands::WholeStreamCommand;
+use crate::context::CommandRegistry;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{hir::Block, CommandAction, ReturnSuccess, Signature, SyntaxShape, Value};
+use nu_source::Tagged;
+
+pub struct Alias;
+
+#[derive(Deserialize)]
+pub struct AliasArgs {
+    pub name: Tagged<String>,
+    pub args: Vec<Value>,
+    pub block: Block,
+}
+
+impl WholeStreamCommand for Alias {
+    fn name(&self) -> &str {
+        "alias"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("alias")
+            .required("name", SyntaxShape::String, "the name of the alias")
+            .required("args", SyntaxShape::Table, "the arguments to the alias")
+            .required(
+                "block",
+                SyntaxShape::Block,
+                "the block to run as the body of the alias",
+            )
+    }
+
+    fn usage(&self) -> &str {
+        "Define a shortcut for another command."
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        args.process(registry, alias)?.run()
+    }
+
+    fn examples(&self) -> &[Example] {
+        &[
+            Example {
+                description: "An alias without parameters",
+                example: "alias say-hi [] { echo 'Hello!' }",
+            },
+            Example {
+                description: "An alias with a single parameter",
+                example: "alias l [x] { ls $x }",
+            },
+        ]
+    }
+}
+
+pub fn alias(
+    AliasArgs {
+        name,
+        args: list,
+        block,
+    }: AliasArgs,
+    _: RunnableContext,
+) -> Result<OutputStream, ShellError> {
+    let stream = async_stream! {
+        let mut args: Vec<String> = vec![];
+        for item in list.iter() {
+            if let Ok(string) = item.as_string() {
+                args.push(format!("${}", string));
+            } else {
+                yield Err(ShellError::labeled_error("Expected a string", "expected a string", item.tag()));
+            }
+        }
+        yield ReturnSuccess::action(CommandAction::AddAlias(name.to_string(), args, block.clone()))
+    };
+
+    Ok(stream.to_output_stream())
+}

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

@@ -0,0 +1,56 @@
+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 examples(&self) -> &[Example] {
+        &[Example {
+            description: "Add something to the end of a list or table",
+            example: "echo [1 2 3] | append 4",
+        }]
+    }
+}
+
+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.chain(after)))
+}

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

@@ -1,4 +1,4 @@
-use crate::data::Value;
+use nu_protocol::Value;
 
 #[derive(Debug)]
 pub enum LogLevel {}

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

@@ -0,0 +1,334 @@
+use crate::commands::UnevaluatedCallInfo;
+use crate::commands::WholeStreamCommand;
+use crate::data::value::format_leaf;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{hir, hir::Expression, hir::Literal, hir::SpannedExpression};
+use nu_protocol::{Primitive, ReturnSuccess, Scope, 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,
+            registry: registry.clone(),
+            shell_manager: args.shell_manager,
+            host: args.host,
+            ctrl_c: args.ctrl_c,
+            name: args.call_info.name_tag,
+        })
+    }
+
+    fn examples(&self) -> &[Example] {
+        &[
+            Example {
+                description: "Automatically view the results",
+                example: "ls | autoview",
+            },
+            Example {
+                description: "Autoview is also implied. The above can be written as",
+                example: "ls",
+            },
+        ]
+    }
+}
+
+pub struct RunnableContextWithoutInput {
+    pub shell_manager: ShellManager,
+    pub host: Arc<parking_lot::Mutex<Box<dyn Host>>>,
+    pub ctrl_c: Arc<AtomicBool>,
+    pub registry: 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,
+            ctrl_c: context.ctrl_c,
+            registry: context.registry,
+            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.registry);
+                            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.registry);
+                                    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.registry);
+                                    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::Boolean(b)),
+                                ..
+                            } => {
+                                out!("{}", b);
+                            }
+                            Value {
+                                value: UntaggedValue::Primitive(Primitive::Duration(d)),
+                                ..
+                            } => {
+                                let output = format_leaf(&x).plain_string(100_000);
+                                out!("{}", output);
+                            }
+                            Value {
+                                value: UntaggedValue::Primitive(Primitive::Date(d)),
+                                ..
+                            } => {
+                                out!("{}", d);
+                            }
+                            Value {
+                                value: UntaggedValue::Primitive(Primitive::Range(_)),
+                                ..
+                            } => {
+                                let output = format_leaf(&x).plain_string(100_000);
+                                out!("{}", output);
+                            }
+
+                            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.registry);
+                                    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.registry);
+                                    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(String::new())),
+                    span,
+                )),
+                positional: None,
+                named: None,
+                span,
+                is_last: true,
+            },
+            name_tag: context.name.clone(),
+            scope: Scope::empty(),
+        },
+    }
+}

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

@@ -0,0 +1,300 @@
+use crate::prelude::*;
+use chrono::{DateTime, Datelike, Local, NaiveDate};
+use nu_errors::ShellError;
+use nu_protocol::Dictionary;
+
+use crate::commands::{command::EvaluatedWholeStreamCommandArgs, WholeStreamCommand};
+use indexmap::IndexMap;
+use nu_protocol::{Signature, SyntaxShape, UntaggedValue, Value};
+
+pub struct Cal;
+
+impl WholeStreamCommand for Cal {
+    fn name(&self) -> &str {
+        "cal"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("cal")
+            .switch("year", "Display the year column", Some('y'))
+            .switch("quarter", "Display the quarter column", Some('q'))
+            .switch("month", "Display the month column", Some('m'))
+            .named(
+                "full-year",
+                SyntaxShape::Int,
+                "Display a year-long calendar for the specified year",
+                None,
+            )
+            .switch(
+                "month-names",
+                "Display the month names instead of integers",
+                None,
+            )
+    }
+
+    fn usage(&self) -> &str {
+        "Display a calendar."
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        cal(args, registry)
+    }
+
+    fn examples(&self) -> &[Example] {
+        &[
+            Example {
+                description: "This month's calendar",
+                example: "cal",
+            },
+            Example {
+                description: "The calendar for all of 2012",
+                example: "cal --full-year 2012",
+            },
+        ]
+    }
+}
+
+pub fn cal(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStream, ShellError> {
+    let args = args.evaluate_once(registry)?;
+    let mut calendar_vec_deque = VecDeque::new();
+    let tag = args.call_info.name_tag.clone();
+
+    let (current_year, current_month, current_day) = get_current_date();
+
+    if args.has("full-year") {
+        let mut day_value: Option<u32> = Some(current_day);
+        let mut year_value = current_year as u64;
+
+        if let Some(year) = args.get("full-year") {
+            if let Ok(year_u64) = year.as_u64() {
+                year_value = year_u64;
+            }
+
+            if year_value != current_year as u64 {
+                day_value = None
+            }
+        }
+
+        add_year_to_table(
+            &mut calendar_vec_deque,
+            &tag,
+            year_value as i32,
+            current_year,
+            current_month,
+            day_value,
+            &args,
+        );
+    } else {
+        let (day_start_offset, number_of_days_in_month, _) =
+            get_month_information(current_year, current_month, current_year);
+
+        add_month_to_table(
+            &mut calendar_vec_deque,
+            &tag,
+            current_year,
+            current_month,
+            Some(current_day),
+            day_start_offset,
+            number_of_days_in_month as usize,
+            &args,
+        );
+    }
+
+    Ok(futures::stream::iter(calendar_vec_deque).to_output_stream())
+}
+
+fn get_current_date() -> (i32, u32, u32) {
+    let local_now: DateTime<Local> = Local::now();
+
+    let current_year: i32 = local_now.date().year();
+    let current_month: u32 = local_now.date().month();
+    let current_day: u32 = local_now.date().day();
+
+    (current_year, current_month, current_day)
+}
+
+fn add_year_to_table(
+    mut calendar_vec_deque: &mut VecDeque<Value>,
+    tag: &Tag,
+    mut selected_year: i32,
+    current_year: i32,
+    current_month: u32,
+    current_day_option: Option<u32>,
+    args: &EvaluatedWholeStreamCommandArgs,
+) {
+    for month_number in 1..=12 {
+        let (day_start_offset, number_of_days_in_month, chosen_date_is_valid) =
+            get_month_information(selected_year, month_number, current_year);
+
+        if !chosen_date_is_valid {
+            selected_year = current_year;
+        }
+
+        let mut new_current_day_option: Option<u32> = None;
+
+        if let Some(current_day) = current_day_option {
+            if month_number == current_month {
+                new_current_day_option = Some(current_day)
+            }
+        }
+
+        add_month_to_table(
+            &mut calendar_vec_deque,
+            &tag,
+            selected_year,
+            month_number,
+            new_current_day_option,
+            day_start_offset,
+            number_of_days_in_month,
+            &args,
+        );
+    }
+}
+
+#[allow(clippy::too_many_arguments)]
+fn add_month_to_table(
+    calendar_vec_deque: &mut VecDeque<Value>,
+    tag: &Tag,
+    year: i32,
+    month: u32,
+    _current_day_option: Option<u32>, // Can be used in the future to display current day
+    day_start_offset: usize,
+    number_of_days_in_month: usize,
+    args: &EvaluatedWholeStreamCommandArgs,
+) {
+    let day_limit = number_of_days_in_month + day_start_offset;
+    let mut day_count: usize = 1;
+
+    let days_of_the_week = [
+        "sunday",
+        "monday",
+        "tuesday",
+        "wednesday",
+        "thurday",
+        "friday",
+        "saturday",
+    ];
+
+    let should_show_year_column = args.has("year");
+    let should_show_month_column = args.has("month");
+    let should_show_quarter_column = args.has("quarter");
+    let should_show_month_names = args.has("month-names");
+
+    while day_count <= day_limit {
+        let mut indexmap = IndexMap::new();
+
+        if should_show_year_column {
+            indexmap.insert("year".to_string(), UntaggedValue::int(year).into_value(tag));
+        }
+
+        if should_show_quarter_column {
+            indexmap.insert(
+                "quarter".to_string(),
+                UntaggedValue::int(get_quarter_number(month)).into_value(tag),
+            );
+        }
+
+        if should_show_month_column {
+            let month_value = if should_show_month_names {
+                UntaggedValue::string(get_month_name(month)).into_value(tag)
+            } else {
+                UntaggedValue::int(month).into_value(tag)
+            };
+
+            indexmap.insert("month".to_string(), month_value);
+        }
+
+        for day in &days_of_the_week {
+            let value = if (day_count <= day_limit) && (day_count > day_start_offset) {
+                UntaggedValue::int(day_count - day_start_offset).into_value(tag)
+            } else {
+                UntaggedValue::nothing().into_value(tag)
+            };
+
+            indexmap.insert((*day).to_string(), value);
+
+            day_count += 1;
+        }
+
+        calendar_vec_deque
+            .push_back(UntaggedValue::Row(Dictionary::from(indexmap)).into_value(tag));
+    }
+}
+
+fn get_quarter_number(month_number: u32) -> u8 {
+    match month_number {
+        1..=3 => 1,
+        4..=6 => 2,
+        7..=9 => 3,
+        _ => 4,
+    }
+}
+
+fn get_month_name(month_number: u32) -> String {
+    let month_name = match month_number {
+        1 => "january",
+        2 => "february",
+        3 => "march",
+        4 => "april",
+        5 => "may",
+        6 => "june",
+        7 => "july",
+        8 => "august",
+        9 => "september",
+        10 => "october",
+        11 => "november",
+        _ => "december",
+    };
+
+    month_name.to_string()
+}
+
+fn get_month_information(
+    selected_year: i32,
+    month: u32,
+    current_year: i32,
+) -> (usize, usize, bool) {
+    let (naive_date, chosen_date_is_valid_one) =
+        get_safe_naive_date(selected_year, month, current_year);
+    let weekday = naive_date.weekday();
+    let (days_in_month, chosen_date_is_valid_two) =
+        get_days_in_month(selected_year, month, current_year);
+
+    (
+        weekday.num_days_from_sunday() as usize,
+        days_in_month,
+        chosen_date_is_valid_one && chosen_date_is_valid_two,
+    )
+}
+
+fn get_days_in_month(selected_year: i32, month: u32, current_year: i32) -> (usize, bool) {
+    // Chrono does not provide a method to output the amount of days in a month
+    // This is a workaround taken from the example code from the Chrono docs here:
+    // https://docs.rs/chrono/0.3.0/chrono/naive/date/struct.NaiveDate.html#example-30
+    let (adjusted_year, adjusted_month) = if month == 12 {
+        (selected_year + 1, 1)
+    } else {
+        (selected_year, month + 1)
+    };
+
+    let (naive_date, chosen_date_is_valid) =
+        get_safe_naive_date(adjusted_year, adjusted_month, current_year);
+
+    (naive_date.pred().day() as usize, chosen_date_is_valid)
+}
+
+fn get_safe_naive_date(
+    selected_year: i32,
+    selected_month: u32,
+    current_year: i32,
+) -> (NaiveDate, bool) {
+    if let Some(naive_date) = NaiveDate::from_ymd_opt(selected_year, selected_month, 1) {
+        return (naive_date, true);
+    }
+
+    (NaiveDate::from_ymd(current_year, selected_month, 1), false)
+}

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

@@ -0,0 +1,74 @@
+use crate::commands::WholeStreamCommand;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{Primitive, ReturnSuccess, UntaggedValue, Value};
+
+pub struct Calc;
+
+#[derive(Deserialize)]
+pub struct CalcArgs {}
+
+impl WholeStreamCommand for Calc {
+    fn name(&self) -> &str {
+        "calc"
+    }
+
+    fn usage(&self) -> &str {
+        "Parse a math expression into a number"
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        args.process(registry, calc)?.run()
+    }
+
+    fn examples(&self) -> &[Example] {
+        &[Example {
+            description: "Calculate math in the pipeline",
+            example: "echo '10 / 4' | calc",
+        }]
+    }
+}
+
+pub fn calc(
+    _: CalcArgs,
+    RunnableContext { input, name, .. }: RunnableContext,
+) -> Result<OutputStream, ShellError> {
+    Ok(input
+        .map(move |input| {
+            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.clone(),
+                ))
+            }
+        })
+        .to_output_stream())
+}
+
+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 +1,66 @@
+use crate::commands::WholeStreamCommand;
+use crate::prelude::*;
+
+use std::path::PathBuf;
+
+use nu_errors::ShellError;
+use nu_protocol::{Signature, SyntaxShape};
+use nu_source::Tagged;
+
+#[derive(Deserialize)]
+pub struct CdArgs {
+    pub(crate) path: Option<Tagged<PathBuf>>,
+}
+
+pub struct Cd;
+
+impl WholeStreamCommand for Cd {
+    fn name(&self) -> &str {
+        "cd"
+    }
+
+    fn signature(&self) -> Signature {
+        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> {
+        args.process(registry, cd)?.run()
+    }
+
+    fn examples(&self) -> &[Example] {
+        &[
+            Example {
+                description: "Change to a new directory called 'dirname'",
+                example: "cd dirname",
+            },
+            Example {
+                description: "Change to your home directory",
+                example: "cd",
+            },
+            Example {
+                description: "Change to your home directory (alternate version)",
+                example: "cd ~",
+            },
+            Example {
+                description: "Change to the previous directory",
+                example: "cd -",
+            },
+        ]
+    }
+}
+
+fn cd(args: CdArgs, context: RunnableContext) -> Result<OutputStream, ShellError> {
+    context.shell_manager.cd(args, &context)
+}

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

@@ -0,0 +1,95 @@
+use crate::commands::classified::expr::run_expression_block;
+use crate::commands::classified::internal::run_internal_command;
+use crate::context::Context;
+use crate::prelude::*;
+use crate::stream::InputStream;
+use futures::stream::TryStreamExt;
+use nu_errors::ShellError;
+use nu_protocol::hir::{Block, ClassifiedCommand, Commands};
+use nu_protocol::{ReturnSuccess, Scope, UntaggedValue, Value};
+use std::sync::atomic::Ordering;
+
+pub(crate) async fn run_block(
+    block: &Block,
+    ctx: &mut Context,
+    mut input: InputStream,
+    scope: &Scope,
+) -> Result<InputStream, ShellError> {
+    let mut output: Result<InputStream, ShellError> = Ok(InputStream::empty());
+    for pipeline in &block.block {
+        match output {
+            Ok(inp) if inp.is_empty() => {}
+            Ok(inp) => {
+                let mut output_stream = inp.to_output_stream();
+
+                loop {
+                    match output_stream.try_next().await {
+                        Ok(Some(ReturnSuccess::Value(Value {
+                            value: UntaggedValue::Error(e),
+                            ..
+                        }))) => return Err(e),
+                        Ok(Some(_item)) => {
+                            if let Some(err) = ctx.get_errors().get(0) {
+                                ctx.clear_errors();
+                                return Err(err.clone());
+                            }
+                            if ctx.ctrl_c.load(Ordering::SeqCst) {
+                                break;
+                            }
+                        }
+                        Ok(None) => {
+                            if let Some(err) = ctx.get_errors().get(0) {
+                                ctx.clear_errors();
+                                return Err(err.clone());
+                            }
+                            break;
+                        }
+                        Err(e) => return Err(e),
+                    }
+                }
+            }
+            Err(e) => {
+                return Err(e);
+            }
+        }
+        output = run_pipeline(pipeline, ctx, input, scope).await;
+
+        input = InputStream::empty();
+    }
+
+    output
+}
+
+async fn run_pipeline(
+    commands: &Commands,
+    ctx: &mut Context,
+    mut input: InputStream,
+    scope: &Scope,
+) -> Result<InputStream, ShellError> {
+    let mut iter = commands.list.clone().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(expr)), _) => {
+                run_expression_block(*expr, ctx, input, scope)?
+            }
+            (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, scope)?
+            }
+
+            (None, _) => break,
+        };
+    }
+
+    Ok(input)
+}

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

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

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

@@ -0,0 +1,27 @@
+use crate::evaluate::evaluate_baseline_expr;
+use crate::prelude::*;
+
+use log::{log_enabled, trace};
+
+use futures::stream::once;
+use nu_errors::ShellError;
+use nu_protocol::hir::SpannedExpression;
+use nu_protocol::Scope;
+
+pub(crate) fn run_expression_block(
+    expr: SpannedExpression,
+    context: &mut Context,
+    _input: InputStream,
+    scope: &Scope,
+) -> Result<InputStream, ShellError> {
+    if log_enabled!(log::Level::Trace) {
+        trace!(target: "nu::run::expr", "->");
+        trace!(target: "nu::run::expr", "{:?}", expr);
+    }
+
+    let scope = scope.clone();
+    let registry = context.registry().clone();
+    let output = evaluate_baseline_expr(&expr, &registry, &scope)?;
+
+    Ok(once(async { Ok(output) }).to_input_stream())
+}

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

@@ -0,0 +1,625 @@
+use crate::evaluate::evaluate_baseline_expr;
+use crate::futures::ThreadedReceiver;
+use crate::prelude::*;
+
+use std::io::Write;
+use std::ops::Deref;
+use std::process::{Command, Stdio};
+use std::sync::mpsc;
+
+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_protocol::hir::ExternalCommand;
+use nu_protocol::{Primitive, Scope, ShellTypeName, UntaggedValue, Value};
+use nu_source::Tag;
+
+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(crate) async fn run_external_command(
+    command: ExternalCommand,
+    context: &mut Context,
+    input: InputStream,
+    scope: &Scope,
+    is_last: bool,
+) -> Result<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,
+        ));
+    }
+
+    run_with_stdin(command, context, input, scope, is_last)
+}
+
+fn run_with_stdin(
+    command: ExternalCommand,
+    context: &mut Context,
+    input: InputStream,
+    scope: &Scope,
+    is_last: bool,
+) -> Result<InputStream, ShellError> {
+    let path = context.shell_manager.path();
+
+    let input = trace_stream!(target: "nu::trace_stream::external::stdin", "input" = input);
+
+    let mut command_args = vec![];
+    for arg in command.args.iter() {
+        let value = evaluate_baseline_expr(arg, &context.registry, scope)?;
+        // Skip any arguments that don't really exist, treating them as optional
+        // FIXME: we may want to preserve the gap in the future, though it's hard to say
+        // what value we would put in its place.
+        if value.value.is_none() {
+            continue;
+        }
+        // Do the cleanup that we need to do on any argument going out:
+        let trimmed_value_string = value.as_string()?.trim_end_matches('\n').to_string();
+
+        let value_string;
+        #[cfg(not(windows))]
+        {
+            value_string = trimmed_value_string
+                .replace('$', "\\$")
+                .replace('"', "\\\"")
+                .to_string()
+        }
+        #[cfg(windows)]
+        {
+            value_string = trimmed_value_string
+        }
+
+        command_args.push(value_string);
+    }
+
+    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) {
+                    add_quotes(&arg)
+                } 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, scope)
+}
+
+fn spawn(
+    command: &ExternalCommand,
+    path: &str,
+    args: &[String],
+    input: InputStream,
+    is_last: bool,
+    scope: &Scope,
+) -> Result<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 {
+                // Clean the args before we use them:
+                let arg = arg.replace("|", "\\|");
+                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);
+
+    process.env_clear();
+    process.envs(scope.env.iter());
+
+    // 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_empty() {
+        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 !input.is_empty() {
+                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(e) => {
+                            // If there's an exit status, it makes sense that we may error when
+                            // trying to read from its stdout pipe (likely been closed). In that
+                            // case, don't emit an error.
+                            let should_error = match child.wait() {
+                                Ok(exit_status) => !exit_status.success(),
+                                Err(_) => true,
+                            };
+
+                            if should_error {
+                                let _ = stdout_read_tx.send(Ok(Value {
+                                    value: UntaggedValue::Error(ShellError::labeled_error(
+                                        format!("Unable to read from stdout ({})", e),
+                                        "unable to read from stdout",
+                                        &stdout_name_tag,
+                                    )),
+                                    tag: stdout_name_tag.clone(),
+                                }));
+                            }
+
+                            return Ok(());
+                        }
+                    }
+                }
+            }
+
+            // We can give an error when we see a non-zero exit code, but this is different
+            // than what other shells will do.
+            let external_failed = match child.wait() {
+                Err(_) => true,
+                Ok(exit_status) => !exit_status.success(),
+            };
+
+            if external_failed {
+                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.clone(),
+                        }));
+                    }
+                }
+                let _ = stdout_read_tx.send(Ok(Value {
+                    value: UntaggedValue::Error(ShellError::external_non_zero()),
+                    tag: stdout_name_tag,
+                }));
+            }
+
+            Ok(())
+        });
+
+        let stream = ThreadedReceiver::new(rx);
+        Ok(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))]
+    {
+        which::which(name).is_ok()
+    }
+
+    #[cfg(windows)]
+    {
+        if which::which(name).is_ok() {
+            true
+        } else {
+            let cmd_builtins = [
+                "call", "cls", "color", "date", "dir", "echo", "find", "hostname", "pause",
+                "start", "time", "title", "ver", "copy", "mkdir", "rename", "rd", "rmdir", "type",
+                "mklink",
+            ];
+
+            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)
+}
+
+#[allow(unused)]
+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, InputStream,
+    };
+    use futures::executor::block_on;
+    use nu_errors::ShellError;
+    use nu_protocol::Scope;
+    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 input = InputStream::empty();
+        let mut ctx = Context::basic().expect("There was a problem creating a basic context.");
+
+        assert!(
+            run_external_command(cmd, &mut ctx, input, &Scope::empty(), 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 +1,186 @@
+use crate::commands::command::whole_stream_command;
+use crate::commands::run_alias::AliasCommand;
+use crate::commands::UnevaluatedCallInfo;
+use crate::prelude::*;
+use log::{log_enabled, trace};
+use nu_errors::ShellError;
+use nu_protocol::hir::InternalCommand;
+use nu_protocol::{CommandAction, Primitive, ReturnSuccess, Scope, UntaggedValue, Value};
+
+pub(crate) fn run_internal_command(
+    command: InternalCommand,
+    context: &mut Context,
+    input: InputStream,
+    scope: &Scope,
+) -> Result<InputStream, ShellError> {
+    if log_enabled!(log::Level::Trace) {
+        trace!(target: "nu::run::internal", "->");
+        trace!(target: "nu::run::internal", "{}", command.name);
+    }
+
+    let objects: InputStream = trace_stream!(target: "nu::trace_stream::internal", "input" = input);
+    let internal_command = context.expect_command(&command.name);
+
+    let result = {
+        context.run_command(
+            internal_command?,
+            Tag::unknown_anchor(command.name_span),
+            command.args.clone(),
+            scope,
+            objects,
+        )
+    };
+
+    let mut result = trace_out_stream!(target: "nu::trace_stream::internal", "output" = result);
+    let mut context = context.clone();
+    let scope = scope.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_protocol::hir::Call {
+                                        head: command.args.head,
+                                        positional: None,
+                                        named: None,
+                                        span: Span::unknown(),
+                                        is_last: false,
+                                    },
+                                    name_tag: Tag::unknown_anchor(command.name_span),
+                                    scope: scope.clone(),
+                                }
+                            };
+                            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::AddAlias(name, args, block) => {
+                        context.add_commands(vec![
+                            whole_stream_command(AliasCommand::new(
+                                name,
+                                args,
+                                block,
+                            ))
+                        ]);
+                    }
+                    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.clone());
+                    yield Err(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(stream.to_input_stream())
+}

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

@@ -0,0 +1,8 @@
+pub(crate) mod block;
+mod dynamic;
+pub(crate) mod expr;
+pub(crate) mod external;
+pub(crate) mod internal;
+
+#[allow(unused_imports)]
+pub(crate) use dynamic::Command as DynamicCommand;

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

@@ -0,0 +1,46 @@
+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 examples(&self) -> &[Example] {
+        &[Example {
+            description: "Clear the screen",
+            example: "clear",
+        }]
+    }
+}
+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 +1,113 @@
+#[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()
+        }
+
+        fn examples(&self) -> &[Example] {
+            &[Example {
+                description: "Save text to the clipboard",
+                example: "echo 'secret value' | clip",
+            }]
+        }
+    }
+
+    pub fn clip(
+        ClipArgs {}: ClipArgs,
+        RunnableContext { input, name, .. }: RunnableContext,
+    ) -> Result<OutputStream, ShellError> {
+        let stream = async_stream! {
+            let values: Vec<Value> = input.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

@@ -0,0 +1,497 @@
+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_protocol::hir;
+use nu_protocol::{CallInfo, EvaluatedArgs, ReturnValue, Scope, Signature, Value};
+use serde::{Deserialize, Serialize};
+use std::ops::Deref;
+use std::sync::atomic::AtomicBool;
+
+#[derive(Deserialize, Serialize, Debug, Clone)]
+pub struct UnevaluatedCallInfo {
+    pub args: hir::Call,
+    pub name_tag: Tag,
+    pub scope: Scope,
+}
+
+impl UnevaluatedCallInfo {
+    pub fn evaluate(self, registry: &CommandRegistry) -> Result<CallInfo, ShellError> {
+        let args = evaluate_args(&self.args, registry, &self.scope)?;
+
+        Ok(CallInfo {
+            args,
+            name_tag: self.name_tag,
+        })
+    }
+
+    pub fn evaluate_with_new_it(
+        self,
+        registry: &CommandRegistry,
+        it: &Value,
+    ) -> Result<CallInfo, ShellError> {
+        let mut scope = self.scope.clone();
+        scope = scope.set_it(it.clone());
+        let args = evaluate_args(&self.args, registry, &scope)?;
+
+        Ok(CallInfo {
+            args,
+            name_tag: self.name_tag,
+        })
+    }
+
+    pub fn switch_present(&self, switch: &str) -> bool {
+        self.args.switch_preset(switch)
+    }
+}
+
+#[derive(Getters)]
+#[get = "pub(crate)"]
+pub struct CommandArgs {
+    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 = "pub(crate)"]
+pub struct RawCommandArgs {
+    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: 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(),
+        }
+    }
+}
+
+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: &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)?;
+
+        Ok(EvaluatedWholeStreamCommandArgs::new(
+            host,
+            ctrl_c,
+            shell_manager,
+            call_info,
+            input,
+        ))
+    }
+
+    pub fn evaluate_once_with_scope(
+        self,
+        registry: &CommandRegistry,
+        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 = UnevaluatedCallInfo {
+            name_tag: self.call_info.name_tag,
+            args: self.call_info.args,
+            scope: scope.clone(),
+        };
+        let call_info = call_info.evaluate(registry)?;
+
+        Ok(EvaluatedWholeStreamCommandArgs::new(
+            host,
+            ctrl_c,
+            shell_manager,
+            call_info,
+            input,
+        ))
+    }
+
+    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 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_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,
+                registry: registry.clone(),
+                shell_manager,
+                name: name_tag,
+                host,
+                ctrl_c,
+            },
+            callback,
+        })
+    }
+
+    pub fn process_raw<'de, T: Deserialize<'de>>(
+        self,
+        registry: &CommandRegistry,
+        callback: fn(T, RunnableContext, RawCommandArgs) -> Result<OutputStream, ShellError>,
+    ) -> 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 host = self.host.clone();
+        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_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,
+                registry: registry.clone(),
+                shell_manager,
+                name: name_tag,
+                host,
+                ctrl_c,
+            },
+            raw_args,
+            callback,
+        })
+    }
+}
+
+pub struct RunnableContext {
+    pub input: InputStream,
+    pub shell_manager: ShellManager,
+    pub host: Arc<parking_lot::Mutex<Box<dyn Host>>>,
+    pub ctrl_c: Arc<AtomicBool>,
+    pub registry: CommandRegistry,
+    pub name: Tag,
+}
+
+impl RunnableContext {
+    pub fn get_command(&self, name: &str) -> Option<Command> {
+        self.registry.get_command(name)
+    }
+}
+
+pub struct RunnableArgs<T, O: ToOutputStream> {
+    args: T,
+    context: RunnableContext,
+    callback: fn(T, RunnableContext) -> Result<O, ShellError>,
+}
+
+impl<T, O: ToOutputStream> RunnableArgs<T, O> {
+    pub fn run(self) -> Result<OutputStream, ShellError> {
+        (self.callback)(self.args, self.context).map(|v| v.to_output_stream())
+    }
+}
+
+pub struct RunnableRawArgs<T> {
+    args: T,
+    raw_args: RawCommandArgs,
+    context: RunnableContext,
+    callback: fn(T, RunnableContext, RawCommandArgs) -> Result<OutputStream, ShellError>,
+}
+
+impl<T> RunnableRawArgs<T> {
+    pub fn run(self) -> OutputStream {
+        match (self.callback)(self.args, self.context, self.raw_args) {
+            Ok(stream) => stream,
+            Err(err) => OutputStream::one(Err(err)),
+        }
+    }
+}
+
+pub struct EvaluatedWholeStreamCommandArgs {
+    pub args: EvaluatedCommandArgs,
+    pub input: InputStream,
+}
+
+impl Deref for EvaluatedWholeStreamCommandArgs {
+    type Target = EvaluatedCommandArgs;
+    fn deref(&self) -> &Self::Target {
+        &self.args
+    }
+}
+
+impl EvaluatedWholeStreamCommandArgs {
+    pub fn new(
+        host: Arc<parking_lot::Mutex<dyn Host>>,
+        ctrl_c: Arc<AtomicBool>,
+        shell_manager: ShellManager,
+        call_info: CallInfo,
+        input: impl Into<InputStream>,
+    ) -> EvaluatedWholeStreamCommandArgs {
+        EvaluatedWholeStreamCommandArgs {
+            args: EvaluatedCommandArgs {
+                host,
+                ctrl_c,
+                shell_manager,
+                call_info,
+            },
+            input: input.into(),
+        }
+    }
+
+    pub fn name_tag(&self) -> Tag {
+        self.args.call_info.name_tag.clone()
+    }
+
+    pub fn parts(self) -> (InputStream, EvaluatedArgs) {
+        let EvaluatedWholeStreamCommandArgs { args, input } = self;
+
+        (input, args.call_info.args)
+    }
+
+    pub fn split(self) -> (InputStream, EvaluatedCommandArgs) {
+        let EvaluatedWholeStreamCommandArgs { args, input } = self;
+
+        (input, args)
+    }
+}
+
+#[derive(Getters)]
+#[get = "pub"]
+pub struct EvaluatedFilterCommandArgs {
+    args: EvaluatedCommandArgs,
+}
+
+impl Deref for EvaluatedFilterCommandArgs {
+    type Target = EvaluatedCommandArgs;
+    fn deref(&self) -> &Self::Target {
+        &self.args
+    }
+}
+
+impl EvaluatedFilterCommandArgs {
+    pub fn new(
+        host: Arc<parking_lot::Mutex<dyn Host>>,
+        ctrl_c: Arc<AtomicBool>,
+        shell_manager: ShellManager,
+        call_info: CallInfo,
+    ) -> EvaluatedFilterCommandArgs {
+        EvaluatedFilterCommandArgs {
+            args: EvaluatedCommandArgs {
+                host,
+                ctrl_c,
+                shell_manager,
+                call_info,
+            },
+        }
+    }
+}
+
+#[derive(Getters, new)]
+#[get = "pub(crate)"]
+pub struct EvaluatedCommandArgs {
+    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 nth(&self, pos: usize) -> Option<&Value> {
+        self.call_info.args.nth(pos)
+    }
+
+    /// Get the nth positional argument, error if not possible
+    pub fn expect_nth(&self, pos: usize) -> Result<&Value, ShellError> {
+        match self.call_info.args.nth(pos) {
+            None => Err(ShellError::unimplemented("Better error: expect_nth")),
+            Some(item) => Ok(item),
+        }
+    }
+
+    pub fn get(&self, name: &str) -> Option<&Value> {
+        self.call_info.args.get(name)
+    }
+
+    pub fn has(&self, name: &str) -> bool {
+        self.call_info.args.has(name)
+    }
+}
+
+pub struct Example {
+    pub example: &'static str,
+    pub description: &'static str,
+}
+
+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: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError>;
+
+    fn is_binary(&self) -> bool {
+        false
+    }
+
+    fn examples(&self) -> &[Example] {
+        &[]
+    }
+}
+
+#[derive(Clone)]
+pub struct Command(Arc<dyn WholeStreamCommand>);
+
+impl PrettyDebugWithSource for Command {
+    fn pretty_debug(&self, source: &str) -> DebugDocBuilder {
+        b::typed(
+            "whole stream command",
+            b::description(self.name())
+                + b::space()
+                + b::equals()
+                + b::space()
+                + self.signature().pretty_debug(source),
+        )
+    }
+}
+
+impl std::fmt::Debug for Command {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "Command({})", self.name())
+    }
+}
+
+impl Command {
+    pub fn name(&self) -> &str {
+        self.0.name()
+    }
+
+    pub fn signature(&self) -> Signature {
+        self.0.signature()
+    }
+
+    pub fn usage(&self) -> &str {
+        self.0.usage()
+    }
+
+    pub fn run(&self, args: CommandArgs, registry: &CommandRegistry) -> OutputStream {
+        if args.call_info.switch_present("help") {
+            get_help(&*self.0, registry).into()
+        } else {
+            match self.0.run(args, registry) {
+                Ok(stream) => stream,
+                Err(err) => OutputStream::one(Err(err)),
+            }
+        }
+    }
+
+    pub fn is_binary(&self) -> bool {
+        self.0.is_binary()
+    }
+
+    pub fn stream_command(&self) -> &dyn WholeStreamCommand {
+        &*self.0
+    }
+}
+
+pub struct FnFilterCommand {
+    name: String,
+    func: fn(EvaluatedFilterCommandArgs) -> Result<OutputStream, ShellError>,
+}
+
+impl WholeStreamCommand for FnFilterCommand {
+    fn name(&self) -> &str {
+        &self.name
+    }
+
+    fn usage(&self) -> &str {
+        "usage"
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        let CommandArgs {
+            host,
+            ctrl_c,
+            shell_manager,
+            call_info,
+            input,
+        } = args;
+
+        let host: Arc<parking_lot::Mutex<dyn Host>> = host.clone();
+        let registry: CommandRegistry = registry.clone();
+        let func = self.func;
+
+        let result = input.map(move |it| {
+            let registry = registry.clone();
+            let call_info = match call_info.clone().evaluate_with_new_it(&registry, &it) {
+                Err(err) => return OutputStream::from(vec![Err(err)]).values,
+                Ok(args) => args,
+            };
+
+            let args = EvaluatedFilterCommandArgs::new(
+                host.clone(),
+                ctrl_c.clone(),
+                shell_manager.clone(),
+                call_info,
+            );
+
+            match func(args) {
+                Err(err) => OutputStream::from(vec![Err(err)]).values,
+                Ok(stream) => stream.values,
+            }
+        });
+
+        let result = result.flatten();
+        let result: BoxStream<ReturnValue> = result.boxed();
+
+        Ok(result.into())
+    }
+}
+
+pub fn whole_stream_command(command: impl WholeStreamCommand + 'static) -> Command {
+    Command(Arc::new(command))
+}

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

@@ -0,0 +1,68 @@
+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()
+    }
+
+    fn examples(&self) -> &[Example] {
+        &[Example {
+            description: "Remove all directory entries, except those with a 'target'",
+            example: "ls -af | compact target",
+        }]
+    }
+}
+
+pub fn compact(
+    CompactArgs { rest: columns }: CompactArgs,
+    RunnableContext { input, .. }: RunnableContext,
+) -> Result<OutputStream, ShellError> {
+    let objects = input.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 +1,221 @@
+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::String,
+                "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()
+    }
+
+    fn examples(&self) -> &[Example] {
+        &[
+            Example {
+                description: "See all config values",
+                example: "config",
+            },
+            Example {
+                description: "Set completion_mode to circular",
+                example: "config --set [completion_mode circular]",
+            },
+            Example {
+                description: "Store the contents of the pipeline as a path",
+                example: "echo ['/usr/bin' '/bin'] | config --set_into path",
+            },
+            Example {
+                description: "Get the current startup commands",
+                example: "config --get startup",
+            },
+            Example {
+                description: "Remove the startup commands",
+                example: "config --remove startup",
+            },
+            Example {
+                description: "Clear the config (be careful!)",
+                example: "config --clear",
+            },
+            Example {
+                description: "Get the path to the current config file",
+                example: "config --path",
+            },
+        ]
+    }
+}
+
+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.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 +1,53 @@
+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 or items."
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        args.process(registry, count)?.run()
+    }
+
+    fn examples(&self) -> &[Example] {
+        &[Example {
+            description: "Count the number of files/directories in the current directory",
+            example: "ls | count",
+        }]
+    }
+}
+
+pub fn count(
+    CountArgs {}: CountArgs,
+    RunnableContext { input, name, .. }: RunnableContext,
+) -> Result<OutputStream, ShellError> {
+    let stream = async_stream! {
+        let rows: Vec<Value> = input.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 +1,63 @@
+use crate::commands::WholeStreamCommand;
+use crate::context::CommandRegistry;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{Signature, SyntaxShape};
+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 WholeStreamCommand 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,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        args.process(registry, cp)?.run()
+    }
+
+    fn examples(&self) -> &[Example] {
+        &[
+            Example {
+                description: "Copy myfile to dir_b",
+                example: "cp myfile dir_b",
+            },
+            Example {
+                description: "Recursively copy dir_a to dir_b",
+                example: "cp -r dir_a dir_b",
+            },
+        ]
+    }
+}
+
+pub fn cp(args: CopyArgs, context: RunnableContext) -> Result<OutputStream, ShellError> {
+    let shell_manager = context.shell_manager.clone();
+    shell_manager.cp(args, &context)
+}

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

@@ -0,0 +1,108 @@
+use crate::prelude::*;
+use chrono::{DateTime, Local, Utc};
+use nu_errors::ShellError;
+use nu_protocol::{Dictionary, Value};
+
+use crate::commands::WholeStreamCommand;
+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,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        date(args, registry)
+    }
+
+    fn examples(&self) -> &[Example] {
+        &[
+            Example {
+                description: "Get the current local time and date",
+                example: "date",
+            },
+            Example {
+                description: "Get the current UTC time and date",
+                example: "date --utc",
+            },
+        ]
+    }
+}
+
+pub fn date_to_value<T: TimeZone>(dt: DateTime<T>, tag: Tag) -> Value
+where
+    T::Offset: Display,
+{
+    let mut indexmap = IndexMap::new();
+
+    indexmap.insert(
+        "year".to_string(),
+        UntaggedValue::int(dt.year()).into_value(&tag),
+    );
+    indexmap.insert(
+        "month".to_string(),
+        UntaggedValue::int(dt.month()).into_value(&tag),
+    );
+    indexmap.insert(
+        "day".to_string(),
+        UntaggedValue::int(dt.day()).into_value(&tag),
+    );
+    indexmap.insert(
+        "hour".to_string(),
+        UntaggedValue::int(dt.hour()).into_value(&tag),
+    );
+    indexmap.insert(
+        "minute".to_string(),
+        UntaggedValue::int(dt.minute()).into_value(&tag),
+    );
+    indexmap.insert(
+        "second".to_string(),
+        UntaggedValue::int(dt.second()).into_value(&tag),
+    );
+
+    let tz = dt.offset();
+    indexmap.insert(
+        "timezone".to_string(),
+        UntaggedValue::string(format!("{}", tz)).into_value(&tag),
+    );
+
+    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 tag = args.call_info.name_tag.clone();
+
+    let value = if args.has("utc") {
+        let utc: DateTime<Utc> = Utc::now();
+        date_to_value(utc, tag)
+    } else {
+        let local: DateTime<Local> = Local::now();
+        date_to_value(local, tag)
+    };
+
+    date_out.push_back(value);
+
+    Ok(futures::stream::iter(date_out).to_output_stream())
+}

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

@@ -0,0 +1,50 @@
+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
+        .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 +1,82 @@
+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 examples(&self) -> &[Example] {
+        &[Example {
+            description: "Give a default 'target' to all file entries",
+            example: "ls -af | default target 'nothing'",
+        }]
+    }
+}
+
+fn default(
+    DefaultArgs { column, value }: DefaultArgs,
+    RunnableContext { input, .. }: RunnableContext,
+) -> Result<OutputStream, ShellError> {
+    let stream = input
+        .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/drop.rs

@@ -0,0 +1,73 @@
+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 Drop;
+
+#[derive(Deserialize)]
+pub struct DropArgs {
+    rows: Option<Tagged<u64>>,
+}
+
+impl WholeStreamCommand for Drop {
+    fn name(&self) -> &str {
+        "drop"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("drop").optional(
+            "rows",
+            SyntaxShape::Number,
+            "starting from the back, the number of rows to drop",
+        )
+    }
+
+    fn usage(&self) -> &str {
+        "Drop the last number of rows."
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        args.process(registry, drop)?.run()
+    }
+
+    fn examples(&self) -> &[Example] {
+        &[
+            Example {
+                description: "Remove the last item of a list/table",
+                example: "echo [1 2 3] | drop",
+            },
+            Example {
+                description: "Remove the last 2 items of a list/table",
+                example: "echo [1 2 3] | drop 2",
+            },
+        ]
+    }
+}
+
+fn drop(DropArgs { rows }: DropArgs, context: RunnableContext) -> Result<OutputStream, ShellError> {
+    let stream = async_stream! {
+        let v: Vec<_> = context.input.into_vec().await;
+
+        let rows_to_drop = if let Some(quantity) = rows {
+            *quantity as usize
+        } else {
+            1
+        };
+
+        if rows_to_drop < v.len() {
+            let k = v.len() - rows_to_drop;
+            for x in v[0..k].iter() {
+                let y: Value = x.clone();
+                yield ReturnSuccess::value(y)
+            }
+        }
+    };
+    Ok(stream.to_output_stream())
+}

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

@@ -0,0 +1,399 @@
+use crate::commands::WholeStreamCommand;
+use crate::prelude::*;
+use filesize::file_real_size_fast;
+use glob::*;
+use indexmap::map::IndexMap;
+use nu_errors::ShellError;
+use nu_protocol::{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 WholeStreamCommand 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,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        args.process(registry, du)?.run()
+    }
+
+    fn examples(&self) -> &[Example] {
+        &[Example {
+            description: "Disk usage of the current directory",
+            example: "du *",
+        }]
+    }
+}
+
+fn du(args: DuArgs, ctx: RunnableContext) -> 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;
+    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())
+}
+
+pub struct DirBuilder {
+    tag: Tag,
+    min: Option<u64>,
+    deref: bool,
+    exclude: Option<Pattern>,
+    all: bool,
+}
+
+impl DirBuilder {
+    pub fn new(
+        tag: Tag,
+        min: Option<u64>,
+        deref: bool,
+        exclude: Option<Pattern>,
+        all: bool,
+    ) -> DirBuilder {
+        DirBuilder {
+            tag,
+            min,
+            deref,
+            exclude,
+            all,
+        }
+    }
+}
+
+pub 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 {
+    pub 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
+    }
+
+    pub fn get_size(&self) -> u64 {
+        self.size
+    }
+}
+
+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/each.rs

@@ -0,0 +1,109 @@
+use crate::commands::classified::block::run_block;
+use crate::commands::WholeStreamCommand;
+use crate::context::CommandRegistry;
+use crate::prelude::*;
+
+use futures::stream::once;
+use nu_errors::ShellError;
+use nu_protocol::{
+    hir::Block, hir::Expression, hir::SpannedExpression, hir::Synthetic, ReturnSuccess, Signature,
+    SyntaxShape,
+};
+
+pub struct Each;
+
+#[derive(Deserialize)]
+pub struct EachArgs {
+    block: Block,
+}
+
+impl WholeStreamCommand for Each {
+    fn name(&self) -> &str {
+        "each"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("each").required(
+            "block",
+            SyntaxShape::Block,
+            "the block to run on each row",
+        )
+    }
+
+    fn usage(&self) -> &str {
+        "Run a block on each row of the table."
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        Ok(args.process_raw(registry, each)?.run())
+    }
+
+    fn examples(&self) -> &[Example] {
+        &[Example {
+            description: "Print the name of each file",
+            example: "ls | each { echo $it.name }",
+        }]
+    }
+}
+
+fn is_expanded_it_usage(head: &SpannedExpression) -> bool {
+    match &*head {
+        SpannedExpression {
+            expr: Expression::Synthetic(Synthetic::String(s)),
+            ..
+        } if s == "expanded-each" => true,
+        _ => false,
+    }
+}
+
+fn each(
+    each_args: EachArgs,
+    context: RunnableContext,
+    raw_args: RawCommandArgs,
+) -> Result<OutputStream, ShellError> {
+    let block = each_args.block;
+    let scope = raw_args.call_info.scope.clone();
+    let registry = context.registry.clone();
+    let mut input_stream = context.input;
+    let stream = async_stream! {
+        while let Some(input) = input_stream.next().await {
+            let mut context = Context::from_raw(&raw_args, &registry);
+
+            let input_clone = input.clone();
+            let input_stream = if is_expanded_it_usage(&raw_args.call_info.args.head) {
+                InputStream::empty()
+            } else {
+                once(async { Ok(input) }).to_input_stream()
+            };
+
+            let result = run_block(
+                &block,
+                &mut context,
+                input_stream,
+                &scope.clone().set_it(input_clone),
+            ).await;
+
+            match result {
+                Ok(mut stream) => {
+                    while let Some(result) = stream.next().await {
+                        yield Ok(ReturnSuccess::Value(result));
+                    }
+
+                    let errors = context.get_errors();
+                    if let Some(error) = errors.first() {
+                        yield Err(error.clone());
+                    }
+                }
+                Err(e) => {
+                    yield Err(e);
+                }
+            }
+        }
+    };
+
+    Ok(stream.to_output_stream())
+}

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

@@ -0,0 +1,78 @@
+use crate::commands::WholeStreamCommand;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{ReturnSuccess, Signature, SyntaxShape, UntaggedValue, Value};
+
+pub struct Echo;
+
+#[derive(Deserialize)]
+pub struct EchoArgs {
+    pub rest: Vec<Value>,
+}
+
+impl WholeStreamCommand 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,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        args.process(registry, echo)?.run()
+    }
+
+    fn examples(&self) -> &[Example] {
+        &[
+            Example {
+                description: "Put a hello message in the pipeline",
+                example: "echo 'hello'",
+            },
+            Example {
+                description: "Print the value of the special '$nu' variable",
+                example: "echo $nu",
+            },
+        ]
+    }
+}
+
+fn echo(args: EchoArgs, _: RunnableContext) -> Result<OutputStream, ShellError> {
+    let mut output = vec![];
+
+    for i in args.rest {
+        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/enter.rs

@@ -0,0 +1,168 @@
+use crate::commands::UnevaluatedCallInfo;
+use crate::commands::WholeStreamCommand;
+use crate::context::CommandRegistry;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{
+    CommandAction, Primitive, ReturnSuccess, Signature, SyntaxShape, UntaggedValue, Value,
+};
+use nu_source::Tagged;
+use std::path::PathBuf;
+
+pub struct Enter;
+
+#[derive(Deserialize)]
+pub struct EnterArgs {
+    location: Tagged<PathBuf>,
+}
+
+impl WholeStreamCommand 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,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        Ok(args.process_raw(registry, enter)?.run())
+    }
+
+    fn examples(&self) -> &[Example] {
+        &[
+            Example {
+                description: "Enter a path as a new shell",
+                example: "enter ../projectB",
+            },
+            Example {
+                description: "Enter a file as a new shell",
+                example: "enter package.json",
+            },
+        ]
+    }
+}
+
+fn enter(
+    EnterArgs { location }: EnterArgs,
+    RunnableContext {
+        registry,
+        name: tag,
+        ..
+    }: RunnableContext,
+    raw_args: RawCommandArgs,
+) -> Result<OutputStream, ShellError> {
+    let location_string = location.display().to_string();
+    let location_clone = location_string.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,
+                    &PathBuf::from(location_clone),
+                    tag.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_protocol::hir::Call {
+                                        head: raw_args.call_info.args.head,
+                                        positional: None,
+                                        named: None,
+                                        span: Span::unknown(),
+                                        is_last: false,
+                                    },
+                                    name_tag: raw_args.call_info.name_tag,
+                                    scope: raw_args.call_info.scope.clone()
+                                },
+                            };
+                            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())
+    }
+}

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.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

@@ -1,7 +1,8 @@
-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;
 
@@ -11,7 +12,7 @@ impl WholeStreamCommand for Exit {
     }
 
     fn signature(&self) -> Signature {
-        Signature::build("exit").switch("now")
+        Signature::build("exit").switch("now", "exit out of the shell immediately", Some('n'))
     }
 
     fn usage(&self) -> &str {
@@ -25,6 +26,19 @@ impl WholeStreamCommand for Exit {
     ) -> Result<OutputStream, ShellError> {
         exit(args, registry)
     }
+
+    fn examples(&self) -> &[Example] {
+        &[
+            Example {
+                description: "Exit the current shell",
+                example: "exit",
+            },
+            Example {
+                description: "Exit all shells (exiting Nu)",
+                example: "exit --now",
+            },
+        ]
+    }
 }
 
 pub fn exit(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStream, ShellError> {

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

@@ -0,0 +1,65 @@
+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 examples(&self) -> &[Example] {
+        &[
+            Example {
+                description: "Return the first item of a list/table",
+                example: "echo [1 2 3] | first",
+            },
+            Example {
+                description: "Return the first 2 items of a list/table",
+                example: "echo [1 2 3] | first 2",
+            },
+        ]
+    }
+}
+
+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.take(rows_desired)))
+}

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

@@ -0,0 +1,173 @@
+use crate::commands::WholeStreamCommand;
+use crate::context::CommandRegistry;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{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;
+
+pub struct Format;
+
+#[derive(Deserialize)]
+pub struct FormatArgs {
+    pattern: Tagged<String>,
+}
+
+impl WholeStreamCommand for Format {
+    fn name(&self) -> &str {
+        "format"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("format").required(
+            "pattern",
+            SyntaxShape::String,
+            "the pattern to output. Eg) \"{foo}: {bar}\"",
+        )
+    }
+
+    fn usage(&self) -> &str {
+        "Format columns into a string using a simple pattern."
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        args.process(registry, format_command)?.run()
+    }
+
+    fn examples(&self) -> &[Example] {
+        &[Example {
+            description: "Print filenames with their sizes",
+            example: "ls | format '{name}: {size}'",
+        }]
+    }
+}
+
+fn format_command(
+    FormatArgs { pattern }: FormatArgs,
+    RunnableContext { input, .. }: RunnableContext,
+) -> Result<OutputStream, ShellError> {
+    let pattern_tag = pattern.tag.clone();
+
+    let format_pattern = format(&pattern);
+    let commands = format_pattern;
+    let mut input = input;
+
+    let stream = async_stream! {
+        while let Some(value) = input.next().await {
+            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
+                            }
+                        }
+                    }
+
+                    yield ReturnSuccess::value(
+                        UntaggedValue::string(output).into_untagged_value())
+                }
+                _ => yield ReturnSuccess::value(
+                    UntaggedValue::string(String::new()).into_untagged_value()),
+            };
+        }
+    };
+
+    Ok(stream.to_output_stream())
+}
+
+#[derive(Debug)]
+enum FormatCommand {
+    Text(String),
+    Column(String),
+}
+
+fn format(input: &str) -> Vec<FormatCommand> {
+    let mut output = vec![];
+
+    let mut loop_input = input.chars();
+    loop {
+        let mut before = String::new();
+
+        while let Some(c) = loop_input.next() {
+            if c == '{' {
+                break;
+            }
+            before.push(c);
+        }
+
+        if !before.is_empty() {
+            output.push(FormatCommand::Text(before.to_string()));
+        }
+        // Look for column as we're now at one
+        let mut column = String::new();
+
+        while let Some(c) = loop_input.next() {
+            if c == '}' {
+                break;
+            }
+            column.push(c);
+        }
+
+        if !column.is_empty() {
+            output.push(FormatCommand::Column(column.to_string()));
+        }
+
+        if before.is_empty() && column.is_empty() {
+            break;
+        }
+    }
+
+    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.rs

@@ -0,0 +1,28 @@
+use crate::commands::WholeStreamCommand;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::Signature;
+
+pub struct From;
+
+impl WholeStreamCommand for From {
+    fn name(&self) -> &str {
+        "from"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("from")
+    }
+
+    fn usage(&self) -> &str {
+        "Parse content (string or binary) as a table (input format based on subcommand, like csv, ini, json, toml)"
+    }
+
+    fn run(
+        &self,
+        _args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        Ok(crate::commands::help::get_help(&*self, registry).into())
+    }
+}

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

@@ -0,0 +1,232 @@
+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 binary as .bson and create table."
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        from_bson(args, registry)
+    }
+
+    fn examples(&self) -> &[Example] {
+        &[Example {
+            description: "Convert bson data to a table",
+            example: "open file.bin | from bson",
+        }]
+    }
+}
+
+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 +1,96 @@
+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 examples(&self) -> &[Example] {
+        &[
+            Example {
+                description: "Convert comma-separated data to a table",
+                example: "open data.txt | from csv",
+            },
+            Example {
+                description: "Convert comma-separated data to a table, ignoring headers",
+                example: "open data.txt | from csv --headerless",
+            },
+            Example {
+                description: "Convert semicolon-separated data to a table",
+                example: "open data.txt | from csv --separator ';'",
+            },
+        ]
+    }
+}
+
+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 +1,105 @@
+use crate::prelude::*;
+use csv::{ErrorKind, ReaderBuilder};
+use nu_errors::ShellError;
+use nu_protocol::{ReturnSuccess, TaggedDictBuilder, UntaggedValue, Value};
+
+fn from_delimited_string_to_value(
+    s: String,
+    headerless: bool,
+    separator: char,
+    tag: impl Into<Tag>,
+) -> Result<Value, csv::Error> {
+    let mut reader = ReaderBuilder::new()
+        .has_headers(!headerless)
+        .delimiter(separator as u8)
+        .from_reader(s.as_bytes());
+    let tag = tag.into();
+
+    let headers = if headerless {
+        (1..=reader.headers()?.len())
+            .map(|i| format!("Column{}", i))
+            .collect::<Vec<String>>()
+    } else {
+        reader.headers()?.iter().map(String::from).collect()
+    };
+
+    let mut rows = vec![];
+    for row in reader.records() {
+        let mut tagged_row = TaggedDictBuilder::new(&tag);
+        for (value, header) in row?.iter().zip(headers.iter()) {
+            if let Ok(i) = value.parse::<i64>() {
+                tagged_row.insert_value(header, UntaggedValue::int(i).into_value(&tag))
+            } else if let Ok(f) = value.parse::<f64>() {
+                tagged_row.insert_value(header, UntaggedValue::decimal(f).into_value(&tag))
+            } else {
+                tagged_row.insert_value(header, UntaggedValue::string(value).into_value(&tag))
+            }
+        }
+        rows.push(tagged_row.into_value());
+    }
+
+    Ok(UntaggedValue::Table(rows).into_value(&tag))
+}
+
+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(x) => match x {
+                Value { value: UntaggedValue::Table(list), .. } => {
+                    for l in list {
+                        yield ReturnSuccess::value(l);
+                    }
+                }
+                x => yield ReturnSuccess::value(x),
+            },
+            Err(err) => {
+                let line_one = match pretty_csv_error(err) {
+                    Some(pretty) => format!("Could not parse as {} ({})", format_name,pretty),
+                    None => 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())
+}
+
+fn pretty_csv_error(err: csv::Error) -> Option<String> {
+    match err.kind() {
+        ErrorKind::UnequalLengths {
+            pos,
+            expected_len,
+            len,
+        } => {
+            if let Some(pos) = pos {
+                Some(format!(
+                    "Line {}: expected {} fields, found {}",
+                    pos.line(),
+                    expected_len,
+                    len
+                ))
+            } else {
+                Some(format!("Expected {} fields, found {}", expected_len, len))
+            }
+        }
+        ErrorKind::Seek => Some("Internal error while parsing csv".to_string()),
+        _ => None,
+    }
+}

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

@@ -0,0 +1,122 @@
+use crate::commands::WholeStreamCommand;
+use crate::prelude::*;
+use ::eml_parser::eml::*;
+use ::eml_parser::EmlParser;
+use nu_errors::ShellError;
+use nu_protocol::{ReturnSuccess, Signature, SyntaxShape, TaggedDictBuilder, UntaggedValue};
+use nu_source::Tagged;
+
+pub struct FromEML;
+
+const DEFAULT_BODY_PREVIEW: usize = 50;
+
+#[derive(Deserialize, Clone)]
+pub struct FromEMLArgs {
+    #[serde(rename(deserialize = "preview-body"))]
+    preview_body: Option<Tagged<usize>>,
+}
+
+impl WholeStreamCommand for FromEML {
+    fn name(&self) -> &str {
+        "from eml"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("from eml").named(
+            "preview-body",
+            SyntaxShape::Int,
+            "How many bytes of the body to preview",
+            Some('b'),
+        )
+    }
+
+    fn usage(&self) -> &str {
+        "Parse text as .eml and create table."
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        args.process(registry, from_eml)?.run()
+    }
+}
+
+fn emailaddress_to_value(tag: &Tag, email_address: &EmailAddress) -> TaggedDictBuilder {
+    let mut dict = TaggedDictBuilder::with_capacity(tag, 2);
+    let (n, a) = match email_address {
+        EmailAddress::AddressOnly { address } => {
+            (UntaggedValue::nothing(), UntaggedValue::string(address))
+        }
+        EmailAddress::NameAndEmailAddress { name, address } => {
+            (UntaggedValue::string(name), UntaggedValue::string(address))
+        }
+    };
+
+    dict.insert_untagged("Name", n);
+    dict.insert_untagged("Address", a);
+
+    dict
+}
+
+fn headerfieldvalue_to_value(tag: &Tag, value: &HeaderFieldValue) -> UntaggedValue {
+    use HeaderFieldValue::*;
+
+    match value {
+        SingleEmailAddress(address) => emailaddress_to_value(tag, address).into_untagged_value(),
+        MultipleEmailAddresses(addresses) => UntaggedValue::Table(
+            addresses
+                .iter()
+                .map(|a| emailaddress_to_value(tag, a).into_value())
+                .collect(),
+        ),
+        Unstructured(s) => UntaggedValue::string(s),
+        Empty => UntaggedValue::nothing(),
+    }
+}
+
+fn from_eml(
+    eml_args: FromEMLArgs,
+    runnable_context: RunnableContext,
+) -> Result<OutputStream, ShellError> {
+    let input = runnable_context.input;
+    let tag = runnable_context.name;
+
+    let stream = async_stream! {
+        let value = input.collect_string(tag.clone()).await?;
+
+        let body_preview = eml_args.preview_body.map(|b| b.item).unwrap_or(DEFAULT_BODY_PREVIEW);
+
+        let eml = EmlParser::from_string(value.item)
+        .with_body_preview(body_preview)
+        .parse()
+        .map_err(|_| ShellError::labeled_error("Could not parse .eml file", "could not parse .eml file", &tag))?;
+
+        let mut dict = TaggedDictBuilder::new(&tag);
+
+        if let Some(subj) = eml.subject {
+           dict.insert_untagged("Subject", UntaggedValue::string(subj));
+        }
+
+        if let Some(from) = eml.from {
+           dict.insert_untagged("From", headerfieldvalue_to_value(&tag, &from));
+        }
+
+        if let Some(to) = eml.to {
+           dict.insert_untagged("To", headerfieldvalue_to_value(&tag, &to));
+        }
+
+        for HeaderField{ name, value } in eml.headers.iter() {
+           dict.insert_untagged(name, headerfieldvalue_to_value(&tag, &value));
+        }
+
+        if let Some(body) = eml.body {
+           dict.insert_untagged("Body", UntaggedValue::string(body));
+        }
+
+        yield ReturnSuccess::value(dict.into_value());
+    };
+
+    Ok(stream.to_output_stream())
+}

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

@@ -1,7 +1,7 @@
 use crate::commands::WholeStreamCommand;
-use crate::data::{Primitive, TaggedDictBuilder, Value};
-use crate::errors::ShellError;
 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;
@@ -10,11 +10,11 @@ pub struct FromSQLite;
 
 impl WholeStreamCommand for FromSQLite {
     fn name(&self) -> &str {
-        "from-sqlite"
+        "from sqlite"
     }
 
     fn signature(&self) -> Signature {
-        Signature::build("from-sqlite")
+        Signature::build("from sqlite")
     }
 
     fn usage(&self) -> &str {
@@ -34,11 +34,11 @@ pub struct FromDB;
 
 impl WholeStreamCommand for FromDB {
     fn name(&self) -> &str {
-        "from-db"
+        "from db"
     }
 
     fn signature(&self) -> Signature {
-        Signature::build("from-db")
+        Signature::build("from db")
     }
 
     fn usage(&self) -> &str {
@@ -57,7 +57,7 @@ impl WholeStreamCommand for FromDB {
 pub fn convert_sqlite_file_to_nu_value(
     path: &Path,
     tag: impl Into<Tag> + Clone,
-) -> Result<Tagged<Value>, rusqlite::Error> {
+) -> Result<Value, rusqlite::Error> {
     let conn = Connection::open(path)?;
 
     let mut meta_out = Vec::new();
@@ -72,48 +72,54 @@ pub fn convert_sqlite_file_to_nu_value(
         while let Some(table_row) = table_rows.next()? {
             out.push(convert_sqlite_row_to_nu_value(table_row, tag.clone())?)
         }
-        meta_dict.insert_tagged(
+        meta_dict.insert_value(
             "table_name".to_string(),
-            Value::Primitive(Primitive::String(table_name)).tagged(tag.clone()),
+            UntaggedValue::Primitive(Primitive::String(table_name)).into_value(tag.clone()),
         );
-        meta_dict.insert_tagged("table_values", Value::Table(out).tagged(tag.clone()));
-        meta_out.push(meta_dict.into_tagged_value());
+        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(Value::Table(meta_out).tagged(tag))
+    Ok(UntaggedValue::Table(meta_out).into_value(tag))
 }
 
 fn convert_sqlite_row_to_nu_value(
     row: &Row,
     tag: impl Into<Tag> + Clone,
-) -> Result<Tagged<Value>, rusqlite::Error> {
+) -> Result<Value, rusqlite::Error> {
     let mut collected = TaggedDictBuilder::new(tag.clone());
     for (i, c) in row.columns().iter().enumerate() {
-        collected.insert_tagged(
+        collected.insert_value(
             c.name().to_string(),
             convert_sqlite_value_to_nu_value(row.get_raw(i), tag.clone()),
         );
     }
-    return Ok(collected.into_tagged_value());
+    Ok(collected.into_value())
 }
 
-fn convert_sqlite_value_to_nu_value(value: ValueRef, tag: impl Into<Tag> + Clone) -> Tagged<Value> {
+fn convert_sqlite_value_to_nu_value(value: ValueRef, tag: impl Into<Tag> + Clone) -> Value {
     match value {
-        ValueRef::Null => Value::Primitive(Primitive::String(String::from(""))).tagged(tag),
-        ValueRef::Integer(i) => Value::number(i).tagged(tag),
-        ValueRef::Real(f) => Value::number(f).tagged(tag),
-        t @ ValueRef::Text(_) => {
-            // this unwrap is safe because we know the ValueRef is Text.
-            Value::Primitive(Primitive::String(t.as_str().unwrap().to_string())).tagged(tag)
+        ValueRef::Null => {
+            UntaggedValue::Primitive(Primitive::String(String::from(""))).into_value(tag)
         }
-        ValueRef::Blob(u) => Value::binary(u.to_owned()).tagged(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<Tagged<Value>, std::io::Error> {
+) -> 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
@@ -131,40 +137,26 @@ fn from_sqlite(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputSt
     let tag = args.name_tag();
     let input = args.input;
 
-    let stream = async_stream_block! {
-        let values: Vec<Tagged<Value>> = input.values.collect().await;
-
-        for value in values {
-            let value_tag = value.tag();
-            match value.item {
-                Value::Primitive(Primitive::Binary(vb)) =>
-                    match from_sqlite_bytes_to_value(vb, tag) {
-                        Ok(x) => match x {
-                            Tagged { item: Value::Table(list), .. } => {
-                                for l in list {
-                                    yield ReturnSuccess::value(l);
-                                }
-                            }
-                            _ => yield ReturnSuccess::value(x),
-                        }
-                        Err(_) => {
-                            yield Err(ShellError::labeled_error_with_secondary(
-                                "Could not parse as SQLite",
-                                "input cannot be parsed as SQLite",
-                                tag,
-                                "value originates from here",
-                                value_tag,
-                            ))
-                        }
+    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 Err(ShellError::labeled_error_with_secondary(
-                    "Expected a string from pipeline",
-                    "requires string input",
-                    tag,
+                }
+                _ => 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",
-                    value_tag,
-                )),
-
+                    bytes.tag,
+                ))
             }
         }
     };

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 +1,254 @@
+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()
+    }
+
+    fn examples(&self) -> &[Example] {
+        &[
+            Example {
+                description: "Extract the name of files as a list",
+                example: "ls | get name",
+            },
+            Example {
+                description: "Extract the cpu list from the sys information",
+                example: "sys | get cpu",
+            },
+        ]
+    }
+}
+
+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
+            .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 +1,234 @@
+use crate::commands::WholeStreamCommand;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{ReturnSuccess, Signature, SyntaxShape, Value};
+use nu_source::Tagged;
+
+pub struct GroupBy;
+
+#[derive(Deserialize)]
+pub struct GroupByArgs {
+    column_name: Tagged<String>,
+    date: Tagged<bool>,
+    format: Option<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",
+            )
+            .named(
+                "format",
+                SyntaxShape::String,
+                "Specify date and time formatting",
+                Some('f'),
+            )
+            .switch("date", "by date", Some('d'))
+    }
+
+    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()
+    }
+
+    fn examples(&self) -> &[Example] {
+        &[Example {
+            description: "Group files by type",
+            example: "ls | group-by type",
+        }]
+    }
+}
+
+enum Grouper {
+    Default,
+    ByDate(Option<String>),
+}
+
+pub fn group_by(
+    GroupByArgs {
+        column_name,
+        date,
+        format,
+    }: GroupByArgs,
+    RunnableContext { input, name, .. }: RunnableContext,
+) -> Result<OutputStream, ShellError> {
+    let stream = async_stream! {
+        let values: Vec<Value> = input.collect().await;
+
+        if values.is_empty() {
+            yield Err(ShellError::labeled_error(
+                    "Expected table from pipeline",
+                    "requires a table input",
+                    column_name.span()
+                ))
+        } else {
+
+            let grouper = if let Tagged { item: true, tag } = date {
+                if let Some(Tagged { item: fmt, tag }) = format {
+                    Grouper::ByDate(Some(fmt))
+                } else {
+                    Grouper::ByDate(None)
+                }
+            } else {
+                Grouper::Default
+            };
+
+            match grouper {
+                Grouper::Default => {
+                    match crate::utils::data::group(column_name, &values, None, &name) {
+                        Ok(grouped) => yield ReturnSuccess::value(grouped),
+                        Err(err) => yield Err(err),
+                    }
+                }
+                Grouper::ByDate(None) => {
+                    match crate::utils::data::group(column_name, &values, Some(Box::new(|row: &Value| row.format("%Y-%b-%d"))), &name) {
+                        Ok(grouped) => yield ReturnSuccess::value(grouped),
+                        Err(err) => yield Err(err),
+                    }
+                }
+                Grouper::ByDate(Some(fmt)) => {
+                    match crate::utils::data::group(column_name, &values, Some(Box::new(move |row: &Value| {
+                        row.format(&fmt)
+                    })), &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> {
+    crate::utils::data::group(column_name.clone(), &values, None, tag)
+}
+
+#[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 +1,90 @@
+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()
+    }
+
+    fn examples(&self) -> &[Example] {
+        &[Example {
+            description: "Create headers for a raw string",
+            example: "echo \"a b c|1 2 3\" | split-row \"|\" | split-column \" \" | headers",
+        }]
+    }
+}
+
+pub fn headers(
+    HeadersArgs {}: HeadersArgs,
+    RunnableContext { input, .. }: RunnableContext,
+) -> Result<OutputStream, ShellError> {
+    let stream = async_stream! {
+        let rows: Vec<Value> = input.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 +1,292 @@
+use crate::commands::WholeStreamCommand;
+use crate::data::command_dict;
+
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{
+    NamedType, PositionalType, ReturnSuccess, Signature, SyntaxShape, TaggedDictBuilder,
+    UntaggedValue,
+};
+use nu_source::{SpannedItem, Tagged};
+use nu_value_ext::get_data_by_key;
+
+pub struct Help;
+
+#[derive(Deserialize)]
+pub struct HelpArgs {
+    rest: Vec<Tagged<String>>,
+}
+
+impl WholeStreamCommand for Help {
+    fn name(&self) -> &str {
+        "help"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("help").rest(SyntaxShape::String, "the name of command to get help on")
+    }
+
+    fn usage(&self) -> &str {
+        "Display help information about commands."
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        args.process(registry, help)?.run()
+    }
+}
+
+fn help(
+    HelpArgs { rest }: HelpArgs,
+    RunnableContext { registry, name, .. }: RunnableContext,
+) -> Result<OutputStream, ShellError> {
+    if let Some(document) = rest.get(0) {
+        let mut help = VecDeque::new();
+        if document.item == "commands" {
+            let mut sorted_names = registry.names();
+            sorted_names.sort();
+            for cmd in sorted_names {
+                // If it's a subcommand, don't list it during the commands list
+                if cmd.contains(' ') {
+                    continue;
+                }
+                let mut short_desc = TaggedDictBuilder::new(name.clone());
+                let document_tag = document.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",
+                            document_tag,
+                        )
+                    })?,
+                    name.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 rest.len() == 2 {
+            // Check for a subcommand
+            let command_name = format!("{} {}", rest[0].item, rest[1].item);
+            if let Some(command) = registry.get_command(&command_name) {
+                return Ok(get_help(command.stream_command(), &registry).into());
+            }
+        } else if let Some(command) = registry.get_command(&document.item) {
+            return Ok(get_help(command.stream_command(), &registry).into());
+        } else {
+            return Err(ShellError::labeled_error(
+                "Can't find command (use 'help commands' for full list)",
+                "can't find command",
+                document.tag.span,
+            ));
+        }
+        let help = futures::stream::iter(help);
+        Ok(help.to_output_stream())
+    } else {
+        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(name),
+        )]);
+
+        Ok(output_stream.to_output_stream())
+    }
+}
+
+#[allow(clippy::cognitive_complexity)]
+pub(crate) fn get_help(
+    cmd: &dyn WholeStreamCommand,
+    registry: &CommandRegistry,
+) -> impl Into<OutputStream> {
+    let cmd_name = cmd.name();
+    let signature = cmd.signature();
+    let mut help = VecDeque::new();
+    let mut long_desc = String::new();
+
+    long_desc.push_str(&cmd.usage());
+    long_desc.push_str("\n");
+
+    let mut subcommands = String::new();
+    for name in registry.names() {
+        if name.starts_with(&format!("{} ", cmd_name)) {
+            let subcommand = registry.get_command(&name).expect("This shouldn't happen");
+
+            subcommands.push_str(&format!("  {} - {}\n", name, subcommand.usage()));
+        }
+    }
+
+    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 !subcommands.is_empty() {
+        one_liner.push_str("<subcommand> ");
+    }
+
+    if !signature.named.is_empty() {
+        one_liner.push_str("{flags} ");
+    }
+
+    long_desc.push_str(&format!("\nUsage:\n  > {}\n", one_liner));
+
+    if !subcommands.is_empty() {
+        long_desc.push_str("\nSubcommands:\n");
+        long_desc.push_str(&subcommands);
+    }
+
+    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);
+        }
+    }
+
+    let examples = cmd.examples();
+    if !examples.is_empty() {
+        long_desc.push_str("\nExamples:");
+    }
+    for example in examples {
+        long_desc.push_str("\n");
+        long_desc.push_str("  ");
+        long_desc.push_str(example.description);
+        let colored_example =
+            crate::shell::helper::Painter::paint_string(example.example, registry);
+        long_desc.push_str(&format!("\n  > {}\n", colored_example));
+    }
+
+    long_desc.push_str("\n");
+
+    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 +1,178 @@
+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::String,
+                "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()
+    }
+
+    fn examples(&self) -> &[Example] {
+        &[
+            Example {
+                description: "Get a histogram for the types of files",
+                example: "ls | histogram type",
+            },
+            Example {
+                description:
+                    "Get a histogram for the types of files, with frequency column named count",
+                example: "ls | histogram type count",
+            },
+            Example {
+                description: "Get a histogram for a list of numbers",
+                example: "echo [1 2 3 1 2 3 1 1 1 1 3 2 1 1 3] | wrap | histogram Column",
+            },
+        ]
+    }
+}
+
+pub fn histogram(
+    HistogramArgs { column_name, rest }: HistogramArgs,
+    RunnableContext { input, name, .. }: RunnableContext,
+) -> Result<OutputStream, ShellError> {
+    let stream = async_stream! {
+        let values: Vec<Value> = input.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 +1,55 @@
+use crate::cli::History as HistoryFile;
+use crate::commands::WholeStreamCommand;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{ReturnSuccess, Signature, UntaggedValue};
+use std::fs::File;
+use std::io::{BufRead, BufReader};
+
+pub struct History;
+
+#[derive(Deserialize)]
+pub struct HistoryArgs {}
+
+impl WholeStreamCommand for History {
+    fn name(&self) -> &str {
+        "history"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("history")
+    }
+
+    fn usage(&self) -> &str {
+        "Display command history."
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        args.process(registry, history)?.run()
+    }
+}
+
+fn history(
+    _: HistoryArgs,
+    RunnableContext { name: tag, .. }: RunnableContext,
+) -> Result<OutputStream, ShellError> {
+    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 +1,77 @@
+use crate::commands::WholeStreamCommand;
+use crate::context::CommandRegistry;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{ColumnPath, ReturnSuccess, Signature, SyntaxShape, UntaggedValue, Value};
+use nu_value_ext::ValueExt;
+
+pub struct Insert;
+
+#[derive(Deserialize)]
+pub struct InsertArgs {
+    column: ColumnPath,
+    value: Value,
+}
+
+impl WholeStreamCommand 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 {
+        "Insert a new column with a given value."
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        args.process(registry, insert)?.run()
+    }
+}
+
+fn insert(
+    InsertArgs { column, value }: InsertArgs,
+    RunnableContext { input, .. }: RunnableContext,
+) -> Result<OutputStream, ShellError> {
+    let mut input = input;
+
+    let stream = async_stream! {
+        match input.next().await {
+            Some(obj @ Value {
+                value: UntaggedValue::Row(_),
+                ..
+            }) => match obj.insert_data_at_column_path(&column, value.clone()) {
+                Ok(v) => yield Ok(ReturnSuccess::Value(v)),
+                Err(err) => yield Err(err),
+            },
+
+            Some(Value { tag, ..}) => {
+                yield Err(ShellError::labeled_error(
+                    "Unrecognized type in stream",
+                    "original value",
+                    tag,
+                ));
+            }
+
+            None => {}
+        };
+
+    };
+    Ok(stream.to_output_stream())
+}

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

@@ -0,0 +1,198 @@
+use crate::commands::WholeStreamCommand;
+use crate::context::CommandRegistry;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{ColumnPath, ReturnSuccess, Signature, SyntaxShape, UntaggedValue, Value};
+use nu_source::Tagged;
+use nu_value_ext::ValueExt;
+
+enum IsEmptyFor {
+    Value,
+    RowWithFieldsAndFallback(Vec<Tagged<ColumnPath>>, Value),
+    RowWithField(Tagged<ColumnPath>),
+    RowWithFieldAndFallback(Box<Tagged<ColumnPath>>, Value),
+}
+
+pub struct IsEmpty;
+
+#[derive(Deserialize)]
+pub struct IsEmptyArgs {
+    rest: Vec<Value>,
+}
+
+impl WholeStreamCommand for IsEmpty {
+    fn name(&self) -> &str {
+        "empty?"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("empty?").rest(
+            SyntaxShape::Any,
+            "the names of the columns to check emptiness followed by the replacement value.",
+        )
+    }
+
+    fn usage(&self) -> &str {
+        "Checks emptiness. The last value is the replacement value for any empty column(s) given to check against the table."
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        args.process(registry, is_empty)?.run()
+    }
+}
+
+fn is_empty(
+    IsEmptyArgs { rest }: IsEmptyArgs,
+    RunnableContext { input, .. }: RunnableContext,
+) -> Result<OutputStream, ShellError> {
+    Ok(input
+        .map(move |value| {
+            let value_tag = value.tag();
+
+            let action = if rest.len() <= 2 {
+                let field = rest.get(0);
+                let replacement_if_true = rest.get(1);
+
+                match (field, replacement_if_true) {
+                    (Some(field), Some(replacement_if_true)) => {
+                        IsEmptyFor::RowWithFieldAndFallback(
+                            Box::new(field.as_column_path()?),
+                            replacement_if_true.clone(),
+                        )
+                    }
+                    (Some(field), None) => IsEmptyFor::RowWithField(field.as_column_path()?),
+                    (_, _) => IsEmptyFor::Value,
+                }
+            } else {
+                // let no_args = vec![];
+                let mut arguments = rest.iter().rev();
+                let replacement_if_true = match arguments.next() {
+                    Some(arg) => arg.clone(),
+                    None => UntaggedValue::boolean(value.is_empty()).into_value(&value_tag),
+                };
+
+                IsEmptyFor::RowWithFieldsAndFallback(
+                    arguments
+                        .map(|a| a.as_column_path())
+                        .filter_map(Result::ok)
+                        .collect(),
+                    replacement_if_true,
+                )
+            };
+
+            match action {
+                IsEmptyFor::Value => Ok(ReturnSuccess::Value(
+                    UntaggedValue::boolean(value.is_empty()).into_value(value_tag),
+                )),
+                IsEmptyFor::RowWithFieldsAndFallback(fields, default) => {
+                    let mut out = value;
+
+                    for field in fields.iter() {
+                        let val =
+                            out.get_data_by_column_path(&field, Box::new(move |(_, _, err)| err))?;
+
+                        let emptiness_value = match out {
+                            obj
+                            @
+                            Value {
+                                value: UntaggedValue::Row(_),
+                                ..
+                            } => {
+                                if val.is_empty() {
+                                    match obj.replace_data_at_column_path(&field, default.clone()) {
+                                        Some(v) => Ok(v),
+                                        None => Err(ShellError::labeled_error(
+                                            "empty? could not find place to check emptiness",
+                                            "column name",
+                                            &field.tag,
+                                        )),
+                                    }
+                                } else {
+                                    Ok(obj)
+                                }
+                            }
+                            _ => Err(ShellError::labeled_error(
+                                "Unrecognized type in stream",
+                                "original value",
+                                &value_tag,
+                            )),
+                        };
+
+                        out = emptiness_value?;
+                    }
+
+                    Ok(ReturnSuccess::Value(out))
+                }
+                IsEmptyFor::RowWithField(field) => {
+                    let val =
+                        value.get_data_by_column_path(&field, Box::new(move |(_, _, err)| err))?;
+
+                    match &value {
+                        obj
+                        @
+                        Value {
+                            value: UntaggedValue::Row(_),
+                            ..
+                        } => {
+                            if val.is_empty() {
+                                match obj.replace_data_at_column_path(
+                                    &field,
+                                    UntaggedValue::boolean(true).into_value(&value_tag),
+                                ) {
+                                    Some(v) => Ok(ReturnSuccess::Value(v)),
+                                    None => Err(ShellError::labeled_error(
+                                        "empty? could not find place to check emptiness",
+                                        "column name",
+                                        &field.tag,
+                                    )),
+                                }
+                            } else {
+                                Ok(ReturnSuccess::Value(value))
+                            }
+                        }
+                        _ => Err(ShellError::labeled_error(
+                            "Unrecognized type in stream",
+                            "original value",
+                            &value_tag,
+                        )),
+                    }
+                }
+                IsEmptyFor::RowWithFieldAndFallback(field, default) => {
+                    let val =
+                        value.get_data_by_column_path(&field, Box::new(move |(_, _, err)| err))?;
+
+                    match &value {
+                        obj
+                        @
+                        Value {
+                            value: UntaggedValue::Row(_),
+                            ..
+                        } => {
+                            if val.is_empty() {
+                                match obj.replace_data_at_column_path(&field, default) {
+                                    Some(v) => Ok(ReturnSuccess::Value(v)),
+                                    None => Err(ShellError::labeled_error(
+                                        "empty? could not find place to check emptiness",
+                                        "column name",
+                                        &field.tag,
+                                    )),
+                                }
+                            } else {
+                                Ok(ReturnSuccess::Value(value))
+                            }
+                        }
+                        _ => Err(ShellError::labeled_error(
+                            "Unrecognized type in stream",
+                            "original value",
+                            &value_tag,
+                        )),
+                    }
+                }
+            }
+        })
+        .to_output_stream())
+}

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

@@ -0,0 +1,62 @@
+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 Keep;
+
+#[derive(Deserialize)]
+pub struct KeepArgs {
+    rows: Option<Tagged<usize>>,
+}
+
+impl WholeStreamCommand for Keep {
+    fn name(&self) -> &str {
+        "keep"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("keep").optional(
+            "rows",
+            SyntaxShape::Int,
+            "starting from the front, the number of rows to keep",
+        )
+    }
+
+    fn usage(&self) -> &str {
+        "Keep the number of rows only"
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        args.process(registry, keep)?.run()
+    }
+
+    fn examples(&self) -> &[Example] {
+        &[
+            Example {
+                description: "Keep the first row",
+                example: "ls | keep",
+            },
+            Example {
+                description: "Keep the first four rows",
+                example: "ls | keep 4",
+            },
+        ]
+    }
+}
+
+fn keep(KeepArgs { rows }: KeepArgs, context: RunnableContext) -> Result<OutputStream, ShellError> {
+    let rows_desired = if let Some(quantity) = rows {
+        *quantity
+    } else {
+        1
+    };
+
+    Ok(OutputStream::from_input(context.input.take(rows_desired)))
+}

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

@@ -0,0 +1,98 @@
+use crate::commands::WholeStreamCommand;
+use crate::evaluate::evaluate_baseline_expr;
+use crate::prelude::*;
+use log::trace;
+use nu_errors::ShellError;
+use nu_protocol::{hir::ClassifiedCommand, Signature, SyntaxShape, UntaggedValue, Value};
+
+pub struct KeepUntil;
+
+impl WholeStreamCommand for KeepUntil {
+    fn name(&self) -> &str {
+        "keep-until"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("keep-until")
+            .required(
+                "condition",
+                SyntaxShape::Math,
+                "the condition that must be met to stop keeping rows",
+            )
+            .filter()
+    }
+
+    fn usage(&self) -> &str {
+        "Keeps rows until the condition matches."
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        let registry = registry.clone();
+        let scope = args.call_info.scope.clone();
+        let call_info = args.evaluate_once(&registry)?;
+
+        let block = call_info.args.expect_nth(0)?.clone();
+
+        let condition = match block {
+            Value {
+                value: UntaggedValue::Block(block),
+                tag,
+            } => {
+                if block.block.len() != 1 {
+                    return Err(ShellError::labeled_error(
+                        "Expected a condition",
+                        "expected a condition",
+                        tag,
+                    ));
+                }
+                match block.block[0].list.get(0) {
+                    Some(item) => match item {
+                        ClassifiedCommand::Expr(expr) => expr.clone(),
+                        _ => {
+                            return Err(ShellError::labeled_error(
+                                "Expected a condition",
+                                "expected a condition",
+                                tag,
+                            ))
+                        }
+                    },
+                    None => {
+                        return Err(ShellError::labeled_error(
+                            "Expected a condition",
+                            "expected a condition",
+                            tag,
+                        ));
+                    }
+                }
+            }
+            Value { tag, .. } => {
+                return Err(ShellError::labeled_error(
+                    "Expected a condition",
+                    "expected a condition",
+                    tag,
+                ));
+            }
+        };
+
+        let objects = call_info.input.take_while(move |item| {
+            let condition = condition.clone();
+            trace!("ITEM = {:?}", item);
+            let result =
+                evaluate_baseline_expr(&*condition, &registry, &scope.clone().set_it(item.clone()));
+            trace!("RESULT = {:?}", result);
+
+            let return_value = match result {
+                Ok(ref v) if v.is_true() => false,
+                _ => true,
+            };
+
+            futures::future::ready(return_value)
+        });
+
+        Ok(objects.from_input_stream())
+    }
+}

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

@@ -0,0 +1,98 @@
+use crate::commands::WholeStreamCommand;
+use crate::evaluate::evaluate_baseline_expr;
+use crate::prelude::*;
+use log::trace;
+use nu_errors::ShellError;
+use nu_protocol::{hir::ClassifiedCommand, Signature, SyntaxShape, UntaggedValue, Value};
+
+pub struct KeepWhile;
+
+impl WholeStreamCommand for KeepWhile {
+    fn name(&self) -> &str {
+        "keep-while"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("keep-while")
+            .required(
+                "condition",
+                SyntaxShape::Math,
+                "the condition that must be met to keep rows",
+            )
+            .filter()
+    }
+
+    fn usage(&self) -> &str {
+        "Keeps rows while the condition matches."
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        let registry = registry.clone();
+        let scope = args.call_info.scope.clone();
+        let call_info = args.evaluate_once(&registry)?;
+
+        let block = call_info.args.expect_nth(0)?.clone();
+
+        let condition = match block {
+            Value {
+                value: UntaggedValue::Block(block),
+                tag,
+            } => {
+                if block.block.len() != 1 {
+                    return Err(ShellError::labeled_error(
+                        "Expected a condition",
+                        "expected a condition",
+                        tag,
+                    ));
+                }
+                match block.block[0].list.get(0) {
+                    Some(item) => match item {
+                        ClassifiedCommand::Expr(expr) => expr.clone(),
+                        _ => {
+                            return Err(ShellError::labeled_error(
+                                "Expected a condition",
+                                "expected a condition",
+                                tag,
+                            ))
+                        }
+                    },
+                    None => {
+                        return Err(ShellError::labeled_error(
+                            "Expected a condition",
+                            "expected a condition",
+                            tag,
+                        ));
+                    }
+                }
+            }
+            Value { tag, .. } => {
+                return Err(ShellError::labeled_error(
+                    "Expected a condition",
+                    "expected a condition",
+                    tag,
+                ));
+            }
+        };
+
+        let objects = call_info.input.take_while(move |item| {
+            let condition = condition.clone();
+            trace!("ITEM = {:?}", item);
+            let result =
+                evaluate_baseline_expr(&*condition, &registry, &scope.clone().set_it(item.clone()));
+            trace!("RESULT = {:?}", result);
+
+            let return_value = match result {
+                Ok(ref v) if v.is_true() => true,
+                _ => false,
+            };
+
+            futures::future::ready(return_value)
+        });
+
+        Ok(objects.from_input_stream())
+    }
+}

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

@@ -0,0 +1,113 @@
+use crate::commands::WholeStreamCommand;
+use crate::context::CommandRegistry;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{Signature, SyntaxShape};
+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 WholeStreamCommand 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,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        args.process(registry, kill)?.run()
+    }
+
+    fn examples(&self) -> &[Example] {
+        &[
+            Example {
+                description: "Kill the pid using the most memory",
+                example: "ps | sort-by mem | last | kill $it.pid",
+            },
+            Example {
+                description: "Force kill a given pid",
+                example: "kill --force 12345",
+            },
+        ]
+    }
+}
+
+fn kill(
+    KillArgs {
+        pid,
+        rest,
+        force,
+        quiet,
+    }: KillArgs,
+    _context: RunnableContext,
+) -> 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 +1,74 @@
+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 examples(&self) -> &[Example] {
+        &[
+            Example {
+                description: "Get the last row",
+                example: "ls | last",
+            },
+            Example {
+                description: "Get the last three rows",
+                example: "ls | last 3",
+            },
+        ]
+    }
+}
+
+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 +1,123 @@
+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 examples(&self) -> &[Example] {
+        &[Example {
+            description: "Split output from an external command into lines",
+            example: "^ls -l | lines",
+        }]
+    }
+}
+
+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.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 +1,90 @@
+use crate::commands::WholeStreamCommand;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{Signature, SyntaxShape};
+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,
+    #[serde(rename = "du")]
+    pub du: bool,
+}
+
+impl WholeStreamCommand 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'),
+            )
+            .switch(
+                "du",
+                "display the apparent directory size in place of the directory metadata size",
+                Some('d'),
+            )
+    }
+
+    fn usage(&self) -> &str {
+        "View the contents of the current or given path."
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        args.process(registry, ls)?.run()
+    }
+
+    fn examples(&self) -> &[Example] {
+        &[
+            Example {
+                description: "List all files in the current directory",
+                example: "ls",
+            },
+            Example {
+                description: "List all files in a subdirectory",
+                example: "ls subdir",
+            },
+            Example {
+                description: "List all rust files",
+                example: "ls *.rs",
+            },
+        ]
+    }
+}
+
+fn ls(args: LsArgs, context: RunnableContext) -> Result<OutputStream, ShellError> {
+    context.shell_manager.ls(args, &context)
+}

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

@@ -45,8 +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,
@@ -54,13 +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
@@ -114,7 +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()?
                 }
             }
         );
@@ -164,7 +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()?
                 }
             }
         );
@@ -214,7 +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()?
                 }
             }
         );
@@ -250,7 +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)* ],
@@ -305,7 +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)* ],

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.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/merge.rs

@@ -0,0 +1,103 @@
+use crate::commands::classified::block::run_block;
+use crate::commands::WholeStreamCommand;
+use crate::context::CommandRegistry;
+use crate::data::value::merge_values;
+use crate::prelude::*;
+
+use indexmap::IndexMap;
+use nu_errors::ShellError;
+use nu_protocol::{hir::Block, ReturnSuccess, Signature, SyntaxShape, UntaggedValue, Value};
+pub struct Merge;
+
+#[derive(Deserialize)]
+pub struct MergeArgs {
+    block: Block,
+}
+
+impl WholeStreamCommand for Merge {
+    fn name(&self) -> &str {
+        "merge"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("merge").required(
+            "block",
+            SyntaxShape::Block,
+            "the block to run and merge into the table",
+        )
+    }
+
+    fn usage(&self) -> &str {
+        "Merge a table."
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        Ok(args.process_raw(registry, merge)?.run())
+    }
+
+    fn examples(&self) -> &[Example] {
+        &[Example {
+            description: "Merge a 1-based index column with some ls output",
+            example: "ls | select name | keep 3 | merge { echo [1 2 3] | wrap index }",
+        }]
+    }
+}
+
+fn merge(
+    merge_args: MergeArgs,
+    context: RunnableContext,
+    raw_args: RawCommandArgs,
+) -> Result<OutputStream, ShellError> {
+    let block = merge_args.block;
+    let registry = context.registry.clone();
+    let mut input = context.input;
+    let scope = raw_args.call_info.scope.clone();
+
+    let mut context = Context::from_raw(&raw_args, &registry);
+
+    let stream = async_stream! {
+        let table: Option<Vec<Value>> = match run_block(&block,
+                &mut context,
+                InputStream::empty(),
+                &scope).await {
+            Ok(mut stream) => Some(stream.drain_vec().await),
+            Err(err) => {
+                yield Err(err);
+                return;
+            }
+        };
+
+
+        let table = table.unwrap_or_else(|| vec![Value {
+            value: UntaggedValue::row(IndexMap::default()),
+            tag: raw_args.call_info.name_tag,
+        }]);
+
+        let mut idx = 0;
+
+        while let Some(value) = input.next().await {
+            let other = table.get(idx);
+
+            match other {
+                Some(replacement) => {
+                    match merge_values(&value.value, &replacement.value) {
+                        Ok(merged_value) => yield ReturnSuccess::value(merged_value.into_value(&value.tag)),
+                        Err(err) => {
+                            let message = format!("The row at {:?} types mismatch", idx);
+                            yield Err(ShellError::labeled_error("Could not merge", &message, &value.tag));
+                        }
+                    }
+                }
+                None => yield ReturnSuccess::value(value),
+            }
+
+            idx += 1;
+        }
+    };
+
+    Ok(stream.to_output_stream())
+}

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

@@ -0,0 +1,48 @@
+use crate::commands::WholeStreamCommand;
+use crate::context::CommandRegistry;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{Signature, SyntaxShape};
+use nu_source::Tagged;
+use std::path::PathBuf;
+
+pub struct Mkdir;
+
+#[derive(Deserialize)]
+pub struct MkdirArgs {
+    pub rest: Vec<Tagged<PathBuf>>,
+}
+
+impl WholeStreamCommand 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,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        args.process(registry, mkdir)?.run()
+    }
+
+    fn examples(&self) -> &[Example] {
+        &[Example {
+            description: "Make a directory named foo",
+            example: "mkdir foo",
+        }]
+    }
+}
+
+fn mkdir(args: MkdirArgs, context: RunnableContext) -> Result<OutputStream, ShellError> {
+    let shell_manager = context.shell_manager.clone();
+    shell_manager.mkdir(args, &context)
+}

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

@@ -0,0 +1,69 @@
+use crate::commands::WholeStreamCommand;
+use crate::context::CommandRegistry;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{Signature, SyntaxShape};
+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 WholeStreamCommand 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,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        args.process(registry, mv)?.run()
+    }
+
+    fn examples(&self) -> &[Example] {
+        &[
+            Example {
+                description: "Rename a file",
+                example: "mv before.txt after.txt",
+            },
+            Example {
+                description: "Move a file into a directory",
+                example: "mv test.txt my/subdirectory",
+            },
+            Example {
+                description: "Move many files into a directory",
+                example: "mv *.txt my/subdirectory",
+            },
+        ]
+    }
+}
+
+fn mv(args: MoveArgs, context: RunnableContext) -> Result<OutputStream, ShellError> {
+    let shell_manager = context.shell_manager.clone();
+    shell_manager.mv(args, &context)
+}

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

@@ -1,7 +1,7 @@
-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;
 

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

@@ -0,0 +1,88 @@
+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::Int,
+                "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 examples(&self) -> &[Example] {
+        &[
+            Example {
+                description: "Get the second row",
+                example: "echo [first second third] | get 1",
+            },
+            Example {
+                description: "Get the first and third rows",
+                example: "echo [first second third] | get 0 2",
+            },
+        ]
+    }
+}
+
+fn nth(
+    NthArgs {
+        row_number,
+        rest: and_rows,
+    }: NthArgs,
+    RunnableContext { input, .. }: RunnableContext,
+) -> Result<OutputStream, ShellError> {
+    let stream = input
+        .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 +1,246 @@
+use crate::commands::WholeStreamCommand;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{CommandAction, ReturnSuccess, Signature, SyntaxShape, UntaggedValue};
+use nu_source::{AnchorLocation, Span, Tagged};
+use std::path::{Path, PathBuf};
+
+pub struct Open;
+
+#[derive(Deserialize)]
+pub struct OpenArgs {
+    path: Tagged<PathBuf>,
+    raw: Tagged<bool>,
+}
+
+impl WholeStreamCommand 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,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        args.process(registry, open)?.run()
+    }
+}
+
+fn open(
+    OpenArgs { path, raw }: OpenArgs,
+    RunnableContext { shell_manager, .. }: RunnableContext,
+) -> Result<OutputStream, ShellError> {
+    let cwd = PathBuf::from(shell_manager.path());
+    let full_path = cwd;
+
+    let stream = async_stream! {
+
+        let result = fetch(&full_path, &path.item, path.tag.span).await;
+
+        if let Err(e) = result {
+            yield Err(e);
+            return;
+        }
+        let (file_extension, contents, contents_tag) = result?;
+
+        let file_extension = if raw.item {
+            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.extension().map(|x| x.to_string_lossy().to_string()))
+        };
+
+        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: &PathBuf,
+    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 +1,167 @@
+use crate::commands::WholeStreamCommand;
+use crate::context::CommandRegistry;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{ReturnSuccess, Signature, SyntaxShape, TaggedDictBuilder, UntaggedValue};
+use nu_source::Tagged;
+use regex::Regex;
+
+#[derive(Debug)]
+enum ParseCommand {
+    Text(String),
+    Column(String),
+}
+
+fn parse(input: &str) -> Vec<ParseCommand> {
+    let mut output = vec![];
+
+    //let mut loop_input = input;
+    let mut loop_input = input.chars();
+    loop {
+        let mut before = String::new();
+
+        while let Some(c) = loop_input.next() {
+            if c == '{' {
+                break;
+            }
+            before.push(c);
+        }
+
+        if !before.is_empty() {
+            output.push(ParseCommand::Text(before.to_string()));
+        }
+        // Look for column as we're now at one
+        let mut column = String::new();
+
+        while let Some(c) = loop_input.next() {
+            if c == '}' {
+                break;
+            }
+            column.push(c);
+        }
+
+        if !column.is_empty() {
+            output.push(ParseCommand::Column(column.to_string()));
+        }
+
+        if before.is_empty() && column.is_empty() {
+            break;
+        }
+    }
+
+    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;
+
+#[derive(Deserialize)]
+pub struct ParseArgs {
+    pattern: Tagged<String>,
+}
+
+impl WholeStreamCommand for Parse {
+    fn name(&self) -> &str {
+        "parse"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("parse").required(
+            "pattern",
+            SyntaxShape::String,
+            "the pattern to match. Eg) \"{foo}: {bar}\"",
+        )
+    }
+
+    fn usage(&self) -> &str {
+        "Parse columns from string data using a simple pattern."
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        args.process(registry, parse_command)?.run()
+    }
+
+    fn examples(&self) -> &[Example] {
+        &[Example {
+            description: "Parse values from a string into a table",
+            example: r#"echo "data: 123" | parse "{key}: {value}""#,
+        }]
+    }
+}
+
+fn parse_command(
+    ParseArgs { pattern }: ParseArgs,
+    RunnableContext { name, input, .. }: RunnableContext,
+) -> Result<OutputStream, ShellError> {
+    let parse_pattern = parse(&pattern.item);
+    let parse_regex = build_regex(&parse_pattern);
+    let column_names = column_names(&parse_pattern);
+    let name = name.span;
+    let regex = Regex::new(&parse_regex).map_err(|_| {
+        ShellError::labeled_error(
+            "Could not parse regex",
+            "could not parse regex",
+            &pattern.tag,
+        )
+    })?;
+
+    Ok(input
+        .map(move |value| {
+            if let Ok(s) = value.as_string() {
+                let mut output = 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()),
+                        );
+                    }
+                    output.push(Ok(ReturnSuccess::Value(dict.into_value())));
+                }
+                output
+            } else {
+                vec![Err(ShellError::labeled_error_with_secondary(
+                    "Expected string input",
+                    "expected string input",
+                    name,
+                    "value originated here",
+                    value.tag,
+                ))]
+            }
+        })
+        .map(futures::stream::iter)
+        .flatten()
+        .to_output_stream())
+}

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

@@ -1,7 +1,11 @@
 use crate::commands::WholeStreamCommand;
-use crate::errors::ShellError;
 use crate::prelude::*;
-use crate::TaggedDictBuilder;
+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;
 
@@ -21,9 +25,20 @@ impl WholeStreamCommand for Pivot {
 
     fn signature(&self) -> Signature {
         Signature::build("pivot")
-            .switch("header-row")
-            .switch("ignore-titles")
-            .rest(SyntaxShape::String)
+            .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 {
@@ -39,25 +54,13 @@ impl WholeStreamCommand for Pivot {
     }
 }
 
-fn merge_descriptors(values: &[Tagged<Value>]) -> Vec<String> {
-    let mut ret = vec![];
-    for value in values {
-        for desc in value.data_descriptors() {
-            if !ret.contains(&desc) {
-                ret.push(desc);
-            }
-        }
-    }
-    ret
-}
-
 pub fn pivot(args: PivotArgs, context: RunnableContext) -> Result<OutputStream, ShellError> {
-    let stream = async_stream_block! {
+    let stream = async_stream! {
         let input = context.input.into_vec().await;
 
         let descs = merge_descriptors(&input);
 
-        let mut headers = vec![];
+        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));
@@ -67,10 +70,10 @@ pub fn pivot(args: PivotArgs, context: RunnableContext) -> Result<OutputStream,
         if args.header_row {
             for i in input.clone() {
                 if let Some(desc) = descs.get(0) {
-                    match i.get_data_by_key(&desc) {
+                    match get_data_by_key(&i, desc[..].spanned_unknown()) {
                         Some(x) => {
                             if let Ok(s) = x.as_string() {
-                                headers.push(s);
+                                headers.push(s.to_string());
                             } else {
                                 yield Err(ShellError::labeled_error("Header row needs string headers", "used non-string headers", context.name));
                                 return;
@@ -87,7 +90,7 @@ pub fn pivot(args: PivotArgs, context: RunnableContext) -> Result<OutputStream,
                 }
             }
         } else {
-            for i in 0..input.len()+1 {
+            for i in 0..=input.len() {
                 if let Some(name) = args.rest.get(i) {
                     headers.push(name.to_string())
                 } else {
@@ -104,26 +107,26 @@ pub fn pivot(args: PivotArgs, context: RunnableContext) -> Result<OutputStream,
 
         for desc in descs {
             let mut column_num: usize = 0;
-            let mut dict = TaggedDictBuilder::new(context.name);
+            let mut dict = TaggedDictBuilder::new(&context.name);
 
             if !args.ignore_titles && !args.header_row {
-                dict.insert(headers[column_num].clone(), Value::string(desc.clone()));
+                dict.insert_untagged(headers[column_num].clone(), UntaggedValue::string(desc.clone()));
                 column_num += 1
             }
 
             for i in input.clone() {
-                match i.get_data_by_key(&desc) {
+                match get_data_by_key(&i, desc[..].spanned_unknown()) {
                     Some(x) => {
-                        dict.insert_tagged(headers[column_num].clone(), x.clone());
+                        dict.insert_value(headers[column_num].clone(), x.clone());
                     }
                     _ => {
-                        dict.insert(headers[column_num].clone(), Value::nothing());
+                        dict.insert_untagged(headers[column_num].clone(), UntaggedValue::nothing());
                     }
                 }
                 column_num += 1;
             }
 
-            yield ReturnSuccess::value(dict.into_tagged_value());
+            yield ReturnSuccess::value(dict.into_value());
         }
 
 

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

@@ -1,9 +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, Signature, UntaggedValue, Value};
 use serde::{self, Deserialize, Serialize};
 use std::io::prelude::*;
 use std::io::BufReader;
@@ -39,7 +39,7 @@ pub enum NuResult {
 pub struct PluginCommand {
     name: String,
     path: String,
-    config: registry::Signature,
+    config: Signature,
 }
 
 impl WholeStreamCommand for PluginCommand {
@@ -47,7 +47,7 @@ impl WholeStreamCommand for PluginCommand {
         &self.name
     }
 
-    fn signature(&self) -> registry::Signature {
+    fn signature(&self) -> Signature {
         self.config.clone()
     }
 
@@ -71,7 +71,13 @@ pub fn filter_plugin(
 ) -> Result<OutputStream, ShellError> {
     trace!("filter_plugin :: {}", path);
 
-    let args = args.evaluate_once(registry)?;
+    let scope = &args
+        .call_info
+        .scope
+        .clone()
+        .set_it(UntaggedValue::string("$it").into_untagged_value());
+
+    let args = args.evaluate_once_with_scope(registry, &scope)?;
 
     let mut child = std::process::Command::new(path)
         .stdin(std::process::Stdio::piped())
@@ -79,22 +85,24 @@ 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(args.input)
         .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");
@@ -103,14 +111,26 @@ 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();
-                match stdin.write(format!("{}\n", request_raw).as_bytes()) {
-                    Ok(_) => {}
-                    Err(err) => {
+                let request_raw = serde_json::to_string(&request);
+
+                match request_raw {
+                    Err(_) => {
                         let mut result = VecDeque::new();
-                        result.push_back(Err(ShellError::unexpected(format!("{}", err))));
+                        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();
@@ -128,7 +148,7 @@ 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
                                 ))));
@@ -138,7 +158,7 @@ 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
                         ))));
@@ -146,8 +166,8 @@ 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");
@@ -176,8 +196,20 @@ 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 _ = stdin.write(format!("{}\n", request_raw).as_bytes()); // TODO: Handle error
+                                    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
                                 }
@@ -189,7 +221,7 @@ 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
                                 ))));
@@ -199,7 +231,7 @@ 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 end_filter: {:?}",
                             e
                         ))));
@@ -218,8 +250,20 @@ 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 _ = stdin.write(format!("{}\n", request_raw).as_bytes()); // TODO: Handle error
+                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) {
@@ -236,8 +280,8 @@ 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
@@ -246,7 +290,7 @@ 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
                         ))));
@@ -255,6 +299,7 @@ pub fn filter_plugin(
                 }
             }
         })
+        .map(futures::stream::iter) // convert to a stream
         .flatten();
 
     Ok(stream.to_output_stream())
@@ -264,7 +309,7 @@ pub fn filter_plugin(
 pub struct PluginSink {
     name: String,
     path: String,
-    config: registry::Signature,
+    config: Signature,
 }
 
 impl WholeStreamCommand for PluginSink {
@@ -272,7 +317,7 @@ impl WholeStreamCommand for PluginSink {
         &self.name
     }
 
-    fn signature(&self) -> registry::Signature {
+    fn signature(&self) -> Signature {
         self.config.clone()
     }
 
@@ -297,21 +342,36 @@ pub fn sink_plugin(
     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.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 _ = writeln!(tmpfile, "{}", request_raw);
-        let _ = tmpfile.flush();
+        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");
+                let mut child = std::process::Command::new(path)
+                    .arg(tmpfile.path())
+                    .spawn();
 
-        let _ = child.wait();
+                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))
 }