Bump to 0.20 (#2588)

* Implement passthrough for benchmark

Add a new option -p,--passthrough to benchmark.
With this option, the benchmark command prints its results to stdout and passes the block's output to the next command in the pipeline.

* Add execution block for benchmark -p

`benchmark --passthrough` now takes a block where the benchmark output is sent.
Example:
`benchmark -p {save bench.toml} {ls}`

.azure/azure-pipelines.yml

@@ -1,11 +1,20 @@
 trigger:
-  - master
+  - main
 
 strategy:
   matrix:
     linux-stable:
       image: ubuntu-18.04
       style: 'unflagged'
+    linux-minimal:
+      image: ubuntu-18.04
+      style: 'minimal'
+    linux-extra:
+      image: ubuntu-18.04
+      style: 'extra'
+    linux-wasm:
+      image: ubuntu-18.04
+      style: 'wasm'
     macos-stable:
       image: macos-10.14
       style: 'unflagged'
@@ -34,6 +43,7 @@ steps:
       if [ -e /etc/debian_version ]
       then
         sudo apt-get -y install libxcb-composite0-dev libx11-dev
+        sudo npm install -g wasm-pack
       fi
       if [ "$(uname)" == "Darwin" ]; then
         curl https://sh.rustup.rs -sSf | sh -s -- -y --no-modify-path --default-toolchain "stable"
@@ -41,23 +51,32 @@ steps:
         rustup component add clippy --toolchain stable-x86_64-apple-darwin
         export PATH=$HOME/.cargo/bin:$PATH
       fi
-      rustup update
-      rustc -Vv
-      echo "##vso[task.prependpath]$HOME/.cargo/bin"
-      rustup component add rustfmt
+  #     rustup update
+  #     rustc -Vv
+  #     echo "##vso[task.prependpath]$HOME/.cargo/bin"
+  #     rustup component add rustfmt
     displayName: Install Rust
-  - bash: RUSTFLAGS="-D warnings" cargo test --all --features stable
+  - bash: RUSTFLAGS="-D warnings" cargo test --all
     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
+  - bash: RUSTFLAGS="-D warnings" cargo clippy --all -- -D clippy::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
+  - bash: RUSTFLAGS="-D warnings" cargo test --all
     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
+  - bash: cd samples/wasm && wasm-pack build
+    condition: eq(variables['style'], 'wasm')
+    displayName: Wasm build
+  - bash: RUSTFLAGS="-D warnings" cargo clippy --all -- -D clippy::unwrap_used
     condition: eq(variables['style'], 'canary')
     displayName: Check clippy lints
+  - bash: RUSTFLAGS="-D warnings" cargo test --all --no-default-features --features=rustyline-support
+    condition: eq(variables['style'], 'minimal')
+    displayName: Run tests
+  - bash: RUSTFLAGS="-D warnings" cargo test --all --features=extra
+    condition: eq(variables['style'], 'extra')
+    displayName: Run tests
   - bash: cargo fmt --all -- --check
     condition: eq(variables['style'], 'fmt')
     displayName: Lint

.cargo/config

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

.circleci/config.yml

@@ -27,7 +27,7 @@ orbs:
 workflows:
   version: 2.0
 
-  # This builds on all pull requests to test, and ignores master
+  # This builds on all pull requests to test, and ignores main
   build_without_deploy:
     jobs:
       - docker/publish:
@@ -39,7 +39,7 @@ workflows:
           filters:
             branches:
               ignore:
-                - master
+                - main
           before_build:
             - pull_cache
           after_build:
@@ -73,7 +73,7 @@ workflows:
             branches:
               ignore: /.*/
             tags:
-              only: /^v.*/
+              only: /^\d+\.\d+\.\d+$/
           before_build:
             - run: docker pull quay.io/nushell/nu:latest
             - run: docker pull quay.io/nushell/nu-base:latest
@@ -98,11 +98,11 @@ workflows:
                    docker push quay.io/nushell/nu
 
 
-  # publish devel to Docker Hub on merge to master (doesn't build --release)
+  # publish devel to Docker Hub on merge to main (doesn't build --release)
   build_with_deploy_devel:
     jobs:
 
-      # Deploy devel tag on merge to master
+      # Deploy devel tag on merge to main
       - docker/publish:
           image: nushell/nu-base
           registry: quay.io
@@ -113,7 +113,7 @@ workflows:
             - pull_cache
           filters:
             branches:
-              only: master
+              only: main
           after_build:
             - run:
                 name: Build Multistage (smaller) container
@@ -137,7 +137,7 @@ workflows:
           filters:
             branches:
               only:
-                - master
+                - main
     jobs:
       - docker/publish:
           image: nushell/nu-base

.github/workflows/release.yml

@@ -11,31 +11,39 @@ jobs:
     steps:
       - name: Check out code
         uses: actions/checkout@v2
+
       - name: Install libxcb
         run: sudo apt-get install libxcb-composite0-dev
+
       - name: Set up cargo
         uses: actions-rs/toolchain@v1
         with:
           profile: minimal
           toolchain: stable
           override: true
+
       - name: Build
         uses: actions-rs/cargo@v1
         with:
           command: build
-          args: --release --all --features=stable
+          args: --release --all --features=extra
+
       - name: Create output directory
         run: mkdir output
+
       - name: Copy files to output
         run: |
           cp target/release/nu target/release/nu_plugin_* output/
           cp README.build.txt output/README.txt
+          cp LICENSE output/LICENSE
           rm output/*.d
           rm output/nu_plugin_core_*
-          rm output/nu_plugin_stable_*
+          rm output/nu_plugin_extra_*
+
       # Note: If OpenSSL changes, this path will need to be updated
       - name: Copy OpenSSL to output
         run: cp /usr/lib/x86_64-linux-gnu/libssl.so.1.1 output/
+
       - name: Upload artifact
         uses: actions/upload-artifact@v2
         with:
@@ -48,26 +56,32 @@ jobs:
     steps:
       - name: Check out code
         uses: actions/checkout@v2
+
       - name: Set up cargo
         uses: actions-rs/toolchain@v1
         with:
           profile: minimal
           toolchain: stable
           override: true
+
       - name: Build
         uses: actions-rs/cargo@v1
         with:
           command: build
-          args: --release --all --features=stable
+          args: --release --all --features=extra
+
       - name: Create output directory
         run: mkdir output
+
       - name: Copy files to output
         run: |
           cp target/release/nu target/release/nu_plugin_* output/
           cp README.build.txt output/README.txt
+          cp LICENSE output/LICENSE
           rm output/*.d
           rm output/nu_plugin_core_*
-          rm output/nu_plugin_stable_*
+          rm output/nu_plugin_extra_*
+
       - name: Upload artifact
         uses: actions/upload-artifact@v2
         with:
@@ -80,47 +94,61 @@ jobs:
     steps:
       - name: Check out code
         uses: actions/checkout@v2
+
       - name: Set up cargo
         uses: actions-rs/toolchain@v1
         with:
           profile: minimal
           toolchain: stable
           override: true
+
       - name: Add cargo-wix subcommand
         uses: actions-rs/cargo@v1
         with:
           command: install
           args: cargo-wix
+
       - name: Build
         uses: actions-rs/cargo@v1
         with:
           command: build
-          args: --release --all --features=stable
+          args: --release --all --features=extra
+
       - name: Create output directory
         run: mkdir output
+
       - name: Download Less Binary
-        run: Invoke-WebRequest -Uri "https://github.com/jftuga/less-Windows/releases/download/less-v562.1/less.exe" -OutFile "target\release\less.exe"
+        run: Invoke-WebRequest -Uri "https://github.com/jftuga/less-Windows/releases/download/less-v562.0/less.exe" -OutFile "target\release\less.exe"
+
+      - name: Download Less License
+        run: Invoke-WebRequest -Uri "https://raw.githubusercontent.com/jftuga/less-Windows/master/LICENSE" -OutFile "target\release\LICENSE-for-less.txt"
+
       - name: Copy files to output
         run: |
           cp target\release\nu.exe output\
+          cp LICENSE output\
+          cp target\release\LICENSE-for-less.txt output\
           rm target\release\nu_plugin_core_*.exe
-          rm target\release\nu_plugin_stable_*.exe
+          rm target\release\nu_plugin_extra_*.exe
           cp target\release\nu_plugin_*.exe output\
           cp README.build.txt output\README.txt
           cp target\release\less.exe output\
       # Note: If the version of `less.exe` needs to be changed, update this URL
       # Similarly, if `less.exe` is checked into the repo, copy from the local path here
       # moved this stuff down to create wix after we download less
+
       - name: Create msi with wix
         uses: actions-rs/cargo@v1
         with:
           command: wix
           args: --no-build --nocapture --output target\wix\nushell-windows.msi
+
       - name: Upload installer
         uses: actions/upload-artifact@v2
         with:
           name: windows-installer
           path: target\wix\nushell-windows.msi
+
       - name: Upload zip
         uses: actions/upload-artifact@v2
         with:
@@ -137,6 +165,7 @@ jobs:
     steps:
       - name: Check out code
         uses: actions/checkout@v2
+
       - name: Determine Release Info
         id: info
         env:
@@ -152,6 +181,7 @@ jobs:
           echo "::set-output name=macosdir::nu_${MAJOR}_${MINOR}_${PATCH}_macOS"
           echo "::set-output name=windowsdir::nu_${MAJOR}_${MINOR}_${PATCH}_windows"
           echo "::set-output name=innerdir::nushell-${VERSION}"
+
       - name: Create Release Draft
         id: create_release
         uses: actions/create-release@v1
@@ -161,19 +191,24 @@ jobs:
           tag_name: ${{ github.ref }}
           release_name: ${{ steps.info.outputs.version }} Release
           draft: true
+
       - name: Create Linux Directory
         run: mkdir -p ${{ steps.info.outputs.linuxdir }}/${{ steps.info.outputs.innerdir }}
+
       - name: Download Linux Artifacts
         uses: actions/download-artifact@v2
         with:
           name: linux
           path: ${{ steps.info.outputs.linuxdir }}/${{ steps.info.outputs.innerdir }}
+
       - name: Restore Linux File Modes
         run: |
           chmod 755 ${{ steps.info.outputs.linuxdir }}/${{ steps.info.outputs.innerdir }}/nu*
           chmod 755 ${{ steps.info.outputs.linuxdir }}/${{ steps.info.outputs.innerdir }}/libssl*
+
       - name: Create Linux tarball
         run: tar -zcvf ${{ steps.info.outputs.linuxdir }}.tar.gz ${{ steps.info.outputs.linuxdir }}
+
       - name: Upload Linux Artifact
         uses: actions/upload-release-asset@v1
         env:
@@ -183,17 +218,22 @@ jobs:
           asset_path: ./${{ steps.info.outputs.linuxdir }}.tar.gz
           asset_name: ${{ steps.info.outputs.linuxdir }}.tar.gz
           asset_content_type: application/gzip
+
       - name: Create macOS Directory
         run: mkdir -p ${{ steps.info.outputs.macosdir }}/${{ steps.info.outputs.innerdir }}
+
       - name: Download macOS Artifacts
         uses: actions/download-artifact@v2
         with:
           name: macos
           path: ${{ steps.info.outputs.macosdir }}/${{ steps.info.outputs.innerdir }}
+
       - name: Restore macOS File Modes
         run: chmod 755 ${{ steps.info.outputs.macosdir }}/${{ steps.info.outputs.innerdir }}/nu*
+
       - name: Create macOS Archive
         run: zip -r ${{ steps.info.outputs.macosdir }}.zip ${{ steps.info.outputs.macosdir }}
+
       - name: Upload macOS Artifact
         uses: actions/upload-release-asset@v1
         env:
@@ -203,18 +243,22 @@ jobs:
           asset_path: ./${{ steps.info.outputs.macosdir }}.zip
           asset_name: ${{ steps.info.outputs.macosdir }}.zip
           asset_content_type: application/zip
+
       - name: Create Windows Directory
         run: mkdir -p ${{ steps.info.outputs.windowsdir }}/${{ steps.info.outputs.innerdir }}
+
       - name: Download Windows zip
         uses: actions/download-artifact@v2
         with:
           name: windows-zip
           path: ${{ steps.info.outputs.windowsdir }}/${{ steps.info.outputs.innerdir }}
-      # TODO: Remove Show
+
       - name: Show Windows Artifacts
         run: ls -la ${{ steps.info.outputs.windowsdir }}/${{ steps.info.outputs.innerdir }}
+
       - name: Create macOS Archive
         run: zip -r ${{ steps.info.outputs.windowsdir }}.zip ${{ steps.info.outputs.windowsdir }}
+
       - name: Upload Windows zip
         uses: actions/upload-release-asset@v1
         env:
@@ -224,11 +268,13 @@ jobs:
           asset_path: ./${{ steps.info.outputs.windowsdir }}.zip
           asset_name: ${{ steps.info.outputs.windowsdir }}.zip
           asset_content_type: application/zip
+
       - name: Download Windows installer
         uses: actions/download-artifact@v2
         with:
           name: windows-installer
           path: ./
+          
       - name: Upload Windows installer
         uses: actions/upload-release-asset@v1
         env:

CONTRIBUTING.md

@@ -25,38 +25,38 @@ cargo build
 
 ### Useful Commands
 
-Build and run Nushell:
+- Build and run Nushell:
 
-```shell
-cargo build --release && cargo run --release
-```
+  ```shell
+  cargo build --release && cargo run --release
+  ```
 
-Run Clippy on Nushell:
+- Run Clippy on Nushell:
 
-```shell
-cargo clippy --all --features=stable
-```
+  ```shell
+  cargo clippy --all --features=stable
+  ```
 
-Run all tests:
+- Run all tests:
 
-```shell
-cargo test --all --features=stable
-```
+  ```shell
+  cargo test --all --features=stable
+  ```
 
-Run all tests for a specific command
+- Run all tests for a specific command
 
-```shell
-cargo test --package nu-cli --test main -- commands::<command_name_here>
-```
+  ```shell
+  cargo test --package nu-cli --test main -- commands::<command_name_here>
+  ```
 
-Check to see if there are code formatting issues
+- Check to see if there are code formatting issues
 
-```shell
-cargo fmt --all -- --check
-```
+  ```shell
+  cargo fmt --all -- --check
+  ```
 
-Format the code in the project
+- Format the code in the project
 
-```shell
-cargo fmt --all
-```
+  ```shell
+  cargo fmt --all
+  ```

Cargo.toml

@@ -1,16 +1,16 @@
 [package]
-name = "nu"
-version = "0.16.0"
 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 = "https://www.nushell.sh"
+description = "A new type of shell"
 documentation = "https://www.nushell.sh/book/"
+edition = "2018"
 exclude = ["images"]
+homepage = "https://www.nushell.sh"
+license = "MIT"
+name = "nu"
+readme = "README.md"
+repository = "https://github.com/nushell/nushell"
+version = "0.20.0"
 
 [workspace]
 members = ["crates/*/"]
@@ -18,67 +18,101 @@ members = ["crates/*/"]
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-nu-cli = { version = "0.16.0", path = "./crates/nu-cli" }
-nu-source = { version = "0.16.0", path = "./crates/nu-source" }
-nu-plugin = { version = "0.16.0", path = "./crates/nu-plugin" }
-nu-protocol = { version = "0.16.0", path = "./crates/nu-protocol" }
-nu-errors = { version = "0.16.0", path = "./crates/nu-errors" }
-nu-parser = { version = "0.16.0", path = "./crates/nu-parser" }
-nu-value-ext = { version = "0.16.0", path = "./crates/nu-value-ext" }
-nu_plugin_binaryview = { version = "0.16.0", path = "./crates/nu_plugin_binaryview", optional=true }
-nu_plugin_fetch = { version = "0.16.0", path = "./crates/nu_plugin_fetch", optional=true }
-nu_plugin_inc = { version = "0.16.0", path = "./crates/nu_plugin_inc", optional=true }
-nu_plugin_match = { version = "0.16.0", path = "./crates/nu_plugin_match", optional=true }
-nu_plugin_post = { version = "0.16.0", path = "./crates/nu_plugin_post", optional=true }
-nu_plugin_ps = { version = "0.16.0", path = "./crates/nu_plugin_ps", optional=true }
-nu_plugin_start = { version = "0.16.0", path = "./crates/nu_plugin_start", optional=true }
-nu_plugin_sys = { version = "0.16.0", path = "./crates/nu_plugin_sys", optional=true }
-nu_plugin_textview = { version = "0.16.0", path = "./crates/nu_plugin_textview", optional=true }
-nu_plugin_tree = { version = "0.16.0", path = "./crates/nu_plugin_tree", optional=true }
+nu-cli = {version = "0.20.0", path = "./crates/nu-cli"}
+nu-data = {version = "0.20.0", path = "./crates/nu-data"}
+nu-errors = {version = "0.20.0", path = "./crates/nu-errors"}
+nu-parser = {version = "0.20.0", path = "./crates/nu-parser"}
+nu-plugin = {version = "0.20.0", path = "./crates/nu-plugin"}
+nu-protocol = {version = "0.20.0", path = "./crates/nu-protocol"}
+nu-source = {version = "0.20.0", path = "./crates/nu-source"}
+nu-value-ext = {version = "0.20.0", path = "./crates/nu-value-ext"}
 
-crossterm = { version = "0.17.5", optional = true }
-semver = { version = "0.10.0", optional = true }
-syntect = { version = "4.2", default-features = false, features = ["default-fancy"], optional = true}
-url = { version = "2.1.1", optional = true }
+nu_plugin_binaryview = {version = "0.20.0", path = "./crates/nu_plugin_binaryview", optional = true}
+nu_plugin_fetch = {version = "0.20.0", path = "./crates/nu_plugin_fetch", optional = true}
+nu_plugin_from_bson = {version = "0.20.0", path = "./crates/nu_plugin_from_bson", optional = true}
+nu_plugin_from_sqlite = {version = "0.20.0", path = "./crates/nu_plugin_from_sqlite", optional = true}
+nu_plugin_inc = {version = "0.20.0", path = "./crates/nu_plugin_inc", optional = true}
+nu_plugin_match = {version = "0.20.0", path = "./crates/nu_plugin_match", optional = true}
+nu_plugin_post = {version = "0.20.0", path = "./crates/nu_plugin_post", optional = true}
+nu_plugin_ps = {version = "0.20.0", path = "./crates/nu_plugin_ps", optional = true}
+nu_plugin_s3 = {version = "0.20.0", path = "./crates/nu_plugin_s3", optional = true}
+nu_plugin_start = {version = "0.20.0", path = "./crates/nu_plugin_start", optional = true}
+nu_plugin_sys = {version = "0.20.0", path = "./crates/nu_plugin_sys", optional = true}
+nu_plugin_textview = {version = "0.20.0", path = "./crates/nu_plugin_textview", optional = true}
+nu_plugin_to_bson = {version = "0.20.0", path = "./crates/nu_plugin_to_bson", optional = true}
+nu_plugin_to_sqlite = {version = "0.20.0", path = "./crates/nu_plugin_to_sqlite", optional = true}
+nu_plugin_tree = {version = "0.20.0", path = "./crates/nu_plugin_tree", optional = true}
 
-clap = "2.33.1"
-ctrlc = "3.1.4"
+crossterm = {version = "0.17", optional = true}
+semver = {version = "0.10.0", optional = true}
+url = {version = "2.1.1", optional = true}
+
+clap = "2.33.3"
+ctrlc = "3.1.6"
 dunce = "1.0.1"
-futures = { version = "0.3", features = ["compat", "io-compat"] }
-log = "0.4.8"
+futures = {version = "0.3.5", features = ["compat", "io-compat"]}
+log = "0.4.11"
 pretty_env_logger = "0.4.0"
-starship = "0.43.0"
+quick-xml = "0.18.1"
 
 [dev-dependencies]
-nu-test-support = { version = "0.16.0", path = "./crates/nu-test-support" }
+nu-test-support = {version = "0.20.0", path = "./crates/nu-test-support"}
 
 [build-dependencies]
+serde = {version = "1.0.115", features = ["derive"]}
 toml = "0.5.6"
-serde = { version = "1.0.110", features = ["derive"] }
-nu-build = { version = "0.16.0", path = "./crates/nu-build" }
 
 [features]
-default = ["sys", "ps", "textview", "inc"]
-stable = ["default", "binaryview", "match", "tree", "post", "fetch", "clipboard-cli", "trash-support", "start"]
+default = [
+  "sys",
+  "ps",
+  "textview",
+  "inc",
+  "git-support",
+  "directories-support",
+  "ctrlc-support",
+  "which-support",
+  "ptree-support",
+  "term-support",
+  "uuid-support",
+  "rustyline-support",
+  "match",
+  "post",
+  "fetch",
+  "rich-benchmark",
+]
+extra = ["default", "binaryview", "tree", "clipboard-cli", "trash-support", "start", "bson", "sqlite", "s3"]
+stable = ["default"]
 
 # Default
-textview = ["crossterm", "syntect", "url", "nu_plugin_textview"]
-sys = ["nu_plugin_sys"]
-ps = ["nu_plugin_ps"]
 inc = ["semver", "nu_plugin_inc"]
+ps = ["nu_plugin_ps"]
+sys = ["nu_plugin_sys"]
+textview = ["crossterm", "url", "nu_plugin_textview"]
 
 # Stable
 binaryview = ["nu_plugin_binaryview"]
+bson = ["nu_plugin_from_bson", "nu_plugin_to_bson"]
 fetch = ["nu_plugin_fetch"]
 match = ["nu_plugin_match"]
 post = ["nu_plugin_post"]
+s3 = ["nu_plugin_s3"]
+sqlite = ["nu_plugin_from_sqlite", "nu_plugin_to_sqlite"]
+start = ["nu_plugin_start"]
 trace = ["nu-parser/trace"]
 tree = ["nu_plugin_tree"]
-start = ["nu_plugin_start"]
 
 clipboard-cli = ["nu-cli/clipboard-cli"]
-# starship-prompt = ["nu-cli/starship-prompt"]
+ctrlc-support = ["nu-cli/ctrlc"]
+directories-support = ["nu-cli/directories", "nu-cli/dirs", "nu-data/directories", "nu-data/dirs"]
+git-support = ["nu-cli/git2"]
+ptree-support = ["nu-cli/ptree"]
+rich-benchmark = ["nu-cli/rich-benchmark"]
+rustyline-support = ["nu-cli/rustyline-support"]
+term-support = ["nu-cli/term"]
 trash-support = ["nu-cli/trash-support"]
+uuid-support = ["nu-cli/uuid_crate"]
+which-support = ["nu-cli/ichwh", "nu-cli/which"]
 
 # Core plugins that ship with `cargo install nu` by default
 # Currently, Cargo limits us to installing only one binary
@@ -103,37 +137,43 @@ name = "nu_plugin_core_sys"
 path = "src/plugins/nu_plugin_core_sys.rs"
 required-features = ["sys"]
 
-# Stable plugins
 [[bin]]
-name = "nu_plugin_stable_fetch"
-path = "src/plugins/nu_plugin_stable_fetch.rs"
+name = "nu_plugin_core_fetch"
+path = "src/plugins/nu_plugin_core_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"
+name = "nu_plugin_core_match"
+path = "src/plugins/nu_plugin_core_match.rs"
 required-features = ["match"]
 
 [[bin]]
-name = "nu_plugin_stable_post"
-path = "src/plugins/nu_plugin_stable_post.rs"
+name = "nu_plugin_core_post"
+path = "src/plugins/nu_plugin_core_post.rs"
 required-features = ["post"]
 
+# Extra plugins
+
 [[bin]]
-name = "nu_plugin_stable_tree"
-path = "src/plugins/nu_plugin_stable_tree.rs"
+name = "nu_plugin_extra_binaryview"
+path = "src/plugins/nu_plugin_extra_binaryview.rs"
+required-features = ["binaryview"]
+
+[[bin]]
+name = "nu_plugin_extra_tree"
+path = "src/plugins/nu_plugin_extra_tree.rs"
 required-features = ["tree"]
 
 [[bin]]
-name = "nu_plugin_stable_start"
-path = "src/plugins/nu_plugin_stable_start.rs"
+name = "nu_plugin_extra_start"
+path = "src/plugins/nu_plugin_extra_start.rs"
 required-features = ["start"]
 
+[[bin]]
+name = "nu_plugin_extra_s3"
+path = "src/plugins/nu_plugin_extra_s3.rs"
+required-features = ["s3"]
+
 # Main nu binary
 [[bin]]
 name = "nu"

README.md

@@ -5,6 +5,7 @@
 [![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](https://img.shields.io/badge/twitter-@nu_shell-1DA1F3?style=flat-square)](https://twitter.com/nu_shell)
 
 ## Nu Shell
 
@@ -50,12 +51,12 @@ To build Nu, you will need to use the **latest stable (1.41 or later)** version
 Required dependencies:
 
 * pkg-config and libssl (only needed on Linux)
-  * on Debian/Ubuntu: `apt install pkg-config libssl-dev`
+  * On Debian/Ubuntu: `apt install pkg-config libssl-dev`
 
 Optional dependencies:
 
 * To use Nu with all possible optional features enabled, you'll also need the following:
-  * on Linux (on Debian/Ubuntu): `apt install libxcb-composite0-dev libx11-dev`
+  * On Linux (on Debian/Ubuntu): `apt install libxcb-composite0-dev libx11-dev`
 
 To install Nu via cargo (make sure you have installed [rustup](https://rustup.rs/) and the latest stable compiler via `rustup install stable`):
 
@@ -66,7 +67,7 @@ cargo install nu
 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:
 
 ```bash
-cargo build --workspace --features=stable
+cargo build --workspace --features=extra
 ```
 
 ### Docker
@@ -193,7 +194,7 @@ For example, you can load a .toml file as structured data and explore it:
 > open Cargo.toml
 ────────────────────┬───────────────────────────
  bin                │ [table 18 rows]
- build-dependencies │ [row nu-build serde toml]
+ build-dependencies │ [row serde toml]
  dependencies       │ [row 29 columns]
  dev-dependencies   │ [row nu-test-support]
  features           │ [row 19 columns]
@@ -235,11 +236,11 @@ Here we use the variable `$it` to refer to the value being piped to the external
 
 Nu has early support for configuring the shell. You can refer to the book for a list of [all supported variables](https://www.nushell.sh/book/en/configuration.html).
 
-To set one of these variables, you can use `config --set`. For example:
+To set one of these variables, you can use `config set`. For example:
 
 ```shell
-> config --set [edit_mode "vi"]
-> config --set [path $nu.path]
+> config set edit_mode "vi"
+> config set path $nu.path
 ```
 
 ### Shells

build.rs

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

crates/nu-build/Cargo.toml

@@ -1,16 +0,0 @@
-[package]
-name = "nu-build"
-version = "0.16.0"
-authors = ["The Nu Project Contributors"]
-edition = "2018"
-description = "Core build system for nushell"
-license = "MIT"
-
-[lib]
-doctest = false
-
-[dependencies]
-serde = { version = "1.0.114", features = ["derive"] }
-lazy_static = "1.4.0"
-serde_json = "1.0.55"
-toml = "0.5.6"

crates/nu-build/src/lib.rs

@@ -1,80 +0,0 @@
-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

@@ -1,115 +1,128 @@
 [package]
-name = "nu-cli"
-version = "0.16.0"
 authors = ["The Nu Project Contributors"]
 description = "CLI for nushell"
 edition = "2018"
 license = "MIT"
+name = "nu-cli"
+version = "0.20.0"
 
 [lib]
 doctest = false
 
 [dependencies]
-nu-source = { version = "0.16.0", path = "../nu-source" }
-nu-plugin = { version = "0.16.0", path = "../nu-plugin" }
-nu-protocol = { version = "0.16.0", path = "../nu-protocol" }
-nu-errors = { version = "0.16.0", path = "../nu-errors" }
-nu-parser = { version = "0.16.0", path = "../nu-parser" }
-nu-value-ext = { version = "0.16.0", path = "../nu-value-ext" }
-nu-test-support = { version = "0.16.0", path = "../nu-test-support" }
-nu-table = {version = "0.16.0", path = "../nu-table"}
+nu-data = {version = "0.20.0", path = "../nu-data"}
+nu-errors = {version = "0.20.0", path = "../nu-errors"}
+nu-parser = {version = "0.20.0", path = "../nu-parser"}
+nu-plugin = {version = "0.20.0", path = "../nu-plugin"}
+nu-protocol = {version = "0.20.0", path = "../nu-protocol"}
+nu-source = {version = "0.20.0", path = "../nu-source"}
+nu-table = {version = "0.20.0", path = "../nu-table"}
+nu-test-support = {version = "0.20.0", path = "../nu-test-support"}
+nu-value-ext = {version = "0.20.0", path = "../nu-value-ext"}
 
 ansi_term = "0.12.1"
-app_dirs = "1.2.1"
 async-recursion = "0.3.1"
-async-trait = "0.1.36"
-directories = "2.0.2"
+async-trait = "0.1.40"
 base64 = "0.12.3"
-bigdecimal = { version = "0.1.2", features = ["serde"] }
-bson = { version = "0.14.1", features = ["decimal128"] }
-byte-unit = "3.1.3"
-bytes = "0.5.5"
-calamine = "0.16"
-cfg-if = "0.1"
-chrono = { version = "0.4.11", features = ["serde"] }
-clap = "2.33.1"
-csv = "1.1"
-ctrlc = "3.1.4"
+bigdecimal = {version = "0.2.0", features = ["serde"]}
+byte-unit = "4.0.9"
+bytes = "0.5.6"
+calamine = "0.16.1"
+chrono = {version = "0.4.15", features = ["serde"]}
+clap = "2.33.3"
+codespan-reporting = "0.9.5"
+csv = "1.1.3"
+ctrlc = {version = "3.1.6", optional = true}
 derive-new = "0.5.8"
-dirs = "2.0.2"
+directories = {version = "3.0.1", optional = true}
+dirs = {version = "3.0.1", optional = true}
+dtparse = "1.1.0"
 dunce = "1.0.1"
 eml-parser = "0.1.0"
 filesize = "0.2.0"
-futures = { version = "0.3", features = ["compat", "io-compat"] }
+fs_extra = "1.2.0"
+futures = {version = "0.3.5", features = ["compat", "io-compat"]}
 futures-util = "0.3.5"
-futures_codec = "0.4"
+futures_codec = "0.4.1"
 getset = "0.1.1"
-git2 = { version = "0.13.6", default_features = false }
+git2 = {version = "0.13.11", default_features = false, optional = true}
 glob = "0.3.0"
-hex = "0.4"
+heim = {version = "0.1.0-beta.3", optional = true}
 htmlescape = "0.3.1"
-ical = "0.6.*"
-ichwh = "0.3.4"
-indexmap = { version = "1.4.0", features = ["serde-1"] }
+ical = "0.6.0"
+ichwh = {version = "0.3.4", optional = true}
+indexmap = {version = "1.6.0", features = ["serde-1"]}
 itertools = "0.9.0"
-codespan-reporting = "0.9.5"
-log = "0.4.8"
-meval = "0.2"
+log = "0.4.11"
+meval = "0.2.0"
 natural = "0.5.0"
-num-bigint = { version = "0.2.6", features = ["serde"] }
-num-traits = "0.2.11"
+num-bigint = {version = "0.3.0", features = ["serde"]}
+num-format = {version = "0.4.0", features = ["with-num-bigint"]}
+num-traits = "0.2.12"
 parking_lot = "0.11.0"
 pin-utils = "0.1.0"
-pretty-hex = "0.1.1"
-pretty_env_logger = "0.4.0"
-ptree = {version = "0.2" }
+pretty-hex = "0.2.0"
+ptree = {version = "0.3.0", optional = true}
 query_interface = "0.3.5"
-rand = "0.7"
-regex = "1"
+rand = "0.7.3"
+regex = "1.3.9"
 roxmltree = "0.13.0"
-rustyline = "6.2.0"
-serde = { version = "1.0.114", features = ["derive"] }
+rust-embed = "5.6.0"
+rustyline = {version = "6.3.0", optional = true}
+serde = {version = "1.0.115", features = ["derive"]}
 serde-hjson = "0.9.1"
 serde_bytes = "0.11.5"
 serde_ini = "0.2.0"
-serde_json = "1.0.55"
-serde_urlencoded = "0.6.1"
-serde_yaml = "0.8"
+serde_json = "1.0.57"
+serde_urlencoded = "0.7.0"
+serde_yaml = "0.8.13"
+sha2 = "0.9.1"
 shellexpand = "2.0.0"
 strip-ansi-escapes = "0.1.0"
 tempfile = "3.1.0"
-term = "0.5.2"
-termcolor = "1.1.0"
+term = {version = "0.6.1", optional = true}
 term_size = "0.3.2"
+termcolor = "1.1.0"
 toml = "0.5.6"
-typetag = "0.1.5"
-umask = "1.0.0"
-unicode-xid = "0.2.1"
-uuid_crate = { package = "uuid", version = "0.8.1", features = ["v4"] }
-which = "4.0.1"
+unicode-segmentation = "1.6.0"
+uom = {version = "0.28.0", features = ["f64", "try-from"]}
+uuid_crate = {package = "uuid", version = "0.8.1", features = ["v4"], optional = true}
+which = {version = "4.0.2", optional = true}
+zip = {version = "0.5.7", optional = true}
 
-trash = { version = "1.0.1", optional = true }
-clipboard = { version = "0.5", optional = true }
-starship = "0.43.0"
-rayon = "1.3.1"
-encoding_rs = "0.8.23"
+Inflector = "0.11"
+clipboard = {version = "0.5.0", optional = true}
+encoding_rs = "0.8.24"
+quick-xml = "0.18.1"
+rayon = "1.4.0"
+trash = {version = "1.1.1", optional = true}
+url = "2.1.1"
 
 [target.'cfg(unix)'.dependencies]
+umask = "1.0.0"
 users = "0.10.0"
 
+# TODO this will be possible with new dependency resolver
+#   (currently on nightly behind -Zfeatures=itarget):
+#   https://github.com/rust-lang/cargo/issues/7914
+#[target.'cfg(not(windows))'.dependencies]
+#num-format = {version = "0.4", features = ["with-system-locale"]}
+
 [dependencies.rusqlite]
-version = "0.23.1"
 features = ["bundled", "blob"]
+optional = true
+version = "0.24.0"
 
 [build-dependencies]
-nu-build = { version = "0.16.0", path = "../nu-build" }
+git2 = {version = "0.13.11", optional = true}
 
 [dev-dependencies]
-quickcheck = "0.9"
-quickcheck_macros = "0.9"
+quickcheck = "0.9.2"
+quickcheck_macros = "0.9.1"
 
 [features]
-stable = []
-# starship-prompt = ["starship"]
 clipboard-cli = ["clipboard"]
+rich-benchmark = ["heim"]
+rustyline-support = ["rustyline"]
+stable = []
 trash-support = ["trash"]

crates/nu-cli/build.rs

@@ -0,0 +1,36 @@
+use std::path::Path;
+use std::{env, fs, io};
+
+fn main() -> Result<(), io::Error> {
+    let out_dir = env::var_os("OUT_DIR").expect(
+    "\
+        OUT_DIR environment variable not found. \
+        OUT_DIR is guaranteed to to exist in a build script by cargo - see \
+        https://doc.rust-lang.org/cargo/reference/environment-variables.html#environment-variables-cargo-sets-for-build-scripts\
+    ");
+
+    let latest_commit_hash = latest_commit_hash(env::current_dir()?).unwrap_or_default();
+
+    let commit_hash_path = Path::new(&out_dir).join("git_commit_hash");
+    fs::write(commit_hash_path, latest_commit_hash)?;
+
+    Ok(())
+}
+
+#[allow(unused_variables)]
+fn latest_commit_hash<P: AsRef<Path>>(dir: P) -> Result<String, Box<dyn std::error::Error>> {
+    #[cfg(feature = "git2")]
+    {
+        use git2::Repository;
+        let dir = dir.as_ref();
+        Ok(Repository::discover(dir)?
+            .head()?
+            .peel_to_commit()?
+            .id()
+            .to_string())
+    }
+    #[cfg(not(feature = "git2"))]
+    {
+        Ok(String::new())
+    }
+}

crates/nu-cli/src/command_registry.rs

@@ -0,0 +1,64 @@
+use crate::commands::Command;
+use indexmap::IndexMap;
+use nu_errors::ShellError;
+use nu_parser::SignatureRegistry;
+use nu_protocol::Signature;
+use parking_lot::Mutex;
+use std::sync::Arc;
+
+#[derive(Debug, Clone, Default)]
+pub struct CommandRegistry {
+    registry: Arc<Mutex<IndexMap<String, Command>>>,
+}
+
+impl SignatureRegistry for CommandRegistry {
+    fn has(&self, name: &str) -> bool {
+        let registry = self.registry.lock();
+        registry.contains_key(name)
+    }
+    fn get(&self, name: &str) -> Option<Signature> {
+        let registry = self.registry.lock();
+        registry.get(name).map(|command| command.signature())
+    }
+    fn clone_box(&self) -> Box<dyn SignatureRegistry> {
+        Box::new(self.clone())
+    }
+}
+
+impl CommandRegistry {
+    pub fn new() -> CommandRegistry {
+        CommandRegistry {
+            registry: Arc::new(Mutex::new(IndexMap::default())),
+        }
+    }
+}
+
+impl CommandRegistry {
+    pub fn get_command(&self, name: &str) -> Option<Command> {
+        let registry = self.registry.lock();
+
+        registry.get(name).cloned()
+    }
+
+    pub fn expect_command(&self, name: &str) -> Result<Command, ShellError> {
+        self.get_command(name).ok_or_else(|| {
+            ShellError::untagged_runtime_error(format!("Could not load command: {}", name))
+        })
+    }
+
+    pub fn has(&self, name: &str) -> bool {
+        let registry = self.registry.lock();
+
+        registry.contains_key(name)
+    }
+
+    pub fn insert(&mut self, name: impl Into<String>, command: Command) {
+        let mut registry = self.registry.lock();
+        registry.insert(name.into(), command);
+    }
+
+    pub fn names(&self) -> Vec<String> {
+        let registry = self.registry.lock();
+        registry.keys().cloned().collect()
+    }
+}

crates/nu-cli/src/commands.rs

@@ -8,18 +8,22 @@ pub(crate) mod alias;
 pub(crate) mod ansi;
 pub(crate) mod append;
 pub(crate) mod args;
+pub(crate) mod autoenv;
+pub(crate) mod autoenv_trust;
+pub(crate) mod autoenv_untrust;
 pub(crate) mod autoview;
+pub(crate) mod benchmark;
 pub(crate) mod build_string;
 pub(crate) mod cal;
-pub(crate) mod calc;
 pub(crate) mod cd;
 pub(crate) mod char_;
 pub(crate) mod classified;
-#[cfg(feature = "clipboard")]
+#[cfg(feature = "clipboard-cli")]
 pub(crate) mod clip;
 pub(crate) mod command;
 pub(crate) mod compact;
 pub(crate) mod config;
+pub(crate) mod constants;
 pub(crate) mod count;
 pub(crate) mod cp;
 pub(crate) mod date;
@@ -31,21 +35,18 @@ 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 every;
+pub(crate) mod exec;
 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;
@@ -61,33 +62,31 @@ pub(crate) mod headers;
 pub(crate) mod help;
 pub(crate) mod histogram;
 pub(crate) mod history;
+pub(crate) mod if_;
 pub(crate) mod insert;
+pub(crate) mod into_int;
 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 math;
 pub(crate) mod merge;
 pub(crate) mod mkdir;
-pub(crate) mod mv;
+pub(crate) mod move_;
 pub(crate) mod next;
 pub(crate) mod nth;
+pub(crate) mod nu;
 pub(crate) mod open;
 pub(crate) mod parse;
+pub(crate) mod path;
 pub(crate) mod pivot;
-pub(crate) mod plugin;
 pub(crate) mod prepend;
 pub(crate) mod prev;
 pub(crate) mod pwd;
 pub(crate) mod random;
 pub(crate) mod range;
-#[allow(unused)]
-pub(crate) mod reduce_by;
+pub(crate) mod reduce;
 pub(crate) mod reject;
 pub(crate) mod rename;
 pub(crate) mod reverse;
@@ -100,30 +99,26 @@ 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 sleep;
 pub(crate) mod sort_by;
 pub(crate) mod split;
 pub(crate) mod split_by;
 pub(crate) mod str_;
-#[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_xml;
 pub(crate) mod to_yaml;
-pub(crate) mod trim;
 pub(crate) mod uniq;
 pub(crate) mod update;
+pub(crate) mod url_;
 pub(crate) mod version;
 pub(crate) mod what;
 pub(crate) mod where_;
@@ -140,23 +135,32 @@ pub(crate) use command::{
 pub(crate) use alias::Alias;
 pub(crate) use ansi::Ansi;
 pub(crate) use append::Append;
+pub(crate) use autoenv::Autoenv;
+pub(crate) use autoenv_trust::AutoenvTrust;
+pub(crate) use autoenv_untrust::AutoenvUnTrust;
+pub(crate) use benchmark::Benchmark;
 pub(crate) use build_string::BuildString;
 pub(crate) use cal::Cal;
-pub(crate) use calc::Calc;
 pub(crate) use char_::Char;
 pub(crate) use compact::Compact;
-pub(crate) use config::Config;
+pub(crate) use config::{
+    Config, ConfigClear, ConfigGet, ConfigLoad, ConfigPath, ConfigRemove, ConfigSet, ConfigSetInto,
+};
 pub(crate) use count::Count;
 pub(crate) use cp::Cpy;
-pub(crate) use date::Date;
+pub(crate) use date::{Date, DateFormat, DateNow, DateUTC};
 pub(crate) use debug::Debug;
 pub(crate) use default::Default;
 pub(crate) use do_::Do;
 pub(crate) use drop::Drop;
 pub(crate) use du::Du;
 pub(crate) use each::Each;
+pub(crate) use each::EachGroup;
+pub(crate) use each::EachWindow;
 pub(crate) use echo::Echo;
+pub(crate) use if_::If;
 pub(crate) use is_empty::IsEmpty;
+pub(crate) use nu::NuPlugin;
 pub(crate) use update::Update;
 pub(crate) mod kill;
 pub(crate) use kill::Kill;
@@ -164,22 +168,18 @@ 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 every::Every;
+pub(crate) use exec::Exec;
 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;
@@ -197,32 +197,35 @@ 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 into_int::IntoInt;
+pub(crate) use keep::{Keep, KeepUntil, 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 math::{
-    Math, MathAverage, MathMaximum, MathMedian, MathMinimum, MathMode, MathSummation,
+    Math, MathAverage, MathEval, MathMaximum, MathMedian, MathMinimum, MathMode, MathProduct,
+    MathStddev, MathSummation, MathVariance,
 };
 pub(crate) use merge::Merge;
 pub(crate) use mkdir::Mkdir;
-pub(crate) use mv::Move;
+pub(crate) use move_::{Move, MoveColumn, Mv};
 pub(crate) use next::Next;
 pub(crate) use nth::Nth;
 pub(crate) use open::Open;
 pub(crate) use parse::Parse;
+pub(crate) use path::{
+    PathBasename, PathCommand, PathDirname, PathExists, PathExpand, PathExtension, PathFilestem,
+    PathType,
+};
 pub(crate) use pivot::Pivot;
 pub(crate) use prepend::Prepend;
 pub(crate) use prev::Previous;
 pub(crate) use pwd::Pwd;
-pub(crate) use random::{Random, RandomBool, RandomDice, RandomUUID};
+#[cfg(feature = "uuid_crate")]
+pub(crate) use random::RandomUUID;
+pub(crate) use random::{Random, RandomBool, RandomDice, RandomInteger};
 pub(crate) use range::Range;
-#[allow(unused_imports)]
-pub(crate) use reduce_by::ReduceBy;
+pub(crate) use reduce::Reduce;
 pub(crate) use reject::Reject;
 pub(crate) use rename::Rename;
 pub(crate) use reverse::Reverse;
@@ -233,37 +236,32 @@ 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 skip::{Skip, SkipUntil, SkipWhile};
+pub(crate) use sleep::Sleep;
 pub(crate) use sort_by::SortBy;
-pub(crate) use split::Split;
-pub(crate) use split::SplitColumn;
-pub(crate) use split::SplitRow;
+pub(crate) use split::{Split, SplitChars, SplitColumn, SplitRow};
 pub(crate) use split_by::SplitBy;
 pub(crate) use str_::{
-    Str, StrCapitalize, StrCollect, StrDowncase, StrFindReplace, StrSet, StrSubstring,
-    StrToDatetime, StrToDecimal, StrToInteger, StrTrim, StrUpcase,
+    Str, StrCamelCase, StrCapitalize, StrCollect, StrContains, StrDowncase, StrEndsWith,
+    StrFindReplace, StrFrom, StrIndexOf, StrKebabCase, StrLength, StrPascalCase, StrReverse,
+    StrScreamingSnakeCase, StrSet, StrSnakeCase, StrStartsWith, StrSubstring, StrToDatetime,
+    StrToDecimal, StrToInteger, StrTrim, StrTrimLeft, StrTrimRight, StrUpcase,
 };
-#[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_xml::ToXML;
 pub(crate) use to_yaml::ToYAML;
 pub(crate) use touch::Touch;
-pub(crate) use trim::Trim;
 pub(crate) use uniq::Uniq;
+pub(crate) use url_::{UrlCommand, UrlHost, UrlPath, UrlQuery, UrlScheme};
 pub(crate) use version::Version;
 pub(crate) use what::What;
 pub(crate) use where_::Where;

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

@@ -1,12 +1,16 @@
+use crate::command_registry::CommandRegistry;
 use crate::commands::WholeStreamCommand;
-use crate::context::CommandRegistry;
-use crate::data::config;
 use crate::prelude::*;
+use nu_data::config;
 use nu_errors::ShellError;
+use nu_parser::SignatureRegistry;
+use nu_protocol::hir::{ClassifiedCommand, Expression, NamedValue, SpannedExpression, Variable};
 use nu_protocol::{
-    hir::Block, CommandAction, ReturnSuccess, Signature, SyntaxShape, UntaggedValue, Value,
+    hir::Block, CommandAction, NamedType, PositionalType, ReturnSuccess, Signature, SyntaxShape,
+    UntaggedValue, Value,
 };
 use nu_source::Tagged;
+use std::collections::HashMap;
 
 pub struct Alias;
 
@@ -15,6 +19,7 @@ pub struct AliasArgs {
     pub name: Tagged<String>,
     pub args: Vec<Value>,
     pub block: Block,
+    pub infer: Option<bool>,
     pub save: Option<bool>,
 }
 
@@ -33,6 +38,7 @@ impl WholeStreamCommand for Alias {
                 SyntaxShape::Block,
                 "the block to run as the body of the alias",
             )
+            .switch("infer", "infer argument types (experimental)", Some('i'))
             .switch("save", "save the alias to your config", Some('s'))
     }
 
@@ -75,6 +81,7 @@ pub async fn alias(
             name,
             args: list,
             block,
+            infer,
             save,
         },
         _ctx,
@@ -82,17 +89,21 @@ pub async fn alias(
     let mut processed_args: Vec<String> = vec![];
 
     if let Some(true) = save {
-        let mut result = crate::data::config::read(name.clone().tag, &None)?;
+        let mut result = nu_data::config::read(name.clone().tag, &None)?;
 
         // process the alias to remove the --save flag
         let left_brace = raw_input.find('{').unwrap_or(0);
         let right_brace = raw_input.rfind('}').unwrap_or_else(|| raw_input.len());
         let left = raw_input[..left_brace]
-            .replace("--save", "")
-            .replace("-s", "");
+            .replace("--save", "") // TODO using regex (or reconstruct string from AST?)
+            .replace("-si", "-i")
+            .replace("-s ", "")
+            .replace("-is", "-i");
         let right = raw_input[right_brace..]
             .replace("--save", "")
-            .replace("-s", "");
+            .replace("-si", "-i")
+            .replace("-s ", "")
+            .replace("-is", "-i");
         raw_input = format!("{}{}{}", left, &raw_input[left_brace..right_brace], right);
 
         // create a value from raw_input alias
@@ -133,9 +144,197 @@ pub async fn alias(
         }
     }
 
-    Ok(OutputStream::one(ReturnSuccess::action(
-        CommandAction::AddAlias(name.to_string(), processed_args, block),
-    )))
+    if let Some(true) = infer {
+        Ok(OutputStream::one(ReturnSuccess::action(
+            CommandAction::AddAlias(
+                name.to_string(),
+                to_arg_shapes(processed_args, &block, &registry)?,
+                block,
+            ),
+        )))
+    } else {
+        Ok(OutputStream::one(ReturnSuccess::action(
+            CommandAction::AddAlias(
+                name.to_string(),
+                processed_args
+                    .into_iter()
+                    .map(|arg| (arg, SyntaxShape::Any))
+                    .collect(),
+                block,
+            ),
+        )))
+    }
+}
+
+fn to_arg_shapes(
+    args: Vec<String>,
+    block: &Block,
+    registry: &CommandRegistry,
+) -> Result<Vec<(String, SyntaxShape)>, ShellError> {
+    match find_block_shapes(block, registry) {
+        Ok(found) => Ok(args
+            .iter()
+            .map(|arg| {
+                (
+                    arg.clone(),
+                    match found.get(arg) {
+                        None | Some((_, None)) => SyntaxShape::Any,
+                        Some((_, Some(shape))) => *shape,
+                    },
+                )
+            })
+            .collect()),
+        Err(err) => Err(err),
+    }
+}
+
+type ShapeMap = HashMap<String, (Span, Option<SyntaxShape>)>;
+
+fn check_insert(
+    existing: &mut ShapeMap,
+    to_add: (String, (Span, Option<SyntaxShape>)),
+) -> Result<(), ShellError> {
+    match (to_add.1).1 {
+        None => match existing.get(&to_add.0) {
+            None => {
+                existing.insert(to_add.0, to_add.1);
+                Ok(())
+            }
+            Some(_) => Ok(()),
+        },
+        Some(new) => match existing.insert(to_add.0.clone(), ((to_add.1).0, Some(new))) {
+            None => Ok(()),
+            Some(exist) => match exist.1 {
+                None => Ok(()),
+                Some(shape) => match shape {
+                    SyntaxShape::Any => Ok(()),
+                    shape if shape == new => Ok(()),
+                    _ => Err(ShellError::labeled_error_with_secondary(
+                        "Type conflict in alias variable use",
+                        format!("{:?}", new),
+                        (to_add.1).0,
+                        format!("{:?}", shape),
+                        exist.0,
+                    )),
+                },
+            },
+        },
+    }
+}
+
+fn check_merge(existing: &mut ShapeMap, new: &ShapeMap) -> Result<(), ShellError> {
+    for (k, v) in new.iter() {
+        check_insert(existing, (k.clone(), *v))?;
+    }
+
+    Ok(())
+}
+
+fn find_expr_shapes(
+    spanned_expr: &SpannedExpression,
+    registry: &CommandRegistry,
+) -> Result<ShapeMap, ShellError> {
+    match &spanned_expr.expr {
+        // TODO range will need similar if/when invocations can be parsed within range expression
+        Expression::Binary(bin) => find_expr_shapes(&bin.left, registry).and_then(|mut left| {
+            find_expr_shapes(&bin.right, registry)
+                .and_then(|right| check_merge(&mut left, &right).map(|()| left))
+        }),
+        Expression::Block(b) => find_block_shapes(&b, registry),
+        Expression::Path(path) => match &path.head.expr {
+            Expression::Invocation(b) => find_block_shapes(&b, registry),
+            Expression::Variable(Variable::Other(var, _)) => {
+                let mut result = HashMap::new();
+                result.insert(var.to_string(), (spanned_expr.span, None));
+                Ok(result)
+            }
+            _ => Ok(HashMap::new()),
+        },
+        _ => Ok(HashMap::new()),
+    }
+}
+
+fn find_block_shapes(block: &Block, registry: &CommandRegistry) -> Result<ShapeMap, ShellError> {
+    let apply_shape = |found: ShapeMap, sig_shape: SyntaxShape| -> ShapeMap {
+        found
+            .iter()
+            .map(|(v, sh)| match sh.1 {
+                None => (v.clone(), (sh.0, Some(sig_shape))),
+                Some(shape) => (v.clone(), (sh.0, Some(shape))),
+            })
+            .collect()
+    };
+
+    let mut arg_shapes = HashMap::new();
+    for pipeline in &block.block {
+        for classified in &pipeline.list {
+            match classified {
+                ClassifiedCommand::Expr(spanned_expr) => {
+                    let found = find_expr_shapes(&spanned_expr, registry)?;
+                    check_merge(&mut arg_shapes, &found)?
+                }
+                ClassifiedCommand::Internal(internal) => {
+                    if let Some(signature) = registry.get(&internal.name) {
+                        if let Some(positional) = &internal.args.positional {
+                            for (i, spanned_expr) in positional.iter().enumerate() {
+                                let found = find_expr_shapes(&spanned_expr, registry)?;
+                                if i >= signature.positional.len() {
+                                    if let Some((sig_shape, _)) = &signature.rest_positional {
+                                        check_merge(
+                                            &mut arg_shapes,
+                                            &apply_shape(found, *sig_shape),
+                                        )?;
+                                    } else {
+                                        unreachable!("should have error'd in parsing");
+                                    }
+                                } else {
+                                    let (pos_type, _) = &signature.positional[i];
+                                    match pos_type {
+                                        // TODO pass on mandatory/optional?
+                                        PositionalType::Mandatory(_, sig_shape)
+                                        | PositionalType::Optional(_, sig_shape) => {
+                                            check_merge(
+                                                &mut arg_shapes,
+                                                &apply_shape(found, *sig_shape),
+                                            )?;
+                                        }
+                                    }
+                                }
+                            }
+                        }
+
+                        if let Some(named) = &internal.args.named {
+                            for (name, val) in named.iter() {
+                                if let NamedValue::Value(_, spanned_expr) = val {
+                                    let found = find_expr_shapes(&spanned_expr, registry)?;
+                                    match signature.named.get(name) {
+                                        None => {
+                                            unreachable!("should have error'd in parsing");
+                                        }
+                                        Some((named_type, _)) => {
+                                            if let NamedType::Mandatory(_, sig_shape)
+                                            | NamedType::Optional(_, sig_shape) = named_type
+                                            {
+                                                check_merge(
+                                                    &mut arg_shapes,
+                                                    &apply_shape(found, *sig_shape),
+                                                )?;
+                                            }
+                                        }
+                                    }
+                                }
+                            }
+                        }
+                    } else {
+                        unreachable!("registry has lost name it provided");
+                    }
+                }
+                ClassifiedCommand::Dynamic(_) | ClassifiedCommand::Error(_) => (),
+            }
+        }
+    }
+
+    Ok(arg_shapes)
 }
 
 #[cfg(test)]

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

@@ -1,5 +1,6 @@
 use crate::commands::WholeStreamCommand;
 use crate::prelude::*;
+use ansi_term::Color;
 use nu_errors::ShellError;
 use nu_protocol::{ReturnSuccess, Signature, SyntaxShape, UntaggedValue, Value};
 
@@ -40,6 +41,14 @@ impl WholeStreamCommand for Ansi {
                 example: r#"ansi reset"#,
                 result: Some(vec![Value::from("\u{1b}[0m")]),
             },
+            Example {
+                description:
+                    "Use ansi to color text (rb = red bold, gb = green bold, pb = purple bold)",
+                example: r#"echo [$(ansi rb) Hello " " $(ansi gb) Nu " " $(ansi pb) World] | str collect"#,
+                result: Some(vec![Value::from(
+                    "\u{1b}[1;31mHello \u{1b}[1;32mNu \u{1b}[1;35mWorld",
+                )]),
+            },
         ]
     }
 
@@ -68,60 +77,56 @@ impl WholeStreamCommand for Ansi {
     }
 }
 
-fn str_to_ansi_color(s: String) -> Option<String> {
+pub fn str_to_ansi_color(s: String) -> Option<String> {
     match s.as_str() {
-        "g" | "green" => Some(ansi_term::Color::Green.prefix().to_string()),
-        "gb" | "green_bold" => Some(ansi_term::Color::Green.bold().prefix().to_string()),
-        "gu" | "green_underline" => Some(ansi_term::Color::Green.underline().prefix().to_string()),
-        "gi" | "green_italic" => Some(ansi_term::Color::Green.italic().prefix().to_string()),
-        "gd" | "green_dimmed" => Some(ansi_term::Color::Green.dimmed().prefix().to_string()),
-        "gr" | "green_reverse" => Some(ansi_term::Color::Green.reverse().prefix().to_string()),
-        "r" | "red" => Some(ansi_term::Color::Red.prefix().to_string()),
-        "rb" | "red_bold" => Some(ansi_term::Color::Red.bold().prefix().to_string()),
-        "ru" | "red_underline" => Some(ansi_term::Color::Red.underline().prefix().to_string()),
-        "ri" | "red_italic" => Some(ansi_term::Color::Red.italic().prefix().to_string()),
-        "rd" | "red_dimmed" => Some(ansi_term::Color::Red.dimmed().prefix().to_string()),
-        "rr" | "red_reverse" => Some(ansi_term::Color::Red.reverse().prefix().to_string()),
-        "u" | "blue" => Some(ansi_term::Color::Blue.prefix().to_string()),
-        "ub" | "blue_bold" => Some(ansi_term::Color::Blue.bold().prefix().to_string()),
-        "uu" | "blue_underline" => Some(ansi_term::Color::Blue.underline().prefix().to_string()),
-        "ui" | "blue_italic" => Some(ansi_term::Color::Blue.italic().prefix().to_string()),
-        "ud" | "blue_dimmed" => Some(ansi_term::Color::Blue.dimmed().prefix().to_string()),
-        "ur" | "blue_reverse" => Some(ansi_term::Color::Blue.reverse().prefix().to_string()),
-        "b" | "black" => Some(ansi_term::Color::Black.prefix().to_string()),
-        "bb" | "black_bold" => Some(ansi_term::Color::Black.bold().prefix().to_string()),
-        "bu" | "black_underline" => Some(ansi_term::Color::Black.underline().prefix().to_string()),
-        "bi" | "black_italic" => Some(ansi_term::Color::Black.italic().prefix().to_string()),
-        "bd" | "black_dimmed" => Some(ansi_term::Color::Black.dimmed().prefix().to_string()),
-        "br" | "black_reverse" => Some(ansi_term::Color::Black.reverse().prefix().to_string()),
-        "y" | "yellow" => Some(ansi_term::Color::Yellow.prefix().to_string()),
-        "yb" | "yellow_bold" => Some(ansi_term::Color::Yellow.bold().prefix().to_string()),
-        "yu" | "yellow_underline" => {
-            Some(ansi_term::Color::Yellow.underline().prefix().to_string())
-        }
-        "yi" | "yellow_italic" => Some(ansi_term::Color::Yellow.italic().prefix().to_string()),
-        "yd" | "yellow_dimmed" => Some(ansi_term::Color::Yellow.dimmed().prefix().to_string()),
-        "yr" | "yellow_reverse" => Some(ansi_term::Color::Yellow.reverse().prefix().to_string()),
-        "p" | "purple" => Some(ansi_term::Color::Purple.prefix().to_string()),
-        "pb" | "purple_bold" => Some(ansi_term::Color::Purple.bold().prefix().to_string()),
-        "pu" | "purple_underline" => {
-            Some(ansi_term::Color::Purple.underline().prefix().to_string())
-        }
-        "pi" | "purple_italic" => Some(ansi_term::Color::Purple.italic().prefix().to_string()),
-        "pd" | "purple_dimmed" => Some(ansi_term::Color::Purple.dimmed().prefix().to_string()),
-        "pr" | "purple_reverse" => Some(ansi_term::Color::Purple.reverse().prefix().to_string()),
-        "c" | "cyan" => Some(ansi_term::Color::Cyan.prefix().to_string()),
-        "cb" | "cyan_bold" => Some(ansi_term::Color::Cyan.bold().prefix().to_string()),
-        "cu" | "cyan_underline" => Some(ansi_term::Color::Cyan.underline().prefix().to_string()),
-        "ci" | "cyan_italic" => Some(ansi_term::Color::Cyan.italic().prefix().to_string()),
-        "cd" | "cyan_dimmed" => Some(ansi_term::Color::Cyan.dimmed().prefix().to_string()),
-        "cr" | "cyan_reverse" => Some(ansi_term::Color::Cyan.reverse().prefix().to_string()),
-        "w" | "white" => Some(ansi_term::Color::White.prefix().to_string()),
-        "wb" | "white_bold" => Some(ansi_term::Color::White.bold().prefix().to_string()),
-        "wu" | "white_underline" => Some(ansi_term::Color::White.underline().prefix().to_string()),
-        "wi" | "white_italic" => Some(ansi_term::Color::White.italic().prefix().to_string()),
-        "wd" | "white_dimmed" => Some(ansi_term::Color::White.dimmed().prefix().to_string()),
-        "wr" | "white_reverse" => Some(ansi_term::Color::White.reverse().prefix().to_string()),
+        "g" | "green" => Some(Color::Green.prefix().to_string()),
+        "gb" | "green_bold" => Some(Color::Green.bold().prefix().to_string()),
+        "gu" | "green_underline" => Some(Color::Green.underline().prefix().to_string()),
+        "gi" | "green_italic" => Some(Color::Green.italic().prefix().to_string()),
+        "gd" | "green_dimmed" => Some(Color::Green.dimmed().prefix().to_string()),
+        "gr" | "green_reverse" => Some(Color::Green.reverse().prefix().to_string()),
+        "r" | "red" => Some(Color::Red.prefix().to_string()),
+        "rb" | "red_bold" => Some(Color::Red.bold().prefix().to_string()),
+        "ru" | "red_underline" => Some(Color::Red.underline().prefix().to_string()),
+        "ri" | "red_italic" => Some(Color::Red.italic().prefix().to_string()),
+        "rd" | "red_dimmed" => Some(Color::Red.dimmed().prefix().to_string()),
+        "rr" | "red_reverse" => Some(Color::Red.reverse().prefix().to_string()),
+        "u" | "blue" => Some(Color::Blue.prefix().to_string()),
+        "ub" | "blue_bold" => Some(Color::Blue.bold().prefix().to_string()),
+        "uu" | "blue_underline" => Some(Color::Blue.underline().prefix().to_string()),
+        "ui" | "blue_italic" => Some(Color::Blue.italic().prefix().to_string()),
+        "ud" | "blue_dimmed" => Some(Color::Blue.dimmed().prefix().to_string()),
+        "ur" | "blue_reverse" => Some(Color::Blue.reverse().prefix().to_string()),
+        "b" | "black" => Some(Color::Black.prefix().to_string()),
+        "bb" | "black_bold" => Some(Color::Black.bold().prefix().to_string()),
+        "bu" | "black_underline" => Some(Color::Black.underline().prefix().to_string()),
+        "bi" | "black_italic" => Some(Color::Black.italic().prefix().to_string()),
+        "bd" | "black_dimmed" => Some(Color::Black.dimmed().prefix().to_string()),
+        "br" | "black_reverse" => Some(Color::Black.reverse().prefix().to_string()),
+        "y" | "yellow" => Some(Color::Yellow.prefix().to_string()),
+        "yb" | "yellow_bold" => Some(Color::Yellow.bold().prefix().to_string()),
+        "yu" | "yellow_underline" => Some(Color::Yellow.underline().prefix().to_string()),
+        "yi" | "yellow_italic" => Some(Color::Yellow.italic().prefix().to_string()),
+        "yd" | "yellow_dimmed" => Some(Color::Yellow.dimmed().prefix().to_string()),
+        "yr" | "yellow_reverse" => Some(Color::Yellow.reverse().prefix().to_string()),
+        "p" | "purple" => Some(Color::Purple.prefix().to_string()),
+        "pb" | "purple_bold" => Some(Color::Purple.bold().prefix().to_string()),
+        "pu" | "purple_underline" => Some(Color::Purple.underline().prefix().to_string()),
+        "pi" | "purple_italic" => Some(Color::Purple.italic().prefix().to_string()),
+        "pd" | "purple_dimmed" => Some(Color::Purple.dimmed().prefix().to_string()),
+        "pr" | "purple_reverse" => Some(Color::Purple.reverse().prefix().to_string()),
+        "c" | "cyan" => Some(Color::Cyan.prefix().to_string()),
+        "cb" | "cyan_bold" => Some(Color::Cyan.bold().prefix().to_string()),
+        "cu" | "cyan_underline" => Some(Color::Cyan.underline().prefix().to_string()),
+        "ci" | "cyan_italic" => Some(Color::Cyan.italic().prefix().to_string()),
+        "cd" | "cyan_dimmed" => Some(Color::Cyan.dimmed().prefix().to_string()),
+        "cr" | "cyan_reverse" => Some(Color::Cyan.reverse().prefix().to_string()),
+        "w" | "white" => Some(Color::White.prefix().to_string()),
+        "wb" | "white_bold" => Some(Color::White.bold().prefix().to_string()),
+        "wu" | "white_underline" => Some(Color::White.underline().prefix().to_string()),
+        "wi" | "white_italic" => Some(Color::White.italic().prefix().to_string()),
+        "wd" | "white_dimmed" => Some(Color::White.dimmed().prefix().to_string()),
+        "wr" | "white_reverse" => Some(Color::White.reverse().prefix().to_string()),
         "reset" => Some("\x1b[0m".to_owned()),
         _ => None,
     }

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

@@ -1,5 +1,5 @@
+use crate::command_registry::CommandRegistry;
 use crate::commands::WholeStreamCommand;
-use crate::context::CommandRegistry;
 use crate::prelude::*;
 use nu_errors::ShellError;
 use nu_protocol::{Signature, SyntaxShape, UntaggedValue, Value};

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

@@ -0,0 +1,92 @@
+use crate::commands::WholeStreamCommand;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{ReturnSuccess, Signature, UntaggedValue};
+use serde::Deserialize;
+use serde::Serialize;
+use sha2::{Digest, Sha256};
+use std::io::Read;
+use std::path::PathBuf;
+pub struct Autoenv;
+
+#[derive(Deserialize, Serialize, Debug, Default)]
+pub struct Trusted {
+    pub files: IndexMap<String, Vec<u8>>,
+}
+impl Trusted {
+    pub fn new() -> Self {
+        Trusted {
+            files: IndexMap::new(),
+        }
+    }
+}
+pub fn file_is_trusted(nu_env_file: &PathBuf, content: &[u8]) -> Result<bool, ShellError> {
+    let contentdigest = Sha256::digest(&content).as_slice().to_vec();
+    let nufile = std::fs::canonicalize(nu_env_file)?;
+
+    let trusted = read_trusted()?;
+    Ok(trusted.files.get(&nufile.to_string_lossy().to_string()) == Some(&contentdigest))
+}
+
+pub fn read_trusted() -> Result<Trusted, ShellError> {
+    let config_path = config::default_path_for(&Some(PathBuf::from("nu-env.toml")))?;
+
+    let mut file = std::fs::OpenOptions::new()
+        .read(true)
+        .create(true)
+        .write(true)
+        .open(config_path)
+        .map_err(|_| ShellError::untagged_runtime_error("Couldn't open nu-env.toml"))?;
+    let mut doc = String::new();
+    file.read_to_string(&mut doc)?;
+
+    let allowed = toml::de::from_str(doc.as_str()).unwrap_or_else(|_| Trusted::new());
+    Ok(allowed)
+}
+
+#[async_trait]
+impl WholeStreamCommand for Autoenv {
+    fn name(&self) -> &str {
+        "autoenv"
+    }
+    fn usage(&self) -> &str {
+        // "Mark a .nu-env file in a directory as trusted. Needs to be re-run after each change to the file or its filepath."
+        r#"Manage directory specific environment variables and scripts. Create a file called .nu-env in any directory and run 'autoenv trust' to let nushell read it when entering the directory.
+The file can contain several optional sections:
+    env: environment variables to set when visiting the directory. The variables are unset after leaving the directory and any overwritten values are restored.
+    scriptvars: environment variables that should be set to the return value of a script. After they have been set, they behave in the same way as variables set in the env section.
+    scripts: scripts to run when entering the directory or leaving it."#
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("autoenv")
+    }
+    async fn run(
+        &self,
+        _args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        let registry = registry.clone();
+        Ok(OutputStream::one(ReturnSuccess::value(
+            UntaggedValue::string(crate::commands::help::get_help(&Autoenv, &registry))
+                .into_value(Tag::unknown()),
+        )))
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![Example {
+            description: "Example .nu-env file",
+            example: r#"cat .nu-env
+    [env]
+    mykey = "myvalue"
+
+    [scriptvars]
+    myscript = "echo myval"
+
+    [scripts]
+    entryscripts = ["touch hello.txt", "touch hello2.txt"]
+    exitscripts = ["touch bye.txt"]"#,
+            result: None,
+        }]
+    }
+}

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

@@ -0,0 +1,83 @@
+use super::autoenv::read_trusted;
+use crate::commands::WholeStreamCommand;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::SyntaxShape;
+use nu_protocol::{Primitive, ReturnSuccess, Signature, UntaggedValue, Value};
+use sha2::{Digest, Sha256};
+use std::{fs, path::PathBuf};
+pub struct AutoenvTrust;
+
+#[async_trait]
+impl WholeStreamCommand for AutoenvTrust {
+    fn name(&self) -> &str {
+        "autoenv trust"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("autoenv trust").optional("dir", SyntaxShape::String, "Directory to allow")
+    }
+
+    fn usage(&self) -> &str {
+        "Trust a .nu-env file in the current or given directory"
+    }
+
+    async fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        let tag = args.call_info.name_tag.clone();
+
+        let file_to_trust = match args.call_info.evaluate(registry).await?.args.nth(0) {
+            Some(Value {
+                value: UntaggedValue::Primitive(Primitive::String(ref path)),
+                tag: _,
+            }) => {
+                let mut dir = fs::canonicalize(path)?;
+                dir.push(".nu-env");
+                dir
+            }
+            _ => {
+                let mut dir = fs::canonicalize(std::env::current_dir()?)?;
+                dir.push(".nu-env");
+                dir
+            }
+        };
+
+        let content = std::fs::read(&file_to_trust)?;
+
+        let filename = file_to_trust.to_string_lossy().to_string();
+        let mut allowed = read_trusted()?;
+        allowed
+            .files
+            .insert(filename, Sha256::digest(&content).as_slice().to_vec());
+
+        let config_path = config::default_path_for(&Some(PathBuf::from("nu-env.toml")))?;
+        let tomlstr = toml::to_string(&allowed).map_err(|_| {
+            ShellError::untagged_runtime_error("Couldn't serialize allowed dirs to nu-env.toml")
+        })?;
+        fs::write(config_path, tomlstr).expect("Couldn't write to toml file");
+
+        Ok(OutputStream::one(ReturnSuccess::value(
+            UntaggedValue::string(".nu-env trusted!").into_value(tag),
+        )))
+    }
+    fn is_binary(&self) -> bool {
+        false
+    }
+    fn examples(&self) -> Vec<Example> {
+        vec![
+            Example {
+                description: "Allow .nu-env file in current directory",
+                example: "autoenv trust",
+                result: None,
+            },
+            Example {
+                description: "Allow .nu-env file in directory foo",
+                example: "autoenv trust foo",
+                result: None,
+            },
+        ]
+    }
+}

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

@@ -0,0 +1,107 @@
+use super::autoenv::Trusted;
+use crate::commands::WholeStreamCommand;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::SyntaxShape;
+use nu_protocol::{Primitive, ReturnSuccess, Signature, UntaggedValue, Value};
+use std::io::Read;
+use std::{fs, path::PathBuf};
+pub struct AutoenvUnTrust;
+
+#[async_trait]
+impl WholeStreamCommand for AutoenvUnTrust {
+    fn name(&self) -> &str {
+        "autoenv untrust"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("autoenv untrust").optional(
+            "dir",
+            SyntaxShape::String,
+            "Directory to disallow",
+        )
+    }
+
+    fn usage(&self) -> &str {
+        "Untrust a .nu-env file in the current or given directory"
+    }
+
+    async fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        let tag = args.call_info.name_tag.clone();
+        let file_to_untrust = match args.call_info.evaluate(registry).await?.args.nth(0) {
+            Some(Value {
+                value: UntaggedValue::Primitive(Primitive::String(ref path)),
+                tag: _,
+            }) => {
+                let mut dir = fs::canonicalize(path)?;
+                dir.push(".nu-env");
+                dir
+            }
+            _ => {
+                let mut dir = std::env::current_dir()?;
+                dir.push(".nu-env");
+                dir
+            }
+        };
+
+        let config_path = config::default_path_for(&Some(PathBuf::from("nu-env.toml")))?;
+
+        let mut file = match std::fs::OpenOptions::new()
+            .read(true)
+            .create(true)
+            .write(true)
+            .open(config_path.clone())
+        {
+            Ok(p) => p,
+            Err(_) => {
+                return Err(ShellError::untagged_runtime_error(
+                    "Couldn't open nu-env.toml",
+                ));
+            }
+        };
+
+        let mut doc = String::new();
+        file.read_to_string(&mut doc)?;
+
+        let mut allowed: Trusted = toml::from_str(doc.as_str()).unwrap_or_else(|_| Trusted::new());
+
+        let file_to_untrust = file_to_untrust.to_string_lossy().to_string();
+
+        if allowed.files.remove(&file_to_untrust).is_none() {
+            return
+                Err(ShellError::untagged_runtime_error(
+                    "No .nu-env file to untrust in the given directory. Is it missing, or already untrusted?",
+                ));
+        }
+
+        let tomlstr = toml::to_string(&allowed).map_err(|_| {
+            ShellError::untagged_runtime_error("Couldn't serialize allowed dirs to nu-env.toml")
+        })?;
+        fs::write(config_path, tomlstr).expect("Couldn't write to toml file");
+
+        Ok(OutputStream::one(ReturnSuccess::value(
+            UntaggedValue::string(".nu-env untrusted!").into_value(tag),
+        )))
+    }
+    fn is_binary(&self) -> bool {
+        false
+    }
+    fn examples(&self) -> Vec<Example> {
+        vec![
+            Example {
+                description: "Disallow .nu-env file in current directory",
+                example: "autoenv untrust",
+                result: None,
+            },
+            Example {
+                description: "Disallow .nu-env file in directory foo",
+                example: "autoenv untrust foo",
+                result: None,
+            },
+        ]
+    }
+}

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

@@ -1,17 +1,19 @@
-use crate::commands::UnevaluatedCallInfo;
-use crate::commands::WholeStreamCommand;
-use crate::data::value::format_leaf;
+use crate::commands::autoview::options::{ConfigExtensions, NuConfig as AutoViewConfiguration};
+use crate::commands::{UnevaluatedCallInfo, WholeStreamCommand};
 use crate::prelude::*;
+use crate::primitive::get_color_config;
+use nu_data::value::format_leaf;
 use nu_errors::ShellError;
-use nu_protocol::{hir, hir::Expression, hir::Literal, hir::SpannedExpression};
+use nu_protocol::hir::{self, Expression, ExternalRedirection, Literal, SpannedExpression};
 use nu_protocol::{Primitive, Scope, Signature, UntaggedValue, Value};
+use nu_table::TextStyle;
 use parking_lot::Mutex;
 use std::sync::atomic::AtomicBool;
 
-pub struct Autoview;
+pub struct Command;
 
 #[async_trait]
-impl WholeStreamCommand for Autoview {
+impl WholeStreamCommand for Command {
     fn name(&self) -> &str {
         "autoview"
     }
@@ -82,31 +84,17 @@ impl RunnableContextWithoutInput {
 }
 
 pub async fn autoview(context: RunnableContext) -> Result<OutputStream, ShellError> {
+    let configuration = AutoViewConfiguration::new();
+
     let binary = context.get_command("binaryview");
     let text = context.get_command("textview");
     let table = context.get_command("table");
 
-    #[derive(PartialEq)]
-    enum AutoPivotMode {
-        Auto,
-        Always,
-        Never,
-    }
-
-    let pivot_mode = crate::data::config::config(Tag::unknown());
-    let pivot_mode = if let Some(v) = pivot_mode?.get("pivot_mode") {
-        match v.as_string() {
-            Ok(m) if m.to_lowercase() == "auto" => AutoPivotMode::Auto,
-            Ok(m) if m.to_lowercase() == "always" => AutoPivotMode::Always,
-            Ok(m) if m.to_lowercase() == "never" => AutoPivotMode::Never,
-            _ => AutoPivotMode::Always,
-        }
-    } else {
-        AutoPivotMode::Always
-    };
+    let pivot_mode = configuration.pivot_mode();
 
     let (mut input_stream, context) = RunnableContextWithoutInput::convert(context);
     let term_width = context.host.lock().width();
+    let color_hm = get_color_config();
 
     if let Some(x) = input_stream.next().await {
         match input_stream.next().await {
@@ -254,8 +242,8 @@ pub async fn autoview(context: RunnableContext) -> Result<OutputStream, ShellErr
                     Value {
                         value: UntaggedValue::Row(row),
                         ..
-                    } if pivot_mode == AutoPivotMode::Always
-                        || (pivot_mode == AutoPivotMode::Auto
+                    } if pivot_mode.is_always()
+                        || (pivot_mode.is_auto()
                             && (row
                                 .entries
                                 .iter()
@@ -271,15 +259,14 @@ pub async fn autoview(context: RunnableContext) -> Result<OutputStream, ShellErr
                             entries.push(vec![
                                 nu_table::StyledString::new(
                                     key.to_string(),
-                                    nu_table::TextStyle {
-                                        alignment: nu_table::Alignment::Left,
-                                        color: Some(ansi_term::Color::Green),
-                                        is_bold: true,
-                                    },
+                                    TextStyle::new()
+                                        .alignment(nu_table::Alignment::Left)
+                                        .fg(ansi_term::Color::Green)
+                                        .bold(Some(true)),
                                 ),
                                 nu_table::StyledString::new(
                                     format_leaf(value).plain_string(100_000),
-                                    nu_table::TextStyle::basic(),
+                                    nu_table::TextStyle::basic_left(),
                                 ),
                             ]);
                         }
@@ -287,7 +274,7 @@ pub async fn autoview(context: RunnableContext) -> Result<OutputStream, ShellErr
                         let table =
                             nu_table::Table::new(vec![], entries, nu_table::Theme::compact());
 
-                        nu_table::draw_table(&table, term_width);
+                        nu_table::draw_table(&table, term_width, &color_hm);
                     }
 
                     Value {
@@ -328,7 +315,7 @@ fn create_default_command_args(context: &RunnableContextWithoutInput) -> RawComm
                 positional: None,
                 named: None,
                 span,
-                is_last: true,
+                external_redirection: ExternalRedirection::Stdout,
             },
             name_tag: context.name.clone(),
             scope: Scope::new(),
@@ -338,12 +325,12 @@ fn create_default_command_args(context: &RunnableContextWithoutInput) -> RawComm
 
 #[cfg(test)]
 mod tests {
-    use super::Autoview;
+    use super::Command;
 
     #[test]
     fn examples_work_as_expected() {
         use crate::examples::test as test_examples;
 
-        test_examples(Autoview {})
+        test_examples(Command {})
     }
 }

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

@@ -0,0 +1,4 @@
+pub mod command;
+mod options;
+
+pub use command::Command as Autoview;

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

@@ -0,0 +1,60 @@
+pub use nu_data::config::NuConfig;
+use std::fmt::Debug;
+
+#[derive(PartialEq, Debug)]
+pub enum AutoPivotMode {
+    Auto,
+    Always,
+    Never,
+}
+
+impl AutoPivotMode {
+    pub fn is_auto(&self) -> bool {
+        match &self {
+            AutoPivotMode::Auto => true,
+            _ => false,
+        }
+    }
+
+    pub fn is_always(&self) -> bool {
+        match &self {
+            AutoPivotMode::Always => true,
+            _ => false,
+        }
+    }
+
+    #[allow(unused)]
+    pub fn is_never(&self) -> bool {
+        match &self {
+            AutoPivotMode::Never => true,
+            _ => false,
+        }
+    }
+}
+
+pub trait ConfigExtensions: Debug + Send {
+    fn pivot_mode(&self) -> AutoPivotMode;
+}
+
+pub fn pivot_mode(config: &NuConfig) -> AutoPivotMode {
+    let vars = &config.vars;
+
+    if let Some(mode) = vars.get("pivot_mode") {
+        let mode = match mode.as_string() {
+            Ok(m) if m.to_lowercase() == "auto" => AutoPivotMode::Auto,
+            Ok(m) if m.to_lowercase() == "always" => AutoPivotMode::Always,
+            Ok(m) if m.to_lowercase() == "never" => AutoPivotMode::Never,
+            _ => AutoPivotMode::Never,
+        };
+
+        return mode;
+    }
+
+    AutoPivotMode::Never
+}
+
+impl ConfigExtensions for NuConfig {
+    fn pivot_mode(&self) -> AutoPivotMode {
+        pivot_mode(self)
+    }
+}

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

@@ -0,0 +1,202 @@
+use crate::commands::classified::block::run_block;
+use crate::commands::WholeStreamCommand;
+use crate::prelude::*;
+#[cfg(feature = "rich-benchmark")]
+use heim::cpu::time;
+use nu_errors::ShellError;
+use nu_protocol::{
+    hir::{Block, ClassifiedCommand, Commands, InternalCommand},
+    Dictionary, Scope, Signature, SyntaxShape, UntaggedValue, Value,
+};
+use std::convert::TryInto;
+use std::time::{Duration, Instant};
+
+pub struct Benchmark;
+
+#[derive(Deserialize, Debug)]
+struct BenchmarkArgs {
+    block: Block,
+    passthrough: Option<Block>,
+}
+
+#[async_trait]
+impl WholeStreamCommand for Benchmark {
+    fn name(&self) -> &str {
+        "benchmark"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("benchmark")
+            .required(
+                "block",
+                SyntaxShape::Block,
+                "the block to run and benchmark",
+            )
+            .named(
+                "passthrough",
+                SyntaxShape::Block,
+                "Display the benchmark results and pass through the block's output",
+                Some('p'),
+            )
+    }
+
+    fn usage(&self) -> &str {
+        "Runs a block and returns the time it took to execute it"
+    }
+
+    async fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        benchmark(args, registry).await
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![
+            Example {
+                description: "Benchmarks a command within a block",
+                example: "benchmark { sleep 500ms }",
+                result: None,
+            },
+            Example {
+                description: "Benchmarks a command within a block and passes its output through",
+                example: "echo 45 | benchmark { sleep 500ms } --passthrough {}",
+                result: Some(vec![UntaggedValue::int(45).into()]),
+            },
+        ]
+    }
+}
+
+async fn benchmark(
+    raw_args: CommandArgs,
+    registry: &CommandRegistry,
+) -> Result<OutputStream, ShellError> {
+    let registry = registry.clone();
+
+    let tag = raw_args.call_info.args.span;
+    let mut context = EvaluationContext::from_raw(&raw_args, &registry);
+    let scope = raw_args.call_info.scope.clone();
+    let (BenchmarkArgs { block, passthrough }, input) = raw_args.process(&registry).await?;
+
+    let start_time = Instant::now();
+
+    #[cfg(feature = "rich-benchmark")]
+    let start = time().await;
+
+    let result = run_block(
+        &block,
+        &mut context,
+        input,
+        &scope.it,
+        &scope.vars,
+        &scope.env,
+    )
+    .await;
+    let output = result?.into_vec().await;
+
+    #[cfg(feature = "rich-benchmark")]
+    let end = time().await;
+
+    let end_time = Instant::now();
+    context.clear_errors();
+
+    // return basic runtime
+    #[cfg(not(feature = "rich-benchmark"))]
+    {
+        let mut indexmap = IndexMap::with_capacity(1);
+
+        let real_time = into_big_int(end_time - start_time);
+        indexmap.insert("real time".to_string(), real_time);
+        benchmark_output(indexmap, output, passthrough, &tag, &mut context, &scope).await
+    }
+    // return advanced stats
+    #[cfg(feature = "rich-benchmark")]
+    if let (Ok(start), Ok(end)) = (start, end) {
+        let mut indexmap = IndexMap::with_capacity(4);
+
+        let real_time = into_big_int(end_time - start_time);
+        indexmap.insert("real time".to_string(), real_time);
+
+        let user_time = into_big_int(end.user() - start.user());
+        indexmap.insert("user time".to_string(), user_time);
+
+        let system_time = into_big_int(end.system() - start.system());
+        indexmap.insert("system time".to_string(), system_time);
+
+        let idle_time = into_big_int(end.idle() - start.idle());
+        indexmap.insert("idle time".to_string(), idle_time);
+
+        benchmark_output(indexmap, output, passthrough, &tag, &mut context, &scope).await
+    } else {
+        Err(ShellError::untagged_runtime_error(
+            "Could not retreive CPU time",
+        ))
+    }
+}
+
+async fn benchmark_output<T, Output>(
+    indexmap: IndexMap<String, BigInt>,
+    block_output: Output,
+    passthrough: Option<Block>,
+    tag: T,
+    context: &mut EvaluationContext,
+    scope: &Scope,
+) -> Result<OutputStream, ShellError>
+where
+    T: Into<Tag> + Copy,
+    Output: Into<OutputStream>,
+{
+    let value = UntaggedValue::Row(Dictionary::from(
+        indexmap
+            .into_iter()
+            .map(|(k, v)| (k, UntaggedValue::duration(v).into_value(tag)))
+            .collect::<IndexMap<String, Value>>(),
+    ))
+    .into_value(tag);
+
+    if let Some(time_block) = passthrough {
+        let benchmark_output = InputStream::one(value);
+
+        // add autoview for an empty block
+        let time_block = add_implicit_autoview(time_block);
+
+        let _ = run_block(
+            &time_block,
+            context,
+            benchmark_output,
+            &scope.it,
+            &scope.vars,
+            &scope.env,
+        )
+        .await?;
+        context.clear_errors();
+
+        Ok(block_output.into())
+    } else {
+        let benchmark_output = OutputStream::one(value);
+        Ok(benchmark_output)
+    }
+}
+
+fn add_implicit_autoview(mut block: Block) -> Block {
+    if block.block.is_empty() {
+        block.push({
+            let mut commands = Commands::new(block.span);
+            commands.push(ClassifiedCommand::Internal(InternalCommand::new(
+                "autoview".to_string(),
+                block.span,
+                block.span,
+            )));
+            commands
+        });
+    }
+    block
+}
+
+fn into_big_int<T: TryInto<Duration>>(time: T) -> BigInt {
+    time.try_into()
+        .unwrap_or_else(|_| Duration::new(0, 0))
+        .as_nanos()
+        .into()
+}

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

@@ -2,7 +2,7 @@ use crate::prelude::*;
 use nu_errors::ShellError;
 
 use crate::commands::WholeStreamCommand;
-use crate::data::value::format_leaf;
+use nu_data::value::format_leaf;
 use nu_protocol::{ReturnSuccess, Signature, SyntaxShape, UntaggedValue, Value};
 
 #[derive(Deserialize)]

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

@@ -100,7 +100,7 @@ pub async fn cal(
         (current_month, current_month)
     };
 
-    let add_months_of_year_to_table_result = add_months_of_year_to_table(
+    add_months_of_year_to_table(
         &args,
         &mut calendar_vec_deque,
         &tag,
@@ -108,12 +108,9 @@ pub async fn cal(
         month_range,
         current_month,
         current_day_option,
-    );
+    )?;
 
-    match add_months_of_year_to_table_result {
-        Ok(()) => Ok(futures::stream::iter(calendar_vec_deque).to_output_stream()),
-        Err(error) => Err(error),
-    }
+    Ok(futures::stream::iter(calendar_vec_deque).to_output_stream())
 }
 
 fn get_invalid_year_shell_error(year_tag: &Tag) -> ShellError {

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

@@ -1,88 +0,0 @@
-use crate::commands::WholeStreamCommand;
-use crate::prelude::*;
-use nu_errors::ShellError;
-use nu_protocol::{Primitive, ReturnSuccess, UntaggedValue, Value};
-
-pub struct Calc;
-
-#[async_trait]
-impl WholeStreamCommand for Calc {
-    fn name(&self) -> &str {
-        "calc"
-    }
-
-    fn usage(&self) -> &str {
-        "Parse a math expression into a number"
-    }
-
-    async fn run(
-        &self,
-        args: CommandArgs,
-        registry: &CommandRegistry,
-    ) -> Result<OutputStream, ShellError> {
-        calc(args, registry).await
-    }
-
-    fn examples(&self) -> Vec<Example> {
-        vec![Example {
-            description: "Calculate math in the pipeline",
-            example: "echo '10 / 4' | calc",
-            result: Some(vec![UntaggedValue::decimal(2.5).into()]),
-        }]
-    }
-}
-
-pub async fn calc(
-    args: CommandArgs,
-    _registry: &CommandRegistry,
-) -> Result<OutputStream, ShellError> {
-    let input = args.input;
-    let name = args.call_info.name_tag.span;
-
-    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,
-                ))
-            }
-        })
-        .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()),
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use super::Calc;
-
-    #[test]
-    fn examples_work_as_expected() {
-        use crate::examples::test as test_examples;
-
-        test_examples(Calc {})
-    }
-}

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

@@ -30,11 +30,22 @@ impl WholeStreamCommand for Char {
     }
 
     fn examples(&self) -> Vec<Example> {
-        vec![Example {
-            description: "Output newline",
-            example: r#"char newline"#,
-            result: Some(vec![Value::from("\n")]),
-        }]
+        vec![
+            Example {
+                description: "Output newline",
+                example: r#"char newline"#,
+                result: Some(vec![Value::from("\n")]),
+            },
+            Example {
+                description: "Output prompt character, newline and a hamburger character",
+                example: r#"echo $(char prompt) $(char newline) $(char hamburger)"#,
+                result: Some(vec![
+                    UntaggedValue::string("\u{25b6}").into(),
+                    UntaggedValue::string("\n").into(),
+                    UntaggedValue::string("\u{2261}").into(),
+                ]),
+            },
+        ]
     }
 
     async fn run(
@@ -64,6 +75,54 @@ fn str_to_character(s: &str) -> Option<String> {
     match s {
         "newline" | "enter" | "nl" => Some("\n".into()),
         "tab" => Some("\t".into()),
+        "sp" | "space" => Some(" ".into()),
+        // Unicode names came from https://www.compart.com/en/unicode
+        // Private Use Area (U+E000-U+F8FF)
+        "branch" => Some('\u{e0a0}'.to_string()),  // 
+        "segment" => Some('\u{e0b0}'.to_string()), // 
+
+        "identical_to" | "hamburger" => Some('\u{2261}'.to_string()), // ≡
+        "not_identical_to" | "branch_untracked" => Some('\u{2262}'.to_string()), // ≢
+        "strictly_equivalent_to" | "branch_identical" => Some('\u{2263}'.to_string()), // ≣
+
+        "upwards_arrow" | "branch_ahead" => Some('\u{2191}'.to_string()), // ↑
+        "downwards_arrow" | "branch_behind" => Some('\u{2193}'.to_string()), // ↓
+        "up_down_arrow" | "branch_ahead_behind" => Some('\u{2195}'.to_string()), // ↕
+
+        "black_right_pointing_triangle" | "prompt" => Some('\u{25b6}'.to_string()), // ▶
+        "vector_or_cross_product" | "failed" => Some('\u{2a2f}'.to_string()),       // ⨯
+        "high_voltage_sign" | "elevated" => Some('\u{26a1}'.to_string()),           // ⚡
+        "tilde" | "twiddle" | "squiggly" | "home" => Some("~".into()),              // ~
+        "hash" | "hashtag" | "pound_sign" | "sharp" | "root" => Some("#".into()),   // #
+
+        // Weather symbols
+        "sun" => Some("\x1b[33;1m\u{2600}\x1b[0m".to_string()), // Yellow Bold ☀
+        "moon" => Some("\x1b[36m\u{263d}\x1b[0m".to_string()),  // Cyan ☽
+        "clouds" => Some("\x1b[37;1m\u{2601}\x1b[0m".to_string()), // White Bold ☁
+        "rain" => Some("\x1b[37;1m\u{2614}\x1b[0m".to_string()), // White Bold ☔
+        "fog" => Some("\x1b[37;1m\u{2592}\x1b[0m".to_string()), // White Bold ▒
+        "mist" => Some("\x1b[34m\u{2591}\x1b[0m".to_string()),  // Blue ░
+        "haze" => Some("\x1b[33m\u{2591}\x1b[0m".to_string()),  // Yellow ░
+        "snow" => Some("\x1b[37;1m\u{2744}\x1b[0m".to_string()), // White Bold ❄
+        "thunderstorm" => Some("\x1b[33;1m\u{26a1}\x1b[0m".to_string()), // Yellow Bold ⚡
+
+        // Reference for ansi codes https://gist.github.com/fnky/458719343aabd01cfb17a3a4f7296797
+        // Another good reference http://ascii-table.com/ansi-escape-sequences.php
+
+        // For setting title like `echo [$(char title) $(pwd) $(char bel)] | str collect`
+        "title" => Some("\x1b]2;".to_string()), // ESC]2; xterm sets window title
+        "bel" => Some('\x07'.to_string()),      // Terminal Bell
+        "backspace" => Some('\x08'.to_string()), // Backspace
+
+        // Ansi Erase Sequences
+        "clear_screen" => Some("\x1b[J".to_string()), // clears the screen
+        "clear_screen_from_cursor_to_end" => Some("\x1b[0J".to_string()), // clears from cursor until end of screen
+        "clear_screen_from_cursor_to_beginning" => Some("\x1b[1J".to_string()), // clears from cursor to beginning of screen
+        "cls" | "clear_entire_screen" => Some("\x1b[2J".to_string()), // clears the entire screen
+        "erase_line" => Some("\x1b[K".to_string()),                   // clears the current line
+        "erase_line_from_cursor_to_end" => Some("\x1b[0K".to_string()), // clears from cursor to end of line
+        "erase_line_from_cursor_to_beginning" => Some("\x1b[1K".to_string()), // clears from cursor to start of line
+        "erase_entire_line" => Some("\x1b[2K".to_string()),                   // clears entire line
         _ => None,
     }
 }

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

@@ -1,6 +1,6 @@
 use crate::commands::classified::expr::run_expression_block;
 use crate::commands::classified::internal::run_internal_command;
-use crate::context::Context;
+use crate::evaluation_context::EvaluationContext;
 use crate::prelude::*;
 use crate::stream::InputStream;
 use futures::stream::TryStreamExt;
@@ -11,7 +11,7 @@ use std::sync::atomic::Ordering;
 
 pub(crate) async fn run_block(
     block: &Block,
-    ctx: &mut Context,
+    ctx: &mut EvaluationContext,
     mut input: InputStream,
     it: &Value,
     vars: &IndexMap<String, Value>,
@@ -64,33 +64,27 @@ pub(crate) async fn run_block(
 
 async fn run_pipeline(
     commands: &Commands,
-    ctx: &mut Context,
+    ctx: &mut EvaluationContext,
     mut input: InputStream,
     it: &Value,
     vars: &IndexMap<String, Value>,
     env: &IndexMap<String, String>,
 ) -> 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(_))) => {
+    for item in commands.list.clone() {
+        input = match item {
+            ClassifiedCommand::Dynamic(_) => {
                 return Err(ShellError::unimplemented("Dynamic commands"))
             }
 
-            (Some(ClassifiedCommand::Expr(expr)), _) => {
+            ClassifiedCommand::Expr(expr) => {
                 run_expression_block(*expr, ctx, it, vars, env).await?
             }
-            (Some(ClassifiedCommand::Error(err)), _) => return Err(err.into()),
-            (_, Some(ClassifiedCommand::Error(err))) => return Err(err.clone().into()),
 
-            (Some(ClassifiedCommand::Internal(left)), _) => {
+            ClassifiedCommand::Error(err) => return Err(err.into()),
+
+            ClassifiedCommand::Internal(left) => {
                 run_internal_command(left, ctx, input, it, vars, env).await?
             }
-
-            (None, _) => break,
         };
     }
 

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

@@ -10,7 +10,7 @@ use nu_protocol::Value;
 
 pub(crate) async fn run_expression_block(
     expr: SpannedExpression,
-    context: &mut Context,
+    context: &mut EvaluationContext,
     it: &Value,
     vars: &IndexMap<String, Value>,
     env: &IndexMap<String, String>,

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

@@ -1,3 +1,4 @@
+use crate::commands::classified::maybe_text_codec::{MaybeTextCodec, StringOrBinary};
 use crate::evaluate::evaluate_baseline_expr;
 use crate::futures::ThreadedReceiver;
 use crate::prelude::*;
@@ -7,91 +8,25 @@ 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::hir::{ExternalCommand, ExternalRedirection};
 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,
+    context: &mut EvaluationContext,
     input: InputStream,
     scope: &Scope,
-    is_last: bool,
+    external_redirection: ExternalRedirection,
 ) -> Result<InputStream, ShellError> {
     trace!(target: "nu::run::external", "-> {}", command.name);
 
-    if !did_find_command(&command.name).await {
+    if !did_find_command(&command.name) {
         return Err(ShellError::labeled_error(
             "Command not found",
             "command not found",
@@ -99,15 +34,15 @@ pub(crate) async fn run_external_command(
         ));
     }
 
-    run_with_stdin(command, context, input, scope, is_last).await
+    run_with_stdin(command, context, input, scope, external_redirection).await
 }
 
 async fn run_with_stdin(
     command: ExternalCommand,
-    context: &mut Context,
+    context: &mut EvaluationContext,
     input: InputStream,
     scope: &Scope,
-    is_last: bool,
+    external_redirection: ExternalRedirection,
 ) -> Result<InputStream, ShellError> {
     let path = context.shell_manager.path();
 
@@ -118,35 +53,55 @@ async fn run_with_stdin(
         let value =
             evaluate_baseline_expr(arg, &context.registry, &scope.it, &scope.vars, &scope.env)
                 .await?;
+
         // 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()
+        match &value.value {
+            UntaggedValue::Table(table) => {
+                for t in table {
+                    match &t.value {
+                        UntaggedValue::Primitive(_) => {
+                            command_args
+                                .push(t.convert_to_string().trim_end_matches('\n').to_string());
+                        }
+                        _ => {
+                            return Err(ShellError::labeled_error(
+                                "Could not convert to positional arguments",
+                                "could not convert to positional arguments",
+                                value.tag(),
+                            ));
+                        }
+                    }
+                }
+            }
+            _ => {
+                let trimmed_value_string = value.as_string()?.trim_end_matches('\n').to_string();
+                command_args.push(trimmed_value_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);
+            let home_dir;
+
+            #[cfg(feature = "dirs")]
+            {
+                home_dir = dirs::home_dir;
+            }
+            #[cfg(not(feature = "dirs"))]
+            {
+                home_dir = || Some(std::path::PathBuf::from("/"));
+            }
+
+            let arg = expand_tilde(arg.deref(), home_dir);
 
             #[cfg(not(windows))]
             {
@@ -167,7 +122,14 @@ async fn run_with_stdin(
         })
         .collect::<Vec<String>>();
 
-    spawn(&command, &path, &process_args[..], input, is_last, scope)
+    spawn(
+        &command,
+        &path,
+        &process_args[..],
+        input,
+        external_redirection,
+        scope,
+    )
 }
 
 fn spawn(
@@ -175,7 +137,7 @@ fn spawn(
     path: &str,
     args: &[String],
     input: InputStream,
-    is_last: bool,
+    external_redirection: ExternalRedirection,
     scope: &Scope,
 ) -> Result<InputStream, ShellError> {
     let command = command.clone();
@@ -211,12 +173,22 @@ fn spawn(
 
     // 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");
-
-        process.stderr(Stdio::piped());
-        trace!(target: "nu::run::external", "set up stderr pipe");
+    match external_redirection {
+        ExternalRedirection::Stdout => {
+            process.stdout(Stdio::piped());
+            trace!(target: "nu::run::external", "set up stdout pipe");
+        }
+        ExternalRedirection::Stderr => {
+            process.stderr(Stdio::piped());
+            trace!(target: "nu::run::external", "set up stderr pipe");
+        }
+        ExternalRedirection::StdoutAndStderr => {
+            process.stdout(Stdio::piped());
+            trace!(target: "nu::run::external", "set up stdout pipe");
+            process.stderr(Stdio::piped());
+            trace!(target: "nu::run::external", "set up stderr pipe");
+        }
+        _ => {}
     }
 
     // open since we have some contents for stdin
@@ -300,7 +272,9 @@ fn spawn(
         });
 
         std::thread::spawn(move || {
-            if !is_last {
+            if external_redirection == ExternalRedirection::Stdout
+                || external_redirection == ExternalRedirection::StdoutAndStderr
+            {
                 let stdout = if let Some(stdout) = child.stdout.take() {
                     stdout
                 } else {
@@ -315,22 +289,8 @@ fn spawn(
                     return Err(());
                 };
 
-                let stderr = if let Some(stderr) = child.stderr.take() {
-                    stderr
-                } else {
-                    let _ = stdout_read_tx.send(Ok(Value {
-                        value: UntaggedValue::Error(ShellError::labeled_error(
-                            "Can't redirect the stderr for external command",
-                            "can't redirect stderr",
-                            &stdout_name_tag,
-                        )),
-                        tag: stdout_name_tag,
-                    }));
-                    return Err(());
-                };
-
                 let file = futures::io::AllowStdIo::new(stdout);
-                let stream = FramedRead::new(file, MaybeTextCodec);
+                let stream = FramedRead::new(file, MaybeTextCodec::default());
 
                 for line in block_on_stream(stream) {
                     match line {
@@ -382,17 +342,34 @@ fn spawn(
                         }
                     }
                 }
+            }
+            if external_redirection == ExternalRedirection::Stderr
+                || external_redirection == ExternalRedirection::StdoutAndStderr
+            {
+                let stderr = if let Some(stderr) = child.stderr.take() {
+                    stderr
+                } else {
+                    let _ = stdout_read_tx.send(Ok(Value {
+                        value: UntaggedValue::Error(ShellError::labeled_error(
+                            "Can't redirect the stderr for external command",
+                            "can't redirect stderr",
+                            &stdout_name_tag,
+                        )),
+                        tag: stdout_name_tag,
+                    }));
+                    return Err(());
+                };
 
                 let file = futures::io::AllowStdIo::new(stderr);
-                let err_stream = FramedRead::new(file, MaybeTextCodec);
+                let stream = FramedRead::new(file, MaybeTextCodec::default());
 
-                for err_line in block_on_stream(err_stream) {
-                    match err_line {
+                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::Error(
-                                        ShellError::untagged_runtime_error(s.clone()),
+                                        ShellError::untagged_runtime_error(s),
                                     ),
                                     tag: stdout_name_tag.clone(),
                                 }));
@@ -404,9 +381,7 @@ fn spawn(
                             StringOrBinary::Binary(_) => {
                                 let result = stdout_read_tx.send(Ok(Value {
                                     value: UntaggedValue::Error(
-                                        ShellError::untagged_runtime_error(
-                                            "Binary in stderr output",
-                                        ),
+                                        ShellError::untagged_runtime_error("<binary stderr>"),
                                     ),
                                     tag: stdout_name_tag.clone(),
                                 }));
@@ -428,8 +403,8 @@ fn spawn(
                             if should_error {
                                 let _ = stdout_read_tx.send(Ok(Value {
                                     value: UntaggedValue::Error(ShellError::labeled_error(
-                                        format!("Unable to read from stderr ({})", e),
-                                        "unable to read from stderr",
+                                        format!("Unable to read from stdout ({})", e),
+                                        "unable to read from stdout",
                                         &stdout_name_tag,
                                     )),
                                     tag: stdout_name_tag.clone(),
@@ -450,7 +425,7 @@ fn spawn(
             };
 
             if external_failed {
-                let cfg = crate::data::config::config(Tag::unknown());
+                let cfg = nu_data::config::config(Tag::unknown());
                 if let Ok(cfg) = cfg {
                     if cfg.contains_key("nonzero_exit_errors") {
                         let _ = stdout_read_tx.send(Ok(Value {
@@ -483,21 +458,28 @@ fn spawn(
     }
 }
 
-async fn did_find_command(name: &str) -> bool {
-    #[cfg(not(windows))]
+pub fn did_find_command(#[allow(unused)] name: &str) -> bool {
+    #[cfg(not(feature = "which"))]
+    {
+        // we can't perform this check, so just assume it can be found
+        true
+    }
+
+    #[cfg(all(feature = "which", unix))]
     {
         which::which(name).is_ok()
     }
 
-    #[cfg(windows)]
+    #[cfg(all(feature = "which", windows))]
     {
         if which::which(name).is_ok() {
             true
         } else {
+            // Reference: https://ss64.com/nt/syntax-internal.html
             let cmd_builtins = [
-                "call", "cls", "color", "date", "dir", "echo", "find", "hostname", "pause",
-                "start", "time", "title", "ver", "copy", "mkdir", "rename", "rd", "rmdir", "type",
-                "mklink",
+                "assoc", "break", "color", "copy", "date", "del", "dir", "dpath", "echo", "erase",
+                "for", "ftype", "md", "mkdir", "mklink", "move", "path", "ren", "rename", "rd",
+                "rmdir", "set", "start", "time", "title", "type", "ver", "verify", "vol",
             ];
 
             cmd_builtins.contains(&name)
@@ -559,11 +541,17 @@ fn shell_os_paths() -> Vec<std::path::PathBuf> {
 mod tests {
     use super::{
         add_quotes, argument_contains_whitespace, argument_is_quoted, expand_tilde, remove_quotes,
-        run_external_command, Context, InputStream,
     };
+    #[cfg(feature = "which")]
+    use super::{run_external_command, EvaluationContext, InputStream};
+
+    #[cfg(feature = "which")]
     use futures::executor::block_on;
+    #[cfg(feature = "which")]
     use nu_errors::ShellError;
+    #[cfg(feature = "which")]
     use nu_protocol::Scope;
+    #[cfg(feature = "which")]
     use nu_test_support::commands::ExternalBuilder;
 
     // async fn read(mut stream: OutputStream) -> Option<Value> {
@@ -579,17 +567,24 @@ mod tests {
     //     }
     // }
 
+    #[cfg(feature = "which")]
     async fn non_existent_run() -> Result<(), ShellError> {
+        use nu_protocol::hir::ExternalRedirection;
         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.");
+        let mut ctx =
+            EvaluationContext::basic().expect("There was a problem creating a basic context.");
 
-        assert!(
-            run_external_command(cmd, &mut ctx, input, &Scope::new(), false)
-                .await
-                .is_err()
-        );
+        assert!(run_external_command(
+            cmd,
+            &mut ctx,
+            input,
+            &Scope::new(),
+            ExternalRedirection::Stdout
+        )
+        .await
+        .is_err());
 
         Ok(())
     }
@@ -597,7 +592,7 @@ mod tests {
     // 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 mut ctx = EvaluationContext::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.");
@@ -618,6 +613,7 @@ mod tests {
     //     block_on(failure_run())
     // }
 
+    #[cfg(feature = "which")]
     #[test]
     fn identifies_command_not_found() -> Result<(), ShellError> {
         block_on(non_existent_run())

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

@@ -4,12 +4,12 @@ use crate::commands::UnevaluatedCallInfo;
 use crate::prelude::*;
 use log::{log_enabled, trace};
 use nu_errors::ShellError;
-use nu_protocol::hir::InternalCommand;
+use nu_protocol::hir::{ExternalRedirection, InternalCommand};
 use nu_protocol::{CommandAction, Primitive, ReturnSuccess, Scope, UntaggedValue, Value};
 
 pub(crate) async fn run_internal_command(
     command: InternalCommand,
-    context: &mut Context,
+    context: &mut EvaluationContext,
     input: InputStream,
     it: &Value,
     vars: &IndexMap<String, Value>,
@@ -28,6 +28,10 @@ pub(crate) async fn run_internal_command(
     let objects: InputStream = trace_stream!(target: "nu::trace_stream::internal", "input" = input);
     let internal_command = context.expect_command(&command.name);
 
+    if command.name == "autoenv untrust" {
+        context.user_recently_used_autoenv_untrust = true;
+    }
+
     let result = {
         context
             .run_command(
@@ -83,7 +87,7 @@ pub(crate) async fn run_internal_command(
                                                 positional: None,
                                                 named: None,
                                                 span: Span::unknown(),
-                                                is_last: false,
+                                                external_redirection: ExternalRedirection::Stdout,
                                             },
                                             name_tag: Tag::unknown_anchor(command.name_span),
                                             scope: (&*scope).clone(),
@@ -178,10 +182,7 @@ pub(crate) async fn run_internal_command(
                             }
                             CommandAction::EnterShell(location) => {
                                 context.shell_manager.insert_at_current(Box::new(
-                                    match FilesystemShell::with_location(
-                                        location,
-                                        context.registry().clone(),
-                                    ) {
+                                    match FilesystemShell::with_location(location) {
                                         Ok(v) => v,
                                         Err(err) => {
                                             return InputStream::one(
@@ -199,6 +200,28 @@ pub(crate) async fn run_internal_command(
                                 )]);
                                 InputStream::from_stream(futures::stream::iter(vec![]))
                             }
+                            CommandAction::AddPlugins(path) => {
+                                match crate::plugin::scan(vec![std::path::PathBuf::from(path)]) {
+                                    Ok(plugins) => {
+                                        context.add_commands(
+                                            plugins
+                                                .into_iter()
+                                                .filter(|p| {
+                                                    !context.is_command_registered(p.name())
+                                                })
+                                                .collect(),
+                                        );
+
+                                        InputStream::from_stream(futures::stream::iter(vec![]))
+                                    }
+                                    Err(reason) => {
+                                        context.error(reason.clone());
+                                        InputStream::one(
+                                            UntaggedValue::Error(reason).into_untagged_value(),
+                                        )
+                                    }
+                                }
+                            }
                             CommandAction::PreviousShell => {
                                 context.shell_manager.prev();
                                 InputStream::from_stream(futures::stream::iter(vec![]))

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

@@ -0,0 +1,127 @@
+use bytes::{BufMut, Bytes, BytesMut};
+
+use nu_errors::ShellError;
+
+extern crate encoding_rs;
+use encoding_rs::{CoderResult, Decoder, Encoding, UTF_8};
+
+#[cfg(not(test))]
+const OUTPUT_BUFFER_SIZE: usize = 8192;
+#[cfg(test)]
+const OUTPUT_BUFFER_SIZE: usize = 4;
+
+#[derive(Debug, Eq, PartialEq)]
+pub enum StringOrBinary {
+    String(String),
+    Binary(Vec<u8>),
+}
+
+pub struct MaybeTextCodec {
+    decoder: Decoder,
+}
+
+impl MaybeTextCodec {
+    // The constructor takes an Option<&'static Encoding>, because an absence of an encoding indicates that we want BOM sniffing enabled
+    pub fn new(encoding: Option<&'static Encoding>) -> Self {
+        let decoder = match encoding {
+            Some(e) => e.new_decoder_with_bom_removal(),
+            None => UTF_8.new_decoder(),
+        };
+        MaybeTextCodec { decoder }
+    }
+}
+
+impl Default for MaybeTextCodec {
+    fn default() -> Self {
+        MaybeTextCodec {
+            decoder: UTF_8.new_decoder(),
+        }
+    }
+}
+
+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 = ShellError;
+
+    fn decode(&mut self, src: &mut BytesMut) -> Result<Option<Self::Item>, Self::Error> {
+        if src.is_empty() {
+            return Ok(None);
+        }
+
+        let mut s = String::with_capacity(OUTPUT_BUFFER_SIZE);
+
+        let (res, _read, replacements) = self.decoder.decode_to_string(src, &mut s, false);
+
+        let result = if replacements {
+            // If we had to make replacements when converting to utf8, fall back to binary
+            StringOrBinary::Binary(src.to_vec())
+        } else {
+            // If original buffer size is too small, we continue to allocate new Strings and append
+            // them to the result until the input buffer is smaller than the allocated String
+            if let CoderResult::OutputFull = res {
+                let mut buffer = String::with_capacity(OUTPUT_BUFFER_SIZE);
+                loop {
+                    let (res, _read, _replacements) =
+                        self.decoder
+                            .decode_to_string(&src[s.len()..], &mut buffer, false);
+                    s.push_str(&buffer);
+
+                    if let CoderResult::InputEmpty = res {
+                        break;
+                    }
+
+                    buffer.clear();
+                }
+            }
+
+            StringOrBinary::String(s)
+        };
+
+        src.clear();
+
+        Ok(Some(result))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::{MaybeTextCodec, StringOrBinary};
+    use bytes::BytesMut;
+    use futures_codec::Decoder;
+
+    // TODO: Write some more tests
+
+    #[test]
+    fn should_consume_all_bytes_from_source_when_temporary_buffer_overflows() {
+        let mut maybe_text = MaybeTextCodec::new(None);
+        let mut bytes = BytesMut::from("0123456789");
+
+        let text = maybe_text.decode(&mut bytes);
+
+        assert_eq!(
+            Ok(Some(StringOrBinary::String("0123456789".to_string()))),
+            text
+        );
+        assert!(bytes.is_empty());
+    }
+}

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

@@ -3,6 +3,8 @@ mod dynamic;
 pub(crate) mod expr;
 pub(crate) mod external;
 pub(crate) mod internal;
+pub(crate) mod maybe_text_codec;
+pub(crate) mod plugin;
 
 #[allow(unused_imports)]
 pub(crate) use dynamic::Command as DynamicCommand;

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

@@ -1,30 +1,16 @@
-use crate::commands::WholeStreamCommand;
+use crate::commands::command::{whole_stream_command, WholeStreamCommand};
 use crate::prelude::*;
 use derive_new::new;
 use log::trace;
 use nu_errors::ShellError;
+use nu_plugin::jsonrpc::JsonRpc;
 use nu_protocol::{Primitive, ReturnValue, Signature, UntaggedValue, Value};
 use serde::{self, Deserialize, Serialize};
 use std::io::prelude::*;
 use std::io::BufReader;
 use std::io::Write;
-
-#[derive(Debug, Serialize, Deserialize)]
-pub struct JsonRpc<T> {
-    jsonrpc: String,
-    pub method: String,
-    pub params: T,
-}
-
-impl<T> JsonRpc<T> {
-    pub fn new<U: Into<String>>(method: U, params: T) -> Self {
-        JsonRpc {
-            jsonrpc: "2.0".into(),
-            method: method.into(),
-            params,
-        }
-    }
-}
+use std::path::Path;
+use std::process::{Child, Command, Stdio};
 
 #[derive(Debug, Serialize, Deserialize)]
 #[serde(tag = "method")]
@@ -35,15 +21,77 @@ pub enum NuResult {
     },
 }
 
+enum PluginCommand {
+    Filter(PluginFilter),
+    Sink(PluginSink),
+}
+
+impl PluginCommand {
+    fn command(self) -> Result<crate::commands::Command, ShellError> {
+        match self {
+            PluginCommand::Filter(cmd) => Ok(whole_stream_command(cmd)),
+            PluginCommand::Sink(cmd) => Ok(whole_stream_command(cmd)),
+        }
+    }
+}
+
+enum PluginMode {
+    Filter,
+    Sink,
+}
+
+pub struct PluginCommandBuilder {
+    mode: PluginMode,
+    name: String,
+    path: String,
+    config: Signature,
+}
+
+impl PluginCommandBuilder {
+    pub fn new(
+        name: impl Into<String>,
+        path: impl Into<String>,
+        config: impl Into<Signature>,
+    ) -> Self {
+        let config = config.into();
+
+        PluginCommandBuilder {
+            mode: if config.is_filter {
+                PluginMode::Filter
+            } else {
+                PluginMode::Sink
+            },
+            name: name.into(),
+            path: path.into(),
+            config,
+        }
+    }
+
+    pub fn build(&self) -> Result<crate::commands::Command, ShellError> {
+        let mode = &self.mode;
+
+        let name = self.name.clone();
+        let path = self.path.clone();
+        let config = self.config.clone();
+
+        let cmd = match mode {
+            PluginMode::Filter => PluginCommand::Filter(PluginFilter { name, path, config }),
+            PluginMode::Sink => PluginCommand::Sink(PluginSink { name, path, config }),
+        };
+
+        cmd.command()
+    }
+}
+
 #[derive(new)]
-pub struct PluginCommand {
+pub struct PluginFilter {
     name: String,
     path: String,
     config: Signature,
 }
 
 #[async_trait]
-impl WholeStreamCommand for PluginCommand {
+impl WholeStreamCommand for PluginFilter {
     fn name(&self) -> &str {
         &self.name
     }
@@ -61,11 +109,11 @@ impl WholeStreamCommand for PluginCommand {
         args: CommandArgs,
         registry: &CommandRegistry,
     ) -> Result<OutputStream, ShellError> {
-        filter_plugin(self.path.clone(), args, registry).await
+        run_filter(self.path.clone(), args, registry).await
     }
 }
 
-pub async fn filter_plugin(
+async fn run_filter(
     path: String,
     args: CommandArgs,
     registry: &CommandRegistry,
@@ -84,11 +132,34 @@ pub async fn filter_plugin(
 
     let args = args.evaluate_once_with_scope(&registry, &scope).await?;
 
-    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 real_path = Path::new(&path);
+    let ext = real_path.extension();
+    let ps1_file = match ext {
+        Some(ext) => ext == "ps1",
+        None => false,
+    };
+
+    let mut child: Child = if ps1_file {
+        Command::new("pwsh")
+            .stdin(Stdio::piped())
+            .stdout(Stdio::piped())
+            .args(&[
+                "-NoLogo",
+                "-NoProfile",
+                "-ExecutionPolicy",
+                "Bypass",
+                "-File",
+                &real_path.to_string_lossy(),
+            ])
+            .spawn()
+            .expect("Failed to spawn PowerShell process")
+    } else {
+        Command::new(path)
+            .stdin(Stdio::piped())
+            .stdout(Stdio::piped())
+            .spawn()
+            .expect("Failed to spawn child process")
+    };
 
     let call_info = args.call_info.clone();
 
@@ -111,6 +182,7 @@ pub async fn filter_plugin(
 
                     let request = JsonRpc::new("begin_filter", call_info.clone());
                     let request_raw = serde_json::to_string(&request);
+                    trace!("begin_filter:request {:?}", &request_raw);
 
                     match request_raw {
                         Err(_) => {
@@ -136,6 +208,8 @@ pub async fn filter_plugin(
                     match reader.read_line(&mut input) {
                         Ok(_) => {
                             let response = serde_json::from_str::<NuResult>(&input);
+                            trace!("begin_filter:response {:?}", &response);
+
                             match response {
                                 Ok(NuResult::response { params }) => match params {
                                     Ok(params) => futures::stream::iter(params).to_output_stream(),
@@ -168,6 +242,7 @@ pub async fn filter_plugin(
 
                     let request: JsonRpc<std::vec::Vec<Value>> = JsonRpc::new("end_filter", vec![]);
                     let request_raw = serde_json::to_string(&request);
+                    trace!("end_filter:request {:?}", &request_raw);
 
                     match request_raw {
                         Err(_) => {
@@ -193,6 +268,8 @@ pub async fn filter_plugin(
                     let stream = match reader.read_line(&mut input) {
                         Ok(_) => {
                             let response = serde_json::from_str::<NuResult>(&input);
+                            trace!("end_filter:response {:?}", &response);
+
                             match response {
                                 Ok(NuResult::response { params }) => match params {
                                     Ok(params) => futures::stream::iter(params).to_output_stream(),
@@ -220,6 +297,7 @@ pub async fn filter_plugin(
 
                     let request: JsonRpc<std::vec::Vec<Value>> = JsonRpc::new("quit", vec![]);
                     let request_raw = serde_json::to_string(&request);
+                    trace!("quit:request {:?}", &request_raw);
 
                     match request_raw {
                         Ok(request_raw) => {
@@ -246,6 +324,8 @@ pub async fn filter_plugin(
 
                     let request = JsonRpc::new("filter", v);
                     let request_raw = serde_json::to_string(&request);
+                    trace!("filter:request {:?}", &request_raw);
+
                     match request_raw {
                         Ok(request_raw) => {
                             let _ = stdin.write(format!("{}\n", request_raw).as_bytes());
@@ -262,6 +342,8 @@ pub async fn filter_plugin(
                     match reader.read_line(&mut input) {
                         Ok(_) => {
                             let response = serde_json::from_str::<NuResult>(&input);
+                            trace!("filter:response {:?}", &response);
+
                             match response {
                                 Ok(NuResult::response { params }) => match params {
                                     Ok(params) => futures::stream::iter(params).to_output_stream(),
@@ -313,11 +395,11 @@ impl WholeStreamCommand for PluginSink {
         args: CommandArgs,
         registry: &CommandRegistry,
     ) -> Result<OutputStream, ShellError> {
-        sink_plugin(self.path.clone(), args, registry).await
+        run_sink(self.path.clone(), args, registry).await
     }
 }
 
-pub async fn sink_plugin(
+async fn run_sink(
     path: String,
     args: CommandArgs,
     registry: &CommandRegistry,
@@ -335,7 +417,33 @@ pub async fn sink_plugin(
             let _ = writeln!(tmpfile, "{}", request_raw);
             let _ = tmpfile.flush();
 
-            let child = std::process::Command::new(path).arg(tmpfile.path()).spawn();
+            let real_path = Path::new(&path);
+            let ext = real_path.extension();
+            let ps1_file = match ext {
+                Some(ext) => ext == "ps1",
+                None => false,
+            };
+
+            // TODO: This sink may not work in powershell, trying to find
+            // an example of what CallInfo would look like in this temp file
+            let child = if ps1_file {
+                Command::new("pwsh")
+                    .args(&[
+                        "-NoLogo",
+                        "-NoProfile",
+                        "-ExecutionPolicy",
+                        "Bypass",
+                        "-File",
+                        &real_path.to_string_lossy(),
+                        &tmpfile
+                            .path()
+                            .to_str()
+                            .expect("Failed getting tmpfile path"),
+                    ])
+                    .spawn()
+            } else {
+                Command::new(path).arg(&tmpfile.path()).spawn()
+            };
 
             if let Ok(mut child) = child {
                 let _ = child.wait();

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

@@ -17,7 +17,7 @@ impl WholeStreamCommand for Clear {
     }
 
     fn usage(&self) -> &str {
-        "clears the terminal"
+        "Clears the terminal"
     }
 
     async fn run(&self, _: CommandArgs, _: &CommandRegistry) -> Result<OutputStream, ShellError> {

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

@@ -1,5 +1,5 @@
+use crate::command_registry::CommandRegistry;
 use crate::commands::WholeStreamCommand;
-use crate::context::CommandRegistry;
 use crate::prelude::*;
 use futures::stream::StreamExt;
 use nu_errors::ShellError;

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

@@ -1,5 +1,5 @@
+use crate::command_registry::CommandRegistry;
 use crate::commands::help::get_help;
-use crate::context::CommandRegistry;
 use crate::deserializer::ConfigDeserializer;
 use crate::evaluate::evaluate_args::evaluate_args;
 use crate::prelude::*;
@@ -262,10 +262,10 @@ impl EvaluatedCommandArgs {
 
     /// 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),
-        }
+        self.call_info
+            .args
+            .nth(pos)
+            .ok_or_else(|| ShellError::unimplemented("Better error: expect_nth"))
     }
 
     pub fn get(&self, name: &str) -> Option<&Value> {
@@ -303,6 +303,11 @@ pub trait WholeStreamCommand: Send + Sync {
         false
     }
 
+    // Commands that are not meant to be run by users
+    fn is_internal(&self) -> bool {
+        false
+    }
+
     fn examples(&self) -> Vec<Example> {
         Vec::new()
     }
@@ -343,6 +348,10 @@ impl Command {
         self.0.usage()
     }
 
+    pub fn examples(&self) -> Vec<Example> {
+        self.0.examples()
+    }
+
     pub async fn run(
         &self,
         args: CommandArgs,
@@ -363,6 +372,10 @@ impl Command {
         self.0.is_binary()
     }
 
+    pub fn is_internal(&self) -> bool {
+        self.0.is_internal()
+    }
+
     pub fn stream_command(&self) -> &dyn WholeStreamCommand {
         &*self.0
     }

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

@@ -1,5 +1,5 @@
+use crate::command_registry::CommandRegistry;
 use crate::commands::WholeStreamCommand;
-use crate::context::CommandRegistry;
 use crate::prelude::*;
 use futures::future;
 use futures::stream::StreamExt;
@@ -40,7 +40,7 @@ impl WholeStreamCommand for Compact {
         vec![
             Example {
                 description: "Filter out all null entries in a list",
-                example: "echo [1 2 $null 3 $null $null] | compact target",
+                example: "echo [1 2 $null 3 $null $null] | compact",
                 result: Some(vec![
                     UntaggedValue::int(1).into(),
                     UntaggedValue::int(2).into(),
@@ -49,7 +49,7 @@ impl WholeStreamCommand for Compact {
             },
             Example {
                 description: "Filter out all directory entries having no 'target'",
-                example: "ls -af | compact target",
+                example: "ls -la | compact target",
                 result: None,
             },
         ]

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

@@ -1,260 +0,0 @@
-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>,
-}
-
-#[async_trait]
-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 given",
-                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."
-    }
-
-    async fn run(
-        &self,
-        args: CommandArgs,
-        registry: &CommandRegistry,
-    ) -> Result<OutputStream, ShellError> {
-        config(args, registry).await
-    }
-
-    fn examples(&self) -> Vec<Example> {
-        vec![
-            Example {
-                description: "See all config values",
-                example: "config",
-                result: None,
-            },
-            Example {
-                description: "Set completion_mode to circular",
-                example: "config --set [completion_mode circular]",
-                result: None,
-            },
-            Example {
-                description: "Store the contents of the pipeline as a path",
-                example: "echo ['/usr/bin' '/bin'] | config --set_into path",
-                result: None,
-            },
-            Example {
-                description: "Get the current startup commands",
-                example: "config --get startup",
-                result: None,
-            },
-            Example {
-                description: "Remove the startup commands",
-                example: "config --remove startup",
-                result: None,
-            },
-            Example {
-                description: "Clear the config (be careful!)",
-                example: "config --clear",
-                result: None,
-            },
-            Example {
-                description: "Get the path to the current config file",
-                example: "config --path",
-                result: None,
-            },
-        ]
-    }
-}
-
-pub async fn config(
-    args: CommandArgs,
-    registry: &CommandRegistry,
-) -> Result<OutputStream, ShellError> {
-    let name_span = args.call_info.name_tag.clone();
-    let name = args.call_info.name_tag.clone();
-    let registry = registry.clone();
-
-    let (
-        ConfigArgs {
-            load,
-            set,
-            set_into,
-            get,
-            clear,
-            remove,
-            path,
-        },
-        input,
-    ) = args.process(&registry).await?;
-
-    let configuration = if let Some(supplied) = load {
-        Some(supplied.item().clone())
-    } else {
-        None
-    };
-
-    let mut result = crate::data::config::read(name_span, &configuration)?;
-
-    Ok(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),
-                ..
-            } => {
-                let list: Vec<_> = list
-                    .iter()
-                    .map(|x| ReturnSuccess::value(x.clone()))
-                    .collect();
-
-                futures::stream::iter(list).to_output_stream()
-            }
-            x => {
-                let x = x.clone();
-                OutputStream::one(ReturnSuccess::value(x))
-            }
-        }
-    } else if let Some((key, value)) = set {
-        result.insert(key.to_string(), value.clone());
-
-        config::write(&result, &configuration)?;
-
-        OutputStream::one(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.is_empty() {
-            return 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, value.clone());
-
-            config::write(&result, &configuration)?;
-
-            OutputStream::one(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, value);
-
-            config::write(&result, &configuration)?;
-
-            OutputStream::one(ReturnSuccess::value(
-                UntaggedValue::Row(result.into()).into_value(name),
-            ))
-        }
-    } else if let Tagged { item: true, tag } = clear {
-        result.clear();
-
-        config::write(&result, &configuration)?;
-
-        OutputStream::one(ReturnSuccess::value(
-            UntaggedValue::Row(result.into()).into_value(tag),
-        ))
-    } else if let Tagged { item: true, tag } = path {
-        let path = config::default_path_for(&configuration)?;
-
-        OutputStream::one(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)?;
-            futures::stream::iter(vec![ReturnSuccess::value(
-                UntaggedValue::Row(result.into()).into_value(v.tag()),
-            )])
-            .to_output_stream()
-        } else {
-            return Err(ShellError::labeled_error(
-                "Key does not exist in config",
-                "key",
-                v.tag(),
-            ));
-        }
-    } else {
-        futures::stream::iter(vec![ReturnSuccess::value(
-            UntaggedValue::Row(result.into()).into_value(name),
-        )])
-        .to_output_stream()
-    })
-}
-
-#[cfg(test)]
-mod tests {
-    use super::Config;
-
-    #[test]
-    fn examples_work_as_expected() {
-        use crate::examples::test as test_examples;
-
-        test_examples(Config {})
-    }
-}

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

@@ -0,0 +1,57 @@
+use crate::command_registry::CommandRegistry;
+use crate::commands::WholeStreamCommand;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{ReturnSuccess, Signature, UntaggedValue};
+
+pub struct SubCommand;
+
+#[async_trait]
+impl WholeStreamCommand for SubCommand {
+    fn name(&self) -> &str {
+        "config clear"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("config clear")
+    }
+
+    fn usage(&self) -> &str {
+        "clear the config"
+    }
+
+    async fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        clear(args, registry).await
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![Example {
+            description: "Clear the config (be careful!)",
+            example: "config clear",
+            result: None,
+        }]
+    }
+}
+
+pub async fn clear(
+    args: CommandArgs,
+    _registry: &CommandRegistry,
+) -> Result<OutputStream, ShellError> {
+    let name_span = args.call_info.name_tag.clone();
+
+    // NOTE: None because we are not loading a new config file, we just want to read from the
+    // existing config
+    let mut result = nu_data::config::read(name_span, &None)?;
+
+    result.clear();
+
+    config::write(&result, &None)?;
+
+    Ok(OutputStream::one(ReturnSuccess::value(
+        UntaggedValue::Row(result.into()).into_value(args.call_info.name_tag),
+    )))
+}

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

@@ -0,0 +1,37 @@
+use crate::commands::WholeStreamCommand;
+use crate::prelude::*;
+use crate::{CommandArgs, CommandRegistry, OutputStream};
+use nu_errors::ShellError;
+use nu_protocol::{ReturnSuccess, Signature, UntaggedValue};
+
+pub struct Command;
+
+#[async_trait]
+impl WholeStreamCommand for Command {
+    fn name(&self) -> &str {
+        "config"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("config")
+    }
+
+    fn usage(&self) -> &str {
+        "Configuration management."
+    }
+
+    async fn run(
+        &self,
+        args: CommandArgs,
+        _registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        let name_span = args.call_info.name_tag.clone();
+        let name = args.call_info.name_tag;
+        let result = nu_data::config::read(name_span, &None)?;
+
+        Ok(futures::stream::iter(vec![ReturnSuccess::value(
+            UntaggedValue::Row(result.into()).into_value(name),
+        )])
+        .to_output_stream())
+    }
+}

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

@@ -0,0 +1,83 @@
+use crate::command_registry::CommandRegistry;
+use crate::commands::WholeStreamCommand;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{ReturnSuccess, Signature, SyntaxShape, UntaggedValue, Value};
+use nu_source::Tagged;
+
+pub struct SubCommand;
+
+#[derive(Deserialize)]
+pub struct GetArgs {
+    get: Tagged<String>,
+}
+
+#[async_trait]
+impl WholeStreamCommand for SubCommand {
+    fn name(&self) -> &str {
+        "config get"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("config get").required(
+            "get",
+            SyntaxShape::Any,
+            "value to get from the config",
+        )
+    }
+
+    fn usage(&self) -> &str {
+        "Gets a value from the config"
+    }
+
+    async fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        get(args, registry).await
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![Example {
+            description: "Get the current startup commands",
+            example: "config get startup",
+            result: None,
+        }]
+    }
+}
+
+pub async fn get(
+    args: CommandArgs,
+    registry: &CommandRegistry,
+) -> Result<OutputStream, ShellError> {
+    let name_span = args.call_info.name_tag.clone();
+    let (GetArgs { get }, _) = args.process(&registry).await?;
+
+    // NOTE: None because we are not loading a new config file, we just want to read from the
+    // existing config
+    let result = nu_data::config::read(name_span, &None)?;
+
+    let key = get.to_string();
+    let value = result
+        .get(&key)
+        .ok_or_else(|| ShellError::labeled_error("Missing key in config", "key", get.tag()))?;
+
+    Ok(match value {
+        Value {
+            value: UntaggedValue::Table(list),
+            ..
+        } => {
+            let list: Vec<_> = list
+                .iter()
+                .map(|x| ReturnSuccess::value(x.clone()))
+                .collect();
+
+            futures::stream::iter(list).to_output_stream()
+        }
+        x => {
+            let x = x.clone();
+            OutputStream::one(ReturnSuccess::value(x))
+        }
+    })
+}

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

@@ -0,0 +1,59 @@
+use crate::command_registry::CommandRegistry;
+use crate::commands::WholeStreamCommand;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{ReturnSuccess, Signature, SyntaxShape, UntaggedValue};
+use nu_source::Tagged;
+use std::path::PathBuf;
+
+pub struct SubCommand;
+
+#[derive(Deserialize)]
+pub struct LoadArgs {
+    load: Tagged<PathBuf>,
+}
+
+#[async_trait]
+impl WholeStreamCommand for SubCommand {
+    fn name(&self) -> &str {
+        "config load"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("config load").required(
+            "load",
+            SyntaxShape::Path,
+            "Path to load the config from",
+        )
+    }
+
+    fn usage(&self) -> &str {
+        "Loads the config from the path given"
+    }
+
+    async fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        set(args, registry).await
+    }
+}
+
+pub async fn set(
+    args: CommandArgs,
+    registry: &CommandRegistry,
+) -> Result<OutputStream, ShellError> {
+    let name = args.call_info.name_tag.clone();
+    let name_span = args.call_info.name_tag.clone();
+    let (LoadArgs { load }, _) = args.process(&registry).await?;
+
+    let configuration = load.item().clone();
+
+    let result = nu_data::config::read(name_span, &Some(configuration))?;
+
+    Ok(futures::stream::iter(vec![ReturnSuccess::value(
+        UntaggedValue::Row(result.into()).into_value(name),
+    )])
+    .to_output_stream())
+}

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

@@ -0,0 +1,17 @@
+pub mod clear;
+pub mod command;
+pub mod get;
+pub mod load;
+pub mod path;
+pub mod remove;
+pub mod set;
+pub mod set_into;
+
+pub use clear::SubCommand as ConfigClear;
+pub use command::Command as Config;
+pub use get::SubCommand as ConfigGet;
+pub use load::SubCommand as ConfigLoad;
+pub use path::SubCommand as ConfigPath;
+pub use remove::SubCommand as ConfigRemove;
+pub use set::SubCommand as ConfigSet;
+pub use set_into::SubCommand as ConfigSetInto;

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

@@ -0,0 +1,49 @@
+use crate::command_registry::CommandRegistry;
+use crate::commands::WholeStreamCommand;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{Primitive, ReturnSuccess, Signature, UntaggedValue};
+
+pub struct SubCommand;
+
+#[async_trait]
+impl WholeStreamCommand for SubCommand {
+    fn name(&self) -> &str {
+        "config path"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("config path")
+    }
+
+    fn usage(&self) -> &str {
+        "return the path to the config file"
+    }
+
+    async fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        path(args, registry).await
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![Example {
+            description: "Get the path to the current config file",
+            example: "config path",
+            result: None,
+        }]
+    }
+}
+
+pub async fn path(
+    args: CommandArgs,
+    _registry: &CommandRegistry,
+) -> Result<OutputStream, ShellError> {
+    let path = config::default_path()?;
+
+    Ok(OutputStream::one(ReturnSuccess::value(
+        UntaggedValue::Primitive(Primitive::Path(path)).into_value(args.call_info.name_tag),
+    )))
+}

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

@@ -0,0 +1,75 @@
+use crate::command_registry::CommandRegistry;
+use crate::commands::WholeStreamCommand;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{ReturnSuccess, Signature, SyntaxShape, UntaggedValue};
+use nu_source::Tagged;
+
+pub struct SubCommand;
+
+#[derive(Deserialize)]
+pub struct RemoveArgs {
+    remove: Tagged<String>,
+}
+
+#[async_trait]
+impl WholeStreamCommand for SubCommand {
+    fn name(&self) -> &str {
+        "config remove"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("config remove").required(
+            "remove",
+            SyntaxShape::Any,
+            "remove a value from the config",
+        )
+    }
+
+    fn usage(&self) -> &str {
+        "Removes a value from the config"
+    }
+
+    async fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        remove(args, registry).await
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![Example {
+            description: "Remove the startup commands",
+            example: "config remove startup",
+            result: None,
+        }]
+    }
+}
+
+pub async fn remove(
+    args: CommandArgs,
+    registry: &CommandRegistry,
+) -> Result<OutputStream, ShellError> {
+    let name_span = args.call_info.name_tag.clone();
+    let (RemoveArgs { remove }, _) = args.process(&registry).await?;
+
+    let mut result = nu_data::config::read(name_span, &None)?;
+
+    let key = remove.to_string();
+
+    if result.contains_key(&key) {
+        result.swap_remove(&key);
+        config::write(&result, &None)?;
+        Ok(futures::stream::iter(vec![ReturnSuccess::value(
+            UntaggedValue::Row(result.into()).into_value(remove.tag()),
+        )])
+        .to_output_stream())
+    } else {
+        Err(ShellError::labeled_error(
+            "Key does not exist in config",
+            "key",
+            remove.tag(),
+        ))
+    }
+}

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

@@ -0,0 +1,67 @@
+use crate::command_registry::CommandRegistry;
+use crate::commands::WholeStreamCommand;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{ReturnSuccess, Signature, SyntaxShape, UntaggedValue, Value};
+use nu_source::Tagged;
+
+pub struct SubCommand;
+
+#[derive(Deserialize)]
+pub struct SetArgs {
+    key: Tagged<String>,
+    value: Value,
+}
+
+#[async_trait]
+impl WholeStreamCommand for SubCommand {
+    fn name(&self) -> &str {
+        "config set"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("config set")
+            .required("key", SyntaxShape::String, "variable name to set")
+            .required("value", SyntaxShape::Any, "value to use")
+    }
+
+    fn usage(&self) -> &str {
+        "Sets a value in the config"
+    }
+
+    async fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        set(args, registry).await
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![Example {
+            description: "Set nonzero_exit_errors to true",
+            example: "config set nonzero_exit_errors $true",
+            result: None,
+        }]
+    }
+}
+
+pub async fn set(
+    args: CommandArgs,
+    registry: &CommandRegistry,
+) -> Result<OutputStream, ShellError> {
+    let name_span = args.call_info.name_tag.clone();
+    let (SetArgs { key, value }, _) = args.process(&registry).await?;
+
+    // NOTE: None because we are not loading a new config file, we just want to read from the
+    // existing config
+    let mut result = nu_data::config::read(name_span, &None)?;
+
+    result.insert(key.to_string(), value.clone());
+
+    config::write(&result, &None)?;
+
+    Ok(OutputStream::one(ReturnSuccess::value(
+        UntaggedValue::Row(result.into()).into_value(&value.tag),
+    )))
+}

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

@@ -0,0 +1,98 @@
+use crate::command_registry::CommandRegistry;
+use crate::commands::WholeStreamCommand;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{ReturnSuccess, Signature, SyntaxShape, UntaggedValue, Value};
+use nu_source::Tagged;
+
+pub struct SubCommand;
+
+#[derive(Deserialize)]
+pub struct SetIntoArgs {
+    set_into: Tagged<String>,
+}
+
+#[async_trait]
+impl WholeStreamCommand for SubCommand {
+    fn name(&self) -> &str {
+        "config set_into"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("config set_into").required(
+            "set_into",
+            SyntaxShape::String,
+            "sets a variable from values in the pipeline",
+        )
+    }
+
+    fn usage(&self) -> &str {
+        "Sets a value in the config"
+    }
+
+    async fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        set_into(args, registry).await
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![Example {
+            description: "Store the contents of the pipeline as a path",
+            example: "echo ['/usr/bin' '/bin'] | config set_into path",
+            result: None,
+        }]
+    }
+}
+
+pub async fn set_into(
+    args: CommandArgs,
+    registry: &CommandRegistry,
+) -> Result<OutputStream, ShellError> {
+    let name_span = args.call_info.name_tag.clone();
+    let name = args.call_info.name_tag.clone();
+
+    let (SetIntoArgs { set_into: v }, input) = args.process(&registry).await?;
+
+    // NOTE: None because we are not loading a new config file, we just want to read from the
+    // existing config
+    let mut result = nu_data::config::read(name_span, &None)?;
+
+    // In the original code, this is set to `Some` if the `load flag is set`
+    let configuration = None;
+
+    let rows: Vec<Value> = input.collect().await;
+    let key = v.to_string();
+
+    Ok(if rows.is_empty() {
+        return 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, value.clone());
+
+        config::write(&result, &configuration)?;
+
+        OutputStream::one(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, value);
+
+        config::write(&result, &configuration)?;
+
+        OutputStream::one(ReturnSuccess::value(
+            UntaggedValue::Row(result.into()).into_value(name),
+        ))
+    })
+}

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

@@ -0,0 +1,358 @@
+pub const BAT_LANGUAGES: &[&str] = &[
+    "as",
+    "csv",
+    "tsv",
+    "applescript",
+    "script editor",
+    "s",
+    "S",
+    "adoc",
+    "asciidoc",
+    "asc",
+    "asa",
+    "yasm",
+    "nasm",
+    "asm",
+    "inc",
+    "mac",
+    "awk",
+    "bat",
+    "cmd",
+    "bib",
+    "sh",
+    "bash",
+    "zsh",
+    ".bash_aliases",
+    ".bash_completions",
+    ".bash_functions",
+    ".bash_login",
+    ".bash_logout",
+    ".bash_profile",
+    ".bash_variables",
+    ".bashrc",
+    ".profile",
+    ".textmate_init",
+    ".zshrc",
+    "PKGBUILD",
+    ".ebuild",
+    ".eclass",
+    "c",
+    "h",
+    "cs",
+    "csx",
+    "cpp",
+    "cc",
+    "cp",
+    "cxx",
+    "c++",
+    "C",
+    "h",
+    "hh",
+    "hpp",
+    "hxx",
+    "h++",
+    "inl",
+    "ipp",
+    "cabal",
+    "clj",
+    "cljc",
+    "cljs",
+    "edn",
+    "CMakeLists.txt",
+    "cmake",
+    "h.in",
+    "hh.in",
+    "hpp.in",
+    "hxx.in",
+    "h++.in",
+    "CMakeCache.txt",
+    "cr",
+    "css",
+    "css.erb",
+    "css.liquid",
+    "d",
+    "di",
+    "dart",
+    "diff",
+    "patch",
+    "Dockerfile",
+    "dockerfile",
+    "ex",
+    "exs",
+    "elm",
+    "erl",
+    "hrl",
+    "Emakefile",
+    "emakefile",
+    "fs",
+    "fsi",
+    "fsx",
+    "fs",
+    "fsi",
+    "fsx",
+    "fish",
+    "attributes",
+    "gitattributes",
+    ".gitattributes",
+    "COMMIT_EDITMSG",
+    "MERGE_MSG",
+    "TAG_EDITMSG",
+    "gitconfig",
+    ".gitconfig",
+    ".gitmodules",
+    "exclude",
+    "gitignore",
+    ".gitignore",
+    ".git",
+    "gitlog",
+    "git-rebase-todo",
+    "go",
+    "dot",
+    "DOT",
+    "gv",
+    "groovy",
+    "gvy",
+    "gradle",
+    "Jenkinsfile",
+    "hs",
+    "hs",
+    "hsc",
+    "show-nonprintable",
+    "html",
+    "htm",
+    "shtml",
+    "xhtml",
+    "asp",
+    "html.eex",
+    "yaws",
+    "rails",
+    "rhtml",
+    "erb",
+    "html.erb",
+    "adp",
+    "twig",
+    "html.twig",
+    "ini",
+    "INI",
+    "INF",
+    "reg",
+    "REG",
+    "lng",
+    "cfg",
+    "CFG",
+    "desktop",
+    "url",
+    "URL",
+    ".editorconfig",
+    ".hgrc",
+    "hgrc",
+    "java",
+    "bsh",
+    "properties",
+    "jsp",
+    "js",
+    "htc",
+    "js",
+    "jsx",
+    "babel",
+    "es6",
+    "js.erb",
+    "json",
+    "sublime-settings",
+    "sublime-menu",
+    "sublime-keymap",
+    "sublime-mousemap",
+    "sublime-theme",
+    "sublime-build",
+    "sublime-project",
+    "sublime-completions",
+    "sublime-commands",
+    "sublime-macro",
+    "sublime-color-scheme",
+    "ipynb",
+    "Pipfile.lock",
+    "jsonnet",
+    "libsonnet",
+    "libjsonnet",
+    "jl",
+    "kt",
+    "kts",
+    "tex",
+    "ltx",
+    "less",
+    "css.less",
+    "lisp",
+    "cl",
+    "clisp",
+    "l",
+    "mud",
+    "el",
+    "scm",
+    "ss",
+    "lsp",
+    "fasl",
+    "lhs",
+    "lua",
+    "make",
+    "GNUmakefile",
+    "makefile",
+    "Makefile",
+    "makefile.am",
+    "Makefile.am",
+    "makefile.in",
+    "Makefile.in",
+    "OCamlMakefile",
+    "mak",
+    "mk",
+    "md",
+    "mdown",
+    "markdown",
+    "markdn",
+    "matlab",
+    "build",
+    "nix",
+    "m",
+    "h",
+    "mm",
+    "M",
+    "h",
+    "ml",
+    "mli",
+    "mll",
+    "mly",
+    "pas",
+    "p",
+    "dpr",
+    "pl",
+    "pm",
+    "pod",
+    "t",
+    "PL",
+    "php",
+    "php3",
+    "php4",
+    "php5",
+    "php7",
+    "phps",
+    "phpt",
+    "phtml",
+    "txt",
+    "ps1",
+    "psm1",
+    "psd1",
+    "proto",
+    "protodevel",
+    "pb.txt",
+    "proto.text",
+    "textpb",
+    "pbtxt",
+    "prototxt",
+    "pp",
+    "epp",
+    "purs",
+    "py",
+    "py3",
+    "pyw",
+    "pyi",
+    "pyx",
+    "pyx.in",
+    "pxd",
+    "pxd.in",
+    "pxi",
+    "pxi.in",
+    "rpy",
+    "cpy",
+    "SConstruct",
+    "Sconstruct",
+    "sconstruct",
+    "SConscript",
+    "gyp",
+    "gypi",
+    "Snakefile",
+    "wscript",
+    "R",
+    "r",
+    "s",
+    "S",
+    "Rprofile",
+    "rd",
+    "re",
+    "rst",
+    "rest",
+    "robot",
+    "rb",
+    "Appfile",
+    "Appraisals",
+    "Berksfile",
+    "Brewfile",
+    "capfile",
+    "cgi",
+    "Cheffile",
+    "config.ru",
+    "Deliverfile",
+    "Fastfile",
+    "fcgi",
+    "Gemfile",
+    "gemspec",
+    "Guardfile",
+    "irbrc",
+    "jbuilder",
+    "Podfile",
+    "podspec",
+    "prawn",
+    "rabl",
+    "rake",
+    "Rakefile",
+    "Rantfile",
+    "rbx",
+    "rjs",
+    "ruby.rail",
+    "Scanfile",
+    "simplecov",
+    "Snapfile",
+    "thor",
+    "Thorfile",
+    "Vagrantfile",
+    "haml",
+    "sass",
+    "rxml",
+    "builder",
+    "rs",
+    "scala",
+    "sbt",
+    "sql",
+    "ddl",
+    "dml",
+    "erbsql",
+    "sql.erb",
+    "swift",
+    "log",
+    "tcl",
+    "tf",
+    "tfvars",
+    "hcl",
+    "sty",
+    "cls",
+    "textile",
+    "toml",
+    "tml",
+    "Cargo.lock",
+    "Gopkg.lock",
+    "Pipfile",
+    "ts",
+    "tsx",
+    "varlink",
+    "vim",
+    ".vimrc",
+    "xml",
+    "xsd",
+    "xslt",
+    "tld",
+    "dtml",
+    "rss",
+    "opml",
+    "svg",
+    "yaml",
+    "yml",
+    "sublime-syntax",
+];

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

@@ -1,5 +1,5 @@
+use crate::command_registry::CommandRegistry;
 use crate::commands::WholeStreamCommand;
-use crate::context::CommandRegistry;
 use crate::prelude::*;
 use futures::stream::StreamExt;
 use nu_errors::ShellError;
@@ -7,6 +7,11 @@ use nu_protocol::{Signature, UntaggedValue, Value};
 
 pub struct Count;
 
+#[derive(Deserialize)]
+pub struct CountArgs {
+    column: bool,
+}
+
 #[async_trait]
 impl WholeStreamCommand for Count {
     fn name(&self) -> &str {
@@ -14,7 +19,11 @@ impl WholeStreamCommand for Count {
     }
 
     fn signature(&self) -> Signature {
-        Signature::build("count")
+        Signature::build("count").switch(
+            "column",
+            "Calculate number of columns in table",
+            Some('c'),
+        )
     }
 
     fn usage(&self) -> &str {
@@ -24,22 +33,47 @@ impl WholeStreamCommand for Count {
     async fn run(
         &self,
         args: CommandArgs,
-        _registry: &CommandRegistry,
+        registry: &CommandRegistry,
     ) -> Result<OutputStream, ShellError> {
-        let name = args.call_info.name_tag.clone();
-        let rows: Vec<Value> = args.input.collect().await;
+        let tag = args.call_info.name_tag.clone();
+        let (CountArgs { column }, input) = args.process(&registry).await?;
+        let rows: Vec<Value> = input.collect().await;
 
-        Ok(OutputStream::one(
-            UntaggedValue::int(rows.len()).into_value(name),
-        ))
+        let count = if column {
+            if rows.is_empty() {
+                0
+            } else {
+                match &rows[0].value {
+                    UntaggedValue::Row(dictionary) => dictionary.length(),
+                    _ => {
+                        return Err(ShellError::labeled_error(
+                            "Cannot obtain column count",
+                            "cannot obtain column count",
+                            tag,
+                        ));
+                    }
+                }
+            }
+        } else {
+            rows.len()
+        };
+
+        Ok(OutputStream::one(UntaggedValue::int(count).into_value(tag)))
     }
 
     fn examples(&self) -> Vec<Example> {
-        vec![Example {
-            description: "Count the number of entries in a list",
-            example: "echo [1 2 3 4 5] | count",
-            result: Some(vec![UntaggedValue::int(5).into()]),
-        }]
+        vec![
+            Example {
+                description: "Count the number of entries in a list",
+                example: "echo [1 2 3 4 5] | count",
+                result: Some(vec![UntaggedValue::int(5).into()]),
+            },
+            Example {
+                description: "Count the number of columns in the calendar table",
+                example: "cal | count -c",
+                result: None,
+            },
+        ]
     }
 }
 

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

@@ -1,5 +1,5 @@
+use crate::command_registry::CommandRegistry;
 use crate::commands::WholeStreamCommand;
-use crate::context::CommandRegistry;
 use crate::prelude::*;
 use nu_errors::ShellError;
 use nu_protocol::{Signature, SyntaxShape};

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

@@ -1,175 +0,0 @@
-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, SyntaxShape, UntaggedValue};
-
-pub struct Date;
-
-#[async_trait]
-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'))
-            .named(
-                "format",
-                SyntaxShape::String,
-                "report datetime in supplied strftime format",
-                Some('f'),
-            )
-            .switch("raw", "print date without tables", Some('r'))
-    }
-
-    fn usage(&self) -> &str {
-        "Get the current datetime."
-    }
-
-    async fn run(
-        &self,
-        args: CommandArgs,
-        registry: &CommandRegistry,
-    ) -> Result<OutputStream, ShellError> {
-        date(args, registry).await
-    }
-
-    fn examples(&self) -> Vec<Example> {
-        vec![
-            Example {
-                description: "Get the current local time and date",
-                example: "date",
-                result: None,
-            },
-            Example {
-                description: "Get the current UTC time and date",
-                example: "date --utc",
-                result: None,
-            },
-            Example {
-                description: "Get the current time and date and report it based on format",
-                example: "date --format '%Y-%m-%d %H:%M:%S.%f %z'",
-                result: None,
-            },
-            Example {
-                description: "Get the current time and date and report it without a table",
-                example: "date --format '%Y-%m-%d %H:%M:%S.%f %z' --raw",
-                result: None,
-            },
-        ]
-    }
-}
-
-pub fn date_to_value_raw<T: TimeZone>(dt: DateTime<T>, dt_format: String) -> String
-where
-    T::Offset: Display,
-{
-    let result = dt.format(&dt_format);
-    format!("{}", result)
-}
-
-pub fn date_to_value<T: TimeZone>(dt: DateTime<T>, tag: Tag, dt_format: String) -> Value
-where
-    T::Offset: Display,
-{
-    let mut indexmap = IndexMap::new();
-
-    if dt_format.is_empty() {
-        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),
-        );
-    } else {
-        let result = dt.format(&dt_format);
-        indexmap.insert(
-            "formatted".to_string(),
-            UntaggedValue::string(format!("{}", result)).into_value(&tag),
-        );
-    }
-
-    UntaggedValue::Row(Dictionary::from(indexmap)).into_value(&tag)
-}
-
-pub async fn date(
-    args: CommandArgs,
-    registry: &CommandRegistry,
-) -> Result<OutputStream, ShellError> {
-    let registry = registry.clone();
-    let args = args.evaluate_once(&registry).await?;
-    let tag = args.call_info.name_tag.clone();
-    let raw = args.has("raw");
-
-    let dt_fmt = if args.has("format") {
-        if let Some(dt_fmt) = args.get("format") {
-            dt_fmt.convert_to_string()
-        } else {
-            "".to_string()
-        }
-    } else {
-        "".to_string()
-    };
-
-    let value = if args.has("utc") {
-        let utc: DateTime<Utc> = Utc::now();
-        if raw {
-            UntaggedValue::string(date_to_value_raw(utc, dt_fmt)).into_untagged_value()
-        } else {
-            date_to_value(utc, tag, dt_fmt)
-        }
-    } else {
-        let local: DateTime<Local> = Local::now();
-        if raw {
-            UntaggedValue::string(date_to_value_raw(local, dt_fmt)).into_untagged_value()
-        } else {
-            date_to_value(local, tag, dt_fmt)
-        }
-    };
-
-    Ok(OutputStream::one(value))
-}
-
-#[cfg(test)]
-mod tests {
-    use super::Date;
-
-    #[test]
-    fn examples_work_as_expected() {
-        use crate::examples::test as test_examples;
-
-        test_examples(Date {})
-    }
-}

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

@@ -0,0 +1,46 @@
+use crate::commands::WholeStreamCommand;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{ReturnSuccess, Signature, UntaggedValue};
+
+pub struct Command;
+
+#[async_trait]
+impl WholeStreamCommand for Command {
+    fn name(&self) -> &str {
+        "date"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("date")
+    }
+
+    fn usage(&self) -> &str {
+        "Apply date function"
+    }
+
+    async fn run(
+        &self,
+        _args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        let registry = registry.clone();
+
+        Ok(OutputStream::one(ReturnSuccess::value(
+            UntaggedValue::string(crate::commands::help::get_help(&Command, &registry))
+                .into_value(Tag::unknown()),
+        )))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::Command;
+
+    #[test]
+    fn examples_work_as_expected() {
+        use crate::examples::test as test_examples;
+
+        test_examples(Command {})
+    }
+}

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

@@ -0,0 +1,63 @@
+use crate::prelude::*;
+use chrono::{DateTime, Local};
+use nu_errors::ShellError;
+
+use crate::commands::date::utils::{date_to_value, date_to_value_raw};
+use crate::commands::WholeStreamCommand;
+use nu_protocol::{Signature, SyntaxShape, UntaggedValue};
+use nu_source::Tagged;
+
+pub struct Date;
+
+#[derive(Deserialize)]
+pub struct FormatArgs {
+    format: Tagged<String>,
+    raw: Option<bool>,
+}
+
+#[async_trait]
+impl WholeStreamCommand for Date {
+    fn name(&self) -> &str {
+        "date format"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("date format")
+            .required("format", SyntaxShape::String, "strftime format")
+            .switch("raw", "print date without tables", Some('r'))
+    }
+
+    fn usage(&self) -> &str {
+        "format the current date using the given format string."
+    }
+
+    async fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        format(args, registry).await
+    }
+}
+
+pub async fn format(
+    args: CommandArgs,
+    registry: &CommandRegistry,
+) -> Result<OutputStream, ShellError> {
+    let registry = registry.clone();
+    let tag = args.call_info.name_tag.clone();
+    let (FormatArgs { format, raw }, _) = args.process(&registry).await?;
+
+    let dt_fmt = format.to_string();
+
+    let value = {
+        let local: DateTime<Local> = Local::now();
+        if let Some(true) = raw {
+            UntaggedValue::string(date_to_value_raw(local, dt_fmt)).into_untagged_value()
+        } else {
+            date_to_value(local, tag, dt_fmt)
+        }
+    };
+
+    Ok(OutputStream::one(value))
+}

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

@@ -0,0 +1,11 @@
+pub mod command;
+pub mod format;
+pub mod now;
+pub mod utc;
+
+mod utils;
+
+pub use command::Command as Date;
+pub use format::Date as DateFormat;
+pub use now::Date as DateNow;
+pub use utc::Date as DateUTC;

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

@@ -0,0 +1,50 @@
+use crate::prelude::*;
+use chrono::{DateTime, Local};
+use nu_errors::ShellError;
+
+use crate::commands::date::utils::date_to_value;
+use crate::commands::WholeStreamCommand;
+use nu_protocol::Signature;
+
+pub struct Date;
+
+#[async_trait]
+impl WholeStreamCommand for Date {
+    fn name(&self) -> &str {
+        "date now"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("date now")
+    }
+
+    fn usage(&self) -> &str {
+        "return the current date."
+    }
+
+    async fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        now(args, registry).await
+    }
+}
+
+pub async fn now(
+    args: CommandArgs,
+    registry: &CommandRegistry,
+) -> Result<OutputStream, ShellError> {
+    let registry = registry.clone();
+    let args = args.evaluate_once(&registry).await?;
+    let tag = args.call_info.name_tag.clone();
+
+    let no_fmt = "".to_string();
+
+    let value = {
+        let local: DateTime<Local> = Local::now();
+        date_to_value(local, tag, no_fmt)
+    };
+
+    Ok(OutputStream::one(value))
+}

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

@@ -0,0 +1,50 @@
+use crate::prelude::*;
+use chrono::{DateTime, Utc};
+use nu_errors::ShellError;
+
+use crate::commands::date::utils::date_to_value;
+use crate::commands::WholeStreamCommand;
+use nu_protocol::Signature;
+
+pub struct Date;
+
+#[async_trait]
+impl WholeStreamCommand for Date {
+    fn name(&self) -> &str {
+        "date utc"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("date utc")
+    }
+
+    fn usage(&self) -> &str {
+        "return the current date in utc."
+    }
+
+    async fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        utc(args, registry).await
+    }
+}
+
+pub async fn utc(
+    args: CommandArgs,
+    registry: &CommandRegistry,
+) -> Result<OutputStream, ShellError> {
+    let registry = registry.clone();
+    let args = args.evaluate_once(&registry).await?;
+    let tag = args.call_info.name_tag.clone();
+
+    let no_fmt = "".to_string();
+
+    let value = {
+        let local: DateTime<Utc> = Utc::now();
+        date_to_value(local, tag, no_fmt)
+    };
+
+    Ok(OutputStream::one(value))
+}

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

@@ -0,0 +1,64 @@
+use crate::prelude::*;
+use chrono::DateTime;
+use nu_protocol::{Dictionary, Value};
+
+use chrono::{Datelike, TimeZone, Timelike};
+use core::fmt::Display;
+use indexmap::IndexMap;
+use nu_protocol::UntaggedValue;
+
+pub fn date_to_value_raw<T: TimeZone>(dt: DateTime<T>, dt_format: String) -> String
+where
+    T::Offset: Display,
+{
+    let result = dt.format(&dt_format);
+    format!("{}", result)
+}
+
+pub fn date_to_value<T: TimeZone>(dt: DateTime<T>, tag: Tag, dt_format: String) -> Value
+where
+    T::Offset: Display,
+{
+    let mut indexmap = IndexMap::new();
+
+    if dt_format.is_empty() {
+        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),
+        );
+    } else {
+        let result = dt.format(&dt_format);
+        indexmap.insert(
+            "formatted".to_string(),
+            UntaggedValue::string(format!("{}", result)).into_value(&tag),
+        );
+    }
+
+    UntaggedValue::Row(Dictionary::from(indexmap)).into_value(&tag)
+}

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

@@ -1,5 +1,5 @@
+use crate::command_registry::CommandRegistry;
 use crate::commands::WholeStreamCommand;
-use crate::context::CommandRegistry;
 use crate::prelude::*;
 use nu_errors::ShellError;
 use nu_protocol::{ReturnSuccess, Signature, SyntaxShape, UntaggedValue, Value};
@@ -45,7 +45,7 @@ impl WholeStreamCommand for Default {
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Give a default 'target' to all file entries",
-            example: "ls -af | default target 'nothing'",
+            example: "ls -la | default target 'nothing'",
             result: None,
         }]
     }
@@ -60,13 +60,13 @@ async fn default(
 
     Ok(input
         .map(move |item| {
-            let should_add = match item {
+            let should_add = matches!(
+                item,
                 Value {
                     value: UntaggedValue::Row(ref r),
                     ..
-                } => r.get_data(&column.item).borrow().is_none(),
-                _ => false,
-            };
+                } if r.get_data(&column.item).borrow().is_none()
+            );
 
             if should_add {
                 match item.insert_data_at_path(&column.item, value.clone()) {

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

@@ -2,7 +2,9 @@ use crate::commands::classified::block::run_block;
 use crate::commands::WholeStreamCommand;
 use crate::prelude::*;
 use nu_errors::ShellError;
-use nu_protocol::{hir::Block, ReturnSuccess, Signature, SyntaxShape, Value};
+use nu_protocol::{
+    hir::Block, hir::ExternalRedirection, ReturnSuccess, Signature, SyntaxShape, Value,
+};
 
 pub struct Do;
 
@@ -19,7 +21,7 @@ impl WholeStreamCommand for Do {
     }
 
     fn signature(&self) -> Signature {
-        Signature::build("with-env")
+        Signature::build("do")
             .required("block", SyntaxShape::Block, "the block to run ")
             .switch(
                 "ignore_errors",
@@ -61,9 +63,9 @@ async fn do_(
     registry: &CommandRegistry,
 ) -> Result<OutputStream, ShellError> {
     let registry = registry.clone();
-    let is_last = raw_args.call_info.args.is_last;
+    let external_redirection = raw_args.call_info.args.external_redirection;
 
-    let mut context = Context::from_raw(&raw_args, &registry);
+    let mut context = EvaluationContext::from_raw(&raw_args, &registry);
     let scope = raw_args.call_info.scope.clone();
     let (
         DoArgs {
@@ -72,7 +74,26 @@ async fn do_(
         },
         input,
     ) = raw_args.process(&registry).await?;
-    block.set_is_last(is_last);
+
+    let block_redirection = match external_redirection {
+        ExternalRedirection::None => {
+            if ignore_errors {
+                ExternalRedirection::Stderr
+            } else {
+                ExternalRedirection::None
+            }
+        }
+        ExternalRedirection::Stdout => {
+            if ignore_errors {
+                ExternalRedirection::StdoutAndStderr
+            } else {
+                ExternalRedirection::Stdout
+            }
+        }
+        x => x,
+    };
+
+    block.set_redirect(block_redirection);
 
     let result = run_block(
         &block,
@@ -85,6 +106,9 @@ async fn do_(
     .await;
 
     if ignore_errors {
+        // To properly ignore errors we need to redirect stderr, consume it, and remove
+        // any errors we see in the process.
+
         match result {
             Ok(mut stream) => {
                 let output = stream.drain_vec().await;

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

@@ -1,5 +1,5 @@
+use crate::command_registry::CommandRegistry;
 use crate::commands::WholeStreamCommand;
-use crate::context::CommandRegistry;
 use crate::prelude::*;
 use nu_errors::ShellError;
 use nu_protocol::{Signature, SyntaxShape, UntaggedValue};
@@ -22,12 +22,12 @@ impl WholeStreamCommand for Drop {
         Signature::build("drop").optional(
             "rows",
             SyntaxShape::Number,
-            "starting from the back, the number of rows to drop",
+            "starting from the back, the number of rows to remove",
         )
     }
 
     fn usage(&self) -> &str {
-        "Drop the last number of rows."
+        "Remove the last number of rows. If you want to remove columns, try 'reject'."
     }
 
     async fn run(
@@ -35,20 +35,7 @@ impl WholeStreamCommand for Drop {
         args: CommandArgs,
         registry: &CommandRegistry,
     ) -> Result<OutputStream, ShellError> {
-        let (DropArgs { rows }, input) = args.process(&registry).await?;
-        let mut v: Vec<_> = input.into_vec().await;
-
-        let rows_to_drop = if let Some(quantity) = rows {
-            *quantity as usize
-        } else {
-            1
-        };
-
-        for _ in 0..rows_to_drop {
-            v.pop();
-        }
-
-        Ok(futures::stream::iter(v).to_output_stream())
+        drop(args, registry).await
     }
 
     fn examples(&self) -> Vec<Example> {
@@ -70,6 +57,31 @@ impl WholeStreamCommand for Drop {
     }
 }
 
+async fn drop(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStream, ShellError> {
+    let (DropArgs { rows }, input) = args.process(&registry).await?;
+    let v: Vec<_> = input.into_vec().await;
+
+    let rows_to_drop = if let Some(quantity) = rows {
+        *quantity as usize
+    } else {
+        1
+    };
+
+    Ok(if rows_to_drop == 0 {
+        futures::stream::iter(v).to_output_stream()
+    } else {
+        let k = if v.len() < rows_to_drop {
+            0
+        } else {
+            v.len() - rows_to_drop
+        };
+
+        let iter = v.into_iter().take(k);
+
+        futures::stream::iter(iter).to_output_stream()
+    })
+}
+
 #[cfg(test)]
 mod tests {
     use super::Drop;

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

@@ -343,7 +343,7 @@ where
         let values = vec.into_iter().map(Into::into).collect::<Vec<Value>>();
         UntaggedValue::Table(values)
     }
-    .retag(tag)
+    .into_value(tag)
 }
 
 impl From<DirInfo> for Value {
@@ -352,17 +352,17 @@ impl From<DirInfo> for Value {
 
         r.insert(
             "path".to_string(),
-            UntaggedValue::path(d.path).retag(&d.tag),
+            UntaggedValue::path(d.path).into_value(&d.tag),
         );
 
         r.insert(
             "apparent".to_string(),
-            UntaggedValue::bytes(d.size).retag(&d.tag),
+            UntaggedValue::filesize(d.size).into_value(&d.tag),
         );
 
         r.insert(
             "physical".to_string(),
-            UntaggedValue::bytes(d.blocks).retag(&d.tag),
+            UntaggedValue::filesize(d.blocks).into_value(&d.tag),
         );
 
         r.insert("directories".to_string(), value_from_vec(d.dirs, &d.tag));
@@ -376,7 +376,7 @@ impl From<DirInfo> for Value {
                     .map(move |e| UntaggedValue::Error(e).into_untagged_value())
                     .collect::<Vec<Value>>(),
             )
-            .retag(&d.tag);
+            .into_value(&d.tag);
 
             r.insert("errors".to_string(), v);
         }
@@ -394,30 +394,33 @@ impl From<FileInfo> for Value {
 
         r.insert(
             "path".to_string(),
-            UntaggedValue::path(f.path).retag(&f.tag),
+            UntaggedValue::path(f.path).into_value(&f.tag),
         );
 
         r.insert(
             "apparent".to_string(),
-            UntaggedValue::bytes(f.size).retag(&f.tag),
+            UntaggedValue::filesize(f.size).into_value(&f.tag),
         );
 
         let b = f
             .blocks
-            .map(UntaggedValue::bytes)
+            .map(UntaggedValue::filesize)
             .unwrap_or_else(UntaggedValue::nothing)
-            .retag(&f.tag);
+            .into_value(&f.tag);
 
         r.insert("physical".to_string(), b);
 
         r.insert(
             "directories".to_string(),
-            UntaggedValue::nothing().retag(&f.tag),
+            UntaggedValue::nothing().into_value(&f.tag),
         );
 
-        r.insert("files".to_string(), UntaggedValue::nothing().retag(&f.tag));
+        r.insert(
+            "files".to_string(),
+            UntaggedValue::nothing().into_value(&f.tag),
+        );
 
-        UntaggedValue::row(r).retag(&f.tag)
+        UntaggedValue::row(r).into_value(&f.tag)
     }
 }
 

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

@@ -1,20 +1,22 @@
+use crate::command_registry::CommandRegistry;
 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, Scope, Signature,
-    SyntaxShape, UntaggedValue, Value,
+    SyntaxShape, TaggedDictBuilder, UntaggedValue, Value,
 };
+use nu_source::Tagged;
 
 pub struct Each;
 
 #[derive(Deserialize)]
 pub struct EachArgs {
     block: Block,
+    numbered: Tagged<bool>,
 }
 
 #[async_trait]
@@ -24,11 +26,13 @@ impl WholeStreamCommand for Each {
     }
 
     fn signature(&self) -> Signature {
-        Signature::build("each").required(
-            "block",
-            SyntaxShape::Block,
-            "the block to run on each row",
-        )
+        Signature::build("each")
+            .required("block", SyntaxShape::Block, "the block to run on each row")
+            .switch(
+                "numbered",
+                "returned a numbered item ($it.index and $it.item)",
+                Some('n'),
+            )
     }
 
     fn usage(&self) -> &str {
@@ -45,6 +49,11 @@ impl WholeStreamCommand for Each {
 
     fn examples(&self) -> Vec<Example> {
         vec![
+            Example {
+                description: "Echo the sum of each row",
+                example: "echo [[1 2] [3 4]] | each { echo $it | math sum }",
+                result: None,
+            },
             Example {
                 description: "Echo the square of each integer",
                 example: "echo [1 2 3] | each { echo $(= $it * $it) }",
@@ -55,32 +64,27 @@ impl WholeStreamCommand for Each {
                 ]),
             },
             Example {
-                description: "Echo the sum of each row",
-                example: "echo [[1 2] [3 4]] | each { echo $it | math sum }",
-                result: Some(vec![
-                    UntaggedValue::int(3).into(),
-                    UntaggedValue::int(7).into(),
-                ]),
+                description: "Number each item and echo a message",
+                example:
+                    "echo ['bob' 'fred'] | each --numbered { echo `{{$it.index}} is {{$it.item}}` }",
+                result: Some(vec![Value::from("0 is bob"), Value::from("1 is fred")]),
             },
         ]
     }
 }
 
 fn is_expanded_it_usage(head: &SpannedExpression) -> bool {
-    match &*head {
-        SpannedExpression {
-            expr: Expression::Synthetic(Synthetic::String(s)),
-            ..
-        } if s == "expanded-each" => true,
-        _ => false,
-    }
+    matches!(&*head, SpannedExpression {
+        expr: Expression::Synthetic(Synthetic::String(s)),
+        ..
+    } if s == "expanded-each")
 }
 
-async fn process_row(
+pub async fn process_row(
     block: Arc<Block>,
     scope: Arc<Scope>,
     head: Arc<Box<SpannedExpression>>,
-    mut context: Arc<Context>,
+    mut context: Arc<EvaluationContext>,
     input: Value,
 ) -> Result<OutputStream, ShellError> {
     let input_clone = input.clone();
@@ -101,6 +105,14 @@ async fn process_row(
     .to_output_stream())
 }
 
+pub(crate) fn make_indexed_item(index: usize, item: Value) -> Value {
+    let mut dict = TaggedDictBuilder::new(item.tag());
+    dict.insert_untagged("index", UntaggedValue::int(index));
+    dict.insert_value("item", item);
+
+    dict.into_value()
+}
+
 async fn each(
     raw_args: CommandArgs,
     registry: &CommandRegistry,
@@ -108,24 +120,47 @@ async fn each(
     let registry = registry.clone();
     let head = Arc::new(raw_args.call_info.args.head.clone());
     let scope = Arc::new(raw_args.call_info.scope.clone());
-    let context = Arc::new(Context::from_raw(&raw_args, &registry));
+    let context = Arc::new(EvaluationContext::from_raw(&raw_args, &registry));
     let (each_args, input): (EachArgs, _) = raw_args.process(&registry).await?;
     let block = Arc::new(each_args.block);
-    Ok(input
-        .then(move |input| {
-            let block = block.clone();
-            let scope = scope.clone();
-            let head = head.clone();
-            let context = context.clone();
-            async {
-                match process_row(block, scope, head, context, input).await {
-                    Ok(s) => s,
-                    Err(e) => OutputStream::one(Err(e)),
+
+    if each_args.numbered.item {
+        Ok(input
+            .enumerate()
+            .then(move |input| {
+                let block = block.clone();
+                let scope = scope.clone();
+                let head = head.clone();
+                let context = context.clone();
+                let row = make_indexed_item(input.0, input.1);
+
+                async {
+                    match process_row(block, scope, head, context, row).await {
+                        Ok(s) => s,
+                        Err(e) => OutputStream::one(Err(e)),
+                    }
                 }
-            }
-        })
-        .flatten()
-        .to_output_stream())
+            })
+            .flatten()
+            .to_output_stream())
+    } else {
+        Ok(input
+            .then(move |input| {
+                let block = block.clone();
+                let scope = scope.clone();
+                let head = head.clone();
+                let context = context.clone();
+
+                async {
+                    match process_row(block, scope, head, context, input).await {
+                        Ok(s) => s,
+                        Err(e) => OutputStream::one(Err(e)),
+                    }
+                }
+            })
+            .flatten()
+            .to_output_stream())
+    }
 }
 
 #[cfg(test)]

crates/nu-cli/src/commands/each/group.rs

@@ -0,0 +1,133 @@
+use crate::commands::each::process_row;
+use crate::commands::WholeStreamCommand;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{
+    hir::Block, hir::SpannedExpression, ReturnSuccess, Scope, Signature, SyntaxShape,
+    UntaggedValue, Value,
+};
+use nu_source::Tagged;
+use serde::Deserialize;
+
+pub struct EachGroup;
+
+#[derive(Deserialize)]
+pub struct EachGroupArgs {
+    group_size: Tagged<usize>,
+    block: Block,
+    //numbered: Tagged<bool>,
+}
+
+#[async_trait]
+impl WholeStreamCommand for EachGroup {
+    fn name(&self) -> &str {
+        "each group"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("each group")
+            .required("group_size", SyntaxShape::Int, "the size of each group")
+            .required(
+                "block",
+                SyntaxShape::Block,
+                "the block to run on each group",
+            )
+    }
+
+    fn usage(&self) -> &str {
+        "Runs a block on groups of `group_size` rows of a table at a time."
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![Example {
+            description: "Echo the sum of each pair",
+            example: "echo [1 2 3 4] | each group 2 { echo $it | math sum }",
+            result: None,
+        }]
+    }
+
+    async fn run(
+        &self,
+        raw_args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        let registry = registry.clone();
+        let head = Arc::new(raw_args.call_info.args.head.clone());
+        let scope = Arc::new(raw_args.call_info.scope.clone());
+        let context = Arc::new(EvaluationContext::from_raw(&raw_args, &registry));
+        let (each_args, input): (EachGroupArgs, _) = raw_args.process(&registry).await?;
+        let block = Arc::new(each_args.block);
+
+        Ok(input
+            .chunks(each_args.group_size.item)
+            .then(move |input| {
+                run_block_on_vec(
+                    input,
+                    block.clone(),
+                    scope.clone(),
+                    head.clone(),
+                    context.clone(),
+                )
+            })
+            .flatten()
+            .to_output_stream())
+    }
+}
+
+pub(crate) fn run_block_on_vec(
+    input: Vec<Value>,
+    block: Arc<Block>,
+    scope: Arc<Scope>,
+    head: Arc<Box<SpannedExpression>>,
+    context: Arc<EvaluationContext>,
+) -> impl Future<Output = OutputStream> {
+    let value = Value {
+        value: UntaggedValue::Table(input),
+        tag: Tag::unknown(),
+    };
+
+    async {
+        match process_row(block, scope, head, context, value).await {
+            Ok(s) => {
+                // We need to handle this differently depending on whether process_row
+                // returned just 1 value or if it returned multiple as a stream.
+                let vec = s.collect::<Vec<_>>().await;
+
+                // If it returned just one value, just take that value
+                if vec.len() == 1 {
+                    return OutputStream::one(vec.into_iter().next().expect(
+                        "This should be impossible, we just checked that vec.len() == 1.",
+                    ));
+                }
+
+                // If it returned multiple values, we need to put them into a table and
+                // return that.
+                let result = vec.into_iter().collect::<Result<Vec<ReturnSuccess>, _>>();
+                let result_table = match result {
+                    Ok(t) => t,
+                    Err(e) => return OutputStream::one(Err(e)),
+                };
+
+                let table = result_table
+                    .into_iter()
+                    .filter_map(|x| x.raw_value())
+                    .collect();
+
+                OutputStream::one(Ok(ReturnSuccess::Value(UntaggedValue::Table(table).into())))
+            }
+            Err(e) => OutputStream::one(Err(e)),
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::EachGroup;
+
+    #[test]
+    fn examples_work_as_expected() {
+        use crate::examples::test as test_examples;
+
+        test_examples(EachGroup {})
+    }
+}

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

@@ -0,0 +1,9 @@
+pub mod command;
+pub mod group;
+pub mod window;
+
+pub(crate) use command::make_indexed_item;
+pub use command::process_row;
+pub use command::Each;
+pub use group::EachGroup;
+pub use window::EachWindow;

crates/nu-cli/src/commands/each/window.rs

@@ -0,0 +1,113 @@
+use crate::commands::each::group::run_block_on_vec;
+use crate::commands::WholeStreamCommand;
+use crate::prelude::*;
+//use itertools::Itertools;
+use nu_errors::ShellError;
+use nu_protocol::{hir::Block, Primitive, Signature, SyntaxShape, UntaggedValue};
+use nu_source::Tagged;
+use serde::Deserialize;
+
+pub struct EachWindow;
+
+#[derive(Deserialize)]
+pub struct EachWindowArgs {
+    window_size: Tagged<usize>,
+    block: Block,
+    stride: Option<Tagged<usize>>,
+}
+
+#[async_trait]
+impl WholeStreamCommand for EachWindow {
+    fn name(&self) -> &str {
+        "each window"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("each window")
+            .required("window_size", SyntaxShape::Int, "the size of each window")
+            .named(
+                "stride",
+                SyntaxShape::Int,
+                "the number of rows to slide over between windows",
+                Some('s'),
+            )
+            .required(
+                "block",
+                SyntaxShape::Block,
+                "the block to run on each group",
+            )
+    }
+
+    fn usage(&self) -> &str {
+        "Runs a block on sliding windows of `window_size` rows of a table at a time."
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![Example {
+            description: "Echo the sum of each window",
+            example: "echo [1 2 3 4] | each window 2 { echo $it | math sum }",
+            result: None,
+        }]
+    }
+
+    async fn run(
+        &self,
+        raw_args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        let registry = registry.clone();
+        let head = Arc::new(raw_args.call_info.args.head.clone());
+        let scope = Arc::new(raw_args.call_info.scope.clone());
+        let context = Arc::new(EvaluationContext::from_raw(&raw_args, &registry));
+        let (each_args, mut input): (EachWindowArgs, _) = raw_args.process(&registry).await?;
+        let block = Arc::new(each_args.block);
+
+        let mut window: Vec<_> = input
+            .by_ref()
+            .take(*each_args.window_size - 1)
+            .collect::<Vec<_>>()
+            .await;
+
+        // `window` must start with dummy values, which will be removed on the first iteration
+        let stride = each_args.stride.map(|x| *x).unwrap_or(1);
+        window.insert(0, UntaggedValue::Primitive(Primitive::Nothing).into());
+
+        Ok(input
+            .enumerate()
+            .then(move |(i, input)| {
+                // This would probably be more efficient if `last` was a VecDeque
+                // But we can't have that because it needs to be put into a Table
+                window.remove(0);
+                window.push(input);
+
+                let block = block.clone();
+                let scope = scope.clone();
+                let head = head.clone();
+                let context = context.clone();
+                let local_window = window.clone();
+
+                async move {
+                    if i % stride == 0 {
+                        Some(run_block_on_vec(local_window, block, scope, head, context).await)
+                    } else {
+                        None
+                    }
+                }
+            })
+            .filter_map(|x| async { x })
+            .flatten()
+            .to_output_stream())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::EachWindow;
+
+    #[test]
+    fn examples_work_as_expected() {
+        use crate::examples::test as test_examples;
+
+        test_examples(EachWindow {})
+    }
+}

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

@@ -3,7 +3,7 @@ use crate::prelude::*;
 use nu_errors::ShellError;
 use nu_protocol::hir::Operator;
 use nu_protocol::{
-    Primitive, RangeInclusion, ReturnSuccess, Signature, SyntaxShape, UntaggedValue, Value,
+    Primitive, Range, RangeInclusion, ReturnSuccess, Signature, SyntaxShape, UntaggedValue, Value,
 };
 
 pub struct Echo;
@@ -55,60 +55,110 @@ async fn echo(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStr
     let registry = registry.clone();
     let (args, _): (EchoArgs, _) = args.process(&registry).await?;
 
-    let stream = args.rest.into_iter().map(|i| {
-        match i.as_string() {
-            Ok(s) => {
-                OutputStream::one(Ok(ReturnSuccess::Value(
-                    UntaggedValue::string(s).into_value(i.tag.clone()),
-                )))
-            }
-            _ => match i {
-                Value {
-                    value: UntaggedValue::Table(table),
-                    ..
-                } => {
-                    futures::stream::iter(table.into_iter().map(ReturnSuccess::value)).to_output_stream()
-                }
-                Value {
-                    value: UntaggedValue::Primitive(Primitive::Range(range)),
-                    tag
-                } => {
-                    let mut output_vec = vec![];
-
-                    let mut current = range.from.0.item;
-                    while current != range.to.0.item {
-                        output_vec.push(Ok(ReturnSuccess::Value(UntaggedValue::Primitive(current.clone()).into_value(&tag))));
-                        current = match crate::data::value::compute_values(Operator::Plus, &UntaggedValue::Primitive(current), &UntaggedValue::int(1)) {
-                            Ok(result) => match result {
-                                UntaggedValue::Primitive(p) => p,
-                                _ => {
-                                    return OutputStream::one(Err(ShellError::unimplemented("Internal error: expected a primitive result from increment")));
-                                }
-                            },
-                            Err((left_type, right_type)) => {
-                                return OutputStream::one(Err(ShellError::coerce_error(
-                                    left_type.spanned(tag.span),
-                                    right_type.spanned(tag.span),
-                                )));
-                            }
-                        }
-                    }
-                    if let RangeInclusion::Inclusive = range.to.1 {
-                            output_vec.push(Ok(ReturnSuccess::Value(UntaggedValue::Primitive(current).into_value(&tag))));
-                    }
-
-                    futures::stream::iter(output_vec.into_iter()).to_output_stream()
-                }
-                _ => {
-                    OutputStream::one(Ok(ReturnSuccess::Value(i.clone())))
-                }
-            },
-        }
+    let stream = args.rest.into_iter().map(|i| match i.as_string() {
+        Ok(s) => OutputStream::one(Ok(ReturnSuccess::Value(
+            UntaggedValue::string(s).into_value(i.tag.clone()),
+        ))),
+        _ => match i {
+            Value {
+                value: UntaggedValue::Table(table),
+                ..
+            } => futures::stream::iter(table.into_iter().map(ReturnSuccess::value))
+                .to_output_stream(),
+            Value {
+                value: UntaggedValue::Primitive(Primitive::Range(range)),
+                tag,
+            } => futures::stream::iter(RangeIterator::new(*range, tag)).to_output_stream(),
+            _ => OutputStream::one(Ok(ReturnSuccess::Value(i.clone()))),
+        },
     });
 
     Ok(futures::stream::iter(stream).flatten().to_output_stream())
 }
 
+struct RangeIterator {
+    curr: Primitive,
+    end: Primitive,
+    tag: Tag,
+    is_end_inclusive: bool,
+}
+
+impl RangeIterator {
+    pub fn new(range: Range, tag: Tag) -> RangeIterator {
+        let start = match range.from.0.item {
+            Primitive::Nothing => Primitive::Int(0.into()),
+            x => x,
+        };
+
+        RangeIterator {
+            curr: start,
+            end: range.to.0.item,
+            tag,
+            is_end_inclusive: matches!(range.to.1, RangeInclusion::Inclusive),
+        }
+    }
+}
+
+impl Iterator for RangeIterator {
+    type Item = Result<ReturnSuccess, ShellError>;
+    fn next(&mut self) -> Option<Self::Item> {
+        let ordering = if self.end == Primitive::Nothing {
+            Ordering::Less
+        } else {
+            let result =
+                nu_data::base::coerce_compare_primitive(&self.curr, &self.end).map_err(|_| {
+                    ShellError::labeled_error(
+                        "Cannot create range",
+                        "unsupported range",
+                        self.tag.span,
+                    )
+                });
+
+            if let Err(result) = result {
+                return Some(Err(result));
+            }
+
+            let result = result
+                .expect("Internal error: the error case was already protected, but that failed");
+
+            result.compare()
+        };
+
+        use std::cmp::Ordering;
+
+        if (ordering == Ordering::Less) || (self.is_end_inclusive && ordering == Ordering::Equal) {
+            let output = UntaggedValue::Primitive(self.curr.clone()).into_value(self.tag.clone());
+
+            let next_value = nu_data::value::compute_values(
+                Operator::Plus,
+                &UntaggedValue::Primitive(self.curr.clone()),
+                &UntaggedValue::int(1),
+            );
+
+            self.curr = match next_value {
+                Ok(result) => match result {
+                    UntaggedValue::Primitive(p) => p,
+                    _ => {
+                        return Some(Err(ShellError::unimplemented(
+                            "Internal error: expected a primitive result from increment",
+                        )));
+                    }
+                },
+                Err((left_type, right_type)) => {
+                    return Some(Err(ShellError::coerce_error(
+                        left_type.spanned(self.tag.span),
+                        right_type.spanned(self.tag.span),
+                    )));
+                }
+            };
+            Some(ReturnSuccess::value(output))
+        } else {
+            // TODO: add inclusive/exclusive ranges
+            None
+        }
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::Echo;

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

@@ -1,8 +1,9 @@
+use crate::command_registry::CommandRegistry;
 use crate::commands::UnevaluatedCallInfo;
 use crate::commands::WholeStreamCommand;
-use crate::context::CommandRegistry;
 use crate::prelude::*;
 use nu_errors::ShellError;
+use nu_protocol::hir::ExternalRedirection;
 use nu_protocol::{
     CommandAction, Primitive, ReturnSuccess, Signature, SyntaxShape, UntaggedValue, Value,
 };
@@ -121,21 +122,16 @@ async fn enter(
 
         let full_path = std::path::PathBuf::from(cwd);
 
-        let (file_extension, contents, contents_tag) = crate::commands::open::fetch(
+        let (file_extension, tagged_contents) = crate::commands::open::fetch(
             &full_path,
             &PathBuf::from(location_clone),
             tag.span,
-            match encoding {
-                Some(e) => e.to_string(),
-                _ => "".to_string(),
-            },
+            encoding,
         )
         .await?;
 
-        match contents {
+        match tagged_contents.value {
             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) {
@@ -150,24 +146,24 @@ async fn enter(
                                     positional: None,
                                     named: None,
                                     span: Span::unknown(),
-                                    is_last: false,
+                                    external_redirection: ExternalRedirection::Stdout,
                                 },
                                 name_tag: tag.clone(),
                                 scope: scope.clone(),
                             },
                         };
+                        let tag = tagged_contents.tag.clone();
                         let mut result = converter
                             .run(new_args.with_input(vec![tagged_contents]), &registry)
                             .await?;
                         let result_vec: Vec<Result<ReturnSuccess, ShellError>> =
                             result.drain_vec().await;
-
                         Ok(futures::stream::iter(result_vec.into_iter().map(
                             move |res| match res {
                                 Ok(ReturnSuccess::Value(Value { value, .. })) => Ok(
                                     ReturnSuccess::Action(CommandAction::EnterValueShell(Value {
                                         value,
-                                        tag: contents_tag.clone(),
+                                        tag: tag.clone(),
                                     })),
                                 ),
                                 x => x,
@@ -185,13 +181,9 @@ async fn enter(
                     )))
                 }
             }
-            _ => {
-                let tagged_contents = contents.into_value(contents_tag);
-
-                Ok(OutputStream::one(ReturnSuccess::action(
-                    CommandAction::EnterValueShell(tagged_contents),
-                )))
-            }
+            _ => Ok(OutputStream::one(ReturnSuccess::action(
+                CommandAction::EnterValueShell(tagged_contents),
+            ))),
         }
     }
 }

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

@@ -1,83 +0,0 @@
-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>>,
-}
-
-#[async_trait]
-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."
-    }
-
-    async fn run(
-        &self,
-        args: CommandArgs,
-        registry: &CommandRegistry,
-    ) -> Result<OutputStream, ShellError> {
-        evaluate_by(args, registry).await
-    }
-}
-
-pub async fn evaluate_by(
-    args: CommandArgs,
-    registry: &CommandRegistry,
-) -> Result<OutputStream, ShellError> {
-    let registry = registry.clone();
-    let name = args.call_info.name_tag.clone();
-    let (EvaluateByArgs { evaluate_with }, mut input) = args.process(&registry).await?;
-    let values: Vec<Value> = input.collect().await;
-
-    if values.is_empty() {
-        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) => Ok(OutputStream::one(ReturnSuccess::value(evaluated))),
-            Err(err) => Err(err),
-        }
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use super::EvaluateBy;
-
-    #[test]
-    fn examples_work_as_expected() {
-        use crate::examples::test as test_examples;
-
-        test_examples(EvaluateBy {})
-    }
-}

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

@@ -1,5 +1,5 @@
+use crate::command_registry::CommandRegistry;
 use crate::commands::WholeStreamCommand;
-use crate::context::CommandRegistry;
 use crate::prelude::*;
 use nu_errors::ShellError;
 use nu_protocol::{ReturnSuccess, Signature, SyntaxShape, UntaggedValue};
@@ -71,25 +71,23 @@ impl WholeStreamCommand for Every {
 async fn every(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStream, ShellError> {
     let registry = registry.clone();
     let (EveryArgs { stride, skip }, input) = args.process(&registry).await?;
-    let v: Vec<_> = input.into_vec().await;
 
-    let stride_desired = if stride.item < 1 { 1 } else { stride.item } as usize;
+    let stride = stride.item;
+    let skip = skip.item;
 
-    let mut values_vec_deque = VecDeque::new();
+    Ok(input
+        .enumerate()
+        .filter_map(move |(i, value)| async move {
+            let stride_desired = if stride < 1 { 1 } else { stride } as usize;
+            let should_include = skip == (i % stride_desired != 0);
 
-    for (i, x) in v.iter().enumerate() {
-        let should_include = if skip.item {
-            i % stride_desired != 0
-        } else {
-            i % stride_desired == 0
-        };
-
-        if should_include {
-            values_vec_deque.push_back(ReturnSuccess::value(x.clone()));
-        }
-    }
-
-    Ok(futures::stream::iter(values_vec_deque).to_output_stream())
+            if should_include {
+                Some(ReturnSuccess::value(value))
+            } else {
+                None
+            }
+        })
+        .to_output_stream())
 }
 
 #[cfg(test)]

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

@@ -0,0 +1,87 @@
+use crate::command_registry::CommandRegistry;
+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 Exec;
+
+#[derive(Deserialize)]
+pub struct ExecArgs {
+    pub command: Tagged<PathBuf>,
+    pub rest: Vec<Tagged<String>>,
+}
+
+#[async_trait]
+impl WholeStreamCommand for Exec {
+    fn name(&self) -> &str {
+        "exec"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("exec")
+            .required("command", SyntaxShape::Path, "the command to execute")
+            .rest(SyntaxShape::Pattern, "any additional arguments for command")
+    }
+
+    fn usage(&self) -> &str {
+        "Execute command"
+    }
+
+    async fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        exec(args, registry).await
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![
+            Example {
+                description: "Execute 'ps aux'",
+                example: "exec ps aux",
+                result: None,
+            },
+            Example {
+                description: "Execute 'nautilus'",
+                example: "exec nautilus",
+                result: None,
+            },
+        ]
+    }
+}
+
+#[cfg(unix)]
+async fn exec(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStream, ShellError> {
+    use std::os::unix::process::CommandExt;
+    use std::process::Command;
+
+    let registry = registry.clone();
+    let name = args.call_info.name_tag.clone();
+    let (args, _): (ExecArgs, _) = args.process(&registry).await?;
+
+    let mut command = Command::new(args.command.item);
+    for tagged_arg in args.rest {
+        command.arg(tagged_arg.item);
+    }
+
+    let err = command.exec(); // this replaces our process, should not return
+
+    Err(ShellError::labeled_error(
+        "Error on exec",
+        format!("{}", err),
+        &name,
+    ))
+}
+
+#[cfg(not(unix))]
+async fn exec(args: CommandArgs, _registry: &CommandRegistry) -> Result<OutputStream, ShellError> {
+    Err(ShellError::labeled_error(
+        "Error on exec",
+        "exec is not supported on your platform",
+        &args.call_info.name_tag,
+    ))
+}

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

@@ -1,5 +1,5 @@
+use crate::command_registry::CommandRegistry;
 use crate::commands::command::WholeStreamCommand;
-use crate::context::CommandRegistry;
 use crate::prelude::*;
 use nu_errors::ShellError;
 use nu_protocol::{CommandAction, ReturnSuccess, Signature};

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

@@ -1,5 +1,5 @@
+use crate::command_registry::CommandRegistry;
 use crate::commands::WholeStreamCommand;
-use crate::context::CommandRegistry;
 use crate::prelude::*;
 use nu_errors::ShellError;
 use nu_protocol::{Signature, SyntaxShape, UntaggedValue};

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

@@ -1,5 +1,5 @@
+use crate::command_registry::CommandRegistry;
 use crate::commands::WholeStreamCommand;
-use crate::context::CommandRegistry;
 use crate::evaluate::evaluate_baseline_expr;
 use crate::prelude::*;
 use nu_errors::ShellError;

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

@@ -14,6 +14,7 @@ fn from_delimited_string_to_value(
         .delimiter(separator as u8)
         .from_reader(s.as_bytes());
     let tag = tag.into();
+    let span = tag.span;
 
     let headers = if headerless {
         (1..=reader.headers()?.len())
@@ -30,7 +31,10 @@ fn from_delimited_string_to_value(
             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))
+                tagged_row.insert_value(
+                    header,
+                    UntaggedValue::decimal_from_float(f, span).into_value(&tag),
+                )
             } else {
                 tagged_row.insert_value(header, UntaggedValue::string(value).into_value(&tag))
             }

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

@@ -39,11 +39,12 @@ impl WholeStreamCommand for FromJSON {
 
 fn convert_json_value_to_nu_value(v: &serde_hjson::Value, tag: impl Into<Tag>) -> Value {
     let tag = tag.into();
+    let span = tag.span;
 
     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::F64(n) => UntaggedValue::decimal_from_float(*n, span).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) => {

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

@@ -1,7 +1,7 @@
 use crate::commands::WholeStreamCommand;
 use crate::prelude::*;
-use crate::TaggedListBuilder;
 use calamine::*;
+use nu_data::TaggedListBuilder;
 use nu_errors::ShellError;
 use nu_protocol::{ReturnSuccess, Signature, TaggedDictBuilder, UntaggedValue};
 use std::io::Cursor;
@@ -45,6 +45,7 @@ async fn from_ods(
     registry: &CommandRegistry,
 ) -> Result<OutputStream, ShellError> {
     let tag = args.call_info.name_tag.clone();
+    let span = tag.span;
     let registry = registry.clone();
 
     let (
@@ -73,7 +74,7 @@ async fn from_ods(
                     let value = match cell {
                         DataType::Empty => UntaggedValue::nothing(),
                         DataType::String(s) => UntaggedValue::string(s),
-                        DataType::Float(f) => UntaggedValue::decimal(*f),
+                        DataType::Float(f) => UntaggedValue::decimal_from_float(*f, span),
                         DataType::Int(i) => UntaggedValue::int(*i),
                         DataType::Bool(b) => UntaggedValue::boolean(*b),
                         _ => UntaggedValue::nothing(),

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

@@ -30,11 +30,12 @@ impl WholeStreamCommand for FromTOML {
 
 pub fn convert_toml_value_to_nu_value(v: &toml::Value, tag: impl Into<Tag>) -> Value {
     let tag = tag.into();
+    let span = tag.span;
 
     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::Float(n) => UntaggedValue::decimal_from_float(*n, span).into_value(tag),
         toml::Value::String(s) => {
             UntaggedValue::Primitive(Primitive::String(String::from(s))).into_value(tag)
         }

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

@@ -5,7 +5,6 @@ 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;
 
@@ -42,28 +41,20 @@ async fn from_vcf(
     let input = args.input;
 
     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);
+    let input_bytes = input_string.into_bytes();
+    let cursor = std::io::Cursor::new(input_bytes);
+    let parser = ical::VcardParser::new(cursor);
 
-    let mut values_vec_deque = VecDeque::new();
+    let iter = parser.map(move |contact| match contact {
+        Ok(c) => ReturnSuccess::value(contact_to_value(c, tag.clone())),
+        Err(_) => Err(ShellError::labeled_error(
+            "Could not parse as .vcf",
+            "input cannot be parsed as .vcf",
+            tag.clone(),
+        )),
+    });
 
-    for contact in parser {
-        match contact {
-            Ok(c) => {
-                values_vec_deque.push_back(ReturnSuccess::value(contact_to_value(c, tag.clone())))
-            }
-            Err(_) => {
-                return Err(ShellError::labeled_error(
-                    "Could not parse as .vcf",
-                    "input cannot be parsed as .vcf",
-                    tag.clone(),
-                ))
-            }
-        }
-    }
-
-    Ok(futures::stream::iter(values_vec_deque).to_output_stream())
+    Ok(futures::stream::iter(iter).to_output_stream())
 }
 
 fn contact_to_value(contact: VcardContact, tag: Tag) -> Value {

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

@@ -1,7 +1,7 @@
 use crate::commands::WholeStreamCommand;
 use crate::prelude::*;
-use crate::TaggedListBuilder;
 use calamine::*;
+use nu_data::TaggedListBuilder;
 use nu_errors::ShellError;
 use nu_protocol::{ReturnSuccess, Signature, TaggedDictBuilder, UntaggedValue};
 use std::io::Cursor;
@@ -45,6 +45,7 @@ async fn from_xlsx(
     registry: &CommandRegistry,
 ) -> Result<OutputStream, ShellError> {
     let tag = args.call_info.name_tag.clone();
+    let span = tag.span;
     let registry = registry.clone();
     let (
         FromXLSXArgs {
@@ -73,7 +74,7 @@ async fn from_xlsx(
                     let value = match cell {
                         DataType::Empty => UntaggedValue::nothing(),
                         DataType::String(s) => UntaggedValue::string(s),
-                        DataType::Float(f) => UntaggedValue::decimal(*f),
+                        DataType::Float(f) => UntaggedValue::decimal_from_float(*f, span),
                         DataType::Int(i) => UntaggedValue::int(*i),
                         DataType::Bool(b) => UntaggedValue::boolean(*b),
                         _ => UntaggedValue::nothing(),

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

@@ -135,7 +135,6 @@ async fn from_xml(
 
 #[cfg(test)]
 mod tests {
-
     use crate::commands::from_xml;
     use indexmap::IndexMap;
     use nu_protocol::{UntaggedValue, Value};

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

@@ -58,6 +58,7 @@ fn convert_yaml_value_to_nu_value(
     tag: impl Into<Tag>,
 ) -> Result<Value, ShellError> {
     let tag = tag.into();
+    let span = tag.span;
 
     let err_not_compatible_number = ShellError::labeled_error(
         "Expected a compatible number",
@@ -69,10 +70,11 @@ fn convert_yaml_value_to_nu_value(
         serde_yaml::Value::Number(n) if n.is_i64() => {
             UntaggedValue::int(n.as_i64().ok_or_else(|| err_not_compatible_number)?).into_value(tag)
         }
-        serde_yaml::Value::Number(n) if n.is_f64() => {
-            UntaggedValue::decimal(n.as_f64().ok_or_else(|| err_not_compatible_number)?)
-                .into_value(tag)
-        }
+        serde_yaml::Value::Number(n) if n.is_f64() => UntaggedValue::decimal_from_float(
+            n.as_f64().ok_or_else(|| err_not_compatible_number)?,
+            span,
+        )
+        .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

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

@@ -4,10 +4,10 @@ use indexmap::set::IndexSet;
 use log::trace;
 use nu_errors::ShellError;
 use nu_protocol::{
-    did_you_mean, ColumnPath, PathMember, Primitive, ReturnSuccess, Signature, SyntaxShape,
-    UnspannedPathMember, UntaggedValue, Value,
+    did_you_mean, ColumnPath, Dictionary, PathMember, Primitive, ReturnSuccess, Signature,
+    SyntaxShape, UnspannedPathMember, UntaggedValue, Value,
 };
-use nu_source::span_for_spanned_list;
+use nu_source::HasFallibleSpan;
 use nu_value_ext::get_data_by_column_path;
 
 pub struct Get;
@@ -58,195 +58,209 @@ impl WholeStreamCommand for Get {
     }
 }
 
-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 async fn get(
     args: CommandArgs,
     registry: &CommandRegistry,
 ) -> Result<OutputStream, ShellError> {
     let registry = registry.clone();
-    let (GetArgs { rest: mut fields }, mut input) = args.process(&registry).await?;
-    if fields.is_empty() {
+    let (GetArgs { rest: column_paths }, mut input) = args.process(&registry).await?;
+    if column_paths.is_empty() {
         let vec = input.drain_vec().await;
 
         let descs = nu_protocol::merge_descriptors(&vec);
 
         Ok(futures::stream::iter(descs.into_iter().map(ReturnSuccess::value)).to_output_stream())
     } else {
-        let member = fields.remove(0);
-        trace!("get {:?} {:?}", member, fields);
-
-        Ok(input
+        trace!("get {:?}", column_paths);
+        let output_stream = input
             .map(move |item| {
-                let member = vec![member.clone()];
-
-                let column_paths = vec![&member, &fields]
-                    .into_iter()
+                let output = column_paths
+                    .iter()
+                    .map(move |path| get_output(&item, path))
                     .flatten()
-                    .collect::<Vec<&ColumnPath>>();
-
-                let mut output = vec![];
-                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 {
-                                    output.push(ReturnSuccess::value(item.clone()));
-                                }
-                            }
-                            Value {
-                                value: UntaggedValue::Primitive(Primitive::Nothing),
-                                ..
-                            } => {}
-                            other => output.push(ReturnSuccess::value(other.clone())),
-                        },
-                        Err(reason) => output.push(ReturnSuccess::value(
-                            UntaggedValue::Error(reason).into_untagged_value(),
-                        )),
-                    }
-                }
-
+                    .collect::<Vec<_>>();
                 futures::stream::iter(output)
             })
             .flatten()
-            .to_output_stream())
+            .to_output_stream();
+        Ok(output_stream)
+    }
+}
+
+fn get_output(item: &Value, path: &ColumnPath) -> Vec<Result<ReturnSuccess, ShellError>> {
+    match get_column_path(path, item) {
+        Ok(Value {
+            value: UntaggedValue::Primitive(Primitive::Nothing),
+            ..
+        }) => vec![],
+        Ok(Value {
+            value: UntaggedValue::Table(rows),
+            ..
+        }) => rows.into_iter().map(ReturnSuccess::value).collect(),
+        Ok(other) => vec![ReturnSuccess::value(other)],
+        Err(reason) => vec![ReturnSuccess::value(
+            UntaggedValue::Error(reason).into_untagged_value(),
+        )],
+    }
+}
+
+pub fn get_column_path(path: &ColumnPath, obj: &Value) -> Result<Value, ShellError> {
+    get_data_by_column_path(obj, path, move |obj_source, column_path_tried, error| {
+        let path_members_span = path.maybe_span().unwrap_or_else(Span::unknown);
+
+        match &obj_source.value {
+            UntaggedValue::Table(rows) => {
+                return get_column_path_from_table_error(
+                    rows,
+                    column_path_tried,
+                    &path_members_span,
+                );
+            }
+            UntaggedValue::Row(columns) => {
+                if let Some(error) = get_column_from_row_error(
+                    columns,
+                    column_path_tried,
+                    &path_members_span,
+                    obj_source,
+                ) {
+                    return error;
+                }
+            }
+            _ => {}
+        }
+
+        if let Some(suggestions) = did_you_mean(&obj_source, column_path_tried) {
+            ShellError::labeled_error(
+                "Unknown column",
+                format!("did you mean '{}'?", suggestions[0].1),
+                column_path_tried.span.since(path_members_span),
+            )
+        } else {
+            error
+        }
+    })
+}
+
+pub fn get_column_path_from_table_error(
+    rows: &[Value],
+    column_path_tried: &PathMember,
+    path_members_span: &Span,
+) -> ShellError {
+    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() {
+                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 {
+                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)
+            };
+
+            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),
+            )
+        }
+    }
+}
+
+pub fn get_column_from_row_error(
+    columns: &Dictionary,
+    column_path_tried: &PathMember,
+    path_members_span: &Span,
+    obj_source: &Value,
+) -> Option<ShellError> {
+    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) {
+                Some(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),
+                ))
+            } else {
+                None
+            }
+        }
+        PathMember {
+            unspanned: UnspannedPathMember::Int(idx),
+            ..
+        } => Some(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),
+        )),
     }
 }
 

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

@@ -10,7 +10,7 @@ pub struct GroupBy;
 
 #[derive(Deserialize)]
 pub struct GroupByArgs {
-    column_name: Option<Tagged<String>>,
+    grouper: Option<Value>,
 }
 
 #[async_trait]
@@ -21,14 +21,14 @@ impl WholeStreamCommand for GroupBy {
 
     fn signature(&self) -> Signature {
         Signature::build("group-by").optional(
-            "column_name",
-            SyntaxShape::String,
-            "the name of the column to group by",
+            "grouper",
+            SyntaxShape::Any,
+            "the grouper value to use",
         )
     }
 
     fn usage(&self) -> &str {
-        "Creates a new table with the data from the table rows grouped by the column given."
+        "Create a new table grouped."
     }
 
     async fn run(
@@ -42,12 +42,17 @@ impl WholeStreamCommand for GroupBy {
     fn examples(&self) -> Vec<Example> {
         vec![
             Example {
-                description: "Group items by type",
+                description: "group items by column named \"type\"",
                 example: r#"ls | group-by type"#,
                 result: None,
             },
             Example {
-                description: "Group items by their value",
+                description: "blocks can be used for generating a grouping key (same as above)",
+                example: r#"ls | group-by { get type }"#,
+                result: None,
+            },
+            Example {
+                description: "you can also group by raw values by leaving out the argument",
                 example: "echo [1 3 1 3 2 1 1] | group-by",
                 result: Some(vec![UntaggedValue::row(indexmap! {
                     "1".to_string() => UntaggedValue::Table(vec![
@@ -68,26 +73,95 @@ impl WholeStreamCommand for GroupBy {
                 })
                 .into()]),
             },
+            Example {
+                description: "write pipelines for a more involved grouping key",
+                example:
+                    "echo [1 3 1 3 2 1 1] | group-by { echo `({{$it}} - 1) % 3` | calc | str from }",
+                result: None,
+            },
         ]
     }
 }
 
 enum Grouper {
     ByColumn(Option<Tagged<String>>),
+    ByBlock,
 }
 
 pub async fn group_by(
     args: CommandArgs,
     registry: &CommandRegistry,
 ) -> Result<OutputStream, ShellError> {
-    let registry = registry.clone();
     let name = args.call_info.name_tag.clone();
-    let (GroupByArgs { column_name }, input) = args.process(&registry).await?;
+    let registry = registry.clone();
+    let head = Arc::new(args.call_info.args.head.clone());
+    let scope = Arc::new(args.call_info.scope.clone());
+    let context = Arc::new(EvaluationContext::from_raw(&args, &registry));
+    let (GroupByArgs { grouper }, input) = args.process(&registry).await?;
+
     let values: Vec<Value> = input.collect().await;
+    let mut keys: Vec<Result<String, ShellError>> = vec![];
+    let mut group_strategy = Grouper::ByColumn(None);
+
+    match grouper {
+        Some(Value {
+            value: UntaggedValue::Block(block_given),
+            ..
+        }) => {
+            let block = Arc::new(block_given);
+            let error_key = "error";
+
+            for value in values.iter() {
+                let run = block.clone();
+                let scope = scope.clone();
+                let head = head.clone();
+                let context = context.clone();
+
+                match crate::commands::each::process_row(run, scope, head, context, value.clone())
+                    .await
+                {
+                    Ok(mut s) => {
+                        let collection: Vec<Result<ReturnSuccess, ShellError>> =
+                            s.drain_vec().await;
+
+                        if collection.len() > 1 {
+                            return Err(ShellError::labeled_error(
+                                "expected one value from the block",
+                                "requires a table with one value for grouping",
+                                &name,
+                            ));
+                        }
+
+                        let value = match collection.get(0) {
+                            Some(Ok(return_value)) => {
+                                return_value.raw_value().unwrap_or_else(|| {
+                                    UntaggedValue::string(error_key).into_value(&name)
+                                })
+                            }
+                            Some(Err(_)) | None => {
+                                UntaggedValue::string(error_key).into_value(&name)
+                            }
+                        };
+
+                        keys.push(as_string(&value));
+                    }
+                    Err(_) => {
+                        keys.push(Ok(error_key.into()));
+                    }
+                }
+            }
+
+            group_strategy = Grouper::ByBlock;
+        }
+        Some(other) => {
+            group_strategy = Grouper::ByColumn(Some(as_string(&other)?.tagged(&name)));
+        }
+        _ => {}
+    }
 
     if values.is_empty() {
         return Err(ShellError::labeled_error(
-            "Expected table from pipeline",
+            "expected table from pipeline",
             "requires a table input",
             name,
         ));
@@ -95,10 +169,22 @@ pub async fn group_by(
 
     let values = UntaggedValue::table(&values).into_value(&name);
 
-    match group(&column_name, &values, name) {
-        Ok(grouped) => Ok(OutputStream::one(ReturnSuccess::value(grouped))),
-        Err(reason) => Err(reason),
-    }
+    let group_value = match group_strategy {
+        Grouper::ByBlock => {
+            let map = keys.clone();
+
+            let block = Box::new(move |idx: usize, row: &Value| match map.get(idx) {
+                Some(Ok(key)) => Ok(key.clone()),
+                Some(Err(reason)) => Err(reason.clone()),
+                None => as_string(row),
+            });
+
+            nu_data::utils::group(&values, &Some(block), &name)
+        }
+        Grouper::ByColumn(column_name) => group(&column_name, &values, name),
+    };
+
+    Ok(OutputStream::one(ReturnSuccess::value(group_value?)))
 }
 
 pub fn suggestions(tried: Tagged<&str>, for_value: &Value) -> ShellError {
@@ -141,100 +227,55 @@ pub fn group(
 
     match grouper {
         Grouper::ByColumn(Some(column_name)) => {
-            let block = Box::new(move |row: &Value| {
+            let block = Box::new(move |_, row: &Value| {
                 match row.get_data_by_key(column_name.borrow_spanned()) {
                     Some(group_key) => Ok(as_string(&group_key)?),
                     None => Err(suggestions(column_name.borrow_tagged(), &row)),
                 }
             });
 
-            crate::utils::data::group(&values, &Some(block), &name)
+            nu_data::utils::group(&values, &Some(block), &name)
         }
         Grouper::ByColumn(None) => {
-            let block = Box::new(move |row: &Value| match as_string(row) {
-                Ok(group_key) => Ok(group_key),
-                Err(reason) => Err(reason),
-            });
+            let block = Box::new(move |_, row: &Value| as_string(row));
 
-            crate::utils::data::group(&values, &Some(block), &name)
+            nu_data::utils::group(&values, &Some(block), &name)
         }
+        Grouper::ByBlock => Err(ShellError::unimplemented(
+            "Block not implemented: This should never happen.",
+        )),
     }
 }
 
 #[cfg(test)]
 mod tests {
     use super::group;
-    use indexmap::IndexMap;
+    use nu_data::utils::helpers::{committers, date, int, row, string, table};
     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_committers() -> 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 = Some(String::from("date").tagged_unknown());
-        let sample = table(&nu_releases_committers());
+        let sample = table(&committers());
 
         assert_eq!(
             group(&for_key, &sample, 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")})
+                "2019-07-23".into() =>  table(&[
+                    row(indexmap!{"name".into() => string("AR"), "country".into() => string("EC"), "date".into() => date("2019-07-23"), "chickens".into() => int(10) }),
+                    row(indexmap!{"name".into() => string("JT"), "country".into() => string("NZ"), "date".into() => date("2019-07-23"), "chickens".into() =>  int(5) }),
+                    row(indexmap!{"name".into() => string("YK"), "country".into() => string("US"), "date".into() => date("2019-07-23"), "chickens".into() =>  int(2) })
                 ]),
-                "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")})
+                "2019-10-10".into() =>  table(&[
+                    row(indexmap!{"name".into() => string("YK"), "country".into() => string("US"), "date".into() => date("2019-10-10"), "chickens".into() =>  int(6) }),
+                    row(indexmap!{"name".into() => string("JT"), "country".into() => string("NZ"), "date".into() => date("2019-10-10"), "chickens".into() => int(15) }),
+                    row(indexmap!{"name".into() => string("AR"), "country".into() => string("EC"), "date".into() => date("2019-10-10"), "chickens".into() => int(30) })
                 ]),
-                "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")})
+                "2019-09-24".into() =>  table(&[
+                    row(indexmap!{"name".into() => string("AR"), "country".into() => string("EC"), "date".into() => date("2019-09-24"), "chickens".into() => int(20) }),
+                    row(indexmap!{"name".into() => string("YK"), "country".into() => string("US"), "date".into() => date("2019-09-24"), "chickens".into() =>  int(4) }),
+                    row(indexmap!{"name".into() => string("JT"), "country".into() => string("NZ"), "date".into() => date("2019-09-24"), "chickens".into() => int(10) })
                 ]),
             })
         );
@@ -245,25 +286,25 @@ mod tests {
     #[test]
     fn groups_table_by_country_column() -> Result<(), ShellError> {
         let for_key = Some(String::from("country").tagged_unknown());
-        let sample = table(&nu_releases_committers());
+        let sample = table(&committers());
 
         assert_eq!(
             group(&for_key, &sample, 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")})
+                    row(indexmap!{"name".into() => string("AR"), "country".into() => string("EC"), "date".into() => date("2019-07-23"), "chickens".into() => int(10) }),
+                    row(indexmap!{"name".into() => string("AR"), "country".into() => string("EC"), "date".into() => date("2019-09-24"), "chickens".into() => int(20) }),
+                    row(indexmap!{"name".into() => string("AR"), "country".into() => string("EC"), "date".into() => date("2019-10-10"), "chickens".into() => int(30) })
                 ]),
                 "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")})
+                    row(indexmap!{"name".into() => string("JT"), "country".into() => string("NZ"), "date".into() => date("2019-07-23"), "chickens".into() =>  int(5) }),
+                    row(indexmap!{"name".into() => string("JT"), "country".into() => string("NZ"), "date".into() => date("2019-10-10"), "chickens".into() => int(15) }),
+                    row(indexmap!{"name".into() => string("JT"), "country".into() => string("NZ"), "date".into() => date("2019-09-24"), "chickens".into() => int(10) })
                 ]),
                 "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")}),
+                    row(indexmap!{"name".into() => string("YK"), "country".into() => string("US"), "date".into() => date("2019-10-10"), "chickens".into() =>  int(6) }),
+                    row(indexmap!{"name".into() => string("YK"), "country".into() => string("US"), "date".into() => date("2019-09-24"), "chickens".into() =>  int(4) }),
+                    row(indexmap!{"name".into() => string("YK"), "country".into() => string("US"), "date".into() => date("2019-07-23"), "chickens".into() =>  int(2) }),
                 ]),
             })
         );

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

@@ -34,7 +34,7 @@ impl WholeStreamCommand for GroupByDate {
     }
 
     fn usage(&self) -> &str {
-        "Creates a new table with the data from the table rows grouped by the column given."
+        "creates a table grouped by date."
     }
 
     async fn run(
@@ -98,54 +98,42 @@ pub async fn group_by_date(
             Grouper::ByDate(None)
         };
 
-        match (grouper_date, grouper_column) {
+        let value_result = match (grouper_date, grouper_column) {
             (Grouper::ByDate(None), GroupByColumn::Name(None)) => {
-                let block = Box::new(move |row: &Value| row.format("%Y-%b-%d"));
+                let block = Box::new(move |_, row: &Value| row.format("%Y-%m-%d"));
 
-                match crate::utils::data::group(&values, &Some(block), &name) {
-                    Ok(grouped) => Ok(OutputStream::one(ReturnSuccess::value(grouped))),
-                    Err(err) => Err(err),
-                }
+                nu_data::utils::group(&values, &Some(block), &name)
             }
             (Grouper::ByDate(None), GroupByColumn::Name(Some(column_name))) => {
-                let block = Box::new(move |row: &Value| {
-                    let group_key = match row.get_data_by_key(column_name.borrow_spanned()) {
-                        Some(group_key) => Ok(group_key),
-                        None => Err(suggestions(column_name.borrow_tagged(), &row)),
-                    };
+                let block = Box::new(move |_, row: &Value| {
+                    let group_key = row
+                        .get_data_by_key(column_name.borrow_spanned())
+                        .ok_or_else(|| suggestions(column_name.borrow_tagged(), &row));
 
-                    group_key?.format("%Y-%b-%d")
+                    group_key?.format("%Y-%m-%d")
                 });
 
-                match crate::utils::data::group(&values, &Some(block), &name) {
-                    Ok(grouped) => Ok(OutputStream::one(ReturnSuccess::value(grouped))),
-                    Err(err) => Err(err),
-                }
+                nu_data::utils::group(&values, &Some(block), &name)
             }
             (Grouper::ByDate(Some(fmt)), GroupByColumn::Name(None)) => {
-                let block = Box::new(move |row: &Value| row.format(&fmt));
+                let block = Box::new(move |_, row: &Value| row.format(&fmt));
 
-                match crate::utils::data::group(&values, &Some(block), &name) {
-                    Ok(grouped) => Ok(OutputStream::one(ReturnSuccess::value(grouped))),
-                    Err(err) => Err(err),
-                }
+                nu_data::utils::group(&values, &Some(block), &name)
             }
             (Grouper::ByDate(Some(fmt)), GroupByColumn::Name(Some(column_name))) => {
-                let block = Box::new(move |row: &Value| {
-                    let group_key = match row.get_data_by_key(column_name.borrow_spanned()) {
-                        Some(group_key) => Ok(group_key),
-                        None => Err(suggestions(column_name.borrow_tagged(), &row)),
-                    };
+                let block = Box::new(move |_, row: &Value| {
+                    let group_key = row
+                        .get_data_by_key(column_name.borrow_spanned())
+                        .ok_or_else(|| suggestions(column_name.borrow_tagged(), &row));
 
                     group_key?.format(&fmt)
                 });
 
-                match crate::utils::data::group(&values, &Some(block), &name) {
-                    Ok(grouped) => Ok(OutputStream::one(ReturnSuccess::value(grouped))),
-                    Err(err) => Err(err),
-                }
+                nu_data::utils::group(&values, &Some(block), &name)
             }
-        }
+        };
+
+        Ok(OutputStream::one(ReturnSuccess::value(value_result?)))
     }
 }
 

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

@@ -1,11 +1,11 @@
+use crate::command_registry::CommandRegistry;
 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};
+use nu_protocol::{Primitive, ReturnSuccess, Signature, UntaggedValue, Value};
 
 pub struct Headers;
 
@@ -32,11 +32,18 @@ impl WholeStreamCommand for Headers {
     }
 
     fn examples(&self) -> Vec<Example> {
-        vec![Example {
-            description: "Create headers for a raw string",
-            example: r#"echo "a b c|1 2 3" | split row "|" | split column " " | headers"#,
-            result: None,
-        }]
+        vec![
+            Example {
+                description: "Create headers for a raw string",
+                example: r#"echo "a b c|1 2 3" | split row "|" | split column " " | headers"#,
+                result: None,
+            },
+            Example {
+                description: "Don't panic on rows with different headers",
+                example: r#"echo "a b c|1 2 3|1 2 3 4" | split row "|" | split column " " | headers"#,
+                result: None,
+            },
+        ]
     }
 }
 
@@ -84,8 +91,13 @@ pub async fn headers(
             match &r.value {
                 UntaggedValue::Row(d) => {
                     let mut entries = IndexMap::new();
-                    for (i, (_, v)) in d.entries.iter().enumerate() {
-                        entries.insert(headers[i].clone(), v.clone());
+                    for (i, header) in headers.iter().enumerate() {
+                        let value = match d.entries.get_index(i) {
+                            Some((_, value)) => value.clone(),
+                            None => UntaggedValue::Primitive(Primitive::Nothing).into(),
+                        };
+
+                        entries.insert(header.clone(), value);
                     }
                     Ok(ReturnSuccess::Value(
                         UntaggedValue::Row(Dictionary { entries }).into_value(r.tag.clone()),

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

@@ -1,12 +1,10 @@
+use crate::commands::command::Command;
 use crate::commands::WholeStreamCommand;
-use crate::data::command_dict;
-
+use crate::documentation::{generate_docs, get_documentation, DocumentationConfig};
 use crate::prelude::*;
+use nu_data::command::signature_dict;
 use nu_errors::ShellError;
-use nu_protocol::{
-    NamedType, PositionalType, ReturnSuccess, Signature, SyntaxShape, TaggedDictBuilder,
-    UntaggedValue,
-};
+use nu_protocol::{ReturnSuccess, Signature, SyntaxShape, TaggedDictBuilder, UntaggedValue, Value};
 use nu_source::{SpannedItem, Tagged};
 use nu_value_ext::get_data_by_key;
 
@@ -40,6 +38,21 @@ impl WholeStreamCommand for Help {
     }
 }
 
+pub(crate) fn command_dict(command: Command, tag: impl Into<Tag>) -> Value {
+    let tag = tag.into();
+
+    let mut cmd_dict = TaggedDictBuilder::new(&tag);
+
+    cmd_dict.insert_untagged("name", UntaggedValue::string(command.name()));
+
+    cmd_dict.insert_untagged("type", UntaggedValue::string("Command"));
+
+    cmd_dict.insert_value("signature", signature_dict(command.signature(), tag));
+    cmd_dict.insert_untagged("usage", UntaggedValue::string(command.usage()));
+
+    cmd_dict.into_value()
+}
+
 async fn help(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStream, ShellError> {
     let registry = registry.clone();
     let name = args.call_info.name_tag.clone();
@@ -50,54 +63,118 @@ async fn help(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStr
             let mut sorted_names = registry.names();
             sorted_names.sort();
 
-            Ok(
-                futures::stream::iter(sorted_names.into_iter().filter_map(move |cmd| {
-                    // If it's a subcommand, don't list it during the commands list
-                    if cmd.contains(' ') {
-                        return None;
-                    }
-                    let mut short_desc = TaggedDictBuilder::new(name.clone());
-                    let document_tag = rest[0].tag.clone();
-                    let value = command_dict(
-                        match registry.get_command(&cmd).ok_or_else(|| {
+            let (mut subcommand_names, command_names) = sorted_names
+                .into_iter()
+                // Internal only commands shouldn't be displayed
+                .filter(|cmd_name| {
+                    registry
+                        .get_command(&cmd_name)
+                        .filter(|command| !command.is_internal())
+                        .is_some()
+                })
+                .partition::<Vec<_>, _>(|cmd_name| cmd_name.contains(' '));
+
+            fn process_name(
+                dict: &mut TaggedDictBuilder,
+                cmd_name: &str,
+                registry: CommandRegistry,
+                rest: Vec<Tagged<String>>,
+                name: Tag,
+            ) -> Result<(), ShellError> {
+                let document_tag = rest[0].tag.clone();
+                let value = command_dict(
+                    registry.get_command(&cmd_name).ok_or_else(|| {
+                        ShellError::labeled_error(
+                            format!("Could not load {}", cmd_name),
+                            "could not load command",
+                            document_tag,
+                        )
+                    })?,
+                    name,
+                );
+
+                dict.insert_untagged("name", cmd_name);
+                dict.insert_untagged(
+                    "description",
+                    get_data_by_key(&value, "usage".spanned_unknown())
+                        .ok_or_else(|| {
                             ShellError::labeled_error(
-                                format!("Could not load {}", cmd),
-                                "could not load command",
-                                document_tag,
+                                "Expected a usage key",
+                                "expected a 'usage' key",
+                                &value.tag,
                             )
-                        }) {
-                            Ok(ok) => ok,
-                            Err(err) => return Some(Err(err)),
-                        },
-                        name.clone(),
-                    );
+                        })?
+                        .as_string()?,
+                );
 
-                    short_desc.insert_untagged("name", cmd);
-                    short_desc.insert_untagged(
-                        "description",
-                        match match get_data_by_key(&value, "usage".spanned_unknown()).ok_or_else(
-                            || {
-                                ShellError::labeled_error(
-                                    "Expected a usage key",
-                                    "expected a 'usage' key",
-                                    &value.tag,
-                                )
-                            },
-                        ) {
-                            Ok(ok) => ok,
-                            Err(err) => return Some(Err(err)),
-                        }
-                        .as_string()
-                        {
-                            Ok(ok) => ok,
-                            Err(err) => return Some(Err(err)),
-                        },
-                    );
+                Ok(())
+            }
 
-                    Some(ReturnSuccess::value(short_desc.into_value()))
-                }))
-                .to_output_stream(),
-            )
+            fn make_subcommands_table(
+                subcommand_names: &mut Vec<String>,
+                cmd_name: &str,
+                registry: CommandRegistry,
+                rest: Vec<Tagged<String>>,
+                name: Tag,
+            ) -> Result<Value, ShellError> {
+                let (matching, not_matching) =
+                    subcommand_names.drain(..).partition(|subcommand_name| {
+                        subcommand_name.starts_with(&format!("{} ", cmd_name))
+                    });
+                *subcommand_names = not_matching;
+                Ok(if !matching.is_empty() {
+                    UntaggedValue::table(
+                        &(matching
+                            .into_iter()
+                            .map(|cmd_name: String| -> Result<_, ShellError> {
+                                let mut short_desc = TaggedDictBuilder::new(name.clone());
+                                process_name(
+                                    &mut short_desc,
+                                    &cmd_name,
+                                    registry.clone(),
+                                    rest.clone(),
+                                    name.clone(),
+                                )?;
+                                Ok(short_desc.into_value())
+                            })
+                            .collect::<Result<Vec<_>, _>>()?[..]),
+                    )
+                    .into_value(name)
+                } else {
+                    UntaggedValue::nothing().into_value(name)
+                })
+            }
+
+            let iterator =
+                command_names
+                    .into_iter()
+                    .map(move |cmd_name| -> Result<_, ShellError> {
+                        let mut short_desc = TaggedDictBuilder::new(name.clone());
+                        process_name(
+                            &mut short_desc,
+                            &cmd_name,
+                            registry.clone(),
+                            rest.clone(),
+                            name.clone(),
+                        )?;
+                        short_desc.insert_value(
+                            "subcommands",
+                            make_subcommands_table(
+                                &mut subcommand_names,
+                                &cmd_name,
+                                registry.clone(),
+                                rest.clone(),
+                                name.clone(),
+                            )?,
+                        );
+                        ReturnSuccess::value(short_desc.into_value())
+                    });
+
+            Ok(futures::stream::iter(iterator).to_output_stream())
+        } else if rest[0].item == "generate_docs" {
+            Ok(OutputStream::one(ReturnSuccess::value(generate_docs(
+                &registry,
+            ))))
         } else if rest.len() == 2 {
             // Check for a subcommand
             let command_name = format!("{} {}", rest[0].item, rest[1].item);
@@ -150,165 +227,8 @@ You can also learn more at https://www.nushell.sh/book/"#;
     }
 }
 
-#[allow(clippy::cognitive_complexity)]
 pub fn get_help(cmd: &dyn WholeStreamCommand, registry: &CommandRegistry) -> String {
-    let cmd_name = cmd.name();
-    let signature = cmd.signature();
-    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(&get_flags_section(&signature))
-    }
-
-    let palette = crate::shell::palette::DefaultPalette {};
-    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, &palette);
-        long_desc.push_str(&format!("\n  > {}\n", colored_example));
-    }
-
-    long_desc.push_str("\n");
-
-    long_desc
-}
-
-fn get_flags_section(signature: &Signature) -> String {
-    let mut long_desc = String::new();
-    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);
-    }
-    long_desc
+    get_documentation(cmd, registry, &DocumentationConfig::default())
 }
 
 #[cfg(test)]

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

@@ -1,22 +1,13 @@
-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,
+    ColumnPath, 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>>,
-}
-
 #[async_trait]
 impl WholeStreamCommand for Histogram {
     fn name(&self) -> &str {
@@ -25,13 +16,14 @@ impl WholeStreamCommand for Histogram {
 
     fn signature(&self) -> Signature {
         Signature::build("histogram")
-            .required(
-                "column_name",
-                SyntaxShape::String,
-                "the name of the column to graph by",
+            .named(
+                "use",
+                SyntaxShape::ColumnPath,
+                "Use data at the column path given as valuator",
+                None,
             )
             .rest(
-                SyntaxShape::String,
+                SyntaxShape::ColumnPath,
                 "column name to give the histogram's frequency column",
             )
     }
@@ -57,8 +49,8 @@ impl WholeStreamCommand for Histogram {
             },
             Example {
                 description:
-                    "Get a histogram for the types of files, with frequency column named count",
-                example: "ls | histogram type count",
+                    "Get a histogram for the types of files, with frequency column named percentage",
+                example: "ls | histogram type percentage",
                 result: None,
             },
             Example {
@@ -76,181 +68,143 @@ pub async fn histogram(
 ) -> Result<OutputStream, ShellError> {
     let registry = registry.clone();
     let name = args.call_info.name_tag.clone();
+    let (input, args) = args.evaluate_once(&registry).await?.parts();
 
-    let (HistogramArgs { column_name, rest }, input) = args.process(&registry).await?;
     let values: Vec<Value> = input.collect().await;
-    let values = UntaggedValue::table(&values).into_value(&name);
 
-    let groups = group(&Some(column_name.clone()), &values, &name)?;
-    let group_labels = columns_sorted(Some(column_name.clone()), &groups, &name);
-    let sorted = t_sort(Some(column_name.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)?;
+    let mut columns = args
+        .positional_iter()
+        .map(|c| c.as_column_path())
+        .filter_map(Result::ok)
+        .collect::<Vec<_>>();
 
-    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();
-
-            let count_column_name = "count".to_string();
-            let count_shell_error = ShellError::labeled_error(
-                "Unable to load group count",
-                "unabled to load group count",
-                &name,
-            );
-            let mut count_values: Vec<u64> = Vec::new();
-
-            for table_entry in reduced.table_entries() {
-                match table_entry {
-                    Value {
-                        value: UntaggedValue::Table(list),
-                        ..
-                    } => {
-                        for i in list {
-                            if let Ok(count) = i.value.clone().into_value(&name).as_u64() {
-                                count_values.push(count);
-                            } else {
-                                return Err(count_shell_error);
-                            }
-                        }
-                    }
-                    _ => {
-                        return Err(count_shell_error);
-                    }
-                }
-            }
-
-            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,
-                )
-            })? {
-                let start = start.clone();
-                Ok(
-                    futures::stream::iter(start.into_iter().map(move |percentage| {
-                        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),
-                        );
-
-                        fact.insert_untagged(
-                            &count_column_name,
-                            UntaggedValue::int(count_values[idx]),
-                        );
-
-                        if let Value {
-                            value: UntaggedValue::Primitive(Primitive::Int(ref num)),
-                            ref tag,
-                        } = percentage
-                        {
-                            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;
-
-                        ReturnSuccess::value(fact.into_value())
-                    }))
-                    .to_output_stream(),
-                )
-            } else {
-                Ok(OutputStream::empty())
-            }
-        }
-        _ => Ok(OutputStream::empty()),
-    }
-}
-
-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(),
+    let evaluate_with = if let Some(path) = args.get("use") {
+        Some(evaluator(path.as_column_path()?.item))
+    } else {
+        None
     };
 
-    Ok(results)
+    let column_grouper = if !columns.is_empty() {
+        match columns.remove(0).split_last() {
+            Some((key, _)) => Some(key.as_string().tagged(&name)),
+            None => None,
+        }
+    } else {
+        None
+    };
+
+    let frequency_column_name = if columns.is_empty() {
+        "frequency".to_string()
+    } else if let Some((key, _)) = columns[0].split_last() {
+        key.as_string()
+    } else {
+        "frecuency".to_string()
+    };
+
+    let column = if let Some(ref column) = column_grouper {
+        column.clone()
+    } else {
+        "value".to_string().tagged(&name)
+    };
+
+    let results = nu_data::utils::report(
+        &UntaggedValue::table(&values).into_value(&name),
+        nu_data::utils::Operation {
+            grouper: Some(Box::new(move |_, _| Ok(String::from("frequencies")))),
+            splitter: Some(splitter(column_grouper)),
+            format: None,
+            eval: &evaluate_with,
+        },
+        &name,
+    )?;
+
+    let labels = results.labels.y.clone();
+    let mut idx = 0;
+
+    Ok(futures::stream::iter(
+        results
+            .percentages
+            .table_entries()
+            .map(move |value| {
+                let values = value.table_entries().cloned().collect::<Vec<_>>();
+                let occurrences = values.len();
+
+                (occurrences, values[occurrences - 1].clone())
+            })
+            .collect::<Vec<_>>()
+            .into_iter()
+            .map(move |(occurrences, value)| {
+                let mut fact = TaggedDictBuilder::new(&name);
+                let column_value = 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.item, column_value);
+                fact.insert_untagged("occurrences", UntaggedValue::int(occurrences));
+
+                let percentage = format!(
+                    "{}%",
+                    // Some(2) < the number of digits
+                    // true < group the digits
+                    crate::commands::str_::from::action(&value, &name, Some(2), true)?
+                        .as_string()?
+                );
+                fact.insert_untagged("percentage", UntaggedValue::string(percentage));
+
+                let string = std::iter::repeat("*")
+                    .take(value.as_u64().map_err(|_| {
+                        ShellError::labeled_error("expected a number", "expected a number", &name)
+                    })? as usize)
+                    .collect::<String>();
+
+                fact.insert_untagged(&frequency_column_name, UntaggedValue::string(string));
+
+                idx += 1;
+
+                ReturnSuccess::value(fact.into_value())
+            }),
+    )
+    .to_output_stream())
+}
+
+fn evaluator(by: ColumnPath) -> Box<dyn Fn(usize, &Value) -> Result<Value, ShellError> + Send> {
+    Box::new(move |_: usize, value: &Value| {
+        let path = by.clone();
+
+        let eval = nu_value_ext::get_data_by_column_path(value, &path, move |_, _, error| error);
+
+        match eval {
+            Ok(with_value) => Ok(with_value),
+            Err(reason) => Err(reason),
+        }
+    })
+}
+
+fn splitter(
+    by: Option<Tagged<String>>,
+) -> Box<dyn Fn(usize, &Value) -> Result<String, ShellError> + Send> {
+    match by {
+        Some(column) => Box::new(move |_, row: &Value| {
+            let key = &column;
+
+            match row.get_data_by_key(key.borrow_spanned()) {
+                Some(key) => nu_value_ext::as_string(&key),
+                None => Err(ShellError::labeled_error(
+                    "unknown column",
+                    "unknown column",
+                    key.tag(),
+                )),
+            }
+        }),
+        None => Box::new(move |_, row: &Value| nu_value_ext::as_string(&row)),
+    }
 }
 
 #[cfg(test)]

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

@@ -1,10 +1,31 @@
-use crate::cli::History as HistoryFile;
 use crate::commands::WholeStreamCommand;
 use crate::prelude::*;
+use nu_data::config::{Conf, NuConfig};
 use nu_errors::ShellError;
 use nu_protocol::{ReturnSuccess, Signature, UntaggedValue};
 use std::fs::File;
 use std::io::{BufRead, BufReader};
+use std::path::PathBuf;
+
+const DEFAULT_LOCATION: &str = "history.txt";
+
+pub fn history_path(config: &dyn Conf) -> PathBuf {
+    let default_path = nu_data::config::user_data()
+        .map(|mut p| {
+            p.push(DEFAULT_LOCATION);
+            p
+        })
+        .unwrap_or_else(|_| PathBuf::from(DEFAULT_LOCATION));
+
+    config
+        .var("history-path")
+        .map_or(default_path.clone(), |custom_path| {
+            match custom_path.as_string() {
+                Ok(path) => PathBuf::from(path),
+                Err(_) => default_path,
+            }
+        })
+}
 
 pub struct History;
 
@@ -32,9 +53,10 @@ impl WholeStreamCommand for History {
 }
 
 fn history(args: CommandArgs, _registry: &CommandRegistry) -> Result<OutputStream, ShellError> {
+    let config: Box<dyn Conf> = Box::new(NuConfig::new());
     let tag = args.call_info.name_tag;
-    let history_path = HistoryFile::path();
-    let file = File::open(history_path);
+    let path = history_path(&config);
+    let file = File::open(path);
     if let Ok(file) = file {
         let reader = BufReader::new(file);
         let output = reader.lines().filter_map(move |line| match line {

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

@@ -0,0 +1,188 @@
+use crate::command_registry::CommandRegistry;
+use crate::commands::classified::block::run_block;
+use crate::commands::WholeStreamCommand;
+use crate::evaluate::evaluate_baseline_expr;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{hir::Block, hir::ClassifiedCommand, Signature, SyntaxShape, UntaggedValue};
+
+pub struct If;
+
+#[derive(Deserialize)]
+pub struct IfArgs {
+    condition: Block,
+    then_case: Block,
+    else_case: Block,
+}
+
+#[async_trait]
+impl WholeStreamCommand for If {
+    fn name(&self) -> &str {
+        "if"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("if")
+            .required(
+                "condition",
+                SyntaxShape::Math,
+                "the condition that must match",
+            )
+            .required(
+                "then_case",
+                SyntaxShape::Block,
+                "block to run if condition is true",
+            )
+            .required(
+                "else_case",
+                SyntaxShape::Block,
+                "block to run if condition is false",
+            )
+    }
+
+    fn usage(&self) -> &str {
+        "Run blocks if a condition is true or false."
+    }
+
+    async fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        if_command(args, registry).await
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![
+            Example {
+                description: "Run a block if a condition is true",
+                example: "echo 10 | if $it > 5 { echo 'greater than 5' } { echo 'less than or equal to 5' }",
+                result: Some(vec![UntaggedValue::string("greater than 5").into()]),
+            },
+            Example {
+                description: "Run a block if a condition is false",
+                example: "echo 1 | if $it > 5 { echo 'greater than 5' } { echo 'less than or equal to 5' }",
+                result: Some(vec![UntaggedValue::string("less than or equal to 5").into()]),
+            },
+        ]
+    }
+}
+async fn if_command(
+    raw_args: CommandArgs,
+    registry: &CommandRegistry,
+) -> Result<OutputStream, ShellError> {
+    let registry = Arc::new(registry.clone());
+    let scope = Arc::new(raw_args.call_info.scope.clone());
+    let tag = raw_args.call_info.name_tag.clone();
+    let context = Arc::new(EvaluationContext::from_raw(&raw_args, &registry));
+
+    let (
+        IfArgs {
+            condition,
+            then_case,
+            else_case,
+        },
+        input,
+    ) = raw_args.process(&registry).await?;
+    let condition = {
+        if condition.block.len() != 1 {
+            return Err(ShellError::labeled_error(
+                "Expected a condition",
+                "expected a condition",
+                tag,
+            ));
+        }
+        match condition.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,
+                ));
+            }
+        }
+    };
+
+    Ok(input
+        .then(move |input| {
+            let condition = condition.clone();
+            let then_case = then_case.clone();
+            let else_case = else_case.clone();
+            let registry = registry.clone();
+            let scope = scope.clone();
+            let mut context = context.clone();
+
+            async move {
+                //FIXME: should we use the scope that's brought in as well?
+                let condition =
+                    evaluate_baseline_expr(&condition, &*registry, &input, &scope.vars, &scope.env)
+                        .await;
+
+                match condition {
+                    Ok(condition) => match condition.as_bool() {
+                        Ok(b) => {
+                            if b {
+                                match run_block(
+                                    &then_case,
+                                    Arc::make_mut(&mut context),
+                                    InputStream::empty(),
+                                    &input,
+                                    &scope.vars,
+                                    &scope.env,
+                                )
+                                .await
+                                {
+                                    Ok(stream) => stream.to_output_stream(),
+                                    Err(e) => futures::stream::iter(vec![Err(e)].into_iter())
+                                        .to_output_stream(),
+                                }
+                            } else {
+                                match run_block(
+                                    &else_case,
+                                    Arc::make_mut(&mut context),
+                                    InputStream::empty(),
+                                    &input,
+                                    &scope.vars,
+                                    &scope.env,
+                                )
+                                .await
+                                {
+                                    Ok(stream) => stream.to_output_stream(),
+                                    Err(e) => futures::stream::iter(vec![Err(e)].into_iter())
+                                        .to_output_stream(),
+                                }
+                            }
+                        }
+                        Err(e) => {
+                            futures::stream::iter(vec![Err(e)].into_iter()).to_output_stream()
+                        }
+                    },
+                    Err(e) => futures::stream::iter(vec![Err(e)].into_iter()).to_output_stream(),
+                }
+            }
+        })
+        .flatten()
+        .to_output_stream())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::If;
+
+    #[test]
+    fn examples_work_as_expected() {
+        use crate::examples::test as test_examples;
+
+        test_examples(If {})
+    }
+}

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

@@ -1,10 +1,14 @@
+use crate::command_registry::CommandRegistry;
+use crate::commands::classified::block::run_block;
 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_protocol::{
+    ColumnPath, Primitive, ReturnSuccess, Scope, Signature, SyntaxShape, UntaggedValue, Value,
+};
 use nu_value_ext::ValueExt;
 
+use futures::stream::once;
 pub struct Insert;
 
 #[derive(Deserialize)]
@@ -26,11 +30,7 @@ impl WholeStreamCommand for Insert {
                 SyntaxShape::ColumnPath,
                 "the column name to insert",
             )
-            .required(
-                "value",
-                SyntaxShape::String,
-                "the value to give the cell(s)",
-            )
+            .required("value", SyntaxShape::Any, "the value to give the cell(s)")
     }
 
     fn usage(&self) -> &str {
@@ -46,27 +46,116 @@ impl WholeStreamCommand for Insert {
     }
 }
 
-async fn insert(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStream, ShellError> {
-    let registry = registry.clone();
+async fn process_row(
+    scope: Arc<Scope>,
+    mut context: Arc<EvaluationContext>,
+    input: Value,
+    mut value: Arc<Value>,
+    field: Arc<ColumnPath>,
+) -> Result<OutputStream, ShellError> {
+    let value = Arc::make_mut(&mut value);
 
-    let (InsertArgs { column, value }, input) = args.process(&registry).await?;
+    Ok(match value {
+        Value {
+            value: UntaggedValue::Block(block),
+            tag: block_tag,
+        } => {
+            let for_block = input.clone();
+            let input_stream = once(async { Ok(for_block) }).to_input_stream();
+
+            let result = run_block(
+                &block,
+                Arc::make_mut(&mut context),
+                input_stream,
+                &input,
+                &scope.vars,
+                &scope.env,
+            )
+            .await;
+
+            match result {
+                Ok(mut stream) => {
+                    let values = stream.drain_vec().await;
+
+                    let errors = context.get_errors();
+                    if let Some(error) = errors.first() {
+                        return Err(error.clone());
+                    }
+
+                    let result = if values.len() == 1 {
+                        let value = values
+                            .get(0)
+                            .ok_or_else(|| ShellError::unexpected("No value to insert with"))?;
+
+                        value.clone()
+                    } else if values.is_empty() {
+                        UntaggedValue::nothing().into_untagged_value()
+                    } else {
+                        UntaggedValue::table(&values).into_untagged_value()
+                    };
+
+                    match input {
+                        obj
+                        @
+                        Value {
+                            value: UntaggedValue::Row(_),
+                            ..
+                        } => match obj.insert_data_at_column_path(&field, result) {
+                            Ok(v) => OutputStream::one(ReturnSuccess::value(v)),
+                            Err(e) => OutputStream::one(Err(e)),
+                        },
+                        _ => OutputStream::one(Err(ShellError::labeled_error(
+                            "Unrecognized type in stream",
+                            "original value",
+                            block_tag.clone(),
+                        ))),
+                    }
+                }
+                Err(e) => OutputStream::one(Err(e)),
+            }
+        }
+        value => match input {
+            Value {
+                value: UntaggedValue::Primitive(Primitive::Nothing),
+                ..
+            } => match scope.it.insert_data_at_column_path(&field, value.clone()) {
+                Ok(v) => OutputStream::one(ReturnSuccess::value(v)),
+                Err(e) => OutputStream::one(Err(e)),
+            },
+            _ => match input.insert_data_at_column_path(&field, value.clone()) {
+                Ok(v) => OutputStream::one(ReturnSuccess::value(v)),
+                Err(e) => OutputStream::one(Err(e)),
+            },
+        },
+    })
+}
+
+async fn insert(
+    raw_args: CommandArgs,
+    registry: &CommandRegistry,
+) -> Result<OutputStream, ShellError> {
+    let registry = registry.clone();
+    let scope = Arc::new(raw_args.call_info.scope.clone());
+    let context = Arc::new(EvaluationContext::from_raw(&raw_args, &registry));
+    let (InsertArgs { column, value }, input) = raw_args.process(&registry).await?;
+    let value = Arc::new(value);
+    let column = Arc::new(column);
 
     Ok(input
-        .map(move |row| match row {
-            Value {
-                value: UntaggedValue::Row(_),
-                ..
-            } => match row.insert_data_at_column_path(&column, value.clone()) {
-                Ok(v) => Ok(ReturnSuccess::Value(v)),
-                Err(err) => Err(err),
-            },
+        .then(move |input| {
+            let scope = scope.clone();
+            let context = context.clone();
+            let value = value.clone();
+            let column = column.clone();
 
-            Value { tag, .. } => Err(ShellError::labeled_error(
-                "Unrecognized type in stream",
-                "original value",
-                tag,
-            )),
+            async {
+                match process_row(scope, context, input, value, column).await {
+                    Ok(s) => s,
+                    Err(e) => OutputStream::one(Err(e)),
+                }
+            }
         })
+        .flatten()
         .to_output_stream())
 }
 

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

@@ -0,0 +1,88 @@
+use crate::commands::WholeStreamCommand;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{Primitive, ReturnSuccess, Signature, SyntaxShape, UntaggedValue, Value};
+
+use num_bigint::ToBigInt;
+
+pub struct IntoInt;
+
+#[derive(Deserialize)]
+pub struct IntoIntArgs {
+    pub rest: Vec<Value>,
+}
+
+#[async_trait]
+impl WholeStreamCommand for IntoInt {
+    fn name(&self) -> &str {
+        "into-int"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("into-int").rest(SyntaxShape::Any, "the values to into-int")
+    }
+
+    fn usage(&self) -> &str {
+        "Convert value to integer"
+    }
+
+    async fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        into_int(args, registry).await
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![Example {
+            description: "Convert filesize to integer",
+            example: "echo 1kb | into-int $it | = $it / 1024",
+            result: Some(vec![UntaggedValue::int(1).into()]),
+        }]
+    }
+}
+
+async fn into_int(
+    args: CommandArgs,
+    registry: &CommandRegistry,
+) -> Result<OutputStream, ShellError> {
+    let registry = registry.clone();
+    let (args, _): (IntoIntArgs, _) = args.process(&registry).await?;
+
+    let stream = args.rest.into_iter().map(|i| match i {
+        Value {
+            value: UntaggedValue::Primitive(primitive_val),
+            tag,
+        } => match primitive_val {
+            Primitive::Filesize(size) => OutputStream::one(Ok(ReturnSuccess::Value(Value {
+                value: UntaggedValue::int(size.to_bigint().expect("Conversion should never fail.")),
+                tag,
+            }))),
+            Primitive::Int(_) => OutputStream::one(Ok(ReturnSuccess::Value(Value {
+                value: UntaggedValue::Primitive(primitive_val),
+                tag,
+            }))),
+            _ => OutputStream::one(Err(ShellError::labeled_error(
+                "Could not convert int value",
+                "original value",
+                tag,
+            ))),
+        },
+        _ => OutputStream::one(Ok(ReturnSuccess::Value(i))),
+    });
+
+    Ok(futures::stream::iter(stream).flatten().to_output_stream())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::IntoInt;
+
+    #[test]
+    fn examples_work_as_expected() {
+        use crate::examples::test as test_examples;
+
+        test_examples(IntoInt {})
+    }
+}

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

@@ -1,5 +1,5 @@
+use crate::command_registry::CommandRegistry;
 use crate::commands::WholeStreamCommand;
-use crate::context::CommandRegistry;
 use crate::prelude::*;
 use nu_errors::ShellError;
 use nu_protocol::{ColumnPath, ReturnSuccess, Signature, SyntaxShape, UntaggedValue, Value};
@@ -50,9 +50,16 @@ async fn is_empty(
     args: CommandArgs,
     registry: &CommandRegistry,
 ) -> Result<OutputStream, ShellError> {
+    let name_tag = args.call_info.name_tag.clone();
     let registry = registry.clone();
     let (IsEmptyArgs { rest }, input) = args.process(&registry).await?;
 
+    if input.is_empty() {
+        return Ok(OutputStream::one(ReturnSuccess::value(
+            UntaggedValue::boolean(true).into_value(name_tag),
+        )));
+    }
+
     Ok(input
         .map(move |value| {
             let value_tag = value.tag();
@@ -72,7 +79,6 @@ async fn is_empty(
                     (_, _) => IsEmptyFor::Value,
                 }
             } else {
-                // let no_args = vec![];
                 let mut arguments = rest.iter().rev();
                 let replacement_if_true = match arguments.next() {
                     Some(arg) => arg.clone(),
@@ -106,14 +112,14 @@ async fn is_empty(
                                 ..
                             } => {
                                 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,
-                                        )),
-                                    }
+                                    obj.replace_data_at_column_path(&field, default.clone())
+                                        .ok_or_else(|| {
+                                            ShellError::labeled_error(
+                                                "empty? could not find place to check emptiness",
+                                                "column name",
+                                                &field.tag,
+                                            )
+                                        })
                                 } else {
                                     Ok(obj)
                                 }

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

@@ -1,19 +1,19 @@
+use crate::command_registry::CommandRegistry;
 use crate::commands::WholeStreamCommand;
-use crate::context::CommandRegistry;
 use crate::prelude::*;
 use nu_errors::ShellError;
 use nu_protocol::{Signature, SyntaxShape, UntaggedValue};
 use nu_source::Tagged;
 
-pub struct Keep;
+pub struct Command;
 
 #[derive(Deserialize)]
-pub struct KeepArgs {
+pub struct Arguments {
     rows: Option<Tagged<usize>>,
 }
 
 #[async_trait]
-impl WholeStreamCommand for Keep {
+impl WholeStreamCommand for Command {
     fn name(&self) -> &str {
         "keep"
     }
@@ -22,7 +22,7 @@ impl WholeStreamCommand for Keep {
         Signature::build("keep").optional(
             "rows",
             SyntaxShape::Int,
-            "starting from the front, the number of rows to keep",
+            "Starting from the front, the number of rows to keep",
         )
     }
 
@@ -61,7 +61,7 @@ impl WholeStreamCommand for Keep {
 
 async fn keep(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStream, ShellError> {
     let registry = registry.clone();
-    let (KeepArgs { rows }, input) = args.process(&registry).await?;
+    let (Arguments { rows }, input) = args.process(&registry).await?;
     let rows_desired = if let Some(quantity) = rows {
         *quantity
     } else {
@@ -73,12 +73,12 @@ async fn keep(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStr
 
 #[cfg(test)]
 mod tests {
-    use super::Keep;
+    use super::Command;
 
     #[test]
     fn examples_work_as_expected() {
         use crate::examples::test as test_examples;
 
-        test_examples(Keep {})
+        test_examples(Command {})
     }
 }