Bump to 0.14 (#1766)

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

.azure/azure-pipelines.yml

@@ -37,6 +37,8 @@ steps:
       fi
       if [ "$(uname)" == "Darwin" ]; then
         curl https://sh.rustup.rs -sSf | sh -s -- -y --no-modify-path --default-toolchain "stable"
+        echo "Installing clippy"
+        rustup component add clippy --toolchain stable-x86_64-apple-darwin
         export PATH=$HOME/.cargo/bin:$PATH
       fi
       rustup update
@@ -59,4 +61,3 @@ steps:
   - bash: cargo fmt --all -- --check
     condition: eq(variables['style'], 'fmt')
     displayName: Lint
-    

.cargo/config

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

.circleci/config.yml

@@ -38,7 +38,7 @@ workflows:
           extra_build_args: --cache-from=quay.io/nushell/nu-base:devel
           filters:
             branches:
-              ignore: 
+              ignore:
                 - master
           before_build:
             - pull_cache

.github/workflows/docker-publish.yml

@@ -24,7 +24,7 @@ jobs:
       run: |
         cross build --target ${{ matrix.arch }} --release
         # leave only the executable file
-        rm -rd target/${{ matrix.arch }}/release/{*/*,*.d,*.rlib,.fingerprint}
+        rm -frd target/${{ matrix.arch }}/release/{*/*,*.d,*.rlib,.fingerprint}
         find . -empty -delete
     - uses: actions/upload-artifact@master
       with:
@@ -52,15 +52,15 @@ jobs:
         - glibc
         - musl
         include:
-        - { tag: alpine,           base-image: alpine,                     arch: x86_64-unknown-linux-musl, plugin: true    }
-        - { tag: slim,             base-image: 'debian:stable-slim',       arch: x86_64-unknown-linux-gnu,  plugin: true    }
-        - { tag: debian,           base-image: debian,                     arch: x86_64-unknown-linux-gnu,  plugin: true    }
-        - { tag: glibc-busybox,    base-image: 'busybox:glibc',            arch: x86_64-unknown-linux-gnu,  use-patch: true }
-        - { tag: musl-busybox,     base-image: 'busybox:musl',             arch: x86_64-unknown-linux-musl,                 }
-        - { tag: musl-distroless,  base-image: 'gcr.io/distroless/static', arch: x86_64-unknown-linux-musl,                 }
-        - { tag: glibc-distroless, base-image: 'gcr.io/distroless/cc',     arch: x86_64-unknown-linux-gnu,  use-patch: true }
-        - { tag: glibc,            base-image: scratch,                    arch: x86_64-unknown-linux-gnu,                  }
-        - { tag: musl,             base-image: scratch,                    arch: x86_64-unknown-linux-musl,                 }
+        - { tag: alpine,           base-image: alpine,                     arch: x86_64-unknown-linux-musl, plugin: true,  use-patch: false}
+        - { tag: slim,             base-image: 'debian:stable-slim',       arch: x86_64-unknown-linux-gnu,  plugin: true,  use-patch: false}
+        - { tag: debian,           base-image: debian,                     arch: x86_64-unknown-linux-gnu,  plugin: true,  use-patch: false}
+        - { tag: glibc-busybox,    base-image: 'busybox:glibc',            arch: x86_64-unknown-linux-gnu,  plugin: false, use-patch: true }
+        - { tag: musl-busybox,     base-image: 'busybox:musl',             arch: x86_64-unknown-linux-musl, plugin: false, use-patch: false}
+        - { tag: musl-distroless,  base-image: 'gcr.io/distroless/static', arch: x86_64-unknown-linux-musl, plugin: false, use-patch: false}
+        - { tag: glibc-distroless, base-image: 'gcr.io/distroless/cc',     arch: x86_64-unknown-linux-gnu,  plugin: false, use-patch: true }
+        - { tag: glibc,            base-image: scratch,                    arch: x86_64-unknown-linux-gnu,  plugin: false, use-patch: false}
+        - { tag: musl,             base-image: scratch,                    arch: x86_64-unknown-linux-musl, plugin: false, use-patch: false}
     steps:
     - uses: actions/checkout@v1
     - uses: actions/download-artifact@master

.gitignore

@@ -11,3 +11,12 @@ debian/debhelper-build-stamp
 debian/files
 debian/nu.substvars
 debian/nu/
+
+# macOS junk
+.DS_Store
+
+# JetBrains' IDE items
+.idea/*
+
+# VSCode's IDE items
+.vscode/*

.gitpod.Dockerfile

@@ -6,4 +6,9 @@ RUN sudo apt-get update && \
     sudo apt-get install -y \
         libssl-dev \
         libxcb-composite0-dev \
-        pkg-config
+        pkg-config \
+        libpython3.6 \
+        rust-lldb \
+    && sudo rm -rf /var/lib/apt/lists/*
+
+ENV RUST_LLDB=/usr/bin/lldb-8

.gitpod.yml

@@ -1,23 +1,19 @@
 image:
   file: .gitpod.Dockerfile
 tasks:
-  - init: cargo install --path . --force --features=stable
+  - name: Clippy
+    init: cargo clippy --all --features=stable -- -D clippy::result_unwrap_used -D clippy::option_unwrap_used
+  - name: Testing
+    init: cargo test --all --features=stable,test-bins
+  - name: Build
+    init: cargo build --features=stable
+  - name: Nu
+    init: cargo install --path . --features=stable
     command: nu
 github:
   prebuilds:
-    # enable for the master/default branch (defaults to true)
-    master: true
-    # enable for all branches in this repo (defaults to false)
     branches: true
-    # enable for pull requests coming from this repo (defaults to true)
-    pullRequests: true
-    # enable for pull requests coming from forks (defaults to false)
     pullRequestsFromForks: true
-    # add a "Review in Gitpod" button as a comment to pull requests (defaults to true)
-    addComment: true
-    # add a "Review in Gitpod" button to pull requests (defaults to false)
-    addBadge: false
-    # add a label once the prebuild is ready to pull requests (defaults to false)
     addLabel: prebuilt-in-gitpod
 vscode:
   extensions:
@@ -25,5 +21,5 @@ vscode:
     - Swellaby.vscode-rust-test-adapter@0.11.0:Xg+YeZZQiVpVUsIkH+uiiw==
     - serayuzgur.crates@0.4.7:HMkoguLcXp9M3ud7ac3eIw==
     - belfz.search-crates-io@1.2.1:kSLnyrOhXtYPjQpKnMr4eQ==
-    - vadimcn.vscode-lldb@1.4.5:lwHCNwtm0kmOBXeQUIPGMQ==
     - bungcip.better-toml@0.3.2:3QfgGxxYtGHfJKQU7H0nEw==
+    - webfreak.debug@0.24.0:1zVcRsAhewYEX3/A9xjMNw==

.theia/launch.json

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

.theia/tasks.json

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

CONTRIBUTING.md

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

Cargo.toml

@@ -1,8 +1,8 @@
 [package]
 name = "nu"
-version = "0.11.0"
-authors = ["Yehuda Katz <wycats@gmail.com>", "Jonathan Turner <jonathan.d.turner@gmail.com>", "Andrés N. Robalino <andres@androbtech.com>"]
-description = "A shell for the GitHub era"
+version = "0.14.0"
+authors = ["The Nu Project Contributors"]
+description = "A new type of shell"
 license = "MIT"
 edition = "2018"
 readme = "README.md"
@@ -18,31 +18,29 @@ members = ["crates/*/"]
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-nu-cli = { version = "0.11.0", path = "./crates/nu-cli" }
-nu-source = { version = "0.11.0", path = "./crates/nu-source" }
-nu-plugin = { version = "0.11.0", path = "./crates/nu-plugin" }
-nu-protocol = { version = "0.11.0", path = "./crates/nu-protocol" }
-nu-errors = { version = "0.11.0", path = "./crates/nu-errors" }
-nu-parser = { version = "0.11.0", path = "./crates/nu-parser" }
-nu-value-ext = { version = "0.11.0", path = "./crates/nu-value-ext" }
-nu_plugin_average = { version = "0.11.0", path = "./crates/nu_plugin_average", optional=true }
-nu_plugin_binaryview = { version = "0.11.0", path = "./crates/nu_plugin_binaryview", optional=true }
-nu_plugin_fetch = { version = "0.11.0", path = "./crates/nu_plugin_fetch", optional=true }
-nu_plugin_inc = { version = "0.11.0", path = "./crates/nu_plugin_inc", optional=true }
-nu_plugin_match = { version = "0.11.0", path = "./crates/nu_plugin_match", optional=true }
-nu_plugin_post = { version = "0.11.0", path = "./crates/nu_plugin_post", optional=true }
-nu_plugin_ps = { version = "0.11.0", path = "./crates/nu_plugin_ps", optional=true }
-nu_plugin_str = { version = "0.11.0", path = "./crates/nu_plugin_str", optional=true }
-nu_plugin_sum = { version = "0.11.0", path = "./crates/nu_plugin_sum", optional=true }
-nu_plugin_sys = { version = "0.11.0", path = "./crates/nu_plugin_sys", optional=true }
-nu_plugin_textview = { version = "0.11.0", path = "./crates/nu_plugin_textview", optional=true }
-nu_plugin_tree = { version = "0.11.0", path = "./crates/nu_plugin_tree", optional=true }
-nu-macros = { version = "0.11.0", path = "./crates/nu-macros" }
+nu-cli = { version = "0.14.0", path = "./crates/nu-cli" }
+nu-source = { version = "0.14.0", path = "./crates/nu-source" }
+nu-plugin = { version = "0.14.0", path = "./crates/nu-plugin" }
+nu-protocol = { version = "0.14.0", path = "./crates/nu-protocol" }
+nu-errors = { version = "0.14.0", path = "./crates/nu-errors" }
+nu-parser = { version = "0.14.0", path = "./crates/nu-parser" }
+nu-value-ext = { version = "0.14.0", path = "./crates/nu-value-ext" }
+nu_plugin_average = { version = "0.14.0", path = "./crates/nu_plugin_average", optional=true }
+nu_plugin_binaryview = { version = "0.14.0", path = "./crates/nu_plugin_binaryview", optional=true }
+nu_plugin_fetch = { version = "0.14.0", path = "./crates/nu_plugin_fetch", optional=true }
+nu_plugin_inc = { version = "0.14.0", path = "./crates/nu_plugin_inc", optional=true }
+nu_plugin_match = { version = "0.14.0", path = "./crates/nu_plugin_match", optional=true }
+nu_plugin_post = { version = "0.14.0", path = "./crates/nu_plugin_post", optional=true }
+nu_plugin_ps = { version = "0.14.0", path = "./crates/nu_plugin_ps", optional=true }
+nu_plugin_start = { version = "0.1.0", path = "./crates/nu_plugin_start", optional=true }
+nu_plugin_str = { version = "0.14.0", path = "./crates/nu_plugin_str", optional=true }
+nu_plugin_sys = { version = "0.14.0", path = "./crates/nu_plugin_sys", optional=true }
+nu_plugin_textview = { version = "0.14.0", path = "./crates/nu_plugin_textview", optional=true }
+nu_plugin_tree = { version = "0.14.0", path = "./crates/nu_plugin_tree", optional=true }
 
-crossterm = { version = "0.16.0", optional = true }
-onig_sys = { version = "=69.1.0", optional = true }
+crossterm = { version = "0.17.2", optional = true }
 semver = { version = "0.9.0", optional = true }
-syntect = { version = "3.2.0", optional = true }
+syntect = { version = "4.1", default-features = false, features = ["default-fancy"], optional = true}
 url = { version = "2.1.1", optional = true }
 
 clap = "2.33.0"
@@ -53,23 +51,22 @@ log = "0.4.8"
 pretty_env_logger = "0.4.0"
 
 [dev-dependencies]
-pretty_assertions = "0.6.1"
-nu-test-support = { version = "0.11.0", path = "./crates/nu-test-support" }
+nu-test-support = { version = "0.14.0", path = "./crates/nu-test-support" }
 
 [build-dependencies]
 toml = "0.5.6"
-serde = { version = "1.0.104", features = ["derive"] }
-nu-build = { version = "0.11.0", path = "./crates/nu-build" }
+serde = { version = "1.0.106", features = ["derive"] }
+nu-build = { version = "0.14.0", path = "./crates/nu-build" }
 
 [features]
 # Test executables
 test-bins = []
 
 default = ["sys", "ps", "textview", "inc", "str"]
-stable = ["default", "starship-prompt", "binaryview", "match", "tree", "average", "sum", "post", "fetch", "clipboard-cli"]
+stable = ["default", "starship-prompt", "binaryview", "match", "tree", "average", "post", "fetch", "clipboard-cli", "trash-support", "start"]
 
 # Default
-textview = ["crossterm", "syntect", "onig_sys", "url", "nu_plugin_textview"]
+textview = ["crossterm", "syntect", "url", "nu_plugin_textview"]
 sys = ["nu_plugin_sys"]
 ps = ["nu_plugin_ps"]
 inc = ["semver", "nu_plugin_inc"]
@@ -81,12 +78,13 @@ binaryview = ["nu_plugin_binaryview"]
 fetch = ["nu_plugin_fetch"]
 match = ["nu_plugin_match"]
 post = ["nu_plugin_post"]
-sum = ["nu_plugin_sum"]
 trace = ["nu-parser/trace"]
 tree = ["nu_plugin_tree"]
+start = ["nu_plugin_start"]
 
 clipboard-cli = ["nu-cli/clipboard-cli"]
 starship-prompt = ["nu-cli/starship-prompt"]
+trash-support = ["nu-cli/trash-support"]
 
 [[bin]]
 name = "fail"
@@ -167,16 +165,16 @@ name = "nu_plugin_stable_post"
 path = "src/plugins/nu_plugin_stable_post.rs"
 required-features = ["post"]
 
-[[bin]]
-name = "nu_plugin_stable_sum"
-path = "src/plugins/nu_plugin_stable_sum.rs"
-required-features = ["sum"]
-
 [[bin]]
 name = "nu_plugin_stable_tree"
 path = "src/plugins/nu_plugin_stable_tree.rs"
 required-features = ["tree"]
 
+[[bin]]
+name = "nu_plugin_stable_start"
+path = "src/plugins/nu_plugin_stable_start.rs"
+required-features = ["start"]
+
 # Main nu binary
 [[bin]]
 name = "nu"

README.md

@@ -13,15 +13,22 @@ A new type of shell.
 
 # Status
 
-This project has reached a minimum-viable product level of quality. While contributors dogfood it as their daily driver, it may be unstable for some commands. Future releases will work to fill out missing features and improve stability. Its design is also subject to change as it matures.
+This project has reached a minimum-viable product level of quality.
+While contributors dogfood it as their daily driver, it may be unstable for some commands.
+Future releases will work to fill out missing features and improve stability.
+Its design is also subject to change as it matures.
 
-Nu comes with a set of built-in commands (listed below). If a command is unknown, the command will shell-out and execute it (using cmd on Windows or bash on Linux and macOS), correctly passing through stdin, stdout, and stderr, so things like your daily git workflows and even `vim` will work just fine.
+Nu comes with a set of built-in commands (listed below).
+If a command is unknown, the command will shell-out and execute it (using cmd on Windows or bash on Linux and macOS), correctly passing through stdin, stdout, and stderr, so things like your daily git workflows and even `vim` will work just fine.
 
 # Learning more
 
-There are a few good resources to learn about Nu. There is a [book](https://www.nushell.sh/book/) about Nu that is currently in progress. The book focuses on using Nu and its core concepts.
+There are a few good resources to learn about Nu.
+There is a [book](https://www.nushell.sh/book/) about Nu that is currently in progress.
+The book focuses on using Nu and its core concepts.
 
-If you're a developer who would like to contribute to Nu, we're also working on a [book for developers](https://www.nushell.sh/contributor-book/) to help you get started. There are also [good first issues](https://github.com/nushell/nushell/issues?q=is%3Aopen+is%3Aissue+label%3A%22good+first+issue%22) to help you dive in.
+If you're a developer who would like to contribute to Nu, we're also working on a [book for developers](https://www.nushell.sh/contributor-book/) to help you get started.
+There are also [good first issues](https://github.com/nushell/nushell/issues?q=is%3Aopen+is%3Aissue+label%3A%22good+first+issue%22) to help you dive in.
 
 We also have an active [Discord](https://discord.gg/NtAbbGn) and [Twitter](https://twitter.com/nu_shell) if you'd like to come and chat with us.
 
@@ -63,6 +70,16 @@ cargo build --workspace --features=stable
 
 ## Docker
 
+### Quickstart
+
+Want to try Nu right away? Execute the following to get started.
+
+```bash
+docker run -it quay.io/nushell/nu:latest
+```
+
+### Guide
+
 If you want to pull a pre-built container, you can browse tags for the [nushell organization](https://quay.io/organization/nushell)
 on Quay.io. Pulling a container would come down to:
 
@@ -107,11 +124,18 @@ The second container is a bit smaller if the size is important to you.
 
 # Philosophy
 
-Nu draws inspiration from projects like PowerShell, functional programming languages, and modern CLI tools. Rather than thinking of files and services as raw streams of text, Nu looks at each input as something with structure. For example, when you list the contents of a directory, what you get back is a table of rows, where each row represents an item in that directory. These values can be piped through a series of steps, in a series of commands called a 'pipeline'.
+Nu draws inspiration from projects like PowerShell, functional programming languages, and modern CLI tools.
+Rather than thinking of files and services as raw streams of text, Nu looks at each input as something with structure.
+For example, when you list the contents of a directory, what you get back is a table of rows, where each row represents an item in that directory.
+These values can be piped through a series of steps, in a series of commands called a 'pipeline'.
 
 ## Pipelines
 
-In Unix, it's common to pipe between commands to split up a sophisticated command over multiple steps. Nu takes this a step further and builds heavily on the idea of _pipelines_. Just as the Unix philosophy, Nu allows commands to output from stdout and read from stdin. Additionally, commands can output structured data (you can think of this as a third kind of stream). Commands that work in the pipeline fit into one of three categories:
+In Unix, it's common to pipe between commands to split up a sophisticated command over multiple steps.
+Nu takes this a step further and builds heavily on the idea of _pipelines_.
+Just as the Unix philosophy, Nu allows commands to output from stdout and read from stdin.
+Additionally, commands can output structured data (you can think of this as a third kind of stream).
+Commands that work in the pipeline fit into one of three categories:
 
 * Commands that produce a stream (eg, `ls`)
 * Commands that filter a stream (eg, `where type == "Directory"`)
@@ -135,13 +159,15 @@ Commands are separated by the pipe symbol (`|`) to denote a pipeline flowing lef
 ────┴───────────┴───────────┴──────────┴────────┴──────────────┴────────────────
 ```
 
-Because most of the time you'll want to see the output of a pipeline, `autoview` is assumed. We could have also written the above:
+Because most of the time you'll want to see the output of a pipeline, `autoview` is assumed.
+We could have also written the above:
 
 ```
 /home/jonathan/Source/nushell(master)> ls | where type == Directory
 ```
 
-Being able to use the same commands and compose them differently is an important philosophy in Nu. For example, we could use the built-in `ps` command as well to get a list of the running processes, using the same `where` as above.
+Being able to use the same commands and compose them differently is an important philosophy in Nu.
+For example, we could use the built-in `ps` command as well to get a list of the running processes, using the same `where` as above.
 
 ```text
 /home/jonathan/Source/nushell(master)> ps | where cpu > 0
@@ -157,7 +183,8 @@ Being able to use the same commands and compose them differently is an important
 
 ## Opening files
 
-Nu can load file and URL contents as raw text or as structured data (if it recognizes the format). For example, you can load a .toml file as structured data and explore it:
+Nu can load file and URL contents as raw text or as structured data (if it recognizes the format).
+For example, you can load a .toml file as structured data and explore it:
 
 ```
 /home/jonathan/Source/nushell(master)> open Cargo.toml
@@ -210,19 +237,26 @@ To set one of these variables, you can use `config --set`. For example:
 
 ## Shells
 
-Nu will work inside of a single directory and allow you to navigate around your filesystem by default. Nu also offers a way of adding additional working directories that you can jump between, allowing you to work in multiple directories at the same time.
+Nu will work inside of a single directory and allow you to navigate around your filesystem by default.
+Nu also offers a way of adding additional working directories that you can jump between, allowing you to work in multiple directories at the same time.
 
-To do so, use the `enter` command, which will allow you create a new "shell" and enter it at the specified path. You can toggle between this new shell and the original shell with the `p` (for previous) and `n` (for next), allowing you to navigate around a ring buffer of shells. Once you're done with a shell, you can `exit` it and remove it from the ring buffer.
+To do so, use the `enter` command, which will allow you create a new "shell" and enter it at the specified path.
+You can toggle between this new shell and the original shell with the `p` (for previous) and `n` (for next), allowing you to navigate around a ring buffer of shells.
+Once you're done with a shell, you can `exit` it and remove it from the ring buffer.
 
 Finally, to get a list of all the current shells, you can use the `shells` command.
 
 ## Plugins
 
-Nu supports plugins that offer additional functionality to the shell and follow the same structured data model that built-in commands use. This allows you to extend nu for your needs.
+Nu supports plugins that offer additional functionality to the shell and follow the same structured data model that built-in commands use.
+This allows you to extend nu for your needs.
 
 There are a few examples in the `plugins` directory.
 
-Plugins are binaries that are available in your path and follow a `nu_plugin_*` naming convention. These binaries interact with nu via a simple JSON-RPC protocol where the command identifies itself and passes along its configuration, which then makes it available for use. If the plugin is a filter, data streams to it one element at a time, and it can stream data back in return via stdin/stdout. If the plugin is a sink, it is given the full vector of final data and is given free reign over stdin/stdout to use as it pleases.
+Plugins are binaries that are available in your path and follow a `nu_plugin_*` naming convention.
+These binaries interact with nu via a simple JSON-RPC protocol where the command identifies itself and passes along its configuration, which then makes it available for use.
+If the plugin is a filter, data streams to it one element at a time, and it can stream data back in return via stdin/stdout.
+If the plugin is a sink, it is given the full vector of final data and is given free reign over stdin/stdout to use as it pleases.
 
 # Goals
 
@@ -240,9 +274,13 @@ Nu adheres closely to a set of goals that make up its design philosophy. As feat
 
 # Commands
 
-You can find a list of Nu commands, complete with documentation, in [quick command references](https://www.nushell.sh/documentation.html#quick-command-references). 
+You can find a list of Nu commands, complete with documentation, in [quick command references](https://www.nushell.sh/documentation.html#quick-command-references).
+
+# Contributing
+
+See [Contributing](CONTRIBUTING.md) for details.
 
 # License
 
-The project is made available under the MIT license. See "LICENSE" for more information.
+The project is made available under the MIT license. See the `LICENSE` file for more information.
 

crates/nu-build/Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "nu-build"
-version = "0.11.0"
-authors = ["Yehuda Katz <wycats@gmail.com>", "Jonathan Turner <jonathan.d.turner@gmail.com>", "Andrés N. Robalino <andres@androbtech.com>"]
+version = "0.14.0"
+authors = ["The Nu Project Contributors"]
 edition = "2018"
 description = "Core build system for nushell"
 license = "MIT"
@@ -10,7 +10,7 @@ license = "MIT"
 doctest = false
 
 [dependencies]
-serde = { version = "1.0.103", features = ["derive"] }
+serde = { version = "1.0.106", features = ["derive"] }
 lazy_static = "1.4.0"
-serde_json = "1.0.44"
-toml = "0.5.5"
+serde_json = "1.0.51"
+toml = "0.5.6"

crates/nu-cli/Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "nu-cli"
-version = "0.11.0"
-authors = ["Yehuda Katz <wycats@gmail.com>", "Jonathan Turner <jonathan.d.turner@gmail.com>", "Andrés N. Robalino <andres@androbtech.com>"]
+version = "0.14.0"
+authors = ["The Nu Project Contributors"]
 description = "CLI for nushell"
 edition = "2018"
 license = "MIT"
@@ -10,21 +10,21 @@ license = "MIT"
 doctest = false
 
 [dependencies]
-nu-source = { version = "0.11.0", path = "../nu-source" }
-nu-plugin = { version = "0.11.0", path = "../nu-plugin" }
-nu-protocol = { version = "0.11.0", path = "../nu-protocol" }
-nu-errors = { version = "0.11.0", path = "../nu-errors" }
-nu-parser = { version = "0.11.0", path = "../nu-parser" }
-nu-value-ext = { version = "0.11.0", path = "../nu-value-ext" }
-nu-macros = { version = "0.11.0", path = "../nu-macros" }
-nu-test-support = { version = "0.11.0", path = "../nu-test-support" }
+nu-source = { version = "0.14.0", path = "../nu-source" }
+nu-plugin = { version = "0.14.0", path = "../nu-plugin" }
+nu-protocol = { version = "0.14.0", path = "../nu-protocol" }
+nu-errors = { version = "0.14.0", path = "../nu-errors" }
+nu-parser = { version = "0.14.0", path = "../nu-parser" }
+nu-value-ext = { version = "0.14.0", path = "../nu-value-ext" }
+nu-test-support = { version = "0.14.0", path = "../nu-test-support" }
+
 
 ansi_term = "0.12.1"
 app_dirs = "1.2.1"
 async-stream = "0.2"
-base64 = "0.11"
+base64 = "0.12.0"
 bigdecimal = { version = "0.1.0", features = ["serde"] }
-bson = { version = "0.14.0", features = ["decimal128"] }
+bson = { version = "0.14.1", features = ["decimal128"] }
 byte-unit = "3.0.3"
 bytes = "0.5.4"
 calamine = "0.16"
@@ -36,24 +36,24 @@ ctrlc = "3.1.4"
 derive-new = "0.5.8"
 dirs = "2.0.2"
 dunce = "1.0.0"
-filesize = "0.1.0"
+eml-parser = "0.1.0"
+filesize = "0.2.0"
 futures = { version = "0.3", features = ["compat", "io-compat"] }
 futures-util = "0.3.4"
 futures_codec = "0.4"
 getset = "0.1.0"
-git2 = { version = "0.11.0", default_features = false }
+git2 = { version = "0.13.1", default_features = false }
 glob = "0.3.0"
 hex = "0.4"
-ichwh = "0.3"
+htmlescape = "0.3.1"
+ical = "0.6.*"
+ichwh = "0.3.4"
 indexmap = { version = "1.3.2", features = ["serde-1"] }
 itertools = "0.9.0"
 language-reporting = "0.4.0"
 log = "0.4.8"
 meval = "0.2"
 natural = "0.5.0"
-nom = "5.0.1"
-nom-tracable = "0.4.1"
-nom_locate = "1.0.0"
 num-bigint = { version = "0.2.6", features = ["serde"] }
 num-traits = "0.2.11"
 parking_lot = "0.10.0"
@@ -65,13 +65,13 @@ ptree = {version = "0.2" }
 query_interface = "0.3.5"
 rand = "0.7"
 regex = "1"
-roxmltree = "0.9.1"
-rustyline = "6.0.0"
-serde = { version = "1.0.104", features = ["derive"] }
+roxmltree = "0.10.1"
+rustyline = "6.1.2"
+serde = { version = "1.0.106", features = ["derive"] }
 serde-hjson = "0.9.1"
 serde_bytes = "0.11.3"
 serde_ini = "0.2.0"
-serde_json = "1.0.48"
+serde_json = "1.0.51"
 serde_urlencoded = "0.6.1"
 serde_yaml = "0.8"
 shellexpand = "2.0.0"
@@ -81,29 +81,32 @@ term = "0.5.2"
 termcolor = "1.1.0"
 textwrap = {version = "0.11.0", features = ["term_size"]}
 toml = "0.5.6"
-trash = "1.0.0"
 typetag = "0.1.4"
 umask = "0.1"
 unicode-xid = "0.2.0"
-which = "3.1.1"
+which = "3"
 
+trash = { version = "1.0.0", optional = true }
 clipboard = { version = "0.5", optional = true }
-starship = { version = "0.37.0", optional = true }
+starship = { version = "0.39.0", optional = true }
+rayon = "1.3.0"
 
 [target.'cfg(unix)'.dependencies]
-users = "0.9"
+users = "0.10.0"
 
 [dependencies.rusqlite]
-version = "0.21.0"
+version = "0.22.0"
 features = ["bundled", "blob"]
 
-[dev-dependencies]
-pretty_assertions = "0.6.1"
-
 [build-dependencies]
-nu-build = { version = "0.11.0", path = "../nu-build" }
+nu-build = { version = "0.14.0", path = "../nu-build" }
+
+[dev-dependencies]
+quickcheck = "0.9"
+quickcheck_macros = "0.9"
 
 [features]
 stable = []
 starship-prompt = ["starship"]
 clipboard-cli = ["clipboard"]
+trash-support = ["trash"]

crates/nu-cli/src/cli.rs

@@ -1,19 +1,20 @@
+use crate::commands::classified::block::run_block;
 use crate::commands::classified::external::{MaybeTextCodec, StringOrBinary};
-use crate::commands::classified::pipeline::run_pipeline;
 use crate::commands::plugin::JsonRpc;
 use crate::commands::plugin::{PluginCommand, PluginSink};
 use crate::commands::whole_stream_command;
 use crate::context::Context;
 #[cfg(not(feature = "starship-prompt"))]
 use crate::git::current_branch;
+use crate::path::canonicalize;
 use crate::prelude::*;
 use futures_codec::FramedRead;
 
 use nu_errors::ShellError;
-use nu_parser::{ClassifiedPipeline, PipelineShape, SpannedToken, TokensIterator};
-use nu_protocol::{Primitive, ReturnSuccess, Signature, UntaggedValue, Value};
+use nu_protocol::hir::{ClassifiedCommand, Expression, InternalCommand, Literal, NamedArguments};
+use nu_protocol::{Primitive, ReturnSuccess, Scope, Signature, UntaggedValue, Value};
 
-use log::{debug, log_enabled, trace};
+use log::{debug, trace};
 use rustyline::error::ReadlineError;
 use rustyline::{
     self, config::Configurer, config::EditMode, At, Cmd, ColorMode, CompletionType, Config, Editor,
@@ -22,9 +23,11 @@ use rustyline::{
 use std::error::Error;
 use std::io::{BufRead, BufReader, Write};
 use std::iter::Iterator;
-use std::path::PathBuf;
+use std::path::{Path, PathBuf};
 use std::sync::atomic::Ordering;
 
+use rayon::prelude::*;
+
 fn load_plugin(path: &std::path::Path, context: &mut Context) -> Result<(), ShellError> {
     let mut child = std::process::Command::new(path)
         .stdin(std::process::Stdio::piped())
@@ -131,62 +134,60 @@ pub fn load_plugins(context: &mut Context) -> Result<(), ShellError> {
 
         pattern.push(std::path::Path::new("nu_plugin_[a-z0-9][a-z0-9]*"));
 
-        match glob::glob_with(&pattern.to_string_lossy(), opts) {
-            Err(_) => {}
-            Ok(binaries) => {
-                for bin in binaries.filter_map(Result::ok) {
-                    if !bin.is_file() {
-                        continue;
+        let plugs: Vec<_> = glob::glob_with(&pattern.to_string_lossy(), opts)?
+            .filter_map(|x| x.ok())
+            .collect();
+
+        let _failures: Vec<_> = plugs
+            .par_iter()
+            .map(|path| {
+                let bin_name = {
+                    if let Some(name) = path.file_name() {
+                        match name.to_str() {
+                            Some(raw) => raw,
+                            None => "",
+                        }
+                    } else {
+                        ""
+                    }
+                };
+
+                let is_valid_name = {
+                    #[cfg(windows)]
+                    {
+                        bin_name
+                            .chars()
+                            .all(|c| c.is_ascii_alphanumeric() || c == '_' || c == '.')
                     }
 
-                    let bin_name = {
-                        if let Some(name) = bin.file_name() {
-                            match name.to_str() {
-                                Some(raw) => raw,
-                                None => continue,
-                            }
-                        } else {
-                            continue;
-                        }
-                    };
-
-                    let is_valid_name = {
-                        #[cfg(windows)]
-                        {
-                            bin_name
-                                .chars()
-                                .all(|c| c.is_ascii_alphanumeric() || c == '_' || c == '.')
-                        }
-
-                        #[cfg(not(windows))]
-                        {
-                            bin_name
-                                .chars()
-                                .all(|c| c.is_ascii_alphanumeric() || c == '_')
-                        }
-                    };
-
-                    let is_executable = {
-                        #[cfg(windows)]
-                        {
-                            bin_name.ends_with(".exe") || bin_name.ends_with(".bat")
-                        }
-
-                        #[cfg(not(windows))]
-                        {
-                            true
-                        }
-                    };
-
-                    if is_valid_name && is_executable {
-                        trace!("Trying {:?}", bin.display());
-
-                        // we are ok if this plugin load fails
-                        let _ = load_plugin(&bin, context);
+                    #[cfg(not(windows))]
+                    {
+                        bin_name
+                            .chars()
+                            .all(|c| c.is_ascii_alphanumeric() || c == '_')
                     }
+                };
+
+                let is_executable = {
+                    #[cfg(windows)]
+                    {
+                        bin_name.ends_with(".exe") || bin_name.ends_with(".bat")
+                    }
+
+                    #[cfg(not(windows))]
+                    {
+                        true
+                    }
+                };
+
+                if is_valid_name && is_executable {
+                    trace!("Trying {:?}", path.display());
+
+                    // we are ok if this plugin load fails
+                    let _ = load_plugin(&path, &mut context.clone());
                 }
-            }
-        }
+            })
+            .collect();
     }
 
     Ok(())
@@ -223,7 +224,8 @@ fn create_default_starship_config() -> Option<toml::Value> {
 }
 
 pub fn create_default_context(
-    syncer: &mut crate::env::environment_syncer::EnvironmentSyncer,
+    syncer: &mut crate::EnvironmentSyncer,
+    interactive: bool,
 ) -> Result<Context, Box<dyn Error>> {
     syncer.load_environment();
 
@@ -237,27 +239,30 @@ pub fn create_default_context(
         context.add_commands(vec![
             // System/file operations
             whole_stream_command(Pwd),
-            per_item_command(Ls),
-            per_item_command(Du),
+            whole_stream_command(Ls),
+            whole_stream_command(Du),
             whole_stream_command(Cd),
-            per_item_command(Remove),
-            per_item_command(Open),
+            whole_stream_command(Remove),
+            whole_stream_command(Open),
             whole_stream_command(Config),
-            per_item_command(Help),
-            per_item_command(History),
+            whole_stream_command(Help),
+            whole_stream_command(History),
             whole_stream_command(Save),
-            per_item_command(Touch),
-            per_item_command(Cpy),
+            whole_stream_command(Touch),
+            whole_stream_command(Cpy),
             whole_stream_command(Date),
-            per_item_command(Calc),
-            per_item_command(Mkdir),
-            per_item_command(Move),
-            per_item_command(Kill),
+            whole_stream_command(Cal),
+            whole_stream_command(Calc),
+            whole_stream_command(Mkdir),
+            whole_stream_command(Move),
+            whole_stream_command(Kill),
             whole_stream_command(Version),
             whole_stream_command(Clear),
             whole_stream_command(What),
             whole_stream_command(Which),
             whole_stream_command(Debug),
+            whole_stream_command(Alias),
+            whole_stream_command(WithEnv),
             // Statistics
             whole_stream_command(Size),
             whole_stream_command(Count),
@@ -267,7 +272,7 @@ pub fn create_default_context(
             whole_stream_command(Next),
             whole_stream_command(Previous),
             whole_stream_command(Shells),
-            per_item_command(Enter),
+            whole_stream_command(Enter),
             whole_stream_command(Exit),
             // Viewers
             whole_stream_command(Autoview),
@@ -277,14 +282,14 @@ pub fn create_default_context(
             whole_stream_command(SplitRow),
             whole_stream_command(Lines),
             whole_stream_command(Trim),
-            per_item_command(Echo),
-            per_item_command(Parse),
+            whole_stream_command(Echo),
+            whole_stream_command(Parse),
             // Column manipulation
             whole_stream_command(Reject),
-            whole_stream_command(Pick),
+            whole_stream_command(Select),
             whole_stream_command(Get),
-            per_item_command(Edit),
-            per_item_command(Insert),
+            whole_stream_command(Update),
+            whole_stream_command(Insert),
             whole_stream_command(SplitBy),
             // Row manipulation
             whole_stream_command(Reverse),
@@ -294,34 +299,49 @@ pub fn create_default_context(
             whole_stream_command(GroupBy),
             whole_stream_command(First),
             whole_stream_command(Last),
-            whole_stream_command(Skip),
             whole_stream_command(Nth),
-            per_item_command(Format),
-            per_item_command(Where),
+            whole_stream_command(Drop),
+            whole_stream_command(Format),
+            whole_stream_command(Where),
             whole_stream_command(Compact),
             whole_stream_command(Default),
+            whole_stream_command(Skip),
+            whole_stream_command(SkipUntil),
             whole_stream_command(SkipWhile),
+            whole_stream_command(Keep),
+            whole_stream_command(KeepUntil),
+            whole_stream_command(KeepWhile),
             whole_stream_command(Range),
             whole_stream_command(Rename),
             whole_stream_command(Uniq),
+            whole_stream_command(Each),
+            whole_stream_command(IsEmpty),
             // Table manipulation
+            whole_stream_command(Merge),
             whole_stream_command(Shuffle),
             whole_stream_command(Wrap),
             whole_stream_command(Pivot),
+            whole_stream_command(Headers),
             // Data processing
             whole_stream_command(Histogram),
+            whole_stream_command(Sum),
             // File format output
+            whole_stream_command(To),
             whole_stream_command(ToBSON),
             whole_stream_command(ToCSV),
+            whole_stream_command(ToHTML),
             whole_stream_command(ToJSON),
             whole_stream_command(ToSQLite),
             whole_stream_command(ToDB),
+            whole_stream_command(ToMarkdown),
             whole_stream_command(ToTOML),
             whole_stream_command(ToTSV),
             whole_stream_command(ToURL),
             whole_stream_command(ToYAML),
             // File format input
+            whole_stream_command(From),
             whole_stream_command(FromCSV),
+            whole_stream_command(FromEML),
             whole_stream_command(FromTSV),
             whole_stream_command(FromSSV),
             whole_stream_command(FromINI),
@@ -336,6 +356,10 @@ pub fn create_default_context(
             whole_stream_command(FromXML),
             whole_stream_command(FromYAML),
             whole_stream_command(FromYML),
+            whole_stream_command(FromIcs),
+            whole_stream_command(FromVcf),
+            // "Private" commands (not intended to be accessed directly)
+            whole_stream_command(RunExternalCommand { interactive }),
         ]);
 
         cfg_if::cfg_if! {
@@ -360,12 +384,66 @@ pub fn create_default_context(
     Ok(context)
 }
 
+pub async fn run_vec_of_pipelines(
+    pipelines: Vec<String>,
+    redirect_stdin: bool,
+) -> Result<(), Box<dyn Error>> {
+    let mut syncer = crate::EnvironmentSyncer::new();
+    let mut context = create_default_context(&mut syncer, false)?;
+
+    let _ = crate::load_plugins(&mut context);
+
+    let cc = context.ctrl_c.clone();
+
+    ctrlc::set_handler(move || {
+        cc.store(true, Ordering::SeqCst);
+    })
+    .expect("Error setting Ctrl-C handler");
+
+    if context.ctrl_c.load(Ordering::SeqCst) {
+        context.ctrl_c.store(false, Ordering::SeqCst);
+    }
+
+    // before we start up, let's run our startup commands
+    if let Ok(config) = crate::data::config::config(Tag::unknown()) {
+        if let Some(commands) = config.get("startup") {
+            match commands {
+                Value {
+                    value: UntaggedValue::Table(pipelines),
+                    ..
+                } => {
+                    for pipeline in pipelines {
+                        if let Ok(pipeline_string) = pipeline.as_string() {
+                            let _ = run_pipeline_standalone(
+                                pipeline_string,
+                                false,
+                                &mut context,
+                                false,
+                            )
+                            .await;
+                        }
+                    }
+                }
+                _ => {
+                    println!("warning: expected a table of pipeline strings as startup commands");
+                }
+            }
+        }
+    }
+
+    for pipeline in pipelines {
+        run_pipeline_standalone(pipeline, redirect_stdin, &mut context, true).await?;
+    }
+    Ok(())
+}
+
 pub async fn run_pipeline_standalone(
     pipeline: String,
     redirect_stdin: bool,
     context: &mut Context,
+    exit_on_error: bool,
 ) -> Result<(), Box<dyn Error>> {
-    let line = process_line(Ok(pipeline), context, redirect_stdin).await;
+    let line = process_line(Ok(pipeline), context, redirect_stdin, false).await;
 
     match line {
         LineResult::Success(line) => {
@@ -381,7 +459,7 @@ pub async fn run_pipeline_standalone(
             };
 
             context.maybe_print_errors(Text::from(line));
-            if error_code != 0 {
+            if error_code != 0 && exit_on_error {
                 std::process::exit(error_code);
             }
         }
@@ -392,7 +470,9 @@ pub async fn run_pipeline_standalone(
             });
 
             context.maybe_print_errors(Text::from(line));
-            std::process::exit(1);
+            if exit_on_error {
+                std::process::exit(1);
+            }
         }
 
         _ => {}
@@ -403,8 +483,13 @@ pub async fn run_pipeline_standalone(
 
 /// The entry point for the CLI. Will register all known internal commands, load experimental commands, load plugins, then prepare the prompt and line reader for input.
 pub async fn cli() -> Result<(), Box<dyn Error>> {
-    let mut syncer = crate::env::environment_syncer::EnvironmentSyncer::new();
-    let mut context = create_default_context(&mut syncer)?;
+    #[cfg(windows)]
+    const DEFAULT_COMPLETION_MODE: CompletionType = CompletionType::Circular;
+    #[cfg(not(windows))]
+    const DEFAULT_COMPLETION_MODE: CompletionType = CompletionType::List;
+
+    let mut syncer = crate::EnvironmentSyncer::new();
+    let mut context = create_default_context(&mut syncer, true)?;
 
     let _ = load_plugins(&mut context);
 
@@ -435,6 +520,34 @@ pub async fn cli() -> Result<(), Box<dyn Error>> {
     })
     .expect("Error setting Ctrl-C handler");
     let mut ctrlcbreak = false;
+
+    // before we start up, let's run our startup commands
+    if let Ok(config) = crate::data::config::config(Tag::unknown()) {
+        if let Some(commands) = config.get("startup") {
+            match commands {
+                Value {
+                    value: UntaggedValue::Table(pipelines),
+                    ..
+                } => {
+                    for pipeline in pipelines {
+                        if let Ok(pipeline_string) = pipeline.as_string() {
+                            let _ = run_pipeline_standalone(
+                                pipeline_string,
+                                false,
+                                &mut context,
+                                false,
+                            )
+                            .await;
+                        }
+                    }
+                }
+                _ => {
+                    println!("warning: expected a table of pipeline strings as startup commands");
+                }
+            }
+        }
+    }
+
     loop {
         if context.ctrl_c.load(Ordering::SeqCst) {
             context.ctrl_c.store(false, Ordering::SeqCst);
@@ -456,14 +569,21 @@ pub async fn cli() -> Result<(), Box<dyn Error>> {
 
         rl.set_edit_mode(edit_mode);
 
+        let key_timeout = config::config(Tag::unknown())?
+            .get("key_timeout")
+            .map(|s| s.value.expect_int())
+            .unwrap_or(1);
+
+        rl.set_keyseq_timeout(key_timeout as i32);
+
         let completion_mode = config::config(Tag::unknown())?
             .get("completion_mode")
             .map(|s| match s.value.expect_string() {
                 "list" => CompletionType::List,
                 "circular" => CompletionType::Circular,
-                _ => CompletionType::Circular,
+                _ => DEFAULT_COMPLETION_MODE,
             })
-            .unwrap_or(CompletionType::Circular);
+            .unwrap_or(DEFAULT_COMPLETION_MODE);
 
         rl.set_completion_type(completion_mode);
 
@@ -514,7 +634,7 @@ pub async fn cli() -> Result<(), Box<dyn Error>> {
             initial_command = None;
         }
 
-        let line = process_line(readline, &mut context, false).await;
+        let line = process_line(readline, &mut context, false, true).await;
 
         // Check the config to see if we need to update the path
         // TODO: make sure config is cached so we don't path this load every call
@@ -597,6 +717,7 @@ async fn process_line(
     readline: Result<String, ReadlineError>,
     ctx: &mut Context,
     redirect_stdin: bool,
+    cli_mode: bool,
 ) -> LineResult {
     match &readline {
         Ok(line) if line.trim() == "" => LineResult::Success(line.clone()),
@@ -604,9 +725,9 @@ async fn process_line(
         Ok(line) => {
             let line = chomp_newline(line);
 
-            let result = match nu_parser::parse(&line) {
+            let result = match nu_parser::lite_parse(&line, 0) {
                 Err(err) => {
-                    return LineResult::Error(line.to_string(), err);
+                    return LineResult::Error(line.to_string(), err.into());
                 }
 
                 Ok(val) => val,
@@ -615,12 +736,101 @@ async fn process_line(
             debug!("=== Parsed ===");
             debug!("{:#?}", result);
 
-            let pipeline = classify_pipeline(&result, ctx, &Text::from(line));
+            let mut classified_block = nu_parser::classify_block(&result, ctx.registry());
 
-            if let Some(failure) = pipeline.failed {
+            debug!("{:#?}", classified_block);
+            //println!("{:#?}", pipeline);
+
+            if let Some(failure) = classified_block.failed {
                 return LineResult::Error(line.to_string(), failure.into());
             }
 
+            // There's a special case to check before we process the pipeline:
+            // If we're giving a path by itself
+            // ...and it's not a command in the path
+            // ...and it doesn't have any arguments
+            // ...and we're in the CLI
+            // ...then change to this directory
+            if cli_mode
+                && classified_block.block.block.len() == 1
+                && classified_block.block.block[0].list.len() == 1
+            {
+                if let ClassifiedCommand::Internal(InternalCommand {
+                    ref name, ref args, ..
+                }) = classified_block.block.block[0].list[0]
+                {
+                    let internal_name = name;
+                    let name = args
+                        .positional
+                        .as_ref()
+                        .and_then(|potionals| {
+                            potionals.get(0).map(|e| {
+                                if let Expression::Literal(Literal::String(ref s)) = e.expr {
+                                    &s
+                                } else {
+                                    ""
+                                }
+                            })
+                        })
+                        .unwrap_or("");
+
+                    if internal_name == "run_external"
+                        && args
+                            .positional
+                            .as_ref()
+                            .map(|ref v| v.len() == 1)
+                            .unwrap_or(true)
+                        && args
+                            .named
+                            .as_ref()
+                            .map(NamedArguments::is_empty)
+                            .unwrap_or(true)
+                        && canonicalize(ctx.shell_manager.path(), name).is_ok()
+                        && Path::new(&name).is_dir()
+                        && which::which(&name).is_err()
+                    {
+                        // Here we work differently if we're in Windows because of the expected Windows behavior
+                        #[cfg(windows)]
+                        {
+                            if name.ends_with(':') {
+                                // This looks like a drive shortcut. We need to a) switch drives and b) go back to the previous directory we were viewing on that drive
+                                // But first, we need to save where we are now
+                                let current_path = ctx.shell_manager.path();
+
+                                let split_path: Vec<_> = current_path.split(':').collect();
+                                if split_path.len() > 1 {
+                                    ctx.windows_drives_previous_cwd
+                                        .lock()
+                                        .insert(split_path[0].to_string(), current_path);
+                                }
+
+                                let name = name.to_uppercase();
+                                let new_drive: Vec<_> = name.split(':').collect();
+
+                                if let Some(val) =
+                                    ctx.windows_drives_previous_cwd.lock().get(new_drive[0])
+                                {
+                                    ctx.shell_manager.set_path(val.to_string());
+                                    return LineResult::Success(line.to_string());
+                                } else {
+                                    ctx.shell_manager
+                                        .set_path(format!("{}\\", name.to_string()));
+                                    return LineResult::Success(line.to_string());
+                                }
+                            } else {
+                                ctx.shell_manager.set_path(name.to_string());
+                                return LineResult::Success(line.to_string());
+                            }
+                        }
+                        #[cfg(not(windows))]
+                        {
+                            ctx.shell_manager.set_path(name.to_string());
+                            return LineResult::Success(line.to_string());
+                        }
+                    }
+                }
+            }
+
             let input_stream = if redirect_stdin {
                 let file = futures::io::AllowStdIo::new(std::io::stdin());
                 let stream = FramedRead::new(file, MaybeTextCodec).map(|line| {
@@ -641,13 +851,17 @@ async fn process_line(
                         panic!("Internal error: could not read lines of text from stdin")
                     }
                 });
-                Some(stream.to_input_stream())
+                stream.to_input_stream()
             } else {
-                None
+                InputStream::empty()
             };
 
-            match run_pipeline(pipeline, ctx, input_stream, line).await {
-                Ok(Some(input)) => {
+            classified_block.block.expand_it_usage();
+
+            trace!("{:#?}", classified_block);
+            let env = ctx.get_env();
+            match run_block(&classified_block.block, ctx, input_stream, &Scope::env(env)).await {
+                Ok(input) => {
                     // Running a pipeline gives us back a stream that we can then
                     // work through. At the top level, we just want to pull on the
                     // values to compute them.
@@ -658,9 +872,8 @@ async fn process_line(
                         shell_manager: ctx.shell_manager.clone(),
                         host: ctx.host.clone(),
                         ctrl_c: ctx.ctrl_c.clone(),
-                        commands: ctx.registry.clone(),
+                        registry: ctx.registry.clone(),
                         name: Tag::unknown(),
-                        source: Text::from(String::new()),
                     };
 
                     if let Ok(mut output_stream) = crate::commands::autoview::autoview(context) {
@@ -675,16 +888,14 @@ async fn process_line(
                                         break;
                                     }
                                 }
-                                _ => {
-                                    break;
-                                }
+                                Ok(None) => break,
+                                Err(e) => return LineResult::Error(line.to_string(), e),
                             }
                         }
                     }
 
                     LineResult::Success(line.to_string())
                 }
-                Ok(None) => LineResult::Success(line.to_string()),
                 Err(err) => LineResult::Error(line.to_string(), err),
             }
         }
@@ -697,39 +908,31 @@ async fn process_line(
     }
 }
 
-pub fn classify_pipeline(
-    pipeline: &SpannedToken,
-    context: &Context,
-    source: &Text,
-) -> ClassifiedPipeline {
-    let pipeline_list = vec![pipeline.clone()];
-    let expand_context = context.expand_context(source);
-    let mut iterator = TokensIterator::new(&pipeline_list, expand_context, pipeline.span());
-
-    let result = iterator.expand_infallible(PipelineShape);
-
-    if log_enabled!(target: "nu::expand_syntax", log::Level::Debug) {
-        outln!("");
-        let _ = ptree::print_tree(&iterator.expand_tracer().print(source.clone()));
-        outln!("");
-    }
-
-    result
-}
-
 pub fn print_err(err: ShellError, host: &dyn Host, source: &Text) {
-    let diag = err.into_diagnostic();
-
-    let writer = host.err_termcolor();
-    let mut source = source.to_string();
-    source.push_str(" ");
-    let files = nu_parser::Files::new(source);
-    let _ = std::panic::catch_unwind(move || {
-        let _ = language_reporting::emit(
-            &mut writer.lock(),
-            &files,
-            &diag,
-            &language_reporting::DefaultConfig,
-        );
-    });
+    if let Some(diag) = err.into_diagnostic() {
+        let writer = host.err_termcolor();
+        let mut source = source.to_string();
+        source.push_str(" ");
+        let files = nu_parser::Files::new(source);
+        let _ = std::panic::catch_unwind(move || {
+            let _ = language_reporting::emit(
+                &mut writer.lock(),
+                &files,
+                &diag,
+                &language_reporting::DefaultConfig,
+            );
+        });
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    #[quickcheck]
+    fn quickcheck_parse(data: String) -> bool {
+        if let Ok(lite_block) = nu_parser::lite_parse(&data, 0) {
+            let context = crate::context::Context::basic().unwrap();
+            let _ = nu_parser::classify_block(&lite_block, context.registry());
+        }
+        true
+    }
 }

crates/nu-cli/src/commands.rs

@@ -4,9 +4,11 @@ pub(crate) mod macros;
 mod from_delimited_data;
 mod to_delimited_data;
 
+pub(crate) mod alias;
 pub(crate) mod append;
 pub(crate) mod args;
 pub(crate) mod autoview;
+pub(crate) mod cal;
 pub(crate) mod calc;
 pub(crate) mod cd;
 pub(crate) mod classified;
@@ -19,17 +21,21 @@ pub(crate) mod cp;
 pub(crate) mod date;
 pub(crate) mod debug;
 pub(crate) mod default;
+pub(crate) mod drop;
 pub(crate) mod du;
+pub(crate) mod each;
 pub(crate) mod echo;
-pub(crate) mod edit;
 pub(crate) mod enter;
 #[allow(unused)]
 pub(crate) mod evaluate_by;
 pub(crate) mod exit;
 pub(crate) mod first;
 pub(crate) mod format;
+pub(crate) mod from;
 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;
@@ -38,27 +44,33 @@ pub(crate) mod from_ssv;
 pub(crate) mod from_toml;
 pub(crate) mod from_tsv;
 pub(crate) mod from_url;
+pub(crate) mod from_vcf;
 pub(crate) mod from_xlsx;
 pub(crate) mod from_xml;
 pub(crate) mod from_yaml;
 pub(crate) mod get;
 pub(crate) mod group_by;
+pub(crate) mod headers;
 pub(crate) mod help;
 pub(crate) mod histogram;
 pub(crate) mod history;
 pub(crate) mod insert;
+pub(crate) mod is_empty;
+pub(crate) mod keep;
+pub(crate) mod keep_until;
+pub(crate) mod keep_while;
 pub(crate) mod last;
 pub(crate) mod lines;
 pub(crate) mod ls;
 #[allow(unused)]
 pub(crate) mod map_max_by;
+pub(crate) mod merge;
 pub(crate) mod mkdir;
 pub(crate) mod mv;
 pub(crate) mod next;
 pub(crate) mod nth;
 pub(crate) mod open;
 pub(crate) mod parse;
-pub(crate) mod pick;
 pub(crate) mod pivot;
 pub(crate) mod plugin;
 pub(crate) mod prepend;
@@ -71,23 +83,31 @@ pub(crate) mod reject;
 pub(crate) mod rename;
 pub(crate) mod reverse;
 pub(crate) mod rm;
+pub(crate) mod run_alias;
+pub(crate) mod run_external;
 pub(crate) mod save;
+pub(crate) mod select;
 pub(crate) mod shells;
 pub(crate) mod shuffle;
 pub(crate) mod size;
 pub(crate) mod skip;
+pub(crate) mod skip_until;
 pub(crate) mod skip_while;
 pub(crate) mod sort_by;
 pub(crate) mod split_by;
 pub(crate) mod split_column;
 pub(crate) mod split_row;
+pub(crate) mod sum;
 #[allow(unused)]
 pub(crate) mod t_sort_by;
 pub(crate) mod table;
 pub(crate) mod tags;
+pub(crate) mod to;
 pub(crate) mod to_bson;
 pub(crate) mod to_csv;
+pub(crate) mod to_html;
 pub(crate) mod to_json;
+pub(crate) mod to_md;
 pub(crate) mod to_sqlite;
 pub(crate) mod to_toml;
 pub(crate) mod to_tsv;
@@ -95,20 +115,23 @@ pub(crate) mod to_url;
 pub(crate) mod to_yaml;
 pub(crate) mod trim;
 pub(crate) mod uniq;
+pub(crate) mod update;
 pub(crate) mod version;
 pub(crate) mod what;
 pub(crate) mod where_;
 pub(crate) mod which_;
+pub(crate) mod with_env;
 pub(crate) mod wrap;
 
 pub(crate) use autoview::Autoview;
 pub(crate) use cd::Cd;
 pub(crate) use command::{
-    per_item_command, whole_stream_command, Command, PerItemCommand, UnevaluatedCallInfo,
-    WholeStreamCommand,
+    whole_stream_command, Command, Example, UnevaluatedCallInfo, WholeStreamCommand,
 };
 
+pub(crate) use alias::Alias;
 pub(crate) use append::Append;
+pub(crate) use cal::Cal;
 pub(crate) use calc::Calc;
 pub(crate) use compact::Compact;
 pub(crate) use config::Config;
@@ -117,9 +140,12 @@ pub(crate) use cp::Cpy;
 pub(crate) use date::Date;
 pub(crate) use debug::Debug;
 pub(crate) use default::Default;
+pub(crate) use drop::Drop;
 pub(crate) use du::Du;
+pub(crate) use each::Each;
 pub(crate) use echo::Echo;
-pub(crate) use edit::Edit;
+pub(crate) use is_empty::IsEmpty;
+pub(crate) use update::Update;
 pub(crate) mod kill;
 pub(crate) use kill::Kill;
 pub(crate) mod clear;
@@ -131,8 +157,11 @@ pub(crate) use evaluate_by::EvaluateBy;
 pub(crate) use exit::Exit;
 pub(crate) use first::First;
 pub(crate) use format::Format;
+pub(crate) use from::From;
 pub(crate) use from_bson::FromBSON;
 pub(crate) use from_csv::FromCSV;
+pub(crate) use from_eml::FromEML;
+pub(crate) use from_ics::FromIcs;
 pub(crate) use from_ini::FromINI;
 pub(crate) use from_json::FromJSON;
 pub(crate) use from_ods::FromODS;
@@ -142,28 +171,33 @@ pub(crate) use from_ssv::FromSSV;
 pub(crate) use from_toml::FromTOML;
 pub(crate) use from_tsv::FromTSV;
 pub(crate) use from_url::FromURL;
+pub(crate) use from_vcf::FromVcf;
 pub(crate) use from_xlsx::FromXLSX;
 pub(crate) use from_xml::FromXML;
 pub(crate) use from_yaml::FromYAML;
 pub(crate) use from_yaml::FromYML;
 pub(crate) use get::Get;
 pub(crate) use group_by::GroupBy;
+pub(crate) use headers::Headers;
 pub(crate) use help::Help;
 pub(crate) use histogram::Histogram;
 pub(crate) use history::History;
 pub(crate) use insert::Insert;
+pub(crate) use keep::Keep;
+pub(crate) use keep_until::KeepUntil;
+pub(crate) use keep_while::KeepWhile;
 pub(crate) use last::Last;
 pub(crate) use lines::Lines;
 pub(crate) use ls::Ls;
 #[allow(unused_imports)]
 pub(crate) use map_max_by::MapMaxBy;
+pub(crate) use merge::Merge;
 pub(crate) use mkdir::Mkdir;
 pub(crate) use mv::Move;
 pub(crate) use next::Next;
 pub(crate) use nth::Nth;
 pub(crate) use open::Open;
 pub(crate) use parse::Parse;
-pub(crate) use pick::Pick;
 pub(crate) use pivot::Pivot;
 pub(crate) use prepend::Prepend;
 pub(crate) use prev::Previous;
@@ -175,23 +209,30 @@ pub(crate) use reject::Reject;
 pub(crate) use rename::Rename;
 pub(crate) use reverse::Reverse;
 pub(crate) use rm::Remove;
+pub(crate) use run_external::RunExternalCommand;
 pub(crate) use save::Save;
+pub(crate) use select::Select;
 pub(crate) use shells::Shells;
 pub(crate) use shuffle::Shuffle;
 pub(crate) use size::Size;
 pub(crate) use skip::Skip;
+pub(crate) use skip_until::SkipUntil;
 pub(crate) use skip_while::SkipWhile;
 pub(crate) use sort_by::SortBy;
 pub(crate) use split_by::SplitBy;
 pub(crate) use split_column::SplitColumn;
 pub(crate) use split_row::SplitRow;
+pub(crate) use sum::Sum;
 #[allow(unused_imports)]
 pub(crate) use t_sort_by::TSortBy;
 pub(crate) use table::Table;
 pub(crate) use tags::Tags;
+pub(crate) use to::To;
 pub(crate) use to_bson::ToBSON;
 pub(crate) use to_csv::ToCSV;
+pub(crate) use to_html::ToHTML;
 pub(crate) use to_json::ToJSON;
+pub(crate) use to_md::ToMarkdown;
 pub(crate) use to_sqlite::ToDB;
 pub(crate) use to_sqlite::ToSQLite;
 pub(crate) use to_toml::ToTOML;
@@ -205,4 +246,5 @@ pub(crate) use version::Version;
 pub(crate) use what::What;
 pub(crate) use where_::Where;
 pub(crate) use which_::Which;
+pub(crate) use with_env::WithEnv;
 pub(crate) use wrap::Wrap;

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

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

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

@@ -35,6 +35,13 @@ impl WholeStreamCommand for Append {
     ) -> Result<OutputStream, ShellError> {
         args.process(registry, append)?.run()
     }
+
+    fn examples(&self) -> &[Example] {
+        &[Example {
+            description: "Add something to the end of a list or table",
+            example: "echo [1 2 3] | append 4",
+        }]
+    }
 }
 
 fn append(
@@ -45,5 +52,5 @@ fn append(
     after.push_back(row);
     let after = futures::stream::iter(after);
 
-    Ok(OutputStream::from_input(input.values.chain(after)))
+    Ok(OutputStream::from_input(input.chain(after)))
 }

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

@@ -1,9 +1,10 @@
 use crate::commands::UnevaluatedCallInfo;
 use crate::commands::WholeStreamCommand;
+use crate::data::value::format_leaf;
 use crate::prelude::*;
 use nu_errors::ShellError;
-use nu_parser::{hir, hir::Expression, hir::Literal, hir::SpannedExpression};
-use nu_protocol::{Primitive, ReturnSuccess, Signature, UntaggedValue, Value};
+use nu_protocol::{hir, hir::Expression, hir::Literal, hir::SpannedExpression};
+use nu_protocol::{Primitive, ReturnSuccess, Scope, Signature, UntaggedValue, Value};
 use std::sync::atomic::AtomicBool;
 use std::sync::atomic::Ordering;
 
@@ -29,22 +30,33 @@ impl WholeStreamCommand for Autoview {
     ) -> Result<OutputStream, ShellError> {
         autoview(RunnableContext {
             input: args.input,
-            commands: registry.clone(),
+            registry: registry.clone(),
             shell_manager: args.shell_manager,
             host: args.host,
-            source: args.call_info.source,
             ctrl_c: args.ctrl_c,
             name: args.call_info.name_tag,
         })
     }
+
+    fn examples(&self) -> &[Example] {
+        &[
+            Example {
+                description: "Automatically view the results",
+                example: "ls | autoview",
+            },
+            Example {
+                description: "Autoview is also implied. The above can be written as",
+                example: "ls",
+            },
+        ]
+    }
 }
 
 pub struct RunnableContextWithoutInput {
     pub shell_manager: ShellManager,
     pub host: Arc<parking_lot::Mutex<Box<dyn Host>>>,
-    pub source: Text,
     pub ctrl_c: Arc<AtomicBool>,
-    pub commands: CommandRegistry,
+    pub registry: CommandRegistry,
     pub name: Tag,
 }
 
@@ -53,9 +65,8 @@ impl RunnableContextWithoutInput {
         let new_context = RunnableContextWithoutInput {
             shell_manager: context.shell_manager,
             host: context.host,
-            source: context.source,
             ctrl_c: context.ctrl_c,
-            commands: context.commands,
+            registry: context.registry,
             name: context.name,
         };
         (context.input, new_context)
@@ -95,7 +106,7 @@ pub fn autoview(context: RunnableContext) -> Result<OutputStream, ShellError> {
 
                         if let Some(table) = table {
                             let command_args = create_default_command_args(&context).with_input(stream);
-                            let result = table.run(command_args, &context.commands);
+                            let result = table.run(command_args, &context.registry);
                             result.collect::<Vec<_>>().await;
                         }
                     }
@@ -109,7 +120,7 @@ pub fn autoview(context: RunnableContext) -> Result<OutputStream, ShellError> {
                                     let mut stream = VecDeque::new();
                                     stream.push_back(UntaggedValue::string(s).into_value(Tag { anchor, span }));
                                     let command_args = create_default_command_args(&context).with_input(stream);
-                                    let result = text.run(command_args, &context.commands);
+                                    let result = text.run(command_args, &context.registry);
                                     result.collect::<Vec<_>>().await;
                                 } else {
                                     out!("{}", s);
@@ -129,7 +140,7 @@ pub fn autoview(context: RunnableContext) -> Result<OutputStream, ShellError> {
                                     let mut stream = VecDeque::new();
                                     stream.push_back(UntaggedValue::string(s).into_value(Tag { anchor, span }));
                                     let command_args = create_default_command_args(&context).with_input(stream);
-                                    let result = text.run(command_args, &context.commands);
+                                    let result = text.run(command_args, &context.registry);
                                     result.collect::<Vec<_>>().await;
                                 } else {
                                     out!("{}\n", s);
@@ -159,13 +170,39 @@ pub fn autoview(context: RunnableContext) -> Result<OutputStream, ShellError> {
                             } => {
                                 out!("{}", n);
                             }
+                            Value {
+                                value: UntaggedValue::Primitive(Primitive::Boolean(b)),
+                                ..
+                            } => {
+                                out!("{}", b);
+                            }
+                            Value {
+                                value: UntaggedValue::Primitive(Primitive::Duration(d)),
+                                ..
+                            } => {
+                                let output = format_leaf(&x).plain_string(100_000);
+                                out!("{}", output);
+                            }
+                            Value {
+                                value: UntaggedValue::Primitive(Primitive::Date(d)),
+                                ..
+                            } => {
+                                out!("{}", d);
+                            }
+                            Value {
+                                value: UntaggedValue::Primitive(Primitive::Range(_)),
+                                ..
+                            } => {
+                                let output = format_leaf(&x).plain_string(100_000);
+                                out!("{}", output);
+                            }
 
                             Value { value: UntaggedValue::Primitive(Primitive::Binary(ref b)), .. } => {
                                 if let Some(binary) = binary {
                                     let mut stream = VecDeque::new();
                                     stream.push_back(x);
                                     let command_args = create_default_command_args(&context).with_input(stream);
-                                    let result = binary.run(command_args, &context.commands);
+                                    let result = binary.run(command_args, &context.registry);
                                     result.collect::<Vec<_>>().await;
                                 } else {
                                     use pretty_hex::*;
@@ -176,12 +213,82 @@ pub fn autoview(context: RunnableContext) -> Result<OutputStream, ShellError> {
                             Value { value: UntaggedValue::Error(e), .. } => {
                                 yield Err(e);
                             }
+
+                            Value { value: UntaggedValue::Row(row), ..} => {
+                                use prettytable::format::{FormatBuilder, LinePosition, LineSeparator};
+                                use prettytable::{color, Attr, Cell, Row, Table};
+                                use crate::data::value::{format_leaf, style_leaf};
+                                use textwrap::fill;
+
+                                let termwidth = std::cmp::max(textwrap::termwidth(), 20);
+
+                                enum TableMode {
+                                    Light,
+                                    Normal,
+                                }
+
+                                let mut table = Table::new();
+                                let table_mode = crate::data::config::config(Tag::unknown());
+
+                                let table_mode = if let Some(s) = table_mode?.get("table_mode") {
+                                    match s.as_string() {
+                                        Ok(typ) if typ == "light" => TableMode::Light,
+                                        _ => TableMode::Normal,
+                                    }
+                                } else {
+                                    TableMode::Normal
+                                };
+
+                                match table_mode {
+                                    TableMode::Light => {
+                                        table.set_format(
+                                            FormatBuilder::new()
+                                                .separator(LinePosition::Title, LineSeparator::new('─', '─', ' ', ' '))
+                                                .padding(1, 1)
+                                                .build(),
+                                        );
+                                    }
+                                    _ => {
+                                        table.set_format(
+                                            FormatBuilder::new()
+                                                .column_separator('│')
+                                                .separator(LinePosition::Top, LineSeparator::new('─', '┬', ' ', ' '))
+                                                .separator(LinePosition::Title, LineSeparator::new('─', '┼', ' ', ' '))
+                                                .separator(LinePosition::Bottom, LineSeparator::new('─', '┴', ' ', ' '))
+                                                .padding(1, 1)
+                                                .build(),
+                                        );
+                                    }
+                                }
+
+                                let mut max_key_len = 0;
+                                for (key, _) in row.entries.iter() {
+                                    max_key_len = std::cmp::max(max_key_len, key.chars().count());
+                                }
+
+                                if max_key_len > (termwidth/2 - 1) {
+                                    max_key_len = termwidth/2 - 1;
+                                }
+
+                                let max_val_len = termwidth - max_key_len - 5;
+
+                                for (key, value) in row.entries.iter() {
+                                    table.add_row(Row::new(vec![Cell::new(&fill(&key, max_key_len)).with_style(Attr::ForegroundColor(color::GREEN)).with_style(Attr::Bold),
+                                        Cell::new(&fill(&format_leaf(value).plain_string(100_000), max_val_len))]));
+                                }
+
+                                table.printstd();
+
+                                // table.print_term(&mut *context.host.lock().out_terminal().ok_or_else(|| ShellError::untagged_runtime_error("Could not open terminal for output"))?)
+                                //     .map_err(|_| ShellError::untagged_runtime_error("Internal error: could not print to terminal (for unix systems check to make sure TERM is set)"))?;
+                            }
+
                             Value { value: ref item, .. } => {
                                 if let Some(table) = table {
                                     let mut stream = VecDeque::new();
                                     stream.push_back(x);
                                     let command_args = create_default_command_args(&context).with_input(stream);
-                                    let result = table.run(command_args, &context.commands);
+                                    let result = table.run(command_args, &context.registry);
                                     result.collect::<Vec<_>>().await;
                                 } else {
                                     out!("{:?}", item);
@@ -212,15 +319,16 @@ fn create_default_command_args(context: &RunnableContextWithoutInput) -> RawComm
         call_info: UnevaluatedCallInfo {
             args: hir::Call {
                 head: Box::new(SpannedExpression::new(
-                    Expression::Literal(Literal::String(span)),
+                    Expression::Literal(Literal::String(String::new())),
                     span,
                 )),
                 positional: None,
                 named: None,
                 span,
+                is_last: true,
             },
-            source: context.source.clone(),
             name_tag: context.name.clone(),
+            scope: Scope::empty(),
         },
     }
 }

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

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

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

@@ -1,11 +1,14 @@
-use crate::commands::PerItemCommand;
+use crate::commands::WholeStreamCommand;
 use crate::prelude::*;
 use nu_errors::ShellError;
-use nu_protocol::{CallInfo, Primitive, ReturnSuccess, UntaggedValue, Value};
+use nu_protocol::{Primitive, ReturnSuccess, UntaggedValue, Value};
 
 pub struct Calc;
 
-impl PerItemCommand for Calc {
+#[derive(Deserialize)]
+pub struct CalcArgs {}
+
+impl WholeStreamCommand for Calc {
     fn name(&self) -> &str {
         "calc"
     }
@@ -16,36 +19,44 @@ impl PerItemCommand for Calc {
 
     fn run(
         &self,
-        _call_info: &CallInfo,
-        _registry: &CommandRegistry,
-        raw_args: &RawCommandArgs,
-        input: Value,
+        args: CommandArgs,
+        registry: &CommandRegistry,
     ) -> Result<OutputStream, ShellError> {
-        calc(input, raw_args)
+        args.process(registry, calc)?.run()
+    }
+
+    fn examples(&self) -> &[Example] {
+        &[Example {
+            description: "Calculate math in the pipeline",
+            example: "echo '10 / 4' | calc",
+        }]
     }
 }
 
-fn calc(input: Value, args: &RawCommandArgs) -> Result<OutputStream, ShellError> {
-    let name_span = &args.call_info.name_tag.span;
-
-    let output = if let Ok(string) = input.as_string() {
-        match parse(&string, &input.tag) {
-            Ok(value) => ReturnSuccess::value(value),
-            Err(err) => Err(ShellError::labeled_error(
-                "Calculation error",
-                err,
-                &input.tag.span,
-            )),
-        }
-    } else {
-        Err(ShellError::labeled_error(
-            "Expected a string from pipeline",
-            "requires string input",
-            name_span,
-        ))
-    };
-
-    Ok(vec![output].into())
+pub fn calc(
+    _: CalcArgs,
+    RunnableContext { input, name, .. }: RunnableContext,
+) -> Result<OutputStream, ShellError> {
+    Ok(input
+        .map(move |input| {
+            if let Ok(string) = input.as_string() {
+                match parse(&string, &input.tag) {
+                    Ok(value) => ReturnSuccess::value(value),
+                    Err(err) => Err(ShellError::labeled_error(
+                        "Calculation error",
+                        err,
+                        &input.tag.span,
+                    )),
+                }
+            } else {
+                Err(ShellError::labeled_error(
+                    "Expected a string from pipeline",
+                    "requires string input",
+                    name.clone(),
+                ))
+            }
+        })
+        .to_output_stream())
 }
 
 pub fn parse(math_expression: &str, tag: impl Into<Tag>) -> Result<Value, String> {

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

@@ -1,8 +1,16 @@
 use crate::commands::WholeStreamCommand;
 use crate::prelude::*;
+
+use std::path::PathBuf;
+
 use nu_errors::ShellError;
-use nu_macros::signature;
 use nu_protocol::{Signature, SyntaxShape};
+use nu_source::Tagged;
+
+#[derive(Deserialize)]
+pub struct CdArgs {
+    pub(crate) path: Option<Tagged<PathBuf>>,
+}
 
 pub struct Cd;
 
@@ -12,17 +20,11 @@ impl WholeStreamCommand for Cd {
     }
 
     fn signature(&self) -> Signature {
-        signature! {
-            def cd {
-                "the directory to change to"
-                directory(optional Path) - "the directory to change to"
-            }
-        }
-        // Signature::build("cd").optional(
-        //     "directory",
-        //     SyntaxShape::Path,
-        //     "the directory to change to",
-        // )
+        Signature::build("cd").optional(
+            "directory",
+            SyntaxShape::Path,
+            "the directory to change to",
+        )
     }
 
     fn usage(&self) -> &str {
@@ -34,12 +36,31 @@ impl WholeStreamCommand for Cd {
         args: CommandArgs,
         registry: &CommandRegistry,
     ) -> Result<OutputStream, ShellError> {
-        cd(args, registry)
+        args.process(registry, cd)?.run()
+    }
+
+    fn examples(&self) -> &[Example] {
+        &[
+            Example {
+                description: "Change to a new directory called 'dirname'",
+                example: "cd dirname",
+            },
+            Example {
+                description: "Change to your home directory",
+                example: "cd",
+            },
+            Example {
+                description: "Change to your home directory (alternate version)",
+                example: "cd ~",
+            },
+            Example {
+                description: "Change to the previous directory",
+                example: "cd -",
+            },
+        ]
     }
 }
 
-fn cd(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStream, ShellError> {
-    let shell_manager = args.shell_manager.clone();
-    let args = args.evaluate_once(registry)?;
-    shell_manager.cd(args)
+fn cd(args: CdArgs, context: RunnableContext) -> Result<OutputStream, ShellError> {
+    context.shell_manager.cd(args, &context)
 }

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

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

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

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

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

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

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

@@ -1,21 +1,23 @@
+use crate::evaluate::evaluate_baseline_expr;
 use crate::futures::ThreadedReceiver;
 use crate::prelude::*;
-use bytes::{BufMut, Bytes, BytesMut};
-use futures::executor::block_on_stream;
-use futures::stream::StreamExt;
-use futures_codec::FramedRead;
-use log::trace;
-use nu_errors::ShellError;
-use nu_parser::commands::classified::external::ExternalArg;
-use nu_parser::ExternalCommand;
-use nu_protocol::{ColumnPath, Primitive, ShellTypeName, UntaggedValue, Value};
-use nu_source::{Tag, Tagged};
-use nu_value_ext::as_column_path;
+
 use std::io::Write;
 use std::ops::Deref;
 use std::process::{Command, Stdio};
 use std::sync::mpsc;
 
+use bytes::{BufMut, Bytes, BytesMut};
+use futures::executor::block_on_stream;
+// use futures::stream::StreamExt;
+use futures_codec::FramedRead;
+use log::trace;
+
+use nu_errors::ShellError;
+use nu_protocol::hir::ExternalCommand;
+use nu_protocol::{Primitive, Scope, ShellTypeName, UntaggedValue, Value};
+use nu_source::Tag;
+
 pub enum StringOrBinary {
     String(String),
     Binary(Vec<u8>),
@@ -80,29 +82,16 @@ impl futures_codec::Decoder for MaybeTextCodec {
     }
 }
 
-pub fn nu_value_to_string(command: &ExternalCommand, from: &Value) -> Result<String, ShellError> {
-    match &from.value {
-        UntaggedValue::Primitive(Primitive::Int(i)) => Ok(i.to_string()),
-        UntaggedValue::Primitive(Primitive::String(s))
-        | UntaggedValue::Primitive(Primitive::Line(s)) => Ok(s.clone()),
-        UntaggedValue::Primitive(Primitive::Path(p)) => Ok(p.to_string_lossy().to_string()),
-        unsupported => Err(ShellError::labeled_error(
-            format!("needs string data (given: {})", unsupported.type_name()),
-            "expected a string",
-            &command.name_tag,
-        )),
-    }
-}
-
-pub(crate) fn run_external_command(
+pub(crate) async fn run_external_command(
     command: ExternalCommand,
     context: &mut Context,
-    input: Option<InputStream>,
+    input: InputStream,
+    scope: &Scope,
     is_last: bool,
-) -> Result<Option<InputStream>, ShellError> {
+) -> Result<InputStream, ShellError> {
     trace!(target: "nu::run::external", "-> {}", command.name);
 
-    if !did_find_command(&command.name) {
+    if !did_find_command(&command.name).await {
         return Err(ShellError::labeled_error(
             "Command not found",
             "command not found",
@@ -110,306 +99,57 @@ pub(crate) fn run_external_command(
         ));
     }
 
-    if command.has_it_argument() || command.has_nu_argument() {
-        run_with_iterator_arg(command, context, input, is_last)
-    } else {
-        run_with_stdin(command, context, input, is_last)
-    }
-}
-
-fn prepare_column_path_for_fetching_it_variable(
-    argument: &ExternalArg,
-) -> Result<Tagged<ColumnPath>, ShellError> {
-    // We have "$it.[contents of interest]"
-    // and start slicing from "$it.[member+]"
-    //                             ^ here.
-    let key = nu_source::Text::from(argument.deref()).slice(4..argument.len());
-
-    to_column_path(&key, &argument.tag)
-}
-
-fn prepare_column_path_for_fetching_nu_variable(
-    argument: &ExternalArg,
-) -> Result<Tagged<ColumnPath>, ShellError> {
-    // We have "$nu.[contents of interest]"
-    // and start slicing from "$nu.[member+]"
-    //                             ^ here.
-    let key = nu_source::Text::from(argument.deref()).slice(4..argument.len());
-
-    to_column_path(&key, &argument.tag)
-}
-
-fn to_column_path(
-    path_members: &str,
-    tag: impl Into<Tag>,
-) -> Result<Tagged<ColumnPath>, ShellError> {
-    let tag = tag.into();
-
-    as_column_path(
-        &UntaggedValue::Table(
-            path_members
-                .split('.')
-                .map(|x| {
-                    let member = match x.parse::<u64>() {
-                        Ok(v) => UntaggedValue::int(v),
-                        Err(_) => UntaggedValue::string(x),
-                    };
-
-                    member.into_value(&tag)
-                })
-                .collect(),
-        )
-        .into_value(&tag),
-    )
-}
-
-fn run_with_iterator_arg(
-    command: ExternalCommand,
-    context: &mut Context,
-    input: Option<InputStream>,
-    is_last: bool,
-) -> Result<Option<InputStream>, ShellError> {
-    let path = context.shell_manager.path();
-
-    let mut inputs: InputStream = if let Some(input) = input {
-        trace_stream!(target: "nu::trace_stream::external::it", "input" = input)
-    } else {
-        InputStream::empty()
-    };
-
-    let stream = async_stream! {
-        while let Some(value) = inputs.next().await {
-            let name = command.name.clone();
-            let name_tag = command.name_tag.clone();
-            let home_dir = dirs::home_dir();
-            let path = &path;
-            let args = command.args.clone();
-
-            let it_replacement = {
-                if command.has_it_argument() {
-                    let empty_arg = ExternalArg {
-                        arg: "".to_string(),
-                        tag: name_tag.clone()
-                    };
-
-                    let key = args.iter()
-                        .find(|arg| arg.looks_like_it())
-                        .unwrap_or_else(|| &empty_arg);
-
-                    if args.iter().all(|arg| !arg.is_it()) {
-                        let key = match prepare_column_path_for_fetching_it_variable(&key) {
-                            Ok(keypath) => keypath,
-                            Err(reason) => {
-                                yield Ok(Value {
-                                    value: UntaggedValue::Error(reason),
-                                    tag: name_tag
-                                });
-                                return;
-                            }
-                        };
-
-                        match crate::commands::get::get_column_path(&key, &value) {
-                            Ok(field) => {
-                                match nu_value_to_string(&command, &field) {
-                                    Ok(val) => Some(val),
-                                    Err(reason) => {
-                                        yield Ok(Value {
-                                            value: UntaggedValue::Error(reason),
-                                            tag: name_tag
-                                        });
-                                        return;
-                                    },
-                                }
-                            },
-                            Err(reason) => {
-                                yield Ok(Value {
-                                    value: UntaggedValue::Error(reason),
-                                    tag: name_tag
-                                });
-                                return;
-                            }
-                        }
-                    } else {
-                        match nu_value_to_string(&command, &value) {
-                            Ok(val) => Some(val),
-                            Err(reason) => {
-                                yield Ok(Value {
-                                    value: UntaggedValue::Error(reason),
-                                    tag: name_tag
-                                });
-                                return;
-                            },
-                        }
-                    }
-                } else {
-                    None
-                }
-            };
-
-            let nu_replacement = {
-                if command.has_nu_argument() {
-                    let empty_arg = ExternalArg {
-                        arg: "".to_string(),
-                        tag: name_tag.clone()
-                    };
-
-                    let key = args.iter()
-                        .find(|arg| arg.looks_like_nu())
-                        .unwrap_or_else(|| &empty_arg);
-
-                    let nu_var = match crate::evaluate::variables::nu(&name_tag) {
-                        Ok(variables) => variables,
-                        Err(reason) => {
-                            yield Ok(Value {
-                                value: UntaggedValue::Error(reason),
-                                tag: name_tag
-                            });
-                            return;
-                        }
-                    };
-
-                    if args.iter().all(|arg| !arg.is_nu()) {
-                        let key = match prepare_column_path_for_fetching_nu_variable(&key) {
-                            Ok(keypath) => keypath,
-                            Err(reason) => {
-                                yield Ok(Value {
-                                    value: UntaggedValue::Error(reason),
-                                    tag: name_tag
-                                });
-                                return;
-                            }
-                        };
-
-                        match crate::commands::get::get_column_path(&key, &nu_var) {
-                            Ok(field) => {
-                                match nu_value_to_string(&command, &field) {
-                                    Ok(val) => Some(val),
-                                    Err(reason) => {
-                                        yield Ok(Value {
-                                            value: UntaggedValue::Error(reason),
-                                            tag: name_tag
-                                        });
-                                        return;
-                                    },
-                                }
-                            },
-                            Err(reason) => {
-                                yield Ok(Value {
-                                    value: UntaggedValue::Error(reason),
-                                    tag: name_tag
-                                });
-                                return;
-                            }
-                        }
-                    } else {
-                        match nu_value_to_string(&command, &nu_var) {
-                            Ok(val) => Some(val),
-                            Err(reason) => {
-                                yield Ok(Value {
-                                    value: UntaggedValue::Error(reason),
-                                    tag: name_tag
-                                });
-                                return;
-                            },
-                        }
-                    }
-                } else {
-                    None
-                }
-            };
-
-            let process_args = args.iter().filter_map(|arg| {
-                if arg.chars().all(|c| c.is_whitespace()) {
-                    None
-                } else {
-                    let arg = if arg.looks_like_it() {
-                        if let Some(mut value) = it_replacement.to_owned() {
-                            let mut value = expand_tilde(&value, || home_dir.as_ref()).as_ref().to_string();
-                            #[cfg(not(windows))]
-                            {
-                                value = {
-                                    if argument_contains_whitespace(&value) && !argument_is_quoted(&value) {
-                                        add_quotes(&value)
-                                    } else {
-                                        value
-                                    }
-                                };
-                            }
-                            Some(value)
-                        } else {
-                            None
-                        }
-                    } else if arg.looks_like_nu() {
-                        if let Some(mut value) = nu_replacement.to_owned() {
-                            #[cfg(not(windows))]
-                            {
-                                value = {
-                                    if argument_contains_whitespace(&value) && !argument_is_quoted(&value) {
-                                        add_quotes(&value)
-                                    } else {
-                                        value
-                                    }
-                                };
-                            }
-                            Some(value)
-                        } else {
-                            None
-                        }
-                    } else {
-                        Some(arg.to_string())
-                    };
-
-                    arg
-                }
-            }).collect::<Vec<String>>();
-
-            match spawn(&command, &path, &process_args[..], None, is_last) {
-                Ok(res) => {
-                    if let Some(mut res) = res {
-                        while let Some(item) = res.next().await {
-                            yield Ok(item)
-                        }
-                    }
-                }
-                Err(reason) => {
-                    yield Ok(Value {
-                        value: UntaggedValue::Error(reason),
-                        tag: name_tag
-                    });
-                    return;
-                }
-            }
-        }
-    };
-
-    Ok(Some(stream.to_input_stream()))
+    run_with_stdin(command, context, input, scope, is_last)
 }
 
 fn run_with_stdin(
     command: ExternalCommand,
     context: &mut Context,
-    input: Option<InputStream>,
+    input: InputStream,
+    scope: &Scope,
     is_last: bool,
-) -> Result<Option<InputStream>, ShellError> {
+) -> Result<InputStream, ShellError> {
     let path = context.shell_manager.path();
 
-    let input = input
-        .map(|input| trace_stream!(target: "nu::trace_stream::external::stdin", "input" = input));
+    let input = trace_stream!(target: "nu::trace_stream::external::stdin", "input" = input);
 
-    let process_args = command
-        .args
+    let mut command_args = vec![];
+    for arg in command.args.iter() {
+        let value = evaluate_baseline_expr(arg, &context.registry, scope)?;
+        // Skip any arguments that don't really exist, treating them as optional
+        // FIXME: we may want to preserve the gap in the future, though it's hard to say
+        // what value we would put in its place.
+        if value.value.is_none() {
+            continue;
+        }
+        // Do the cleanup that we need to do on any argument going out:
+        let trimmed_value_string = value.as_string()?.trim_end_matches('\n').to_string();
+
+        let value_string;
+        #[cfg(not(windows))]
+        {
+            value_string = trimmed_value_string
+                .replace('$', "\\$")
+                .replace('"', "\\\"")
+                .to_string()
+        }
+        #[cfg(windows)]
+        {
+            value_string = trimmed_value_string
+        }
+
+        command_args.push(value_string);
+    }
+
+    let process_args = command_args
         .iter()
         .map(|arg| {
             let arg = expand_tilde(arg.deref(), dirs::home_dir);
 
             #[cfg(not(windows))]
             {
-                if argument_contains_whitespace(&arg) && argument_is_quoted(&arg) {
-                    if let Some(unquoted) = remove_quotes(&arg) {
-                        format!(r#""{}""#, unquoted)
-                    } else {
-                        arg.as_ref().to_string()
-                    }
+                if argument_contains_whitespace(&arg) && !argument_is_quoted(&arg) {
+                    add_quotes(&arg)
                 } else {
                     arg.as_ref().to_string()
                 }
@@ -425,16 +165,17 @@ fn run_with_stdin(
         })
         .collect::<Vec<String>>();
 
-    spawn(&command, &path, &process_args[..], input, is_last)
+    spawn(&command, &path, &process_args[..], input, is_last, scope)
 }
 
 fn spawn(
     command: &ExternalCommand,
     path: &str,
     args: &[String],
-    input: Option<InputStream>,
+    input: InputStream,
     is_last: bool,
-) -> Result<Option<InputStream>, ShellError> {
+    scope: &Scope,
+) -> Result<InputStream, ShellError> {
     let command = command.clone();
 
     let mut process = {
@@ -444,6 +185,8 @@ fn spawn(
             process.arg("/c");
             process.arg(&command.name);
             for arg in args {
+                // Clean the args before we use them:
+                let arg = arg.replace("|", "\\|");
                 process.arg(&arg);
             }
             process
@@ -461,6 +204,9 @@ fn spawn(
     process.current_dir(path);
     trace!(target: "nu::run::external", "cwd = {:?}", &path);
 
+    process.env_clear();
+    process.envs(scope.env.iter());
+
     // We want stdout regardless of what
     // we are doing ($it case or pipe stdin)
     if !is_last {
@@ -469,7 +215,7 @@ fn spawn(
     }
 
     // open since we have some contents for stdin
-    if input.is_some() {
+    if !input.is_empty() {
         process.stdin(Stdio::piped());
         trace!(target: "nu::run::external", "set up stdin pipe");
     }
@@ -488,7 +234,7 @@ fn spawn(
         let stdout_name_tag = command.name_tag;
 
         std::thread::spawn(move || {
-            if let Some(input) = input {
+            if !input.is_empty() {
                 let mut stdin_write = stdin
                     .take()
                     .expect("Internal error: could not get stdin pipe for external command");
@@ -593,16 +339,27 @@ fn spawn(
                                 }
                             }
                         },
-                        Err(_) => {
-                            let _ = stdout_read_tx.send(Ok(Value {
-                                value: UntaggedValue::Error(ShellError::labeled_error(
-                                    "Unable to read from stdout.",
-                                    "unable to read from stdout",
-                                    &stdout_name_tag,
-                                )),
-                                tag: stdout_name_tag.clone(),
-                            }));
-                            break;
+                        Err(e) => {
+                            // If there's an exit status, it makes sense that we may error when
+                            // trying to read from its stdout pipe (likely been closed). In that
+                            // case, don't emit an error.
+                            let should_error = match child.wait() {
+                                Ok(exit_status) => !exit_status.success(),
+                                Err(_) => true,
+                            };
+
+                            if should_error {
+                                let _ = stdout_read_tx.send(Ok(Value {
+                                    value: UntaggedValue::Error(ShellError::labeled_error(
+                                        format!("Unable to read from stdout ({})", e),
+                                        "unable to read from stdout",
+                                        &stdout_name_tag,
+                                    )),
+                                    tag: stdout_name_tag.clone(),
+                                }));
+                            }
+
+                            return Ok(());
                         }
                     }
                 }
@@ -610,7 +367,12 @@ fn spawn(
 
             // We can give an error when we see a non-zero exit code, but this is different
             // than what other shells will do.
-            if child.wait().is_err() {
+            let external_failed = match child.wait() {
+                Err(_) => true,
+                Ok(exit_status) => !exit_status.success(),
+            };
+
+            if external_failed {
                 let cfg = crate::data::config::config(Tag::unknown());
                 if let Ok(cfg) = cfg {
                     if cfg.contains_key("nonzero_exit_errors") {
@@ -620,27 +382,31 @@ fn spawn(
                                 "command failed",
                                 &stdout_name_tag,
                             )),
-                            tag: stdout_name_tag,
+                            tag: stdout_name_tag.clone(),
                         }));
                     }
                 }
+                let _ = stdout_read_tx.send(Ok(Value {
+                    value: UntaggedValue::Error(ShellError::external_non_zero()),
+                    tag: stdout_name_tag,
+                }));
             }
 
             Ok(())
         });
 
         let stream = ThreadedReceiver::new(rx);
-        Ok(Some(stream.to_input_stream()))
+        Ok(stream.to_input_stream())
     } else {
         Err(ShellError::labeled_error(
-            "Command not found",
-            "command not found",
+            "Failed to spawn process",
+            "failed to spawn",
             &command.name_tag,
         ))
     }
 }
 
-fn did_find_command(name: &str) -> bool {
+async fn did_find_command(name: &str) -> bool {
     #[cfg(not(windows))]
     {
         which::which(name).is_ok()
@@ -654,6 +420,7 @@ fn did_find_command(name: &str) -> bool {
             let cmd_builtins = [
                 "call", "cls", "color", "date", "dir", "echo", "find", "hostname", "pause",
                 "start", "time", "title", "ver", "copy", "mkdir", "rename", "rd", "rmdir", "type",
+                "mklink",
             ];
 
             cmd_builtins.contains(&name)
@@ -689,6 +456,7 @@ fn add_quotes(argument: &str) -> String {
     format!("\"{}\"", argument)
 }
 
+#[allow(unused)]
 fn remove_quotes(argument: &str) -> Option<&str> {
     if !argument_is_quoted(argument) {
         return None;
@@ -714,10 +482,11 @@ 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,
+        run_external_command, Context, InputStream,
     };
     use futures::executor::block_on;
     use nu_errors::ShellError;
+    use nu_protocol::Scope;
     use nu_test_support::commands::ExternalBuilder;
 
     // async fn read(mut stream: OutputStream) -> Option<Value> {
@@ -736,9 +505,14 @@ mod tests {
     async fn non_existent_run() -> Result<(), ShellError> {
         let cmd = ExternalBuilder::for_name("i_dont_exist.exe").build();
 
+        let input = InputStream::empty();
         let mut ctx = Context::basic().expect("There was a problem creating a basic context.");
 
-        assert!(run_external_command(cmd, &mut ctx, None, false).is_err());
+        assert!(
+            run_external_command(cmd, &mut ctx, input, &Scope::empty(), false)
+                .await
+                .is_err()
+        );
 
         Ok(())
     }

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

@@ -1,43 +1,39 @@
+use crate::commands::command::whole_stream_command;
+use crate::commands::run_alias::AliasCommand;
 use crate::commands::UnevaluatedCallInfo;
 use crate::prelude::*;
 use log::{log_enabled, trace};
 use nu_errors::ShellError;
-use nu_parser::InternalCommand;
-use nu_protocol::{CommandAction, Primitive, ReturnSuccess, UntaggedValue, Value};
+use nu_protocol::hir::InternalCommand;
+use nu_protocol::{CommandAction, Primitive, ReturnSuccess, Scope, UntaggedValue, Value};
 
 pub(crate) fn run_internal_command(
     command: InternalCommand,
     context: &mut Context,
-    input: Option<InputStream>,
-    source: Text,
-) -> Result<Option<InputStream>, ShellError> {
+    input: InputStream,
+    scope: &Scope,
+) -> Result<InputStream, ShellError> {
     if log_enabled!(log::Level::Trace) {
         trace!(target: "nu::run::internal", "->");
         trace!(target: "nu::run::internal", "{}", command.name);
-        trace!(target: "nu::run::internal", "{}", command.args.debug(&source));
     }
 
-    let objects: InputStream = if let Some(input) = input {
-        trace_stream!(target: "nu::trace_stream::internal", "input" = input)
-    } else {
-        InputStream::empty()
-    };
-
+    let objects: InputStream = trace_stream!(target: "nu::trace_stream::internal", "input" = input);
     let internal_command = context.expect_command(&command.name);
 
     let result = {
         context.run_command(
             internal_command?,
-            command.name_tag.clone(),
+            Tag::unknown_anchor(command.name_span),
             command.args.clone(),
-            &source,
+            scope,
             objects,
         )
     };
 
-    let result = trace_out_stream!(target: "nu::trace_stream::internal", "output" = result);
-    let mut result = result.values;
+    let mut result = trace_out_stream!(target: "nu::trace_stream::internal", "output" = result);
     let mut context = context.clone();
+    let scope = scope.clone();
 
     let stream = async_stream! {
         let mut soft_errs: Vec<ShellError> = vec![];
@@ -56,7 +52,7 @@ pub(crate) fn run_internal_command(
                     }
                     CommandAction::AutoConvert(tagged_contents, extension) => {
                         let contents_tag = tagged_contents.tag.clone();
-                        let command_name = format!("from-{}", extension);
+                        let command_name = format!("from {}", extension);
                         let command = command.clone();
                         if let Some(converter) = context.registry.get_command(&command_name) {
                             let new_args = RawCommandArgs {
@@ -64,14 +60,15 @@ pub(crate) fn run_internal_command(
                                 ctrl_c: context.ctrl_c.clone(),
                                 shell_manager: context.shell_manager.clone(),
                                 call_info: UnevaluatedCallInfo {
-                                    args: nu_parser::hir::Call {
+                                    args: nu_protocol::hir::Call {
                                         head: command.args.head,
                                         positional: None,
                                         named: None,
-                                        span: Span::unknown()
+                                        span: Span::unknown(),
+                                        is_last: false,
                                     },
-                                    source: source.clone(),
-                                    name_tag: command.name_tag,
+                                    name_tag: Tag::unknown_anchor(command.name_span),
+                                    scope: scope.clone(),
                                 }
                             };
                             let mut result = converter.run(new_args.with_input(vec![tagged_contents]), &context.registry);
@@ -121,9 +118,18 @@ pub(crate) fn run_internal_command(
                     }
                     CommandAction::EnterShell(location) => {
                         context.shell_manager.insert_at_current(Box::new(
-                            FilesystemShell::with_location(location, context.registry().clone()),
+                            FilesystemShell::with_location(location, context.registry().clone())?,
                         ));
                     }
+                    CommandAction::AddAlias(name, args, block) => {
+                        context.add_commands(vec![
+                            whole_stream_command(AliasCommand::new(
+                                name,
+                                args,
+                                block,
+                            ))
+                        ]);
+                    }
                     CommandAction::PreviousShell => {
                         context.shell_manager.prev();
                     }
@@ -142,7 +148,8 @@ pub(crate) fn run_internal_command(
                     value: UntaggedValue::Error(err),
                     ..
                 })) => {
-                    context.error(err);
+                    context.error(err.clone());
+                    yield Err(err);
                     break;
                 }
 
@@ -175,5 +182,5 @@ pub(crate) fn run_internal_command(
         }
     };
 
-    Ok(Some(stream.to_input_stream()))
+    Ok(stream.to_input_stream())
 }

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

@@ -1,7 +1,8 @@
+pub(crate) mod block;
 mod dynamic;
+pub(crate) mod expr;
 pub(crate) mod external;
 pub(crate) mod internal;
-pub(crate) mod pipeline;
 
 #[allow(unused_imports)]
 pub(crate) use dynamic::Command as DynamicCommand;

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

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

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

@@ -23,6 +23,12 @@ impl WholeStreamCommand for Clear {
     ) -> Result<OutputStream, ShellError> {
         clear(args, registry)
     }
+    fn examples(&self) -> &[Example] {
+        &[Example {
+            description: "Clear the screen",
+            example: "clear",
+        }]
+    }
 }
 fn clear(_args: CommandArgs, _registry: &CommandRegistry) -> Result<OutputStream, ShellError> {
     if cfg!(windows) {

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

@@ -34,6 +34,13 @@ pub mod clipboard {
         ) -> Result<OutputStream, ShellError> {
             args.process(registry, clip)?.run()
         }
+
+        fn examples(&self) -> &[Example] {
+            &[Example {
+                description: "Save text to the clipboard",
+                example: "echo 'secret value' | clip",
+            }]
+        }
     }
 
     pub fn clip(
@@ -41,7 +48,7 @@ pub mod clipboard {
         RunnableContext { input, name, .. }: RunnableContext,
     ) -> Result<OutputStream, ShellError> {
         let stream = async_stream! {
-            let values: Vec<Value> = input.values.collect().await;
+            let values: Vec<Value> = input.collect().await;
 
             let mut clip_stream = inner_clip(values, name).await;
             while let Some(value) = clip_stream.next().await {

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

@@ -6,7 +6,7 @@ use crate::prelude::*;
 use derive_new::new;
 use getset::Getters;
 use nu_errors::ShellError;
-use nu_parser::hir;
+use nu_protocol::hir;
 use nu_protocol::{CallInfo, EvaluatedArgs, ReturnValue, Scope, Signature, Value};
 use serde::{Deserialize, Serialize};
 use std::ops::Deref;
@@ -15,17 +15,28 @@ use std::sync::atomic::AtomicBool;
 #[derive(Deserialize, Serialize, Debug, Clone)]
 pub struct UnevaluatedCallInfo {
     pub args: hir::Call,
-    pub source: Text,
     pub name_tag: Tag,
+    pub scope: Scope,
 }
 
 impl UnevaluatedCallInfo {
-    pub fn evaluate(
+    pub fn evaluate(self, registry: &CommandRegistry) -> Result<CallInfo, ShellError> {
+        let args = evaluate_args(&self.args, registry, &self.scope)?;
+
+        Ok(CallInfo {
+            args,
+            name_tag: self.name_tag,
+        })
+    }
+
+    pub fn evaluate_with_new_it(
         self,
         registry: &CommandRegistry,
-        scope: &Scope,
+        it: &Value,
     ) -> Result<CallInfo, ShellError> {
-        let args = evaluate_args(&self.args, registry, scope, &self.source)?;
+        let mut scope = self.scope.clone();
+        scope = scope.set_it(it.clone());
+        let args = evaluate_args(&self.args, registry, &scope)?;
 
         Ok(CallInfo {
             args,
@@ -38,36 +49,6 @@ impl UnevaluatedCallInfo {
     }
 }
 
-pub trait CallInfoExt {
-    fn process<'de, T: Deserialize<'de>>(
-        &self,
-        shell_manager: &ShellManager,
-        ctrl_c: Arc<AtomicBool>,
-        callback: fn(T, &RunnablePerItemContext) -> Result<OutputStream, ShellError>,
-    ) -> Result<RunnablePerItemArgs<T>, ShellError>;
-}
-
-impl CallInfoExt for CallInfo {
-    fn process<'de, T: Deserialize<'de>>(
-        &self,
-        shell_manager: &ShellManager,
-        ctrl_c: Arc<AtomicBool>,
-        callback: fn(T, &RunnablePerItemContext) -> Result<OutputStream, ShellError>,
-    ) -> Result<RunnablePerItemArgs<T>, ShellError> {
-        let mut deserializer = ConfigDeserializer::from_call_info(self.clone());
-
-        Ok(RunnablePerItemArgs {
-            args: T::deserialize(&mut deserializer)?,
-            context: RunnablePerItemContext {
-                shell_manager: shell_manager.clone(),
-                name: self.name_tag.clone(),
-                ctrl_c,
-            },
-            callback,
-        })
-    }
-}
-
 #[derive(Getters)]
 #[get = "pub(crate)"]
 pub struct CommandArgs {
@@ -114,7 +95,7 @@ impl CommandArgs {
         let ctrl_c = self.ctrl_c.clone();
         let shell_manager = self.shell_manager.clone();
         let input = self.input;
-        let call_info = self.call_info.evaluate(registry, &Scope::empty())?;
+        let call_info = self.call_info.evaluate(registry)?;
 
         Ok(EvaluatedWholeStreamCommandArgs::new(
             host,
@@ -134,7 +115,12 @@ impl CommandArgs {
         let ctrl_c = self.ctrl_c.clone();
         let shell_manager = self.shell_manager.clone();
         let input = self.input;
-        let call_info = self.call_info.evaluate(registry, scope)?;
+        let call_info = UnevaluatedCallInfo {
+            name_tag: self.call_info.name_tag,
+            args: self.call_info.args,
+            scope: scope.clone(),
+        };
+        let call_info = call_info.evaluate(registry)?;
 
         Ok(EvaluatedWholeStreamCommandArgs::new(
             host,
@@ -145,10 +131,6 @@ impl CommandArgs {
         ))
     }
 
-    pub fn source(&self) -> Text {
-        self.call_info.source.clone()
-    }
-
     pub fn process<'de, T: Deserialize<'de>, O: ToOutputStream>(
         self,
         registry: &CommandRegistry,
@@ -156,7 +138,6 @@ impl CommandArgs {
     ) -> Result<RunnableArgs<T, O>, ShellError> {
         let shell_manager = self.shell_manager.clone();
         let host = self.host.clone();
-        let source = self.source();
         let ctrl_c = self.ctrl_c.clone();
         let args = self.evaluate_once(registry)?;
         let call_info = args.call_info.clone();
@@ -168,8 +149,7 @@ impl CommandArgs {
             args: T::deserialize(&mut deserializer)?,
             context: RunnableContext {
                 input,
-                commands: registry.clone(),
-                source,
+                registry: registry.clone(),
                 shell_manager,
                 name: name_tag,
                 host,
@@ -193,7 +173,6 @@ impl CommandArgs {
 
         let shell_manager = self.shell_manager.clone();
         let host = self.host.clone();
-        let source = self.source();
         let ctrl_c = self.ctrl_c.clone();
         let args = self.evaluate_once(registry)?;
         let call_info = args.call_info.clone();
@@ -206,8 +185,7 @@ impl CommandArgs {
             args: T::deserialize(&mut deserializer)?,
             context: RunnableContext {
                 input,
-                commands: registry.clone(),
-                source,
+                registry: registry.clone(),
                 shell_manager,
                 name: name_tag,
                 host,
@@ -219,37 +197,18 @@ impl CommandArgs {
     }
 }
 
-pub struct RunnablePerItemContext {
-    pub shell_manager: ShellManager,
-    pub name: Tag,
-    pub ctrl_c: Arc<AtomicBool>,
-}
-
 pub struct RunnableContext {
     pub input: InputStream,
     pub shell_manager: ShellManager,
     pub host: Arc<parking_lot::Mutex<Box<dyn Host>>>,
-    pub source: Text,
     pub ctrl_c: Arc<AtomicBool>,
-    pub commands: CommandRegistry,
+    pub registry: CommandRegistry,
     pub name: Tag,
 }
 
 impl RunnableContext {
-    pub fn get_command(&self, name: &str) -> Option<Arc<Command>> {
-        self.commands.get_command(name)
-    }
-}
-
-pub struct RunnablePerItemArgs<T> {
-    args: T,
-    context: RunnablePerItemContext,
-    callback: fn(T, &RunnablePerItemContext) -> Result<OutputStream, ShellError>,
-}
-
-impl<T> RunnablePerItemArgs<T> {
-    pub fn run(self) -> Result<OutputStream, ShellError> {
-        (self.callback)(self.args, &self.context)
+    pub fn get_command(&self, name: &str) -> Option<Command> {
+        self.registry.get_command(name)
     }
 }
 
@@ -374,6 +333,14 @@ impl EvaluatedCommandArgs {
         self.call_info.args.nth(pos)
     }
 
+    /// Get the nth positional argument, error if not possible
+    pub fn expect_nth(&self, pos: usize) -> Result<&Value, ShellError> {
+        match self.call_info.args.nth(pos) {
+            None => Err(ShellError::unimplemented("Better error: expect_nth")),
+            Some(item) => Ok(item),
+        }
+    }
+
     pub fn get(&self, name: &str) -> Option<&Value> {
         self.call_info.args.get(name)
     }
@@ -383,6 +350,11 @@ impl EvaluatedCommandArgs {
     }
 }
 
+pub struct Example {
+    pub example: &'static str,
+    pub description: &'static str,
+}
+
 pub trait WholeStreamCommand: Send + Sync {
     fn name(&self) -> &str;
 
@@ -401,147 +373,64 @@ pub trait WholeStreamCommand: Send + Sync {
     fn is_binary(&self) -> bool {
         false
     }
-}
 
-pub trait PerItemCommand: Send + Sync {
-    fn name(&self) -> &str;
-
-    fn signature(&self) -> Signature {
-        Signature::new(self.name()).desc(self.usage()).filter()
-    }
-
-    fn usage(&self) -> &str;
-
-    fn run(
-        &self,
-        call_info: &CallInfo,
-        registry: &CommandRegistry,
-        raw_args: &RawCommandArgs,
-        input: Value,
-    ) -> Result<OutputStream, ShellError>;
-
-    fn is_binary(&self) -> bool {
-        false
+    fn examples(&self) -> &[Example] {
+        &[]
     }
 }
 
-pub enum Command {
-    WholeStream(Arc<dyn WholeStreamCommand>),
-    PerItem(Arc<dyn PerItemCommand>),
-}
+#[derive(Clone)]
+pub struct Command(Arc<dyn WholeStreamCommand>);
 
 impl PrettyDebugWithSource for Command {
     fn pretty_debug(&self, source: &str) -> DebugDocBuilder {
-        match self {
-            Command::WholeStream(command) => b::typed(
-                "whole stream command",
-                b::description(command.name())
-                    + b::space()
-                    + b::equals()
-                    + b::space()
-                    + command.signature().pretty_debug(source),
-            ),
-            Command::PerItem(command) => b::typed(
-                "per item command",
-                b::description(command.name())
-                    + b::space()
-                    + b::equals()
-                    + b::space()
-                    + command.signature().pretty_debug(source),
-            ),
-        }
+        b::typed(
+            "whole stream command",
+            b::description(self.name())
+                + b::space()
+                + b::equals()
+                + b::space()
+                + self.signature().pretty_debug(source),
+        )
     }
 }
 
 impl std::fmt::Debug for Command {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        match self {
-            Command::WholeStream(command) => write!(f, "WholeStream({})", command.name()),
-            Command::PerItem(command) => write!(f, "PerItem({})", command.name()),
-        }
+        write!(f, "Command({})", self.name())
     }
 }
 
 impl Command {
     pub fn name(&self) -> &str {
-        match self {
-            Command::WholeStream(command) => command.name(),
-            Command::PerItem(command) => command.name(),
-        }
+        self.0.name()
     }
 
     pub fn signature(&self) -> Signature {
-        match self {
-            Command::WholeStream(command) => command.signature(),
-            Command::PerItem(command) => command.signature(),
-        }
+        self.0.signature()
     }
 
     pub fn usage(&self) -> &str {
-        match self {
-            Command::WholeStream(command) => command.usage(),
-            Command::PerItem(command) => command.usage(),
-        }
+        self.0.usage()
     }
 
     pub fn run(&self, args: CommandArgs, registry: &CommandRegistry) -> OutputStream {
         if args.call_info.switch_present("help") {
-            get_help(self.name(), self.usage(), self.signature()).into()
+            get_help(&*self.0, registry).into()
         } else {
-            match self {
-                Command::WholeStream(command) => match command.run(args, registry) {
-                    Ok(stream) => stream,
-                    Err(err) => OutputStream::one(Err(err)),
-                },
-                Command::PerItem(command) => {
-                    self.run_helper(command.clone(), args, registry.clone())
-                }
+            match self.0.run(args, registry) {
+                Ok(stream) => stream,
+                Err(err) => OutputStream::one(Err(err)),
             }
         }
     }
 
-    fn run_helper(
-        &self,
-        command: Arc<dyn PerItemCommand>,
-        args: CommandArgs,
-        registry: CommandRegistry,
-    ) -> OutputStream {
-        let raw_args = RawCommandArgs {
-            host: args.host,
-            ctrl_c: args.ctrl_c,
-            shell_manager: args.shell_manager,
-            call_info: args.call_info,
-        };
-
-        let out = args
-            .input
-            .values
-            .map(move |x| {
-                let call_info = raw_args
-                    .clone()
-                    .call_info
-                    .evaluate(&registry, &Scope::it_value(x.clone()));
-
-                match call_info {
-                    Ok(call_info) => match command.run(&call_info, &registry, &raw_args, x) {
-                        Ok(o) => o,
-                        Err(e) => {
-                            futures::stream::iter(vec![ReturnValue::Err(e)]).to_output_stream()
-                        }
-                    },
-                    Err(e) => futures::stream::iter(vec![ReturnValue::Err(e)]).to_output_stream(),
-                }
-            })
-            .flatten();
-
-        out.to_output_stream()
+    pub fn is_binary(&self) -> bool {
+        self.0.is_binary()
     }
 
-    pub fn is_binary(&self) -> bool {
-        match self {
-            Command::WholeStream(command) => command.is_binary(),
-            Command::PerItem(command) => command.is_binary(),
-        }
+    pub fn stream_command(&self) -> &dyn WholeStreamCommand {
+        &*self.0
     }
 }
 
@@ -576,9 +465,9 @@ impl WholeStreamCommand for FnFilterCommand {
         let registry: CommandRegistry = registry.clone();
         let func = self.func;
 
-        let result = input.values.map(move |it| {
+        let result = input.map(move |it| {
             let registry = registry.clone();
-            let call_info = match call_info.clone().evaluate(&registry, &Scope::it_value(it)) {
+            let call_info = match call_info.clone().evaluate_with_new_it(&registry, &it) {
                 Err(err) => return OutputStream::from(vec![Err(err)]).values,
                 Ok(args) => args,
             };
@@ -603,10 +492,6 @@ impl WholeStreamCommand for FnFilterCommand {
     }
 }
 
-pub fn whole_stream_command(command: impl WholeStreamCommand + 'static) -> Arc<Command> {
-    Arc::new(Command::WholeStream(Arc::new(command)))
-}
-
-pub fn per_item_command(command: impl PerItemCommand + 'static) -> Arc<Command> {
-    Arc::new(Command::PerItem(Arc::new(command)))
+pub fn whole_stream_command(command: impl WholeStreamCommand + 'static) -> Command {
+    Command(Arc::new(command))
 }

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

@@ -33,13 +33,20 @@ impl WholeStreamCommand for Compact {
     ) -> Result<OutputStream, ShellError> {
         args.process(registry, compact)?.run()
     }
+
+    fn examples(&self) -> &[Example] {
+        &[Example {
+            description: "Remove all directory entries, except those with a 'target'",
+            example: "ls -af | compact target",
+        }]
+    }
 }
 
 pub fn compact(
     CompactArgs { rest: columns }: CompactArgs,
     RunnableContext { input, .. }: RunnableContext,
 ) -> Result<OutputStream, ShellError> {
-    let objects = input.values.filter(move |item| {
+    let objects = input.filter(move |item| {
         let keep = if columns.is_empty() {
             item.is_some()
         } else {

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

@@ -41,7 +41,7 @@ impl WholeStreamCommand for Config {
             )
             .named(
                 "set_into",
-                SyntaxShape::Member,
+                SyntaxShape::String,
                 "sets a variable from values in the pipeline",
                 Some('i'),
             )
@@ -72,6 +72,39 @@ impl WholeStreamCommand for Config {
     ) -> Result<OutputStream, ShellError> {
         args.process(registry, config)?.run()
     }
+
+    fn examples(&self) -> &[Example] {
+        &[
+            Example {
+                description: "See all config values",
+                example: "config",
+            },
+            Example {
+                description: "Set completion_mode to circular",
+                example: "config --set [completion_mode circular]",
+            },
+            Example {
+                description: "Store the contents of the pipeline as a path",
+                example: "echo ['/usr/bin' '/bin'] | config --set_into path",
+            },
+            Example {
+                description: "Get the current startup commands",
+                example: "config --get startup",
+            },
+            Example {
+                description: "Remove the startup commands",
+                example: "config --remove startup",
+            },
+            Example {
+                description: "Clear the config (be careful!)",
+                example: "config --clear",
+            },
+            Example {
+                description: "Get the path to the current config file",
+                example: "config --path",
+            },
+        ]
+    }
 }
 
 pub fn config(
@@ -124,7 +157,7 @@ pub fn config(
             yield ReturnSuccess::value(UntaggedValue::Row(result.into()).into_value(&value.tag));
         }
         else if let Some(v) = set_into {
-            let rows: Vec<Value> = input.values.collect().await;
+            let rows: Vec<Value> = input.collect().await;
             let key = v.to_string();
 
             if rows.len() == 0 {

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

@@ -20,7 +20,7 @@ impl WholeStreamCommand for Count {
     }
 
     fn usage(&self) -> &str {
-        "Show the total number of rows."
+        "Show the total number of rows or items."
     }
 
     fn run(
@@ -30,6 +30,13 @@ impl WholeStreamCommand for Count {
     ) -> Result<OutputStream, ShellError> {
         args.process(registry, count)?.run()
     }
+
+    fn examples(&self) -> &[Example] {
+        &[Example {
+            description: "Count the number of files/directories in the current directory",
+            example: "ls | count",
+        }]
+    }
 }
 
 pub fn count(
@@ -37,7 +44,7 @@ pub fn count(
     RunnableContext { input, name, .. }: RunnableContext,
 ) -> Result<OutputStream, ShellError> {
     let stream = async_stream! {
-        let rows: Vec<Value> = input.values.collect().await;
+        let rows: Vec<Value> = input.collect().await;
 
         yield ReturnSuccess::value(UntaggedValue::int(rows.len()).into_value(name))
     };

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

@@ -1,8 +1,8 @@
-use crate::commands::command::RunnablePerItemContext;
+use crate::commands::WholeStreamCommand;
 use crate::context::CommandRegistry;
 use crate::prelude::*;
 use nu_errors::ShellError;
-use nu_protocol::{CallInfo, Signature, SyntaxShape, Value};
+use nu_protocol::{Signature, SyntaxShape};
 use nu_source::Tagged;
 use std::path::PathBuf;
 
@@ -15,7 +15,7 @@ pub struct CopyArgs {
     pub recursive: Tagged<bool>,
 }
 
-impl PerItemCommand for Cpy {
+impl WholeStreamCommand for Cpy {
     fn name(&self) -> &str {
         "cp"
     }
@@ -37,18 +37,27 @@ impl PerItemCommand for Cpy {
 
     fn run(
         &self,
-        call_info: &CallInfo,
-        _registry: &CommandRegistry,
-        raw_args: &RawCommandArgs,
-        _input: Value,
+        args: CommandArgs,
+        registry: &CommandRegistry,
     ) -> Result<OutputStream, ShellError> {
-        call_info
-            .process(&raw_args.shell_manager, raw_args.ctrl_c.clone(), cp)?
-            .run()
+        args.process(registry, cp)?.run()
+    }
+
+    fn examples(&self) -> &[Example] {
+        &[
+            Example {
+                description: "Copy myfile to dir_b",
+                example: "cp myfile dir_b",
+            },
+            Example {
+                description: "Recursively copy dir_a to dir_b",
+                example: "cp -r dir_a dir_b",
+            },
+        ]
     }
 }
 
-fn cp(args: CopyArgs, context: &RunnablePerItemContext) -> Result<OutputStream, ShellError> {
+pub fn cp(args: CopyArgs, context: RunnableContext) -> Result<OutputStream, ShellError> {
     let shell_manager = context.shell_manager.clone();
-    shell_manager.cp(args, context)
+    shell_manager.cp(args, &context)
 }

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

@@ -33,6 +33,19 @@ impl WholeStreamCommand for Date {
     ) -> Result<OutputStream, ShellError> {
         date(args, registry)
     }
+
+    fn examples(&self) -> &[Example] {
+        &[
+            Example {
+                description: "Get the current local time and date",
+                example: "date",
+            },
+            Example {
+                description: "Get the current UTC time and date",
+                example: "date --utc",
+            },
+        ]
+    }
 }
 
 pub fn date_to_value<T: TimeZone>(dt: DateTime<T>, tag: Tag) -> Value

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

@@ -37,7 +37,6 @@ fn debug_value(
     RunnableContext { input, .. }: RunnableContext,
 ) -> Result<impl ToOutputStream, ShellError> {
     Ok(input
-        .values
         .map(move |v| {
             if raw {
                 ReturnSuccess::value(

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

@@ -40,6 +40,13 @@ impl WholeStreamCommand for Default {
     ) -> Result<OutputStream, ShellError> {
         args.process(registry, default)?.run()
     }
+
+    fn examples(&self) -> &[Example] {
+        &[Example {
+            description: "Give a default 'target' to all file entries",
+            example: "ls -af | default target 'nothing'",
+        }]
+    }
 }
 
 fn default(
@@ -47,7 +54,6 @@ fn default(
     RunnableContext { input, .. }: RunnableContext,
 ) -> Result<OutputStream, ShellError> {
     let stream = input
-        .values
         .map(move |item| {
             let mut result = VecDeque::new();
 

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

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

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

@@ -1,15 +1,12 @@
-extern crate filesize;
-
-use crate::commands::command::RunnablePerItemContext;
+use crate::commands::WholeStreamCommand;
 use crate::prelude::*;
 use filesize::file_real_size_fast;
 use glob::*;
 use indexmap::map::IndexMap;
 use nu_errors::ShellError;
-use nu_protocol::{CallInfo, ReturnSuccess, Signature, SyntaxShape, UntaggedValue, Value};
+use nu_protocol::{ReturnSuccess, Signature, SyntaxShape, UntaggedValue, Value};
 use nu_source::Tagged;
 use std::path::PathBuf;
-use std::sync::atomic::Ordering;
 
 const NAME: &str = "du";
 const GLOB_PARAMS: MatchOptions = MatchOptions {
@@ -32,7 +29,7 @@ pub struct DuArgs {
     min_size: Option<Tagged<u64>>,
 }
 
-impl PerItemCommand for Du {
+impl WholeStreamCommand for Du {
     fn name(&self) -> &str {
         NAME
     }
@@ -42,7 +39,7 @@ impl PerItemCommand for Du {
             .optional("path", SyntaxShape::Pattern, "starting directory")
             .switch(
                 "all",
-                "Output File sizes as well as directory sizes",
+                "Output file sizes as well as directory sizes",
                 Some('a'),
             )
             .switch(
@@ -76,113 +73,110 @@ impl PerItemCommand for Du {
 
     fn run(
         &self,
-        call_info: &CallInfo,
-        _registry: &CommandRegistry,
-        raw_args: &RawCommandArgs,
-        _input: Value,
+        args: CommandArgs,
+        registry: &CommandRegistry,
     ) -> Result<OutputStream, ShellError> {
-        call_info
-            .process(&raw_args.shell_manager, raw_args.ctrl_c.clone(), du)?
-            .run()
+        args.process(registry, du)?.run()
+    }
+
+    fn examples(&self) -> &[Example] {
+        &[Example {
+            description: "Disk usage of the current directory",
+            example: "du *",
+        }]
     }
 }
 
-fn du(args: DuArgs, ctx: &RunnablePerItemContext) -> Result<OutputStream, ShellError> {
+fn du(args: DuArgs, ctx: RunnableContext) -> Result<OutputStream, ShellError> {
     let tag = ctx.name.clone();
 
-    let exclude = args
-        .exclude
-        .clone()
-        .map_or(Ok(None), move |x| match Pattern::new(&x.item) {
-            Ok(p) => Ok(Some(p)),
-            Err(e) => Err(ShellError::labeled_error(
-                e.msg,
-                "Glob error",
-                x.tag.clone(),
-            )),
-        })?;
-    let path = args.path.clone();
-    let filter_files = path.is_none();
-    let paths = match path {
-        Some(p) => match glob::glob_with(
-            p.item.to_str().expect("Why isn't this encoded properly?"),
-            GLOB_PARAMS,
-        ) {
-            Ok(g) => Ok(g),
-            Err(e) => Err(ShellError::labeled_error(
-                e.msg,
-                "Glob error",
-                p.tag.clone(),
-            )),
-        },
-        None => match glob::glob_with("*", GLOB_PARAMS) {
-            Ok(g) => Ok(g),
-            Err(e) => Err(ShellError::labeled_error(e.msg, "Glob error", tag.clone())),
-        },
-    }?
+    let exclude = args.exclude.map_or(Ok(None), move |x| {
+        Pattern::new(&x.item)
+            .map(Option::Some)
+            .map_err(|e| ShellError::labeled_error(e.msg, "glob error", x.tag.clone()))
+    })?;
+
+    let include_files = args.all;
+    let paths = match args.path {
+        Some(p) => {
+            let p = p.item.to_str().expect("Why isn't this encoded properly?");
+            glob::glob_with(p, GLOB_PARAMS)
+        }
+        None => glob::glob_with("*", GLOB_PARAMS),
+    }
+    .map_err(|e| ShellError::labeled_error(e.msg, "glob error", tag.clone()))?
     .filter(move |p| {
-        if filter_files {
+        if include_files {
+            true
+        } else {
             match p {
                 Ok(f) if f.is_dir() => true,
                 Err(e) if e.path().is_dir() => true,
                 _ => false,
             }
-        } else {
-            true
         }
     })
-    .map(move |p| match p {
-        Err(e) => Err(glob_err_into(e)),
-        Ok(s) => Ok(s),
-    });
+    .map(|v| v.map_err(glob_err_into));
 
-    let ctrl_c = ctx.ctrl_c.clone();
+    let ctrl_c = ctx.ctrl_c;
     let all = args.all;
     let deref = args.deref;
     let max_depth = args.max_depth.map(|f| f.item);
     let min_size = args.min_size.map(|f| f.item);
 
-    let stream = async_stream! {
-        let params = DirBuilder {
-            tag: tag.clone(),
-            min: min_size,
-            deref,
-            ex: exclude,
-            all,
-        };
-        for path in paths {
-            if ctrl_c.load(Ordering::SeqCst) {
-                break;
-            }
-            match path {
-                Ok(p) => {
-                    if p.is_dir() {
-                        yield Ok(ReturnSuccess::Value(
-                            DirInfo::new(p, &params, max_depth).into(),
-                        ));
-                    } else {
-                        match FileInfo::new(p, deref, tag.clone()) {
-                            Ok(f) => yield Ok(ReturnSuccess::Value(f.into())),
-                            Err(e) => yield Err(e)
-                        }
-                    }
-                }
-                Err(e) => yield Err(e),
-            }
-        }
+    let params = DirBuilder {
+        tag: tag.clone(),
+        min: min_size,
+        deref,
+        exclude,
+        all,
     };
+
+    let stream = futures::stream::iter(paths)
+        .interruptible(ctrl_c)
+        .map(move |path| match path {
+            Ok(p) => {
+                if p.is_dir() {
+                    Ok(ReturnSuccess::Value(
+                        DirInfo::new(p, &params, max_depth).into(),
+                    ))
+                } else {
+                    FileInfo::new(p, deref, tag.clone()).map(|v| ReturnSuccess::Value(v.into()))
+                }
+            }
+            Err(e) => Err(e),
+        });
+
     Ok(stream.to_output_stream())
 }
 
-struct DirBuilder {
+pub struct DirBuilder {
     tag: Tag,
     min: Option<u64>,
     deref: bool,
-    ex: Option<Pattern>,
+    exclude: Option<Pattern>,
     all: bool,
 }
 
-struct DirInfo {
+impl DirBuilder {
+    pub fn new(
+        tag: Tag,
+        min: Option<u64>,
+        deref: bool,
+        exclude: Option<Pattern>,
+        all: bool,
+    ) -> DirBuilder {
+        DirBuilder {
+            tag,
+            min,
+            deref,
+            exclude,
+            all,
+        }
+    }
+}
+
+pub struct DirInfo {
     dirs: Vec<DirInfo>,
     files: Vec<FileInfo>,
     errors: Vec<ShellError>,
@@ -225,7 +219,7 @@ impl FileInfo {
 }
 
 impl DirInfo {
-    fn new(path: impl Into<PathBuf>, params: &DirBuilder, depth: Option<u64>) -> Self {
+    pub fn new(path: impl Into<PathBuf>, params: &DirBuilder, depth: Option<u64>) -> Self {
         let path = path.into();
 
         let mut s = Self {
@@ -243,15 +237,11 @@ impl DirInfo {
                 for f in d {
                     match f {
                         Ok(i) => match i.file_type() {
-                            Ok(t) if t.is_dir() => {
-                                s = s.add_dir(i.path(), depth, &params);
-                            }
-                            Ok(_t) => {
-                                s = s.add_file(i.path(), &params);
-                            }
-                            Err(e) => s = s.add_error(ShellError::from(e)),
+                            Ok(t) if t.is_dir() => s = s.add_dir(i.path(), depth, &params),
+                            Ok(_t) => s = s.add_file(i.path(), &params),
+                            Err(e) => s = s.add_error(e.into()),
                         },
-                        Err(e) => s = s.add_error(ShellError::from(e)),
+                        Err(e) => s = s.add_error(e.into()),
                     }
                 }
             }
@@ -283,8 +273,11 @@ impl DirInfo {
 
     fn add_file(mut self, f: impl Into<PathBuf>, params: &DirBuilder) -> Self {
         let f = f.into();
-        let ex = params.ex.as_ref().map_or(false, |x| x.matches_path(&f));
-        if !ex {
+        let include = params
+            .exclude
+            .as_ref()
+            .map_or(true, |x| !x.matches_path(&f));
+        if include {
             match FileInfo::new(f, params.deref, self.tag.clone()) {
                 Ok(file) => {
                     let inc = params.min.map_or(true, |s| file.size >= s);
@@ -306,6 +299,10 @@ impl DirInfo {
         self.errors.push(e);
         self
     }
+
+    pub fn get_size(&self) -> u64 {
+        self.size
+    }
 }
 
 fn glob_err_into(e: GlobError) -> ShellError {
@@ -313,55 +310,51 @@ fn glob_err_into(e: GlobError) -> ShellError {
     ShellError::from(e)
 }
 
+fn value_from_vec<V>(vec: Vec<V>, tag: &Tag) -> Value
+where
+    V: Into<Value>,
+{
+    if vec.is_empty() {
+        UntaggedValue::nothing()
+    } else {
+        let values = vec.into_iter().map(Into::into).collect::<Vec<Value>>();
+        UntaggedValue::Table(values)
+    }
+    .retag(tag)
+}
+
 impl From<DirInfo> for Value {
     fn from(d: DirInfo) -> Self {
         let mut r: IndexMap<String, Value> = IndexMap::new();
+
         r.insert(
             "path".to_string(),
-            UntaggedValue::path(d.path).retag(d.tag.clone()),
+            UntaggedValue::path(d.path).retag(&d.tag),
         );
+
         r.insert(
             "apparent".to_string(),
-            UntaggedValue::bytes(d.size).retag(d.tag.clone()),
+            UntaggedValue::bytes(d.size).retag(&d.tag),
         );
+
         r.insert(
             "physical".to_string(),
-            UntaggedValue::bytes(d.blocks).retag(d.tag.clone()),
+            UntaggedValue::bytes(d.blocks).retag(&d.tag),
         );
-        if !d.files.is_empty() {
-            let v = Value {
-                value: UntaggedValue::Table(
-                    d.files
-                        .into_iter()
-                        .map(move |f| f.into())
-                        .collect::<Vec<Value>>(),
-                ),
-                tag: d.tag.clone(),
-            };
-            r.insert("files".to_string(), v);
-        }
-        if !d.dirs.is_empty() {
-            let v = Value {
-                value: UntaggedValue::Table(
-                    d.dirs
-                        .into_iter()
-                        .map(move |d| d.into())
-                        .collect::<Vec<Value>>(),
-                ),
-                tag: d.tag.clone(),
-            };
-            r.insert("directories".to_string(), v);
-        }
+
+        r.insert("directories".to_string(), value_from_vec(d.dirs, &d.tag));
+
+        r.insert("files".to_string(), value_from_vec(d.files, &d.tag));
+
         if !d.errors.is_empty() {
-            let v = Value {
-                value: UntaggedValue::Table(
-                    d.errors
-                        .into_iter()
-                        .map(move |e| UntaggedValue::Error(e).into_untagged_value())
-                        .collect::<Vec<Value>>(),
-                ),
-                tag: d.tag.clone(),
-            };
+            let v = UntaggedValue::Table(
+                d.errors
+                    .into_iter()
+                    .map(move |e| UntaggedValue::Error(e).into_untagged_value())
+                    .collect::<Vec<Value>>(),
+            )
+            .retag(&d.tag);
+
             r.insert("errors".to_string(), v);
         }
 
@@ -375,22 +368,32 @@ impl From<DirInfo> for Value {
 impl From<FileInfo> for Value {
     fn from(f: FileInfo) -> Self {
         let mut r: IndexMap<String, Value> = IndexMap::new();
+
         r.insert(
             "path".to_string(),
-            UntaggedValue::path(f.path).retag(f.tag.clone()),
+            UntaggedValue::path(f.path).retag(&f.tag),
         );
+
         r.insert(
             "apparent".to_string(),
-            UntaggedValue::bytes(f.size).retag(f.tag.clone()),
+            UntaggedValue::bytes(f.size).retag(&f.tag),
         );
-        let b = match f.blocks {
-            Some(k) => UntaggedValue::bytes(k).retag(f.tag.clone()),
-            None => UntaggedValue::nothing().retag(f.tag.clone()),
-        };
+
+        let b = f
+            .blocks
+            .map(UntaggedValue::bytes)
+            .unwrap_or_else(UntaggedValue::nothing)
+            .retag(&f.tag);
+
         r.insert("physical".to_string(), b);
-        Value {
-            value: UntaggedValue::row(r),
-            tag: f.tag,
-        }
+
+        r.insert(
+            "directories".to_string(),
+            UntaggedValue::nothing().retag(&f.tag),
+        );
+
+        r.insert("files".to_string(), UntaggedValue::nothing().retag(&f.tag));
+
+        UntaggedValue::row(r).retag(&f.tag)
     }
 }

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

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

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

@@ -1,10 +1,16 @@
+use crate::commands::WholeStreamCommand;
 use crate::prelude::*;
 use nu_errors::ShellError;
-use nu_protocol::{CallInfo, ReturnSuccess, Signature, SyntaxShape, UntaggedValue, Value};
+use nu_protocol::{ReturnSuccess, Signature, SyntaxShape, UntaggedValue, Value};
 
 pub struct Echo;
 
-impl PerItemCommand for Echo {
+#[derive(Deserialize)]
+pub struct EchoArgs {
+    pub rest: Vec<Value>,
+}
+
+impl WholeStreamCommand for Echo {
     fn name(&self) -> &str {
         "echo"
     }
@@ -19,44 +25,49 @@ impl PerItemCommand for Echo {
 
     fn run(
         &self,
-        call_info: &CallInfo,
+        args: CommandArgs,
         registry: &CommandRegistry,
-        raw_args: &RawCommandArgs,
-        _input: Value,
     ) -> Result<OutputStream, ShellError> {
-        run(call_info, registry, raw_args)
+        args.process(registry, echo)?.run()
+    }
+
+    fn examples(&self) -> &[Example] {
+        &[
+            Example {
+                description: "Put a hello message in the pipeline",
+                example: "echo 'hello'",
+            },
+            Example {
+                description: "Print the value of the special '$nu' variable",
+                example: "echo $nu",
+            },
+        ]
     }
 }
 
-fn run(
-    call_info: &CallInfo,
-    _registry: &CommandRegistry,
-    _raw_args: &RawCommandArgs,
-) -> Result<OutputStream, ShellError> {
+fn echo(args: EchoArgs, _: RunnableContext) -> Result<OutputStream, ShellError> {
     let mut output = vec![];
 
-    if let Some(ref positional) = call_info.args.positional {
-        for i in positional {
-            match i.as_string() {
-                Ok(s) => {
-                    output.push(Ok(ReturnSuccess::Value(
-                        UntaggedValue::string(s).into_value(i.tag.clone()),
-                    )));
-                }
-                _ => match i {
-                    Value {
-                        value: UntaggedValue::Table(table),
-                        ..
-                    } => {
-                        for value in table {
-                            output.push(Ok(ReturnSuccess::Value(value.clone())));
-                        }
-                    }
-                    _ => {
-                        output.push(Ok(ReturnSuccess::Value(i.clone())));
-                    }
-                },
+    for i in args.rest {
+        match i.as_string() {
+            Ok(s) => {
+                output.push(Ok(ReturnSuccess::Value(
+                    UntaggedValue::string(s).into_value(i.tag.clone()),
+                )));
             }
+            _ => match i {
+                Value {
+                    value: UntaggedValue::Table(table),
+                    ..
+                } => {
+                    for value in table {
+                        output.push(Ok(ReturnSuccess::Value(value.clone())));
+                    }
+                }
+                _ => {
+                    output.push(Ok(ReturnSuccess::Value(i.clone())));
+                }
+            },
         }
     }
 

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

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

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

@@ -1,15 +1,22 @@
-use crate::commands::PerItemCommand;
 use crate::commands::UnevaluatedCallInfo;
+use crate::commands::WholeStreamCommand;
 use crate::context::CommandRegistry;
 use crate::prelude::*;
 use nu_errors::ShellError;
 use nu_protocol::{
-    CallInfo, CommandAction, Primitive, ReturnSuccess, Signature, SyntaxShape, UntaggedValue, Value,
+    CommandAction, Primitive, ReturnSuccess, Signature, SyntaxShape, UntaggedValue, Value,
 };
+use nu_source::Tagged;
+use std::path::PathBuf;
 
 pub struct Enter;
 
-impl PerItemCommand for Enter {
+#[derive(Deserialize)]
+pub struct EnterArgs {
+    location: Tagged<PathBuf>,
+}
+
+impl WholeStreamCommand for Enter {
     fn name(&self) -> &str {
         "enter"
     }
@@ -28,129 +35,134 @@ impl PerItemCommand for Enter {
 
     fn run(
         &self,
-        call_info: &CallInfo,
+        args: CommandArgs,
         registry: &CommandRegistry,
-        raw_args: &RawCommandArgs,
-        _input: Value,
     ) -> Result<OutputStream, ShellError> {
-        let registry = registry.clone();
-        let raw_args = raw_args.clone();
-        match call_info.args.expect_nth(0)? {
-            Value {
-                value: UntaggedValue::Primitive(Primitive::Path(location)),
-                tag,
-                ..
-            } => {
-                let location_string = location.display().to_string();
-                let location_clone = location_string.clone();
-                let tag_clone = tag.clone();
+        Ok(args.process_raw(registry, enter)?.run())
+    }
 
-                if location_string.starts_with("help") {
-                    let spec = location_string.split(':').collect::<Vec<&str>>();
-
-                    if spec.len() == 2 {
-                        let (_, command) = (spec[0], spec[1]);
-
-                        if registry.has(command) {
-                            return Ok(vec![Ok(ReturnSuccess::Action(
-                                CommandAction::EnterHelpShell(
-                                    UntaggedValue::string(command).into_value(Tag::unknown()),
-                                ),
-                            ))]
-                            .into());
-                        }
-                    }
-                    Ok(vec![Ok(ReturnSuccess::Action(CommandAction::EnterHelpShell(
-                        UntaggedValue::nothing().into_value(Tag::unknown()),
-                    )))]
-                    .into())
-                } else if location.is_dir() {
-                    Ok(vec![Ok(ReturnSuccess::Action(CommandAction::EnterShell(
-                        location_clone,
-                    )))]
-                    .into())
-                } else {
-                    let stream = async_stream! {
-                        // If it's a file, attempt to open the file as a value and enter it
-                        let cwd = raw_args.shell_manager.path();
-
-                        let full_path = std::path::PathBuf::from(cwd);
-
-                        let (file_extension, contents, contents_tag) =
-                            crate::commands::open::fetch(
-                                &full_path,
-                                &location_clone,
-                                tag_clone.span,
-                            ).await?;
-
-                        match contents {
-                            UntaggedValue::Primitive(Primitive::String(_)) => {
-                                let tagged_contents = contents.into_value(&contents_tag);
-
-                                if let Some(extension) = file_extension {
-                                    let command_name = format!("from-{}", extension);
-                                    if let Some(converter) =
-                                        registry.get_command(&command_name)
-                                    {
-                                        let new_args = RawCommandArgs {
-                                            host: raw_args.host,
-                                            ctrl_c: raw_args.ctrl_c,
-                                            shell_manager: raw_args.shell_manager,
-                                            call_info: UnevaluatedCallInfo {
-                                                args: nu_parser::hir::Call {
-                                                    head: raw_args.call_info.args.head,
-                                                    positional: None,
-                                                    named: None,
-                                                    span: Span::unknown()
-                                                },
-                                                source: raw_args.call_info.source,
-                                                name_tag: raw_args.call_info.name_tag,
-                                            },
-                                        };
-                                        let mut result = converter.run(
-                                            new_args.with_input(vec![tagged_contents]),
-                                            &registry,
-                                        );
-                                        let result_vec: Vec<Result<ReturnSuccess, ShellError>> =
-                                            result.drain_vec().await;
-                                        for res in result_vec {
-                                            match res {
-                                                Ok(ReturnSuccess::Value(Value {
-                                                    value,
-                                                    ..
-                                                })) => {
-                                                    yield Ok(ReturnSuccess::Action(CommandAction::EnterValueShell(
-                                                        Value {
-                                                            value,
-                                                            tag: contents_tag.clone(),
-                                                        })));
-                                                }
-                                                x => yield x,
-                                            }
-                                        }
-                                    } else {
-                                        yield Ok(ReturnSuccess::Action(CommandAction::EnterValueShell(tagged_contents)));
-                                    }
-                                } else {
-                                    yield Ok(ReturnSuccess::Action(CommandAction::EnterValueShell(tagged_contents)));
-                                }
-                            }
-                            _ => {
-                                let tagged_contents = contents.into_value(contents_tag);
-
-                                yield Ok(ReturnSuccess::Action(CommandAction::EnterValueShell(tagged_contents)));
-                            }
-                        }
-                    };
-                    Ok(stream.to_output_stream())
-                }
-            }
-            x => Ok(
-                vec![Ok(ReturnSuccess::Action(CommandAction::EnterValueShell(
-                    x.clone(),
-                )))]
-                .into(),
-            ),
-        }
+    fn examples(&self) -> &[Example] {
+        &[
+            Example {
+                description: "Enter a path as a new shell",
+                example: "enter ../projectB",
+            },
+            Example {
+                description: "Enter a file as a new shell",
+                example: "enter package.json",
+            },
+        ]
+    }
+}
+
+fn enter(
+    EnterArgs { location }: EnterArgs,
+    RunnableContext {
+        registry,
+        name: tag,
+        ..
+    }: RunnableContext,
+    raw_args: RawCommandArgs,
+) -> Result<OutputStream, ShellError> {
+    let location_string = location.display().to_string();
+    let location_clone = location_string.clone();
+
+    if location_string.starts_with("help") {
+        let spec = location_string.split(':').collect::<Vec<&str>>();
+
+        if spec.len() == 2 {
+            let (_, command) = (spec[0], spec[1]);
+
+            if registry.has(command) {
+                return Ok(vec![Ok(ReturnSuccess::Action(CommandAction::EnterHelpShell(
+                    UntaggedValue::string(command).into_value(Tag::unknown()),
+                )))]
+                .into());
+            }
+        }
+        Ok(vec![Ok(ReturnSuccess::Action(CommandAction::EnterHelpShell(
+            UntaggedValue::nothing().into_value(Tag::unknown()),
+        )))]
+        .into())
+    } else if location.is_dir() {
+        Ok(vec![Ok(ReturnSuccess::Action(CommandAction::EnterShell(
+            location_clone,
+        )))]
+        .into())
+    } else {
+        let stream = async_stream! {
+            // If it's a file, attempt to open the file as a value and enter it
+            let cwd = raw_args.shell_manager.path();
+
+            let full_path = std::path::PathBuf::from(cwd);
+
+            let (file_extension, contents, contents_tag) =
+                crate::commands::open::fetch(
+                    &full_path,
+                    &PathBuf::from(location_clone),
+                    tag.span,
+                ).await?;
+
+            match contents {
+                UntaggedValue::Primitive(Primitive::String(_)) => {
+                    let tagged_contents = contents.into_value(&contents_tag);
+
+                    if let Some(extension) = file_extension {
+                        let command_name = format!("from {}", extension);
+                        if let Some(converter) =
+                            registry.get_command(&command_name)
+                        {
+                            let new_args = RawCommandArgs {
+                                host: raw_args.host,
+                                ctrl_c: raw_args.ctrl_c,
+                                shell_manager: raw_args.shell_manager,
+                                call_info: UnevaluatedCallInfo {
+                                    args: nu_protocol::hir::Call {
+                                        head: raw_args.call_info.args.head,
+                                        positional: None,
+                                        named: None,
+                                        span: Span::unknown(),
+                                        is_last: false,
+                                    },
+                                    name_tag: raw_args.call_info.name_tag,
+                                    scope: raw_args.call_info.scope.clone()
+                                },
+                            };
+                            let mut result = converter.run(
+                                new_args.with_input(vec![tagged_contents]),
+                                &registry,
+                            );
+                            let result_vec: Vec<Result<ReturnSuccess, ShellError>> =
+                                result.drain_vec().await;
+                            for res in result_vec {
+                                match res {
+                                    Ok(ReturnSuccess::Value(Value {
+                                        value,
+                                        ..
+                                    })) => {
+                                        yield Ok(ReturnSuccess::Action(CommandAction::EnterValueShell(
+                                            Value {
+                                                value,
+                                                tag: contents_tag.clone(),
+                                            })));
+                                    }
+                                    x => yield x,
+                                }
+                            }
+                        } else {
+                            yield Ok(ReturnSuccess::Action(CommandAction::EnterValueShell(tagged_contents)));
+                        }
+                    } else {
+                        yield Ok(ReturnSuccess::Action(CommandAction::EnterValueShell(tagged_contents)));
+                    }
+                }
+                _ => {
+                    let tagged_contents = contents.into_value(contents_tag);
+
+                    yield Ok(ReturnSuccess::Action(CommandAction::EnterValueShell(tagged_contents)));
+                }
+            }
+        };
+        Ok(stream.to_output_stream())
     }
 }

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

@@ -45,7 +45,7 @@ pub fn evaluate_by(
     RunnableContext { input, name, .. }: RunnableContext,
 ) -> Result<OutputStream, ShellError> {
     let stream = async_stream! {
-        let values: Vec<Value> = input.values.collect().await;
+        let values: Vec<Value> = input.collect().await;
 
         if values.is_empty() {
             yield Err(ShellError::labeled_error(

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

@@ -26,6 +26,19 @@ impl WholeStreamCommand for Exit {
     ) -> Result<OutputStream, ShellError> {
         exit(args, registry)
     }
+
+    fn examples(&self) -> &[Example] {
+        &[
+            Example {
+                description: "Exit the current shell",
+                example: "exit",
+            },
+            Example {
+                description: "Exit all shells (exiting Nu)",
+                example: "exit --now",
+            },
+        ]
+    }
 }
 
 pub fn exit(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStream, ShellError> {

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

@@ -36,6 +36,19 @@ impl WholeStreamCommand for First {
     ) -> Result<OutputStream, ShellError> {
         args.process(registry, first)?.run()
     }
+
+    fn examples(&self) -> &[Example] {
+        &[
+            Example {
+                description: "Return the first item of a list/table",
+                example: "echo [1 2 3] | first",
+            },
+            Example {
+                description: "Return the first 2 items of a list/table",
+                example: "echo [1 2 3] | first 2",
+            },
+        ]
+    }
 }
 
 fn first(
@@ -48,7 +61,5 @@ fn first(
         1
     };
 
-    Ok(OutputStream::from_input(
-        context.input.values.take(rows_desired),
-    ))
+    Ok(OutputStream::from_input(context.input.take(rows_desired)))
 }

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

@@ -1,22 +1,20 @@
-use crate::commands::PerItemCommand;
+use crate::commands::WholeStreamCommand;
 use crate::context::CommandRegistry;
 use crate::prelude::*;
 use nu_errors::ShellError;
-use nu_protocol::{
-    CallInfo, ColumnPath, ReturnSuccess, Signature, SyntaxShape, UntaggedValue, Value,
-};
+use nu_protocol::{ColumnPath, ReturnSuccess, Signature, SyntaxShape, UntaggedValue, Value};
 use nu_source::Tagged;
 use nu_value_ext::{as_column_path, get_data_by_column_path};
 use std::borrow::Borrow;
 
-use nom::{
-    bytes::complete::{tag, take_while},
-    IResult,
-};
-
 pub struct Format;
 
-impl PerItemCommand for Format {
+#[derive(Deserialize)]
+pub struct FormatArgs {
+    pattern: Tagged<String>,
+}
+
+impl WholeStreamCommand for Format {
     fn name(&self) -> &str {
         "format"
     }
@@ -24,7 +22,7 @@ impl PerItemCommand for Format {
     fn signature(&self) -> Signature {
         Signature::build("format").required(
             "pattern",
-            SyntaxShape::Any,
+            SyntaxShape::String,
             "the pattern to output. Eg) \"{foo}: {bar}\"",
         )
     }
@@ -35,67 +33,74 @@ impl PerItemCommand for Format {
 
     fn run(
         &self,
-        call_info: &CallInfo,
-        _registry: &CommandRegistry,
-        _raw_args: &RawCommandArgs,
-        value: Value,
+        args: CommandArgs,
+        registry: &CommandRegistry,
     ) -> Result<OutputStream, ShellError> {
-        //let value_tag = value.tag();
-        let pattern = call_info.args.expect_nth(0)?;
-        let pattern_tag = pattern.tag.clone();
-        let pattern = pattern.as_string()?;
+        args.process(registry, format_command)?.run()
+    }
 
-        let format_pattern = format(&pattern).map_err(|_| {
-            ShellError::labeled_error(
-                "Could not create format pattern",
-                "could not create format pattern",
-                &pattern_tag,
-            )
-        })?;
-        let commands = format_pattern.1;
+    fn examples(&self) -> &[Example] {
+        &[Example {
+            description: "Print filenames with their sizes",
+            example: "ls | format '{name}: {size}'",
+        }]
+    }
+}
 
-        let output = match value {
-            value
-            @
-            Value {
-                value: UntaggedValue::Row(_),
-                ..
-            } => {
-                let mut output = String::new();
+fn format_command(
+    FormatArgs { pattern }: FormatArgs,
+    RunnableContext { input, .. }: RunnableContext,
+) -> Result<OutputStream, ShellError> {
+    let pattern_tag = pattern.tag.clone();
 
-                for command in &commands {
-                    match command {
-                        FormatCommand::Text(s) => {
-                            output.push_str(s);
-                        }
-                        FormatCommand::Column(c) => {
-                            let key = to_column_path(&c, &pattern_tag)?;
+    let format_pattern = format(&pattern);
+    let commands = format_pattern;
+    let mut input = input;
 
-                            let fetcher = get_data_by_column_path(
-                                &value,
-                                &key,
-                                Box::new(move |(_, _, error)| error),
-                            );
+    let stream = async_stream! {
+        while let Some(value) = input.next().await {
+            match value {
+                value
+                @
+                Value {
+                    value: UntaggedValue::Row(_),
+                    ..
+                } => {
+                    let mut output = String::new();
 
-                            if let Ok(c) = fetcher {
-                                output
-                                    .push_str(&value::format_leaf(c.borrow()).plain_string(100_000))
+                    for command in &commands {
+                        match command {
+                            FormatCommand::Text(s) => {
+                                output.push_str(&s);
+                            }
+                            FormatCommand::Column(c) => {
+                                let key = to_column_path(&c, &pattern_tag)?;
+
+                                let fetcher = get_data_by_column_path(
+                                    &value,
+                                    &key,
+                                    Box::new(move |(_, _, error)| error),
+                                );
+
+                                if let Ok(c) = fetcher {
+                                    output
+                                        .push_str(&value::format_leaf(c.borrow()).plain_string(100_000))
+                                }
+                                // That column doesn't match, so don't emit anything
                             }
-                            // That column doesn't match, so don't emit anything
                         }
                     }
+
+                    yield ReturnSuccess::value(
+                        UntaggedValue::string(output).into_untagged_value())
                 }
+                _ => yield ReturnSuccess::value(
+                    UntaggedValue::string(String::new()).into_untagged_value()),
+            };
+        }
+    };
 
-                output
-            }
-            _ => String::new(),
-        };
-
-        Ok(futures::stream::iter(vec![ReturnSuccess::value(
-            UntaggedValue::string(output).into_untagged_value(),
-        )])
-        .to_output_stream())
-    }
+    Ok(stream.to_output_stream())
 }
 
 #[derive(Debug)]
@@ -104,32 +109,43 @@ enum FormatCommand {
     Column(String),
 }
 
-fn format(input: &str) -> IResult<&str, Vec<FormatCommand>> {
+fn format(input: &str) -> Vec<FormatCommand> {
     let mut output = vec![];
 
-    let mut loop_input = input;
+    let mut loop_input = input.chars();
     loop {
-        let (input, before) = take_while(|c| c != '{')(loop_input)?;
+        let mut before = String::new();
+
+        while let Some(c) = loop_input.next() {
+            if c == '{' {
+                break;
+            }
+            before.push(c);
+        }
+
         if !before.is_empty() {
             output.push(FormatCommand::Text(before.to_string()));
         }
-        if input != "" {
-            // Look for column as we're now at one
-            let (input, _) = tag("{")(input)?;
-            let (input, column) = take_while(|c| c != '}')(input)?;
-            let (input, _) = tag("}")(input)?;
+        // Look for column as we're now at one
+        let mut column = String::new();
 
-            output.push(FormatCommand::Column(column.to_string()));
-            loop_input = input;
-        } else {
-            loop_input = input;
+        while let Some(c) = loop_input.next() {
+            if c == '}' {
+                break;
+            }
+            column.push(c);
         }
-        if loop_input == "" {
+
+        if !column.is_empty() {
+            output.push(FormatCommand::Column(column.to_string()));
+        }
+
+        if before.is_empty() && column.is_empty() {
             break;
         }
     }
 
-    Ok((loop_input, output))
+    output
 }
 
 fn to_column_path(

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

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

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

@@ -10,15 +10,15 @@ pub struct FromBSON;
 
 impl WholeStreamCommand for FromBSON {
     fn name(&self) -> &str {
-        "from-bson"
+        "from bson"
     }
 
     fn signature(&self) -> Signature {
-        Signature::build("from-bson")
+        Signature::build("from bson")
     }
 
     fn usage(&self) -> &str {
-        "Parse text as .bson and create table."
+        "Parse binary as .bson and create table."
     }
 
     fn run(
@@ -28,6 +28,13 @@ impl WholeStreamCommand for FromBSON {
     ) -> Result<OutputStream, ShellError> {
         from_bson(args, registry)
     }
+
+    fn examples(&self) -> &[Example] {
+        &[Example {
+            description: "Convert bson data to a table",
+            example: "open file.bin | from bson",
+        }]
+    }
 }
 
 fn bson_array(input: &[Bson], tag: Tag) -> Result<Vec<Value>, ShellError> {

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

@@ -14,11 +14,11 @@ pub struct FromCSVArgs {
 
 impl WholeStreamCommand for FromCSV {
     fn name(&self) -> &str {
-        "from-csv"
+        "from csv"
     }
 
     fn signature(&self) -> Signature {
-        Signature::build("from-csv")
+        Signature::build("from csv")
             .named(
                 "separator",
                 SyntaxShape::String,
@@ -43,6 +43,23 @@ impl WholeStreamCommand for FromCSV {
     ) -> Result<OutputStream, ShellError> {
         args.process(registry, from_csv)?.run()
     }
+
+    fn examples(&self) -> &[Example] {
+        &[
+            Example {
+                description: "Convert comma-separated data to a table",
+                example: "open data.txt | from csv",
+            },
+            Example {
+                description: "Convert comma-separated data to a table, ignoring headers",
+                example: "open data.txt | from csv --headerless",
+            },
+            Example {
+                description: "Convert semicolon-separated data to a table",
+                example: "open data.txt | from csv --separator ';'",
+            },
+        ]
+    }
 }
 
 fn from_csv(

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

@@ -1,7 +1,7 @@
 use crate::prelude::*;
-use csv::ReaderBuilder;
+use csv::{ErrorKind, ReaderBuilder};
 use nu_errors::ShellError;
-use nu_protocol::{Primitive, ReturnSuccess, TaggedDictBuilder, UntaggedValue, Value};
+use nu_protocol::{ReturnSuccess, TaggedDictBuilder, UntaggedValue, Value};
 
 fn from_delimited_string_to_value(
     s: String,
@@ -27,10 +27,13 @@ fn from_delimited_string_to_value(
     for row in reader.records() {
         let mut tagged_row = TaggedDictBuilder::new(&tag);
         for (value, header) in row?.iter().zip(headers.iter()) {
-            tagged_row.insert_value(
-                header,
-                UntaggedValue::Primitive(Primitive::String(String::from(value))).into_value(&tag),
-            )
+            if let Ok(i) = value.parse::<i64>() {
+                tagged_row.insert_value(header, UntaggedValue::int(i).into_value(&tag))
+            } else if let Ok(f) = value.parse::<f64>() {
+                tagged_row.insert_value(header, UntaggedValue::decimal(f).into_value(&tag))
+            } else {
+                tagged_row.insert_value(header, UntaggedValue::string(value).into_value(&tag))
+            }
         }
         rows.push(tagged_row.into_value());
     }
@@ -58,8 +61,11 @@ pub fn from_delimited_data(
                 }
                 x => yield ReturnSuccess::value(x),
             },
-            Err(_) => {
-                let line_one = format!("Could not parse as {}", format_name);
+            Err(err) => {
+                let line_one = match pretty_csv_error(err) {
+                    Some(pretty) => format!("Could not parse as {} ({})", format_name,pretty),
+                    None => format!("Could not parse as {}", format_name),
+                };
                 let line_two = format!("input cannot be parsed as {}", format_name);
                 yield Err(ShellError::labeled_error_with_secondary(
                     line_one,
@@ -74,3 +80,26 @@ pub fn from_delimited_data(
 
     Ok(stream.to_output_stream())
 }
+
+fn pretty_csv_error(err: csv::Error) -> Option<String> {
+    match err.kind() {
+        ErrorKind::UnequalLengths {
+            pos,
+            expected_len,
+            len,
+        } => {
+            if let Some(pos) = pos {
+                Some(format!(
+                    "Line {}: expected {} fields, found {}",
+                    pos.line(),
+                    expected_len,
+                    len
+                ))
+            } else {
+                Some(format!("Expected {} fields, found {}", expected_len, len))
+            }
+        }
+        ErrorKind::Seek => Some("Internal error while parsing csv".to_string()),
+        _ => None,
+    }
+}

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

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

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

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

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

@@ -8,11 +8,11 @@ pub struct FromINI;
 
 impl WholeStreamCommand for FromINI {
     fn name(&self) -> &str {
-        "from-ini"
+        "from ini"
     }
 
     fn signature(&self) -> Signature {
-        Signature::build("from-ini")
+        Signature::build("from ini")
     }
 
     fn usage(&self) -> &str {

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

@@ -12,11 +12,11 @@ pub struct FromJSONArgs {
 
 impl WholeStreamCommand for FromJSON {
     fn name(&self) -> &str {
-        "from-json"
+        "from json"
     }
 
     fn signature(&self) -> Signature {
-        Signature::build("from-json").switch(
+        Signature::build("from json").switch(
             "objects",
             "treat each line as a separate value",
             Some('o'),

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

@@ -15,11 +15,11 @@ pub struct FromODSArgs {
 
 impl WholeStreamCommand for FromODS {
     fn name(&self) -> &str {
-        "from-ods"
+        "from ods"
     }
 
     fn signature(&self) -> Signature {
-        Signature::build("from-ods").switch(
+        Signature::build("from ods").switch(
             "headerless",
             "don't treat the first row as column names",
             None,

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

@@ -10,11 +10,11 @@ pub struct FromSQLite;
 
 impl WholeStreamCommand for FromSQLite {
     fn name(&self) -> &str {
-        "from-sqlite"
+        "from sqlite"
     }
 
     fn signature(&self) -> Signature {
-        Signature::build("from-sqlite")
+        Signature::build("from sqlite")
     }
 
     fn usage(&self) -> &str {
@@ -34,11 +34,11 @@ pub struct FromDB;
 
 impl WholeStreamCommand for FromDB {
     fn name(&self) -> &str {
-        "from-db"
+        "from db"
     }
 
     fn signature(&self) -> Signature {
-        Signature::build("from-db")
+        Signature::build("from db")
     }
 
     fn usage(&self) -> &str {

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

@@ -17,7 +17,7 @@ pub struct FromSSVArgs {
     minimum_spaces: Option<Tagged<usize>>,
 }
 
-const STRING_REPRESENTATION: &str = "from-ssv";
+const STRING_REPRESENTATION: &str = "from ssv";
 const DEFAULT_MINIMUM_SPACES: usize = 2;
 
 impl WholeStreamCommand for FromSSV {

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

@@ -7,11 +7,11 @@ pub struct FromTOML;
 
 impl WholeStreamCommand for FromTOML {
     fn name(&self) -> &str {
-        "from-toml"
+        "from toml"
     }
 
     fn signature(&self) -> Signature {
-        Signature::build("from-toml")
+        Signature::build("from toml")
     }
 
     fn usage(&self) -> &str {

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

@@ -13,11 +13,11 @@ pub struct FromTSVArgs {
 
 impl WholeStreamCommand for FromTSV {
     fn name(&self) -> &str {
-        "from-tsv"
+        "from tsv"
     }
 
     fn signature(&self) -> Signature {
-        Signature::build("from-tsv").switch(
+        Signature::build("from tsv").switch(
             "headerless",
             "don't treat the first row as column names",
             None,

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

@@ -7,11 +7,11 @@ pub struct FromURL;
 
 impl WholeStreamCommand for FromURL {
     fn name(&self) -> &str {
-        "from-url"
+        "from url"
     }
 
     fn signature(&self) -> Signature {
-        Signature::build("from-url")
+        Signature::build("from url")
     }
 
     fn usage(&self) -> &str {

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

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

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

@@ -15,11 +15,11 @@ pub struct FromXLSXArgs {
 
 impl WholeStreamCommand for FromXLSX {
     fn name(&self) -> &str {
-        "from-xlsx"
+        "from xlsx"
     }
 
     fn signature(&self) -> Signature {
-        Signature::build("from-xlsx").switch(
+        Signature::build("from xlsx").switch(
             "headerless",
             "don't treat the first row as column names",
             None,

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

@@ -7,11 +7,11 @@ pub struct FromXML;
 
 impl WholeStreamCommand for FromXML {
     fn name(&self) -> &str {
-        "from-xml"
+        "from xml"
     }
 
     fn signature(&self) -> Signature {
-        Signature::build("from-xml")
+        Signature::build("from xml")
     }
 
     fn usage(&self) -> &str {

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

@@ -7,11 +7,11 @@ pub struct FromYAML;
 
 impl WholeStreamCommand for FromYAML {
     fn name(&self) -> &str {
-        "from-yaml"
+        "from yaml"
     }
 
     fn signature(&self) -> Signature {
-        Signature::build("from-yaml")
+        Signature::build("from yaml")
     }
 
     fn usage(&self) -> &str {
@@ -31,11 +31,11 @@ pub struct FromYML;
 
 impl WholeStreamCommand for FromYML {
     fn name(&self) -> &str {
-        "from-yml"
+        "from yml"
     }
 
     fn signature(&self) -> Signature {
-        Signature::build("from-yml")
+        Signature::build("from yml")
     }
 
     fn usage(&self) -> &str {

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

@@ -4,8 +4,8 @@ use indexmap::set::IndexSet;
 use log::trace;
 use nu_errors::ShellError;
 use nu_protocol::{
-    did_you_mean, ColumnPath, PathMember, ReturnSuccess, ReturnValue, Signature, SyntaxShape,
-    UnspannedPathMember, UntaggedValue, Value,
+    did_you_mean, ColumnPath, PathMember, Primitive, ReturnSuccess, ReturnValue, Signature,
+    SyntaxShape, UnspannedPathMember, UntaggedValue, Value,
 };
 use nu_source::span_for_spanned_list;
 use nu_value_ext::get_data_by_column_path;
@@ -40,6 +40,19 @@ impl WholeStreamCommand for Get {
     ) -> Result<OutputStream, ShellError> {
         args.process(registry, get)?.run()
     }
+
+    fn examples(&self) -> &[Example] {
+        &[
+            Example {
+                description: "Extract the name of files as a list",
+                example: "ls | get name",
+            },
+            Example {
+                description: "Extract the cpu list from the sys information",
+                example: "sys | get cpu",
+            },
+        ]
+    }
 }
 
 pub fn get_column_path(path: &ColumnPath, obj: &Value) -> Result<Value, ShellError> {
@@ -197,7 +210,6 @@ pub fn get(
         let member = fields.remove(0);
         trace!("get {:?} {:?}", member, fields);
         let stream = input
-            .values
             .map(move |item| {
                 let mut result = VecDeque::new();
 
@@ -221,6 +233,10 @@ pub fn get(
                                     result.push_back(ReturnSuccess::value(item.clone()));
                                 }
                             }
+                            Value {
+                                value: UntaggedValue::Primitive(Primitive::Nothing),
+                                ..
+                            } => {}
                             other => result.push_back(ReturnSuccess::value(other.clone())),
                         },
                         Err(reason) => result.push_back(ReturnSuccess::value(

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

@@ -1,15 +1,16 @@
 use crate::commands::WholeStreamCommand;
 use crate::prelude::*;
 use nu_errors::ShellError;
-use nu_protocol::{ReturnSuccess, Signature, SyntaxShape, TaggedDictBuilder, UntaggedValue, Value};
+use nu_protocol::{ReturnSuccess, Signature, SyntaxShape, Value};
 use nu_source::Tagged;
-use nu_value_ext::get_data_by_key;
 
 pub struct GroupBy;
 
 #[derive(Deserialize)]
 pub struct GroupByArgs {
     column_name: Tagged<String>,
+    date: Tagged<bool>,
+    format: Option<Tagged<String>>,
 }
 
 impl WholeStreamCommand for GroupBy {
@@ -18,11 +19,19 @@ impl WholeStreamCommand for GroupBy {
     }
 
     fn signature(&self) -> Signature {
-        Signature::build("group-by").required(
-            "column_name",
-            SyntaxShape::String,
-            "the name of the column to group by",
-        )
+        Signature::build("group-by")
+            .required(
+                "column_name",
+                SyntaxShape::String,
+                "the name of the column to group by",
+            )
+            .named(
+                "format",
+                SyntaxShape::String,
+                "Specify date and time formatting",
+                Some('f'),
+            )
+            .switch("date", "by date", Some('d'))
     }
 
     fn usage(&self) -> &str {
@@ -36,14 +45,30 @@ impl WholeStreamCommand for GroupBy {
     ) -> Result<OutputStream, ShellError> {
         args.process(registry, group_by)?.run()
     }
+
+    fn examples(&self) -> &[Example] {
+        &[Example {
+            description: "Group files by type",
+            example: "ls | group-by type",
+        }]
+    }
+}
+
+enum Grouper {
+    Default,
+    ByDate(Option<String>),
 }
 
 pub fn group_by(
-    GroupByArgs { column_name }: GroupByArgs,
+    GroupByArgs {
+        column_name,
+        date,
+        format,
+    }: GroupByArgs,
     RunnableContext { input, name, .. }: RunnableContext,
 ) -> Result<OutputStream, ShellError> {
     let stream = async_stream! {
-        let values: Vec<Value> = input.values.collect().await;
+        let values: Vec<Value> = input.collect().await;
 
         if values.is_empty() {
             yield Err(ShellError::labeled_error(
@@ -52,9 +77,38 @@ pub fn group_by(
                     column_name.span()
                 ))
         } else {
-            match group(&column_name, values, name) {
-                Ok(grouped) => yield ReturnSuccess::value(grouped),
-                Err(err) => yield Err(err)
+
+            let grouper = if let Tagged { item: true, tag } = date {
+                if let Some(Tagged { item: fmt, tag }) = format {
+                    Grouper::ByDate(Some(fmt))
+                } else {
+                    Grouper::ByDate(None)
+                }
+            } else {
+                Grouper::Default
+            };
+
+            match grouper {
+                Grouper::Default => {
+                    match crate::utils::data::group(column_name, &values, None, &name) {
+                        Ok(grouped) => yield ReturnSuccess::value(grouped),
+                        Err(err) => yield Err(err),
+                    }
+                }
+                Grouper::ByDate(None) => {
+                    match crate::utils::data::group(column_name, &values, Some(Box::new(|row: &Value| row.format("%Y-%b-%d"))), &name) {
+                        Ok(grouped) => yield ReturnSuccess::value(grouped),
+                        Err(err) => yield Err(err),
+                    }
+                }
+                Grouper::ByDate(Some(fmt)) => {
+                    match crate::utils::data::group(column_name, &values, Some(Box::new(move |row: &Value| {
+                        row.format(&fmt)
+                    })), &name) {
+                        Ok(grouped) => yield ReturnSuccess::value(grouped),
+                        Err(err) => yield Err(err),
+                    }
+                }
             }
         }
     };
@@ -67,50 +121,7 @@ pub fn group(
     values: Vec<Value>,
     tag: impl Into<Tag>,
 ) -> Result<Value, ShellError> {
-    let tag = tag.into();
-
-    let mut groups: indexmap::IndexMap<String, Vec<Value>> = indexmap::IndexMap::new();
-
-    for value in values {
-        let group_key = get_data_by_key(&value, column_name.borrow_spanned());
-
-        if let Some(group_key) = group_key {
-            let group_key = group_key.as_string()?.to_string();
-            let group = groups.entry(group_key).or_insert(vec![]);
-            group.push(value);
-        } else {
-            let possibilities = value.data_descriptors();
-
-            let mut possible_matches: Vec<_> = possibilities
-                .iter()
-                .map(|x| (natural::distance::levenshtein_distance(x, column_name), x))
-                .collect();
-
-            possible_matches.sort();
-
-            if !possible_matches.is_empty() {
-                return Err(ShellError::labeled_error(
-                    "Unknown column",
-                    format!("did you mean '{}'?", possible_matches[0].1),
-                    column_name.tag(),
-                ));
-            } else {
-                return Err(ShellError::labeled_error(
-                    "Unknown column",
-                    "row does not contain this column",
-                    column_name.tag(),
-                ));
-            }
-        }
-    }
-
-    let mut out = TaggedDictBuilder::new(&tag);
-
-    for (k, v) in groups.iter() {
-        out.insert_untagged(k, UntaggedValue::table(v));
-    }
-
-    Ok(out.into_value())
+    crate::utils::data::group(column_name.clone(), &values, None, tag)
 }
 
 #[cfg(test)]

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

@@ -0,0 +1,90 @@
+use crate::commands::WholeStreamCommand;
+use crate::context::CommandRegistry;
+use crate::prelude::*;
+use futures::stream::StreamExt;
+use indexmap::IndexMap;
+use nu_errors::ShellError;
+use nu_protocol::Dictionary;
+use nu_protocol::{ReturnSuccess, Signature, UntaggedValue, Value};
+
+pub struct Headers;
+#[derive(Deserialize)]
+pub struct HeadersArgs {}
+
+impl WholeStreamCommand for Headers {
+    fn name(&self) -> &str {
+        "headers"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("headers")
+    }
+
+    fn usage(&self) -> &str {
+        "Use the first row of the table as column names"
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        args.process(registry, headers)?.run()
+    }
+
+    fn examples(&self) -> &[Example] {
+        &[Example {
+            description: "Create headers for a raw string",
+            example: "echo \"a b c|1 2 3\" | split-row \"|\" | split-column \" \" | headers",
+        }]
+    }
+}
+
+pub fn headers(
+    HeadersArgs {}: HeadersArgs,
+    RunnableContext { input, .. }: RunnableContext,
+) -> Result<OutputStream, ShellError> {
+    let stream = async_stream! {
+        let rows: Vec<Value> = input.collect().await;
+
+        if rows.len() < 1 {
+            yield Err(ShellError::untagged_runtime_error("Couldn't find headers, was the input a properly formatted, non-empty table?"));
+        }
+
+        //the headers are the first row in the table
+        let headers: Vec<String> = match &rows[0].value {
+            UntaggedValue::Row(d) => {
+                Ok(d.entries.iter().map(|(k, v)| {
+                    match v.as_string() {
+                        Ok(s) => s,
+                        Err(_) => { //If a cell that should contain a header name is empty, we name the column Column[index]
+                            match d.entries.get_full(k) {
+                                Some((index, _, _)) => format!("Column{}", index),
+                                None => "unknownColumn".to_string()
+                            }
+                        }
+                    }
+                }).collect())
+            }
+            _ => Err(ShellError::unexpected_eof("Could not get headers, is the table empty?", rows[0].tag.span))
+        }?;
+
+        //Each row is a dictionary with the headers as keys
+        for r in rows.iter().skip(1) {
+            match &r.value {
+                UntaggedValue::Row(d) => {
+                    let mut i = 0;
+                    let mut entries = IndexMap::new();
+                    for (_, v) in d.entries.iter() {
+                        entries.insert(headers[i].clone(), v.clone());
+                        i += 1;
+                    }
+                    yield Ok(ReturnSuccess::Value(UntaggedValue::Row(Dictionary{entries}).into_value(r.tag.clone())))
+                }
+                _ => yield Err(ShellError::unexpected_eof("Couldn't iterate through rows, was the input a properly formatted table?", r.tag.span))
+            }
+        }
+    };
+
+    Ok(stream.to_output_stream())
+}

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

@@ -1,24 +1,29 @@
-use crate::commands::PerItemCommand;
+use crate::commands::WholeStreamCommand;
 use crate::data::command_dict;
 
 use crate::prelude::*;
 use nu_errors::ShellError;
 use nu_protocol::{
-    CallInfo, NamedType, PositionalType, Primitive, ReturnSuccess, Signature, SyntaxShape,
-    TaggedDictBuilder, UntaggedValue, Value,
+    NamedType, PositionalType, ReturnSuccess, Signature, SyntaxShape, TaggedDictBuilder,
+    UntaggedValue,
 };
-use nu_source::SpannedItem;
+use nu_source::{SpannedItem, Tagged};
 use nu_value_ext::get_data_by_key;
 
 pub struct Help;
 
-impl PerItemCommand for Help {
+#[derive(Deserialize)]
+pub struct HelpArgs {
+    rest: Vec<Tagged<String>>,
+}
+
+impl WholeStreamCommand for Help {
     fn name(&self) -> &str {
         "help"
     }
 
     fn signature(&self) -> Signature {
-        Signature::build("help").rest(SyntaxShape::Any, "the name of command(s) to get help on")
+        Signature::build("help").rest(SyntaxShape::String, "the name of command to get help on")
     }
 
     fn usage(&self) -> &str {
@@ -27,68 +32,82 @@ impl PerItemCommand for Help {
 
     fn run(
         &self,
-        call_info: &CallInfo,
+        args: CommandArgs,
         registry: &CommandRegistry,
-        _raw_args: &RawCommandArgs,
-        _input: Value,
     ) -> Result<OutputStream, ShellError> {
-        let tag = &call_info.name_tag;
+        args.process(registry, help)?.run()
+    }
+}
 
-        match call_info.args.nth(0) {
-            Some(Value {
-                value: UntaggedValue::Primitive(Primitive::String(document)),
-                tag,
-            }) => {
-                let mut help = VecDeque::new();
-                if document == "commands" {
-                    let mut sorted_names = registry.names();
-                    sorted_names.sort();
-                    for cmd in sorted_names {
-                        let mut short_desc = TaggedDictBuilder::new(tag.clone());
-                        let value = command_dict(
-                            registry.get_command(&cmd).ok_or_else(|| {
-                                ShellError::labeled_error(
-                                    format!("Could not load {}", cmd),
-                                    "could not load command",
-                                    tag,
-                                )
-                            })?,
-                            tag.clone(),
-                        );
-
-                        short_desc.insert_untagged("name", cmd);
-                        short_desc.insert_untagged(
-                            "description",
-                            get_data_by_key(&value, "usage".spanned_unknown())
-                                .ok_or_else(|| {
-                                    ShellError::labeled_error(
-                                        "Expected a usage key",
-                                        "expected a 'usage' key",
-                                        &value.tag,
-                                    )
-                                })?
-                                .as_string()?,
-                        );
-
-                        help.push_back(ReturnSuccess::value(short_desc.into_value()));
-                    }
-                } else if let Some(command) = registry.get_command(document) {
-                    return Ok(
-                        get_help(&command.name(), &command.usage(), command.signature()).into(),
-                    );
+fn help(
+    HelpArgs { rest }: HelpArgs,
+    RunnableContext { registry, name, .. }: RunnableContext,
+) -> Result<OutputStream, ShellError> {
+    if let Some(document) = rest.get(0) {
+        let mut help = VecDeque::new();
+        if document.item == "commands" {
+            let mut sorted_names = registry.names();
+            sorted_names.sort();
+            for cmd in sorted_names {
+                // If it's a subcommand, don't list it during the commands list
+                if cmd.contains(' ') {
+                    continue;
                 }
-                let help = futures::stream::iter(help);
-                Ok(help.to_output_stream())
+                let mut short_desc = TaggedDictBuilder::new(name.clone());
+                let document_tag = document.tag.clone();
+                let value = command_dict(
+                    registry.get_command(&cmd).ok_or_else(|| {
+                        ShellError::labeled_error(
+                            format!("Could not load {}", cmd),
+                            "could not load command",
+                            document_tag,
+                        )
+                    })?,
+                    name.clone(),
+                );
+
+                short_desc.insert_untagged("name", cmd);
+                short_desc.insert_untagged(
+                    "description",
+                    get_data_by_key(&value, "usage".spanned_unknown())
+                        .ok_or_else(|| {
+                            ShellError::labeled_error(
+                                "Expected a usage key",
+                                "expected a 'usage' key",
+                                &value.tag,
+                            )
+                        })?
+                        .as_string()?,
+                );
+
+                help.push_back(ReturnSuccess::value(short_desc.into_value()));
             }
-            _ => {
-                let msg = r#"Welcome to Nushell.
+        } else if rest.len() == 2 {
+            // Check for a subcommand
+            let command_name = format!("{} {}", rest[0].item, rest[1].item);
+            if let Some(command) = registry.get_command(&command_name) {
+                return Ok(get_help(command.stream_command(), &registry).into());
+            }
+        } else if let Some(command) = registry.get_command(&document.item) {
+            return Ok(get_help(command.stream_command(), &registry).into());
+        } else {
+            return Err(ShellError::labeled_error(
+                "Can't find command (use 'help commands' for full list)",
+                "can't find command",
+                document.tag.span,
+            ));
+        }
+        let help = futures::stream::iter(help);
+        Ok(help.to_output_stream())
+    } else {
+        let msg = r#"Welcome to Nushell.
 
 Here are some tips to help you get started.
   * help commands - list all available commands
   * help <command name> - display help about a particular command
 
-Nushell works on the idea of a "pipeline". Pipelines are commands connected with the '|' character. Each stage 
-in the pipeline works together to load, parse, and display information to you.
+Nushell works on the idea of a "pipeline". Pipelines are commands connected with the '|' character.
+Each stage in the pipeline works together to load, parse, and display information to you.
 
 [Examples]
 
@@ -103,28 +122,35 @@ Get the processes on your system actively using CPU:
 
 You can also learn more at https://www.nushell.sh/book/"#;
 
-                let output_stream = futures::stream::iter(vec![ReturnSuccess::value(
-                    UntaggedValue::string(msg).into_value(tag),
-                )]);
+        let output_stream = futures::stream::iter(vec![ReturnSuccess::value(
+            UntaggedValue::string(msg).into_value(name),
+        )]);
 
-                Ok(output_stream.to_output_stream())
-            }
-        }
+        Ok(output_stream.to_output_stream())
     }
 }
 
+#[allow(clippy::cognitive_complexity)]
 pub(crate) fn get_help(
-    cmd_name: &str,
-    cmd_usage: &str,
-    cmd_sig: Signature,
+    cmd: &dyn WholeStreamCommand,
+    registry: &CommandRegistry,
 ) -> impl Into<OutputStream> {
+    let cmd_name = cmd.name();
+    let signature = cmd.signature();
     let mut help = VecDeque::new();
     let mut long_desc = String::new();
 
-    long_desc.push_str(&cmd_usage);
+    long_desc.push_str(&cmd.usage());
     long_desc.push_str("\n");
 
-    let signature = cmd_sig;
+    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);
@@ -145,14 +171,23 @@ pub(crate) fn get_help(
         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");
+        long_desc.push_str("\nParameters:\n");
         for positional in signature.positional {
             match positional.0 {
                 PositionalType::Mandatory(name, _m) => {
@@ -169,7 +204,7 @@ pub(crate) fn get_help(
         }
     }
     if !signature.named.is_empty() {
-        long_desc.push_str("\nflags:\n");
+        long_desc.push_str("\nFlags:\n");
         for (flag, ty) in signature.named {
             let msg = match ty.0 {
                 NamedType::Switch(s) => {
@@ -235,6 +270,21 @@ pub(crate) fn get_help(
         }
     }
 
+    let examples = cmd.examples();
+    if !examples.is_empty() {
+        long_desc.push_str("\nExamples:");
+    }
+    for example in examples {
+        long_desc.push_str("\n");
+        long_desc.push_str("  ");
+        long_desc.push_str(example.description);
+        let colored_example =
+            crate::shell::helper::Painter::paint_string(example.example, registry);
+        long_desc.push_str(&format!("\n  > {}\n", colored_example));
+    }
+
+    long_desc.push_str("\n");
+
     help.push_back(ReturnSuccess::value(
         UntaggedValue::string(long_desc).into_value(Tag::from((0, cmd_name.len(), None))),
     ));

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

@@ -30,7 +30,7 @@ impl WholeStreamCommand for Histogram {
                 "the name of the column to graph by",
             )
             .rest(
-                SyntaxShape::Member,
+                SyntaxShape::String,
                 "column name to give the histogram's frequency column",
             )
     }
@@ -46,6 +46,24 @@ impl WholeStreamCommand for Histogram {
     ) -> Result<OutputStream, ShellError> {
         args.process(registry, histogram)?.run()
     }
+
+    fn examples(&self) -> &[Example] {
+        &[
+            Example {
+                description: "Get a histogram for the types of files",
+                example: "ls | histogram type",
+            },
+            Example {
+                description:
+                    "Get a histogram for the types of files, with frequency column named count",
+                example: "ls | histogram type count",
+            },
+            Example {
+                description: "Get a histogram for a list of numbers",
+                example: "echo [1 2 3 1 2 3 1 1 1 1 3 2 1 1 3] | wrap | histogram Column",
+            },
+        ]
+    }
 }
 
 pub fn histogram(
@@ -53,7 +71,7 @@ pub fn histogram(
     RunnableContext { input, name, .. }: RunnableContext,
 ) -> Result<OutputStream, ShellError> {
     let stream = async_stream! {
-        let values: Vec<Value> = input.values.collect().await;
+        let values: Vec<Value> = input.collect().await;
 
         let Tagged { item: group_by, .. } = column_name.clone();
 

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

@@ -1,14 +1,17 @@
 use crate::cli::History as HistoryFile;
-use crate::commands::PerItemCommand;
+use crate::commands::WholeStreamCommand;
 use crate::prelude::*;
 use nu_errors::ShellError;
-use nu_protocol::{CallInfo, ReturnSuccess, Signature, UntaggedValue, Value};
+use nu_protocol::{ReturnSuccess, Signature, UntaggedValue};
 use std::fs::File;
 use std::io::{BufRead, BufReader};
 
 pub struct History;
 
-impl PerItemCommand for History {
+#[derive(Deserialize)]
+pub struct HistoryArgs {}
+
+impl WholeStreamCommand for History {
     fn name(&self) -> &str {
         "history"
     }
@@ -23,27 +26,30 @@ impl PerItemCommand for History {
 
     fn run(
         &self,
-        call_info: &CallInfo,
-        _registry: &CommandRegistry,
-        _raw_args: &RawCommandArgs,
-        _input: Value,
+        args: CommandArgs,
+        registry: &CommandRegistry,
     ) -> Result<OutputStream, ShellError> {
-        let tag = call_info.name_tag.clone();
-
-        let stream = async_stream! {
-            let history_path = HistoryFile::path();
-            let file = File::open(history_path);
-            if let Ok(file) = file {
-                let reader = BufReader::new(file);
-                for line in reader.lines() {
-                    if let Ok(line) = line {
-                        yield ReturnSuccess::value(UntaggedValue::string(line).into_value(tag.clone()));
-                    }
-                }
-            } else {
-                yield Err(ShellError::labeled_error("Could not open history", "history file could not be opened", tag.clone()));
-            }
-        };
-        Ok(stream.to_output_stream())
+        args.process(registry, history)?.run()
     }
 }
+
+fn history(
+    _: HistoryArgs,
+    RunnableContext { name: tag, .. }: RunnableContext,
+) -> Result<OutputStream, ShellError> {
+    let stream = async_stream! {
+        let history_path = HistoryFile::path();
+        let file = File::open(history_path);
+        if let Ok(file) = file {
+            let reader = BufReader::new(file);
+            for line in reader.lines() {
+                if let Ok(line) = line {
+                    yield ReturnSuccess::value(UntaggedValue::string(line).into_value(tag.clone()));
+                }
+            }
+        } else {
+            yield Err(ShellError::labeled_error("Could not open history", "history file could not be opened", tag.clone()));
+        }
+    };
+    Ok(stream.to_output_stream())
+}

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

@@ -1,13 +1,19 @@
-use crate::commands::PerItemCommand;
+use crate::commands::WholeStreamCommand;
 use crate::context::CommandRegistry;
 use crate::prelude::*;
 use nu_errors::ShellError;
-use nu_protocol::{CallInfo, ReturnSuccess, Signature, SyntaxShape, UntaggedValue, Value};
+use nu_protocol::{ColumnPath, ReturnSuccess, Signature, SyntaxShape, UntaggedValue, Value};
 use nu_value_ext::ValueExt;
 
 pub struct Insert;
 
-impl PerItemCommand for Insert {
+#[derive(Deserialize)]
+pub struct InsertArgs {
+    column: ColumnPath,
+    value: Value,
+}
+
+impl WholeStreamCommand for Insert {
     fn name(&self) -> &str {
         "insert"
     }
@@ -27,40 +33,45 @@ impl PerItemCommand for Insert {
     }
 
     fn usage(&self) -> &str {
-        "Edit an existing column to have a new value."
+        "Insert a new column with a given value."
     }
 
     fn run(
         &self,
-        call_info: &CallInfo,
-        _registry: &CommandRegistry,
-        _raw_args: &RawCommandArgs,
-        value: Value,
+        args: CommandArgs,
+        registry: &CommandRegistry,
     ) -> Result<OutputStream, ShellError> {
-        let value_tag = value.tag();
-        let field = call_info.args.expect_nth(0)?.as_column_path()?;
-        let replacement = call_info.args.expect_nth(1)?.tagged_unknown();
-
-        let stream = match value {
-            obj
-            @
-            Value {
-                value: UntaggedValue::Row(_),
-                ..
-            } => match obj.insert_data_at_column_path(&field, replacement.item.clone()) {
-                Ok(v) => futures::stream::iter(vec![Ok(ReturnSuccess::Value(v))]),
-                Err(err) => return Err(err),
-            },
-
-            _ => {
-                return Err(ShellError::labeled_error(
-                    "Unrecognized type in stream",
-                    "original value",
-                    value_tag,
-                ))
-            }
-        };
-
-        Ok(stream.to_output_stream())
+        args.process(registry, insert)?.run()
     }
 }
+
+fn insert(
+    InsertArgs { column, value }: InsertArgs,
+    RunnableContext { input, .. }: RunnableContext,
+) -> Result<OutputStream, ShellError> {
+    let mut input = input;
+
+    let stream = async_stream! {
+        match input.next().await {
+            Some(obj @ Value {
+                value: UntaggedValue::Row(_),
+                ..
+            }) => match obj.insert_data_at_column_path(&column, value.clone()) {
+                Ok(v) => yield Ok(ReturnSuccess::Value(v)),
+                Err(err) => yield Err(err),
+            },
+
+            Some(Value { tag, ..}) => {
+                yield Err(ShellError::labeled_error(
+                    "Unrecognized type in stream",
+                    "original value",
+                    tag,
+                ));
+            }
+
+            None => {}
+        };
+
+    };
+    Ok(stream.to_output_stream())
+}

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

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

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

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

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

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

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

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

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

@@ -1,8 +1,8 @@
-use crate::commands::command::RunnablePerItemContext;
+use crate::commands::WholeStreamCommand;
 use crate::context::CommandRegistry;
 use crate::prelude::*;
 use nu_errors::ShellError;
-use nu_protocol::{CallInfo, Signature, SyntaxShape, Value};
+use nu_protocol::{Signature, SyntaxShape};
 use nu_source::Tagged;
 use std::process::{Command, Stdio};
 
@@ -16,7 +16,7 @@ pub struct KillArgs {
     pub quiet: Tagged<bool>,
 }
 
-impl PerItemCommand for Kill {
+impl WholeStreamCommand for Kill {
     fn name(&self) -> &str {
         "kill"
     }
@@ -39,14 +39,23 @@ impl PerItemCommand for Kill {
 
     fn run(
         &self,
-        call_info: &CallInfo,
-        _registry: &CommandRegistry,
-        raw_args: &RawCommandArgs,
-        _input: Value,
+        args: CommandArgs,
+        registry: &CommandRegistry,
     ) -> Result<OutputStream, ShellError> {
-        call_info
-            .process(&raw_args.shell_manager, raw_args.ctrl_c.clone(), kill)?
-            .run()
+        args.process(registry, kill)?.run()
+    }
+
+    fn examples(&self) -> &[Example] {
+        &[
+            Example {
+                description: "Kill the pid using the most memory",
+                example: "ps | sort-by mem | last | kill $it.pid",
+            },
+            Example {
+                description: "Force kill a given pid",
+                example: "kill --force 12345",
+            },
+        ]
     }
 }
 
@@ -57,7 +66,7 @@ fn kill(
         force,
         quiet,
     }: KillArgs,
-    _context: &RunnablePerItemContext,
+    _context: RunnableContext,
 ) -> Result<OutputStream, ShellError> {
     let mut cmd = if cfg!(windows) {
         let mut cmd = Command::new("taskkill");

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

@@ -36,6 +36,19 @@ impl WholeStreamCommand for Last {
     ) -> Result<OutputStream, ShellError> {
         args.process(registry, last)?.run()
     }
+
+    fn examples(&self) -> &[Example] {
+        &[
+            Example {
+                description: "Get the last row",
+                example: "ls | last",
+            },
+            Example {
+                description: "Get the last three rows",
+                example: "ls | last 3",
+            },
+        ]
+    }
 }
 
 fn last(LastArgs { rows }: LastArgs, context: RunnableContext) -> Result<OutputStream, ShellError> {

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

@@ -25,6 +25,13 @@ impl WholeStreamCommand for Lines {
     ) -> Result<OutputStream, ShellError> {
         lines(args, registry)
     }
+
+    fn examples(&self) -> &[Example] {
+        &[Example {
+            description: "Split output from an external command into lines",
+            example: "^ls -l | lines",
+        }]
+    }
 }
 
 fn ends_with_line_ending(st: &str) -> bool {
@@ -47,7 +54,7 @@ fn lines(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStream,
     let mut leftover_string = String::new();
     let stream = async_stream! {
         loop {
-            match input.values.next().await {
+            match input.next().await {
                 Some(Value { value: UntaggedValue::Primitive(Primitive::String(st)), ..}) => {
                     let mut st = leftover_string.clone() + &st;
                     leftover.clear();

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

@@ -1,7 +1,7 @@
-use crate::commands::command::RunnablePerItemContext;
+use crate::commands::WholeStreamCommand;
 use crate::prelude::*;
 use nu_errors::ShellError;
-use nu_protocol::{CallInfo, Signature, SyntaxShape, Value};
+use nu_protocol::{Signature, SyntaxShape};
 use nu_source::Tagged;
 use std::path::PathBuf;
 
@@ -10,14 +10,17 @@ pub struct Ls;
 #[derive(Deserialize)]
 pub struct LsArgs {
     pub path: Option<Tagged<PathBuf>>,
+    pub all: bool,
     pub full: bool,
     #[serde(rename = "short-names")]
     pub short_names: bool,
     #[serde(rename = "with-symlink-targets")]
     pub with_symlink_targets: bool,
+    #[serde(rename = "du")]
+    pub du: bool,
 }
 
-impl PerItemCommand for Ls {
+impl WholeStreamCommand for Ls {
     fn name(&self) -> &str {
         "ls"
     }
@@ -29,6 +32,7 @@ impl PerItemCommand for Ls {
                 SyntaxShape::Pattern,
                 "a path to get the directory contents from",
             )
+            .switch("all", "also show hidden files", Some('a'))
             .switch(
                 "full",
                 "list all available columns for each entry",
@@ -44,6 +48,11 @@ impl PerItemCommand for Ls {
                 "display the paths to the target files that symlinks point to",
                 Some('w'),
             )
+            .switch(
+                "du",
+                "display the apparent directory size in place of the directory metadata size",
+                Some('d'),
+            )
     }
 
     fn usage(&self) -> &str {
@@ -52,17 +61,30 @@ impl PerItemCommand for Ls {
 
     fn run(
         &self,
-        call_info: &CallInfo,
-        _registry: &CommandRegistry,
-        raw_args: &RawCommandArgs,
-        _input: Value,
+        args: CommandArgs,
+        registry: &CommandRegistry,
     ) -> Result<OutputStream, ShellError> {
-        call_info
-            .process(&raw_args.shell_manager, raw_args.ctrl_c.clone(), ls)?
-            .run()
+        args.process(registry, ls)?.run()
+    }
+
+    fn examples(&self) -> &[Example] {
+        &[
+            Example {
+                description: "List all files in the current directory",
+                example: "ls",
+            },
+            Example {
+                description: "List all files in a subdirectory",
+                example: "ls subdir",
+            },
+            Example {
+                description: "List all rust files",
+                example: "ls *.rs",
+            },
+        ]
     }
 }
 
-fn ls(args: LsArgs, context: &RunnablePerItemContext) -> Result<OutputStream, ShellError> {
-    context.shell_manager.ls(args, context)
+fn ls(args: LsArgs, context: RunnableContext) -> Result<OutputStream, ShellError> {
+    context.shell_manager.ls(args, &context)
 }

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

@@ -46,7 +46,7 @@ pub fn map_max_by(
     RunnableContext { input, name, .. }: RunnableContext,
 ) -> Result<OutputStream, ShellError> {
     let stream = async_stream! {
-        let values: Vec<Value> = input.values.collect().await;
+        let values: Vec<Value> = input.collect().await;
 
 
         if values.is_empty() {

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

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

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

@@ -1,8 +1,8 @@
-use crate::commands::command::RunnablePerItemContext;
+use crate::commands::WholeStreamCommand;
 use crate::context::CommandRegistry;
 use crate::prelude::*;
 use nu_errors::ShellError;
-use nu_protocol::{CallInfo, Signature, SyntaxShape, Value};
+use nu_protocol::{Signature, SyntaxShape};
 use nu_source::Tagged;
 use std::path::PathBuf;
 
@@ -13,7 +13,7 @@ pub struct MkdirArgs {
     pub rest: Vec<Tagged<PathBuf>>,
 }
 
-impl PerItemCommand for Mkdir {
+impl WholeStreamCommand for Mkdir {
     fn name(&self) -> &str {
         "mkdir"
     }
@@ -28,18 +28,21 @@ impl PerItemCommand for Mkdir {
 
     fn run(
         &self,
-        call_info: &CallInfo,
-        _registry: &CommandRegistry,
-        raw_args: &RawCommandArgs,
-        _input: Value,
+        args: CommandArgs,
+        registry: &CommandRegistry,
     ) -> Result<OutputStream, ShellError> {
-        call_info
-            .process(&raw_args.shell_manager, raw_args.ctrl_c.clone(), mkdir)?
-            .run()
+        args.process(registry, mkdir)?.run()
+    }
+
+    fn examples(&self) -> &[Example] {
+        &[Example {
+            description: "Make a directory named foo",
+            example: "mkdir foo",
+        }]
     }
 }
 
-fn mkdir(args: MkdirArgs, context: &RunnablePerItemContext) -> Result<OutputStream, ShellError> {
+fn mkdir(args: MkdirArgs, context: RunnableContext) -> Result<OutputStream, ShellError> {
     let shell_manager = context.shell_manager.clone();
-    shell_manager.mkdir(args, context)
+    shell_manager.mkdir(args, &context)
 }

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

@@ -1,8 +1,8 @@
-use crate::commands::command::RunnablePerItemContext;
+use crate::commands::WholeStreamCommand;
 use crate::context::CommandRegistry;
 use crate::prelude::*;
 use nu_errors::ShellError;
-use nu_protocol::{CallInfo, Signature, SyntaxShape, Value};
+use nu_protocol::{Signature, SyntaxShape};
 use nu_source::Tagged;
 use std::path::PathBuf;
 
@@ -14,7 +14,7 @@ pub struct MoveArgs {
     pub dst: Tagged<PathBuf>,
 }
 
-impl PerItemCommand for Move {
+impl WholeStreamCommand for Move {
     fn name(&self) -> &str {
         "mv"
     }
@@ -39,18 +39,31 @@ impl PerItemCommand for Move {
 
     fn run(
         &self,
-        call_info: &CallInfo,
-        _registry: &CommandRegistry,
-        raw_args: &RawCommandArgs,
-        _input: Value,
+        args: CommandArgs,
+        registry: &CommandRegistry,
     ) -> Result<OutputStream, ShellError> {
-        call_info
-            .process(&raw_args.shell_manager, raw_args.ctrl_c.clone(), mv)?
-            .run()
+        args.process(registry, mv)?.run()
+    }
+
+    fn examples(&self) -> &[Example] {
+        &[
+            Example {
+                description: "Rename a file",
+                example: "mv before.txt after.txt",
+            },
+            Example {
+                description: "Move a file into a directory",
+                example: "mv test.txt my/subdirectory",
+            },
+            Example {
+                description: "Move many files into a directory",
+                example: "mv *.txt my/subdirectory",
+            },
+        ]
     }
 }
 
-fn mv(args: MoveArgs, context: &RunnablePerItemContext) -> Result<OutputStream, ShellError> {
+fn mv(args: MoveArgs, context: RunnableContext) -> Result<OutputStream, ShellError> {
     let shell_manager = context.shell_manager.clone();
-    shell_manager.mv(args, context)
+    shell_manager.mv(args, &context)
 }

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

@@ -22,7 +22,7 @@ impl WholeStreamCommand for Nth {
         Signature::build("nth")
             .required(
                 "row number",
-                SyntaxShape::Any,
+                SyntaxShape::Int,
                 "the number of the row to return",
             )
             .rest(SyntaxShape::Any, "Optionally return more rows")
@@ -39,6 +39,19 @@ impl WholeStreamCommand for Nth {
     ) -> Result<OutputStream, ShellError> {
         args.process(registry, nth)?.run()
     }
+
+    fn examples(&self) -> &[Example] {
+        &[
+            Example {
+                description: "Get the second row",
+                example: "echo [first second third] | get 1",
+            },
+            Example {
+                description: "Get the first and third rows",
+                example: "echo [first second third] | get 0 2",
+            },
+        ]
+    }
 }
 
 fn nth(
@@ -49,7 +62,6 @@ fn nth(
     RunnableContext { input, .. }: RunnableContext,
 ) -> Result<OutputStream, ShellError> {
     let stream = input
-        .values
         .enumerate()
         .map(move |(idx, item)| {
             let row_number = vec![row_number.clone()];

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

@@ -1,14 +1,19 @@
+use crate::commands::WholeStreamCommand;
 use crate::prelude::*;
 use nu_errors::ShellError;
-use nu_protocol::{
-    CallInfo, CommandAction, ReturnSuccess, Signature, SyntaxShape, UntaggedValue, Value,
-};
-use nu_source::{AnchorLocation, Span};
+use nu_protocol::{CommandAction, ReturnSuccess, Signature, SyntaxShape, UntaggedValue};
+use nu_source::{AnchorLocation, Span, Tagged};
 use std::path::{Path, PathBuf};
 
 pub struct Open;
 
-impl PerItemCommand for Open {
+#[derive(Deserialize)]
+pub struct OpenArgs {
+    path: Tagged<PathBuf>,
+    raw: Tagged<bool>,
+}
+
+impl WholeStreamCommand for Open {
     fn name(&self) -> &str {
         "open"
     }
@@ -33,36 +38,23 @@ impl PerItemCommand for Open {
 
     fn run(
         &self,
-        call_info: &CallInfo,
-        _registry: &CommandRegistry,
-        raw_args: &RawCommandArgs,
-        _input: Value,
+        args: CommandArgs,
+        registry: &CommandRegistry,
     ) -> Result<OutputStream, ShellError> {
-        run(call_info, raw_args)
+        args.process(registry, open)?.run()
     }
 }
 
-fn run(call_info: &CallInfo, raw_args: &RawCommandArgs) -> Result<OutputStream, ShellError> {
-    let shell_manager = &raw_args.shell_manager;
+fn open(
+    OpenArgs { path, raw }: OpenArgs,
+    RunnableContext { shell_manager, .. }: RunnableContext,
+) -> Result<OutputStream, ShellError> {
     let cwd = PathBuf::from(shell_manager.path());
     let full_path = cwd;
 
-    let path = call_info.args.nth(0).ok_or_else(|| {
-        ShellError::labeled_error(
-            "No file or directory specified",
-            "for command",
-            &call_info.name_tag,
-        )
-    })?;
-
-    let path_buf = path.as_path()?;
-    let path_str = path_buf.display().to_string();
-    let path_span = path.tag.span;
-    let has_raw = call_info.args.has("raw");
-
     let stream = async_stream! {
 
-        let result = fetch(&full_path, &path_str, path_span).await;
+        let result = fetch(&full_path, &path.item, path.tag.span).await;
 
         if let Err(e) = result {
             yield Err(e);
@@ -70,12 +62,12 @@ fn run(call_info: &CallInfo, raw_args: &RawCommandArgs) -> Result<OutputStream,
         }
         let (file_extension, contents, contents_tag) = result?;
 
-        let file_extension = if has_raw {
+        let file_extension = if raw.item {
             None
         } else {
             // If the extension could not be determined via mimetype, try to use the path
             // extension. Some file types do not declare their mimetypes (such as bson files).
-            file_extension.or(path_str.split('.').last().map(String::from))
+            file_extension.or(path.extension().map(|x| x.to_string_lossy().to_string()))
         };
 
         let tagged_contents = contents.into_value(&contents_tag);
@@ -92,7 +84,7 @@ fn run(call_info: &CallInfo, raw_args: &RawCommandArgs) -> Result<OutputStream,
 
 pub async fn fetch(
     cwd: &PathBuf,
-    location: &str,
+    location: &PathBuf,
     span: Span,
 ) -> Result<(Option<String>, UntaggedValue, Tag), ShellError> {
     let mut cwd = cwd.clone();

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

@@ -1,15 +1,9 @@
-use crate::commands::PerItemCommand;
+use crate::commands::WholeStreamCommand;
 use crate::context::CommandRegistry;
 use crate::prelude::*;
 use nu_errors::ShellError;
-use nu_protocol::{
-    CallInfo, ReturnSuccess, Signature, SyntaxShape, TaggedDictBuilder, UntaggedValue, Value,
-};
-
-use nom::{
-    bytes::complete::{tag, take_while},
-    IResult,
-};
+use nu_protocol::{ReturnSuccess, Signature, SyntaxShape, TaggedDictBuilder, UntaggedValue};
+use nu_source::Tagged;
 use regex::Regex;
 
 #[derive(Debug)]
@@ -18,32 +12,44 @@ enum ParseCommand {
     Column(String),
 }
 
-fn parse(input: &str) -> IResult<&str, Vec<ParseCommand>> {
+fn parse(input: &str) -> Vec<ParseCommand> {
     let mut output = vec![];
 
-    let mut loop_input = input;
+    //let mut loop_input = input;
+    let mut loop_input = input.chars();
     loop {
-        let (input, before) = take_while(|c| c != '{')(loop_input)?;
+        let mut before = String::new();
+
+        while let Some(c) = loop_input.next() {
+            if c == '{' {
+                break;
+            }
+            before.push(c);
+        }
+
         if !before.is_empty() {
             output.push(ParseCommand::Text(before.to_string()));
         }
-        if input != "" {
-            // Look for column as we're now at one
-            let (input, _) = tag("{")(input)?;
-            let (input, column) = take_while(|c| c != '}')(input)?;
-            let (input, _) = tag("}")(input)?;
+        // Look for column as we're now at one
+        let mut column = String::new();
 
-            output.push(ParseCommand::Column(column.to_string()));
-            loop_input = input;
-        } else {
-            loop_input = input;
+        while let Some(c) = loop_input.next() {
+            if c == '}' {
+                break;
+            }
+            column.push(c);
         }
-        if loop_input == "" {
+
+        if !column.is_empty() {
+            output.push(ParseCommand::Column(column.to_string()));
+        }
+
+        if before.is_empty() && column.is_empty() {
             break;
         }
     }
 
-    Ok((loop_input, output))
+    output
 }
 
 fn column_names(commands: &[ParseCommand]) -> Vec<String> {
@@ -76,7 +82,12 @@ fn build_regex(commands: &[ParseCommand]) -> String {
 }
 pub struct Parse;
 
-impl PerItemCommand for Parse {
+#[derive(Deserialize)]
+pub struct ParseArgs {
+    pattern: Tagged<String>,
+}
+
+impl WholeStreamCommand for Parse {
     fn name(&self) -> &str {
         "parse"
     }
@@ -84,7 +95,7 @@ impl PerItemCommand for Parse {
     fn signature(&self) -> Signature {
         Signature::build("parse").required(
             "pattern",
-            SyntaxShape::Any,
+            SyntaxShape::String,
             "the pattern to match. Eg) \"{foo}: {bar}\"",
         )
     }
@@ -95,47 +106,62 @@ impl PerItemCommand for Parse {
 
     fn run(
         &self,
-        call_info: &CallInfo,
-        _registry: &CommandRegistry,
-        _raw_args: &RawCommandArgs,
-        value: Value,
+        args: CommandArgs,
+        registry: &CommandRegistry,
     ) -> Result<OutputStream, ShellError> {
-        //let value_tag = value.tag();
-        let pattern = call_info.args.expect_nth(0)?.as_string()?;
+        args.process(registry, parse_command)?.run()
+    }
 
-        let parse_pattern = parse(&pattern).map_err(|_| {
-            ShellError::labeled_error(
-                "Could not create parse pattern",
-                "could not create parse pattern",
-                &value.tag,
-            )
-        })?;
-        let parse_regex = build_regex(&parse_pattern.1);
-
-        let column_names = column_names(&parse_pattern.1);
-        let regex = Regex::new(&parse_regex).map_err(|_| {
-            ShellError::labeled_error("Could not parse regex", "could not parse regex", &value.tag)
-        })?;
-
-        let output = if let Ok(s) = value.as_string() {
-            let mut results = vec![];
-            for cap in regex.captures_iter(&s) {
-                let mut dict = TaggedDictBuilder::new(value.tag());
-
-                for (idx, column_name) in column_names.iter().enumerate() {
-                    dict.insert_untagged(
-                        column_name,
-                        UntaggedValue::string(&cap[idx + 1].to_string()),
-                    );
-                }
-
-                results.push(ReturnSuccess::value(dict.into_value()));
-            }
-
-            VecDeque::from(results)
-        } else {
-            VecDeque::new()
-        };
-        Ok(output.into())
+    fn examples(&self) -> &[Example] {
+        &[Example {
+            description: "Parse values from a string into a table",
+            example: r#"echo "data: 123" | parse "{key}: {value}""#,
+        }]
     }
 }
+
+fn parse_command(
+    ParseArgs { pattern }: ParseArgs,
+    RunnableContext { name, input, .. }: RunnableContext,
+) -> Result<OutputStream, ShellError> {
+    let parse_pattern = parse(&pattern.item);
+    let parse_regex = build_regex(&parse_pattern);
+    let column_names = column_names(&parse_pattern);
+    let name = name.span;
+    let regex = Regex::new(&parse_regex).map_err(|_| {
+        ShellError::labeled_error(
+            "Could not parse regex",
+            "could not parse regex",
+            &pattern.tag,
+        )
+    })?;
+
+    Ok(input
+        .map(move |value| {
+            if let Ok(s) = value.as_string() {
+                let mut output = vec![];
+                for cap in regex.captures_iter(&s) {
+                    let mut dict = TaggedDictBuilder::new(value.tag());
+                    for (idx, column_name) in column_names.iter().enumerate() {
+                        dict.insert_untagged(
+                            column_name,
+                            UntaggedValue::string(cap[idx + 1].to_string()),
+                        );
+                    }
+                    output.push(Ok(ReturnSuccess::Value(dict.into_value())));
+                }
+                output
+            } else {
+                vec![Err(ShellError::labeled_error_with_secondary(
+                    "Expected string input",
+                    "expected string input",
+                    name,
+                    "value originated here",
+                    value.tag,
+                ))]
+            }
+        })
+        .map(futures::stream::iter)
+        .flatten()
+        .to_output_stream())
+}

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

@@ -3,7 +3,7 @@ use crate::prelude::*;
 use derive_new::new;
 use log::trace;
 use nu_errors::ShellError;
-use nu_protocol::{Primitive, ReturnSuccess, ReturnValue, Scope, Signature, UntaggedValue, Value};
+use nu_protocol::{Primitive, ReturnSuccess, ReturnValue, Signature, UntaggedValue, Value};
 use serde::{self, Deserialize, Serialize};
 use std::io::prelude::*;
 use std::io::BufReader;
@@ -71,10 +71,13 @@ pub fn filter_plugin(
 ) -> Result<OutputStream, ShellError> {
     trace!("filter_plugin :: {}", path);
 
-    let args = args.evaluate_once_with_scope(
-        registry,
-        &Scope::it_value(UntaggedValue::string("$it").into_untagged_value()),
-    )?;
+    let scope = &args
+        .call_info
+        .scope
+        .clone()
+        .set_it(UntaggedValue::string("$it").into_untagged_value());
+
+    let args = args.evaluate_once_with_scope(registry, &scope)?;
 
     let mut child = std::process::Command::new(path)
         .stdin(std::process::Stdio::piped())
@@ -95,7 +98,7 @@ pub fn filter_plugin(
     trace!("filtering :: {:?}", call_info);
 
     let stream = bos
-        .chain(args.input.values)
+        .chain(args.input)
         .chain(eos)
         .map(move |v| match v {
             Value {
@@ -340,7 +343,7 @@ pub fn sink_plugin(
     let call_info = args.call_info.clone();
 
     let stream = async_stream! {
-        let input: Vec<Value> = args.input.values.collect().await;
+        let input: Vec<Value> = args.input.collect().await;
 
         let request = JsonRpc::new("sink", (call_info.clone(), input));
         let request_raw = serde_json::to_string(&request);

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

@@ -35,6 +35,13 @@ impl WholeStreamCommand for Prepend {
     ) -> Result<OutputStream, ShellError> {
         args.process(registry, prepend)?.run()
     }
+
+    fn examples(&self) -> &[Example] {
+        &[Example {
+            description: "Add something to the beginning of a list or table",
+            example: "echo [2 3 4] | prepend 1",
+        }]
+    }
 }
 
 fn prepend(
@@ -43,5 +50,5 @@ fn prepend(
 ) -> Result<OutputStream, ShellError> {
     let prepend = futures::stream::iter(vec![row]);
 
-    Ok(OutputStream::from_input(prepend.chain(input.values)))
+    Ok(prepend.chain(input).to_output_stream())
 }

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

@@ -25,6 +25,13 @@ impl WholeStreamCommand for Pwd {
     ) -> Result<OutputStream, ShellError> {
         pwd(args, registry)
     }
+
+    fn examples(&self) -> &[Example] {
+        &[Example {
+            description: "Print the current working directory",
+            example: "pwd",
+        }]
+    }
 }
 
 pub fn pwd(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStream, ShellError> {

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

@@ -50,7 +50,5 @@ fn range(
     let from = *from as usize;
     let to = *to as usize;
 
-    Ok(OutputStream::from_input(
-        input.values.skip(from).take(to - from + 1),
-    ))
+    Ok(input.skip(from).take(to - from + 1).to_output_stream())
 }

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

@@ -45,7 +45,7 @@ pub fn reduce_by(
     RunnableContext { input, name, .. }: RunnableContext,
 ) -> Result<OutputStream, ShellError> {
     let stream = async_stream! {
-        let values: Vec<Value> = input.values.collect().await;
+        let values: Vec<Value> = input.collect().await;
 
         if values.is_empty() {
             yield Err(ShellError::labeled_error(

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

@@ -18,7 +18,7 @@ impl WholeStreamCommand for Reject {
     }
 
     fn signature(&self) -> Signature {
-        Signature::build("reject").rest(SyntaxShape::Member, "the names of columns to remove")
+        Signature::build("reject").rest(SyntaxShape::String, "the names of columns to remove")
     }
 
     fn usage(&self) -> &str {
@@ -48,9 +48,7 @@ fn reject(
 
     let fields: Vec<_> = fields.iter().map(|f| f.item.clone()).collect();
 
-    let stream = input
-        .values
-        .map(move |item| reject_fields(&item, &fields, &item.tag));
+    let stream = input.map(move |item| reject_fields(&item, &fields, &item.tag));
 
     Ok(stream.from_input_stream())
 }

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

@@ -23,12 +23,9 @@ impl WholeStreamCommand for Rename {
             .required(
                 "column_name",
                 SyntaxShape::String,
-                "the name of the column to rename for",
-            )
-            .rest(
-                SyntaxShape::Member,
-                "Additional column name(s) to rename for",
+                "the new name for the first column",
             )
+            .rest(SyntaxShape::String, "the new name for additional columns")
     }
 
     fn usage(&self) -> &str {
@@ -42,6 +39,19 @@ impl WholeStreamCommand for Rename {
     ) -> Result<OutputStream, ShellError> {
         args.process(registry, rename)?.run()
     }
+
+    fn examples(&self) -> &[Example] {
+        &[
+            Example {
+                description: "Rename a column",
+                example: "ls | rename my_name",
+            },
+            Example {
+                description: "Rename many columns",
+                example: "echo \"{a: 1, b: 2, c: 3}\" | from json | rename spam eggs cars",
+            },
+        ]
+    }
 }
 
 pub fn rename(
@@ -54,7 +64,6 @@ pub fn rename(
     let new_column_names = new_column_names.into_iter().flatten().collect::<Vec<_>>();
 
     let stream = input
-        .values
         .map(move |item| {
             let mut result = VecDeque::new();
 

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

@@ -26,13 +26,20 @@ impl WholeStreamCommand for Reverse {
     ) -> Result<OutputStream, ShellError> {
         reverse(args, registry)
     }
+
+    fn examples(&self) -> &[Example] {
+        &[Example {
+            description: "Sort files in descending file size",
+            example: "ls | sort-by size | reverse",
+        }]
+    }
 }
 
 fn reverse(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStream, ShellError> {
     let args = args.evaluate_once(registry)?;
     let (input, _args) = args.parts();
 
-    let input = input.values.collect::<Vec<_>>();
+    let input = input.collect::<Vec<_>>();
 
     let output = input.map(move |mut vec| {
         vec.reverse();

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

@@ -1,8 +1,8 @@
-use crate::commands::command::RunnablePerItemContext;
+use crate::commands::WholeStreamCommand;
 use crate::context::CommandRegistry;
 use crate::prelude::*;
 use nu_errors::ShellError;
-use nu_protocol::{CallInfo, Signature, SyntaxShape, Value};
+use nu_protocol::{Signature, SyntaxShape};
 use nu_source::Tagged;
 use std::path::PathBuf;
 
@@ -10,45 +10,55 @@ pub struct Remove;
 
 #[derive(Deserialize)]
 pub struct RemoveArgs {
-    pub target: Tagged<PathBuf>,
+    pub rest: Vec<Tagged<PathBuf>>,
     pub recursive: Tagged<bool>,
+    #[allow(unused)]
     pub trash: Tagged<bool>,
 }
 
-impl PerItemCommand for Remove {
+impl WholeStreamCommand for Remove {
     fn name(&self) -> &str {
         "rm"
     }
 
     fn signature(&self) -> Signature {
         Signature::build("rm")
-            .required("path", SyntaxShape::Pattern, "the file path to remove")
             .switch(
                 "trash",
                 "use the platform's recycle bin instead of permanently deleting",
                 Some('t'),
             )
             .switch("recursive", "delete subdirectories recursively", Some('r'))
+            .rest(SyntaxShape::Pattern, "the file path(s) to remove")
     }
 
     fn usage(&self) -> &str {
-        "Remove a file"
+        "Remove file(s)"
     }
 
     fn run(
         &self,
-        call_info: &CallInfo,
-        _registry: &CommandRegistry,
-        raw_args: &RawCommandArgs,
-        _input: Value,
+        args: CommandArgs,
+        registry: &CommandRegistry,
     ) -> Result<OutputStream, ShellError> {
-        call_info
-            .process(&raw_args.shell_manager, raw_args.ctrl_c.clone(), rm)?
-            .run()
+        args.process(registry, rm)?.run()
+    }
+
+    fn examples(&self) -> &[Example] {
+        &[
+            Example {
+                description: "Delete a file",
+                example: "rm file.txt",
+            },
+            Example {
+                description: "Move a file to the system trash",
+                example: "rm --trash file.txt",
+            },
+        ]
     }
 }
 
-fn rm(args: RemoveArgs, context: &RunnablePerItemContext) -> Result<OutputStream, ShellError> {
+fn rm(args: RemoveArgs, context: RunnableContext) -> Result<OutputStream, ShellError> {
     let shell_manager = context.shell_manager.clone();
-    shell_manager.rm(args, context)
+    shell_manager.rm(args, &context)
 }

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

@@ -0,0 +1,103 @@
+use crate::commands::classified::block::run_block;
+use crate::commands::WholeStreamCommand;
+use crate::prelude::*;
+
+use derive_new::new;
+use nu_errors::ShellError;
+use nu_protocol::{hir::Block, ReturnSuccess, Signature, SyntaxShape};
+
+#[derive(new, Clone)]
+pub struct AliasCommand {
+    name: String,
+    args: Vec<String>,
+    block: Block,
+}
+
+impl WholeStreamCommand for AliasCommand {
+    fn name(&self) -> &str {
+        &self.name
+    }
+
+    fn signature(&self) -> Signature {
+        let mut alias = Signature::build(&self.name);
+
+        for arg in &self.args {
+            alias = alias.optional(arg, SyntaxShape::Any, "");
+        }
+
+        alias
+    }
+
+    fn usage(&self) -> &str {
+        ""
+    }
+
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        let tag = args.call_info.name_tag.clone();
+        let call_info = args.call_info.clone();
+        let registry = registry.clone();
+        let block = self.block.clone();
+        let alias_command = self.clone();
+        let mut context = Context::from_args(&args, &registry);
+        let input = args.input;
+
+        let stream = async_stream! {
+            let mut scope = call_info.scope.clone();
+            let evaluated = call_info.evaluate(&registry)?;
+            if let Some(positional) = &evaluated.args.positional {
+                for (pos, arg) in positional.iter().enumerate() {
+                    scope = scope.set_var(alias_command.args[pos].to_string(), arg.clone());
+                }
+            }
+
+            let result = run_block(
+                &block,
+                &mut context,
+                input,
+                &scope,
+            ).await;
+
+            match result {
+                Ok(stream) if stream.is_empty() => {
+                    yield Err(ShellError::labeled_error(
+                        "Expected a block",
+                        "alias needs a block",
+                        tag,
+                    ));
+                }
+                Ok(mut stream) => {
+                    // We collect first to ensure errors are put into the context
+                    while let Some(result) = stream.next().await {
+                        yield Ok(ReturnSuccess::Value(result));
+                    }
+
+                    let errors = context.get_errors();
+                    if let Some(x) = errors.first() {
+                        yield Err(ShellError::labeled_error_with_secondary(
+                            "Alias failed to run",
+                            "alias failed to run",
+                            tag.clone(),
+                            x.to_string(),
+                            tag
+                        ));
+                    }
+                }
+                Err(e) => {
+                    yield Err(ShellError::labeled_error_with_secondary(
+                        "Alias failed to run",
+                        "alias failed to run",
+                        tag.clone(),
+                        e.to_string(),
+                        tag
+                    ));
+                }
+            }
+        };
+
+        Ok(stream.to_output_stream())
+    }
+}