Bump to 0.36 (#3963)

* rolling and cumulative operations

* update polars to 0.15.1

* change reference in function

.azure/azure-pipelines.yml

@@ -21,15 +21,6 @@ strategy:
     windows-stable:
       image: windows-2019
       style: 'unflagged'
-    linux-nightly-canary:
-      image: ubuntu-18.04
-      style: 'canary'
-    macos-nightly-canary:
-      image: macos-10.14
-      style: 'canary'
-    windows-nightly-canary:
-      image: windows-2019
-      style: 'canary'
     fmt:
       image: ubuntu-18.04
       style: 'fmt'
@@ -43,7 +34,6 @@ steps:
       if [ -e /etc/debian_version ]
       then
         sudo apt-get -y install libxcb-composite0-dev libx11-dev
-        sudo npm install -g wasm-pack
       fi
       if [ "$(uname)" == "Darwin" ]; then
         curl https://sh.rustup.rs -sSf | sh -s -- -y --no-modify-path --default-toolchain "stable"
@@ -59,18 +49,12 @@ steps:
   - bash: RUSTFLAGS="-D warnings" cargo test --all
     condition: eq(variables['style'], 'unflagged')
     displayName: Run tests
-  - bash: RUSTFLAGS="-D warnings" cargo clippy --all -- -D clippy::unwrap_used
+  - bash: RUSTFLAGS="-D warnings" cargo clippy --all -- -D clippy::unwrap_used -A clippy::needless_collect
     condition: eq(variables['style'], 'unflagged')
     displayName: Check clippy lints
-  - bash: RUSTFLAGS="-D warnings" cargo test --all
+  - bash: cd samples/wasm && npm install wasm-pack && node ./node_modules/wasm-pack/run.js build
-    condition: eq(variables['style'], 'canary')
-    displayName: Run tests
-  - bash: cd samples/wasm && wasm-pack build
     condition: eq(variables['style'], 'wasm')
     displayName: Wasm build
-  - bash: RUSTFLAGS="-D warnings" cargo clippy --all -- -D clippy::unwrap_used
-    condition: eq(variables['style'], 'canary')
-    displayName: Check clippy lints
   - bash: RUSTFLAGS="-D warnings" cargo test --all --no-default-features --features=rustyline-support
     condition: eq(variables['style'], 'minimal')
     displayName: Run tests

.github/ISSUE_TEMPLATE/bug_report.md

@@ -1,47 +0,0 @@
----
-name: Bug report
-about: Create a report to help us improve
-title: ''
-labels: ''
-assignees: ''
-
----
-
-**Describe the bug**
-A clear and concise description of what the bug is.
-
-**To Reproduce**
-Steps to reproduce the behavior:
-1.
-2.
-3.
-
-**Expected behavior**
-A clear and concise description of what you expected to happen.
-
-**Screenshots**
-If applicable, add screenshots to help explain your problem.
-
-**Configuration (please complete the following information):**
-
-Run `version | pivot` and paste the output to show OS, features, etc.
-
-```
-> version | pivot
-╭───┬────────────────────┬───────────────────────────────────────────────────────────────────────╮
-│ # │ Column0            │ Column1                                                               │
-├───┼────────────────────┼───────────────────────────────────────────────────────────────────────┤
-│ 0 │ version            │ 0.24.1                                                                │
-│ 1 │ build_os           │ macos-x86_64                                                          │
-│ 2 │ rust_version       │ rustc 1.48.0                                                          │
-│ 3 │ cargo_version      │ cargo 1.48.0                                                          │
-│ 4 │ pkg_version        │ 0.24.1                                                                │
-│ 5 │ build_time         │ 2020-12-18 09:54:09                                                   │
-│ 6 │ build_rust_channel │ release                                                               │
-│ 7 │ features           │ ctrlc, default, directories, dirs, git, ichwh, ptree, rich-benchmark, │
-│   │                    │ rustyline, term, uuid, which, zip                                     │
-╰───┴────────────────────┴───────────────────────────────────────────────────────────────────────╯
-```
-
-
-**Add any other context about the problem here.**

.github/ISSUE_TEMPLATE/bug_report.yml

@@ -0,0 +1,65 @@
+name: Bug Report
+description: Create a report to help us improve
+body:
+  - type: textarea
+    id: description
+    attributes:
+      label: Describe the bug
+      description: A clear and concise description of what the bug is.
+    validations:
+      required: true
+  - type: textarea
+    id: repro
+    attributes:
+      label: How to reproduce
+      description: Steps to reproduce the behavior
+      placeholder: |
+        1.
+        2.
+        3.
+    validations:
+      required: true
+  - type: textarea
+    id: expected
+    attributes:
+      label: Expected behavior
+      description: A clear and concise description of what you expected to happen.
+      placeholder: I expected nu to...
+    validations:
+      required: true
+  - type: textarea
+    id: screenshots
+    attributes:
+      label: Screenshots
+      description: Please add any relevant screenshots here, if any
+    validations:
+      required: false
+  - type: textarea
+    id: config
+    attributes:
+      label: Configuration
+      description: "Please run `> version | pivot` and paste the output to show OS, features, etc"
+      placeholder: |
+        > version | pivot key value | to md
+        ╭───┬────────────────────┬───────────────────────────────────────────────────────────────────────╮
+        │ # │ key                │ value                                                                 │
+        ├───┼────────────────────┼───────────────────────────────────────────────────────────────────────┤
+        │ 0 │ version            │ 0.24.1                                                                │
+        │ 1 │ build_os           │ macos-x86_64                                                          │
+        │ 2 │ rust_version       │ rustc 1.48.0                                                          │
+        │ 3 │ cargo_version      │ cargo 1.48.0                                                          │
+        │ 4 │ pkg_version        │ 0.24.1                                                                │
+        │ 5 │ build_time         │ 2020-12-18 09:54:09                                                   │
+        │ 6 │ build_rust_channel │ release                                                               │
+        │ 7 │ features           │ ctrlc, default, directories, dirs, git, ichwh, rich-benchmark,        │
+        │   │                    │ rustyline, term, uuid, which, zip                                     │
+        ╰───┴────────────────────┴───────────────────────────────────────────────────────────────────────╯
+    validations:
+      required: false
+  - type: textarea
+    id: context
+    attributes:
+      label: Additional context
+      description: Add any other context about the problem here.
+    validations:
+      required: false

.github/ISSUE_TEMPLATE/feature_request.md

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

.github/ISSUE_TEMPLATE/feature_request.yml

@@ -0,0 +1,34 @@
+name: Feature Request
+description: "When you want a new feature for something that doesn't already exist"
+body:
+  - type: textarea
+    id: problem
+    attributes:
+      label: Related problem
+      description: Is your feature request related to a problem? Please describe.
+      placeholder: |
+        A clear and concise description of what the problem is.
+        Example: I am trying to do [...] but [...]
+    validations:
+      required: false
+  - type: textarea
+    id: desired
+    attributes:
+      label: "Describe the solution you'd like"
+      description: A clear and concise description of what you want to happen.
+    validations:
+      required: true
+  - type: textarea
+    id: alternatives
+    attributes:
+      label: "Describe alternatives you've considered"
+      description: "A clear and concise description of any alternative solutions or features you've considered."
+    validations:
+      required: false
+  - type: textarea
+    id: context
+    attributes:
+      label: Additional context and details
+      description: Add any other context or screenshots about the feature request here.
+    validations:
+      required: false

.github/workflows/release.yml

@@ -283,4 +283,4 @@ jobs:
           upload_url: ${{ steps.create_release.outputs.upload_url }}
           asset_path: ./nushell-windows.msi
           asset_name: ${{ steps.info.outputs.windowsdir }}.msi
-          asset_content_type: applictaion/x-msi
+          asset_content_type: application/x-msi

.github/workflows/stale.yml

@@ -0,0 +1,29 @@
+name: 'Close stale issues and PRs'
+#on: [workflow_dispatch]
+on:
+  schedule:
+    - cron: '30 1 * * *'
+
+permissions:
+  issues: write
+  pull-requests: write
+
+jobs:
+  stale:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/stale@v3
+        with:
+          #debug-only: true
+          ascending: true
+          operations-per-run: 520
+          enable-statistics: true
+          repo-token: ${{ secrets.GITHUB_TOKEN }}
+          stale-issue-message: 'This issue is being marked stale because it has been open for 90 days without activity. If you feel that this is in error, please comment below and we will keep it marked as active.'
+          stale-pr-message: 'This PR is being marked stale because it has been open for 45 days without activity. If this PR is still active, please comment below and we will keep it marked as active.'
+          close-issue-message: 'This issue has been marked stale for more than 10 days without activity. Closing this issue, but if you find that the issue is still valid, please reopen.'
+          close-pr-message: 'This PR has been marked stale for more than 10 days without activity. Closing this PR, but if you are still working on it, please reopen.'
+          days-before-issue-stale: 90
+          days-before-pr-stale: 45
+          days-before-issue-close: 10
+          days-before-pr-close: 10

.github/workflows/winget-submission.yml

@@ -0,0 +1,18 @@
+name: Submit Nushell package to Windows Package Manager Community Repository 
+
+on:
+  release:
+    types: [published]
+
+jobs:
+
+  winget:
+    name: Publish winget package
+    runs-on: windows-latest
+    steps:
+      - name: Submit package to Windows Package Manager Community Repository
+        run: |
+          iwr https://aka.ms/wingetcreate/latest -OutFile wingetcreate.exe
+          $github = Get-Content '${{ github.event_path }}' | ConvertFrom-Json
+          $installerUrl = $github.release.assets | Where-Object -Property name -match 'windows.msi' | Select -ExpandProperty browser_download_url -First 1
+          .\wingetcreate.exe update Nushell.Nushell -s -v $github.release.tag_name -u $installerUrl -t ${{ secrets.NUSHELL_PAT }}

Cargo.toml

@@ -10,7 +10,7 @@ license = "MIT"
 name = "nu"
 readme = "README.md"
 repository = "https://github.com/nushell/nushell"
-version = "0.32.0"
+version = "0.36.0"
 
 [workspace]
 members = ["crates/*/"]
@@ -18,76 +18,64 @@ members = ["crates/*/"]
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-nu-cli = { version = "0.32.0", path = "./crates/nu-cli", default-features = false }
+nu-cli = { version = "0.36.0", path="./crates/nu-cli", default-features=false }
-nu-command = { version = "0.32.0", path = "./crates/nu-command" }
+nu-command = { version = "0.36.0", path="./crates/nu-command" }
-nu-data = { version = "0.32.0", path = "./crates/nu-data" }
+nu-completion = { version = "0.36.0", path="./crates/nu-completion" }
-nu-engine = { version = "0.32.0", path = "./crates/nu-engine" }
+nu-data = { version = "0.36.0", path="./crates/nu-data" }
-nu-errors = { version = "0.32.0", path = "./crates/nu-errors" }
+nu-engine = { version = "0.36.0", path="./crates/nu-engine" }
-nu-parser = { version = "0.32.0", path = "./crates/nu-parser" }
+nu-errors = { version = "0.36.0", path="./crates/nu-errors" }
-nu-plugin = { version = "0.32.0", path = "./crates/nu-plugin" }
+nu-parser = { version = "0.36.0", path="./crates/nu-parser" }
-nu-protocol = { version = "0.32.0", path = "./crates/nu-protocol" }
+nu-path = { version = "0.36.0", path="./crates/nu-path" }
-nu-source = { version = "0.32.0", path = "./crates/nu-source" }
+nu-plugin = { version = "0.36.0", path="./crates/nu-plugin" }
-nu-value-ext = { version = "0.32.0", path = "./crates/nu-value-ext" }
+nu-protocol = { version = "0.36.0", path="./crates/nu-protocol" }
+nu-source = { version = "0.36.0", path="./crates/nu-source" }
+nu-value-ext = { version = "0.36.0", path="./crates/nu-value-ext" }
 
-nu_plugin_binaryview = { version = "0.32.0", path = "./crates/nu_plugin_binaryview", optional = true }
+nu_plugin_binaryview = { version = "0.36.0", path="./crates/nu_plugin_binaryview", optional=true }
-nu_plugin_chart = { version = "0.32.0", path = "./crates/nu_plugin_chart", optional = true }
+nu_plugin_chart = { version = "0.36.0", path="./crates/nu_plugin_chart", optional=true }
-nu_plugin_fetch = { version = "0.32.0", path = "./crates/nu_plugin_fetch", optional = true }
+nu_plugin_fetch = { version = "0.36.0", path="./crates/nu_plugin_fetch", optional=true }
-nu_plugin_from_bson = { version = "0.32.0", path = "./crates/nu_plugin_from_bson", optional = true }
+nu_plugin_from_bson = { version = "0.36.0", path="./crates/nu_plugin_from_bson", optional=true }
-nu_plugin_from_sqlite = { version = "0.32.0", path = "./crates/nu_plugin_from_sqlite", optional = true }
+nu_plugin_from_sqlite = { version = "0.36.0", path="./crates/nu_plugin_from_sqlite", optional=true }
-nu_plugin_inc = { version = "0.32.0", path = "./crates/nu_plugin_inc", optional = true }
+nu_plugin_inc = { version = "0.36.0", path="./crates/nu_plugin_inc", optional=true }
-nu_plugin_match = { version = "0.32.0", path = "./crates/nu_plugin_match", optional = true }
+nu_plugin_match = { version = "0.36.0", path="./crates/nu_plugin_match", optional=true }
-nu_plugin_post = { version = "0.32.0", path = "./crates/nu_plugin_post", optional = true }
+nu_plugin_post = { version = "0.36.0", path="./crates/nu_plugin_post", optional=true }
-nu_plugin_ps = { version = "0.32.0", path = "./crates/nu_plugin_ps", optional = true }
+nu_plugin_ps = { version = "0.36.0", path="./crates/nu_plugin_ps", optional=true }
-nu_plugin_query_json = { version = "0.32.0", path = "./crates/nu_plugin_query_json", optional = true }
+nu_plugin_query_json = { version = "0.36.0", path="./crates/nu_plugin_query_json", optional=true }
-nu_plugin_s3 = { version = "0.32.0", path = "./crates/nu_plugin_s3", optional = true }
+nu_plugin_s3 = { version = "0.36.0", path="./crates/nu_plugin_s3", optional=true }
-nu_plugin_selector = { version = "0.32.0", path = "./crates/nu_plugin_selector", optional = true }
+nu_plugin_selector = { version = "0.36.0", path="./crates/nu_plugin_selector", optional=true }
-nu_plugin_start = { version = "0.32.0", path = "./crates/nu_plugin_start", optional = true }
+nu_plugin_start = { version = "0.36.0", path="./crates/nu_plugin_start", optional=true }
-nu_plugin_sys = { version = "0.32.0", path = "./crates/nu_plugin_sys", optional = true }
+nu_plugin_sys = { version = "0.36.0", path="./crates/nu_plugin_sys", optional=true }
-nu_plugin_textview = { version = "0.32.0", path = "./crates/nu_plugin_textview", optional = true }
+nu_plugin_textview = { version = "0.36.0", path="./crates/nu_plugin_textview", optional=true }
-nu_plugin_to_bson = { version = "0.32.0", path = "./crates/nu_plugin_to_bson", optional = true }
+nu_plugin_to_bson = { version = "0.36.0", path="./crates/nu_plugin_to_bson", optional=true }
-nu_plugin_to_sqlite = { version = "0.32.0", path = "./crates/nu_plugin_to_sqlite", optional = true }
+nu_plugin_to_sqlite = { version = "0.36.0", path="./crates/nu_plugin_to_sqlite", optional=true }
-nu_plugin_tree = { version = "0.32.0", path = "./crates/nu_plugin_tree", optional = true }
+nu_plugin_tree = { version = "0.36.0", path="./crates/nu_plugin_tree", optional=true }
-nu_plugin_xpath = { version = "0.32.0", path = "./crates/nu_plugin_xpath", optional = true }
+nu_plugin_xpath = { version = "0.36.0", path="./crates/nu_plugin_xpath", optional=true }
 
 # Required to bootstrap the main binary
-clap = "2.33.3"
+ctrlc = { version="3.1.7", optional=true }
-ctrlc = { version = "3.1.7", optional = true }
+futures = { version="0.3.12", features=["compat", "io-compat"] }
-futures = { version = "0.3.12", features = ["compat", "io-compat"] }
 itertools = "0.10.0"
-log = "0.4.14"
-pretty_env_logger = "0.4.0"
 
 [dev-dependencies]
-nu-test-support = { version = "0.32.0", path = "./crates/nu-test-support" }
+nu-test-support = { version = "0.36.0", path="./crates/nu-test-support" }
 dunce = "1.0.1"
 serial_test = "0.5.1"
 hamcrest2 = "0.3.0"
-
+rstest = "0.10.0"
 
 [build-dependencies]
 
 [features]
 ctrlc-support = ["nu-cli/ctrlc", "nu-command/ctrlc"]
-directories-support = [
-    "nu-cli/directories",
-    "nu-cli/dirs",
-    "nu-command/directories",
-    "nu-command/dirs",
-    "nu-data/directories",
-    "nu-data/dirs",
-    "nu-engine/dirs",
-]
-ptree-support = ["nu-cli/ptree", "nu-command/ptree"]
 rustyline-support = ["nu-cli/rustyline-support", "nu-command/rustyline-support"]
-term-support = ["nu-cli/term", "nu-command/term"]
+term-support = ["nu-command/term"]
-uuid-support = ["nu-cli/uuid_crate", "nu-command/uuid_crate"]
+uuid-support = ["nu-command/uuid_crate"]
-which-support = ["nu-cli/which", "nu-command/which", "nu-engine/which"]
+which-support = ["nu-command/which", "nu-engine/which"]
 
 default = [
     "nu-cli/shadow-rs",
     "sys",
     "ps",
-    "directories-support",
     "ctrlc-support",
     "which-support",
     "term-support",
@@ -96,6 +84,7 @@ default = [
     "post",
     "fetch",
     "zip-support",
+    "dataframe",
 ]
 
 stable = ["default"]
@@ -104,7 +93,6 @@ extra = [
     "binaryview",
     "inc",
     "tree",
-    "ptree-support",
     "textview",
     "clipboard-cli",
     "trash-support",
@@ -119,9 +107,7 @@ extra = [
     "query-json",
 ]
 
-wasi = ["inc", "match", "ptree-support", "match", "tree", "rustyline-support"]
+wasi = ["inc", "match", "match", "tree", "rustyline-support"]
-
-trace = ["nu-parser/trace"]
 
 # Stable (Default)
 fetch = ["nu_plugin_fetch"]
@@ -136,26 +122,26 @@ textview = ["nu_plugin_textview"]
 binaryview = ["nu_plugin_binaryview"]
 bson = ["nu_plugin_from_bson", "nu_plugin_to_bson"]
 chart = ["nu_plugin_chart"]
-clipboard-cli = ["nu-cli/clipboard-cli", "nu-command/clipboard-cli"]
+clipboard-cli = ["nu-command/clipboard-cli"]
 query-json = ["nu_plugin_query_json"]
 s3 = ["nu_plugin_s3"]
 selector = ["nu_plugin_selector"]
 sqlite = ["nu_plugin_from_sqlite", "nu_plugin_to_sqlite"]
 start = ["nu_plugin_start"]
 trash-support = [
-    "nu-cli/trash-support",
     "nu-command/trash-support",
     "nu-engine/trash-support",
 ]
 tree = ["nu_plugin_tree"]
 xpath = ["nu_plugin_xpath"]
-zip-support = ["nu-cli/zip", "nu-command/zip"]
+zip-support = ["nu-command/zip"]
 
 #This is disabled in extra for now
 table-pager = ["nu-command/table-pager"]
 
 #dataframe feature for nushell
 dataframe = [
+    "nu-engine/dataframe",
     "nu-protocol/dataframe",
     "nu-command/dataframe",
     "nu-value-ext/dataframe",
@@ -164,13 +150,8 @@ dataframe = [
     "nu_plugin_to_bson/dataframe",
 ]
 
-
 [profile.release]
-#strip = "symbols" #Couldn't get working +nightly
+opt-level = "z"  # Optimize for size.
-codegen-units = 1 #Reduce parallel codegen units
-lto = true #Link Time Optimization
-# opt-level = 'z' #Optimize for size
-# debug = true
 
 # Core plugins that ship with `cargo install nu` by default
 # Currently, Cargo limits us to installing only one binary

README.md

@@ -61,13 +61,19 @@ Optional dependencies:
 
 To install Nu via cargo (make sure you have installed [rustup](https://rustup.rs/) and the latest stable compiler via `rustup install stable`):
 
-```bash
+```shell
 cargo install nu
 ```
 
+To install Nu via the [Windows Package Manager](https://aka.ms/winget-cli):
+
+```shell
+winget install nu
+```
+
 You can also build Nu yourself with all the bells and whistles (be sure to have installed the [dependencies](https://www.nushell.sh/book/installation.html#dependencies) for your platform), once you have checked out this repo with git:
 
-```bash
+```shell
 cargo build --workspace --features=extra
 ```
 
@@ -77,7 +83,7 @@ cargo build --workspace --features=extra
 
 Want to try Nu right away? Execute the following to get started.
 
-```bash
+```shell
 docker run -it quay.io/nushell/nu:latest
 ```
 
@@ -86,30 +92,30 @@ docker run -it quay.io/nushell/nu:latest
 If you want to pull a pre-built container, you can browse tags for the [nushell organization](https://quay.io/organization/nushell)
 on Quay.io. Pulling a container would come down to:
 
-```bash
+```shell
 docker pull quay.io/nushell/nu
 docker pull quay.io/nushell/nu-base
 ```
 
-Both "nu-base" and "nu" provide the nu binary, however nu-base also includes the source code at `/code`
+Both "nu-base" and "nu" provide the nu binary, however, nu-base also includes the source code at `/code`
 in the container and all dependencies.
 
 Optionally, you can also build the containers locally using the [dockerfiles provided](docker):
 To build the base image:
 
-```bash
+```shell
 docker build -f docker/Dockerfile.nu-base -t nushell/nu-base .
 ```
 
 And then to build the smaller container (using a Multistage build):
 
-```bash
+```shell
 docker build -f docker/Dockerfile -t nushell/nu .
 ```
 
 Either way, you can run either container as follows:
 
-```bash
+```shell
 docker run -it nushell/nu-base
 docker run -it nushell/nu
 /> exit
@@ -136,13 +142,13 @@ These values can be piped through a series of steps, in a series of commands cal
 
 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.
+Just as the Unix philosophy, Nu allows commands to output to 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 produce a stream (e.g., `ls`)
 -   Commands that filter a stream (eg, `where type == "Dir"`)
--   Commands that consume the output of the pipeline (eg, `autoview`)
+-   Commands that consume the output of the pipeline (e.g., `autoview`)
 
 Commands are separated by the pipe symbol (`|`) to denote a pipeline flowing left to right.
 
@@ -171,7 +177,7 @@ We could have also written the 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.
+For example, we could use the built-in `ps` command to get a list of the running processes, using the same `where` as above.
 
 ```shell
 > ps | where cpu > 0
@@ -188,7 +194,7 @@ For example, we could use the built-in `ps` command as well to get a list of the
 
 ### Opening files
 
-Nu can load file and URL contents as raw text or as structured data (if it recognizes the format).
+Nu can load file and URL contents as raw text or structured data (if it recognizes the format).
 For example, you can load a .toml file as structured data and explore it:
 
 ```shell
@@ -231,8 +237,6 @@ Finally, we can use commands outside of Nu once we have the data we want:
 0.32.0
 ```
 
-Here we use the variable `$it` to refer to the value being piped to the external command.
-
 ### Configuration
 
 Nu has early support for configuring the shell. You can refer to the book for a list of [all supported variables](https://www.nushell.sh/book/configuration.html).
@@ -247,9 +251,9 @@ 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 also offers a way of adding additional working directories that you can jump between, allowing you to work in multiple directories simultaneously.
 
-To do so, use the `enter` command, which will allow you create a new "shell" and enter it at the specified path.
+To do so, use the `enter` command, which will allow you to 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.
 
@@ -263,7 +267,7 @@ 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.
+These binaries interact with nu via a simple JSON-RPC protocol where the command identifies itself and passes along its configuration, making 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.
 
@@ -271,7 +275,7 @@ If the plugin is a sink, it is given the full vector of final data and is given
 
 Nu adheres closely to a set of goals that make up its design philosophy. As features are added, they are checked against these goals.
 
--   First and foremost, Nu is cross-platform. Commands and techniques should carry between platforms and offer first-class consistent support for Windows, macOS, and Linux.
+-   First and foremost, Nu is cross-platform. Commands and techniques should carry between platforms and offer consistent first-class support for Windows, macOS, and Linux.
 
 -   Nu ensures direct compatibility with existing platform-specific executables that make up people's workflows.
 
@@ -287,28 +291,34 @@ You can find a list of Nu commands, complete with documentation, in [quick comma
 
 ## Progress
 
-Nu is in heavy development, and will naturally change as it matures and people use it. The chart below isn't meant to be exhaustive, but rather helps give an idea for some of the areas of development and their relative completion:
+Nu is in heavy development and will naturally change as it matures and people use it. The chart below isn't meant to be exhaustive, but rather helps give an idea for some of the areas of development and their relative completion:
 
 | Features      | Not started | Prototype | MVP | Preview | Mature | Notes                                                                |
 | ------------- | :---------: | :-------: | :-: | :-----: | :----: | -------------------------------------------------------------------- |
-| Aliases       |             |     X     |     |         |        | Initial implementation but lacks necessary features                  |
+| Aliases       |             |           |  X  |         |        | Aliases allow for shortening large commands, while passing flags     |
 | Notebook      |             |     X     |     |         |        | Initial jupyter support, but it loses state and lacks features       |
 | File ops      |             |           |  X  |         |        | cp, mv, rm, mkdir have some support, but lacking others              |
-| Environment   |             |     X     |     |         |        | Temporary environment, but no session-wide env variables             |
+| Environment   |             |           |  X  |         |        | Temporary environment and scoped environment variables               |
 | Shells        |             |     X     |     |         |        | Basic value and file shells, but no opt-in/opt-out for commands      |
 | Protocol      |             |           |  X  |         |        | Streaming protocol is serviceable                                    |
 | Plugins       |             |     X     |     |         |        | Plugins work on one row at a time, lack batching and expression eval |
 | Errors        |             |           |  X  |         |        | Error reporting works, but could use usability polish                |
-| Documentation |             |     X     |     |         |        | Book and related are barebones and lack task-based lessons           |
+| Documentation |             |           |  X  |         |        | Book updated to latest release, including usage examples             |
 | Paging        |             |     X     |     |         |        | Textview has paging, but we'd like paging for tables                 |
-| Functions     |             |     X     |     |         |        | No functions, yet, only aliases                                      |
+| Functions     |             |           |  X  |         |        | Functions and aliases are supported                                  |
-| Variables     |             |     X     |     |         |        | Nu doesn't yet support variables                                     |
+| Variables     |             |           |  X  |         |        | Nu supports variables and environment variables                      |
-| Completions   |             |     X     |     |         |        | Completions are currently barebones, at best                         |
+| Completions   |             |           |  X  |         |        | Completions for filepaths                                            |
-| Type-checking |             |     X     |     |         |        | Commands check basic types, but input/output isn't checked           |
+| Type-checking |             |           |  X  |         |        | Commands check basic types, but input/output isn't checked           |
 
-## Current Roadmap
+## Officially Supported By
 
-We've added a `Roadmap Board` to help collaboratively capture the direction we're going for the current release as well as capture some important issues we'd like to see in Nushell. You can find the Roadmap [here](https://github.com/nushell/nushell/projects/2).
+Please submit an issue or PR to be added to this list.
+
+###   Integrations
+-   [zoxide](https://github.com/ajeetdsouza/zoxide)
+-   [starship](https://github.com/starship/starship)
+###   Mentions
+-   [The Python Launcher for Unix](https://github.com/brettcannon/python-launcher#how-do-i-get-a-table-of-python-executables-in-nushell)
 
 ## Contributing
 

crates/README.md

@@ -0,0 +1,13 @@
+# Nushell core libraries and plugins
+
+These sub-crates form both the foundation for Nu and a set of plugins which extend Nu with additional functionality.
+
+Foundational libraries are split into two kinds of crates:
+
+* Core crates - those crates that work together to build the Nushell language engine
+* Support crates - a set of crates that support the engine with additional features like JSON support, ANSI support, and more.
+
+Plugins are likewise also split into two types:
+
+* Core plugins - plugins that provide part of the default experience of Nu, including access to the system properties, processes, and web-connectivity features.
+* Extra plugins - these plugins run a wide range of differnt capabilities like working with different file types, charting, viewing binary data, and more.

crates/nu-ansi-term/Cargo.toml

@@ -9,7 +9,7 @@ description = "Library for ANSI terminal colors and styles (bold, underline)"
 edition = "2018"
 license = "MIT"
 name = "nu-ansi-term"
-version = "0.32.0"
+version = "0.36.0"
 
 [lib]
 doctest = false
@@ -18,10 +18,15 @@ doctest = false
 [features]
 derive_serde_style = ["serde"]
 
-[dependencies.serde]
+[dependencies]
-version = "1.0.90"
+overload = "0.1.1"
-features = ["derive"]
+serde = { version="1.0.90", features=["derive"], optional=true }
-optional = true
+itertools = "0.10.0"
+
+# [dependencies.serde]
+# version = "1.0.90"
+# features = ["derive"]
+# optional = true
 
 [target.'cfg(target_os="windows")'.dependencies.winapi]
 version = "0.3.4"

crates/nu-ansi-term/examples/gradient_colors.rs

@@ -0,0 +1,37 @@
+use nu_ansi_term::{build_all_gradient_text, Color, Gradient, Rgb, TargetGround};
+
+fn main() {
+    let text = "lorem ipsum quia dolor sit amet, consectetur, adipisci velit";
+
+    // a gradient from hex colors
+    let start = Rgb::from_hex(0x40c9ff);
+    let end = Rgb::from_hex(0xe81cff);
+    let grad0 = Gradient::new(start, end);
+
+    // a gradient from color::rgb()
+    let start = Color::Rgb(64, 201, 255);
+    let end = Color::Rgb(232, 28, 255);
+    let gradient = Gradient::from_color_rgb(start, end);
+
+    // a slightly different gradient
+    let start2 = Color::Rgb(128, 64, 255);
+    let end2 = Color::Rgb(0, 28, 255);
+    let gradient2 = Gradient::from_color_rgb(start2, end2);
+
+    // reverse the gradient
+    let gradient3 = gradient.reverse();
+
+    let build_fg = gradient.build(text, TargetGround::Foreground);
+    println!("{}", build_fg);
+    let build_bg = gradient.build(text, TargetGround::Background);
+    println!("{}", build_bg);
+    let bgt = build_all_gradient_text(text, gradient, gradient2);
+    println!("{}", bgt);
+    let bgt2 = build_all_gradient_text(text, gradient, gradient3);
+    println!("{}", bgt2);
+
+    println!(
+        "{}",
+        grad0.build("nushell is awesome", TargetGround::Foreground)
+    );
+}

crates/nu-ansi-term/src/ansi.rs

@@ -320,7 +320,7 @@ impl fmt::Display for Infix {
                 let f: &mut dyn fmt::Write = f;
                 write!(f, "{}{}", RESET, self.1.prefix())
             }
-            Difference::NoDifference => {
+            Difference::Empty => {
                 Ok(()) // nothing to write
             }
         }

crates/nu-ansi-term/src/difference.rs

@@ -14,7 +14,7 @@ pub enum Difference {
 
     /// The before style is exactly the same as the after style, so no further
     /// control codes need to be printed.
-    NoDifference,
+    Empty,
 }
 
 impl Difference {
@@ -40,7 +40,7 @@ impl Difference {
         // it commented out for now, and defaulting to Reset.
 
         if first == next {
-            return NoDifference;
+            return Empty;
         }
 
         // Cannot un-bold, so must Reset.
@@ -153,10 +153,10 @@ mod test {
         };
     }
 
-    test!(nothing:    Green.normal(); Green.normal()  => NoDifference);
+    test!(nothing:    Green.normal(); Green.normal()  => Empty);
     test!(uppercase:  Green.normal(); Green.bold()    => ExtraStyles(style().bold()));
     test!(lowercase:  Green.bold();   Green.normal()  => Reset);
-    test!(nothing2:   Green.bold();   Green.bold()    => NoDifference);
+    test!(nothing2:   Green.bold();   Green.bold()    => Empty);
 
     test!(color_change: Red.normal(); Blue.normal() => ExtraStyles(Blue.normal()));
 

crates/nu-ansi-term/src/display.rs

@@ -266,7 +266,7 @@ where
             match Difference::between(&window[0].style, &window[1].style) {
                 ExtraStyles(style) => write!(w, "{}", style.prefix())?,
                 Reset => write!(w, "{}{}", RESET, window[1].style.prefix())?,
-                NoDifference => { /* Do nothing! */ }
+                Empty => { /* Do nothing! */ }
             }
 
             w.write_str(&window[1].string)?;

crates/nu-ansi-term/src/gradient.rs

@@ -0,0 +1,105 @@
+use crate::{rgb::Rgb, Color};
+
+/// Linear color gradient between two color stops
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub struct Gradient {
+    /// Start Color of Gradient
+    pub start: Rgb,
+
+    /// End Color of Gradient
+    pub end: Rgb,
+}
+
+impl Gradient {
+    /// Creates a new [Gradient] with two [Rgb] colors, `start` and `end`
+    #[inline]
+    pub const fn new(start: Rgb, end: Rgb) -> Self {
+        Self { start, end }
+    }
+    pub const fn from_color_rgb(start: Color, end: Color) -> Self {
+        let start_grad = match start {
+            Color::Rgb(r, g, b) => Rgb { r, g, b },
+            _ => Rgb { r: 0, g: 0, b: 0 },
+        };
+        let end_grad = match end {
+            Color::Rgb(r, g, b) => Rgb { r, g, b },
+            _ => Rgb { r: 0, g: 0, b: 0 },
+        };
+
+        Self {
+            start: start_grad,
+            end: end_grad,
+        }
+    }
+
+    /// Computes the [Rgb] color between `start` and `end` for `t`
+    pub fn at(&self, t: f32) -> Rgb {
+        self.start.lerp(self.end, t)
+    }
+
+    /// Returns the reverse of `self`
+    #[inline]
+    pub const fn reverse(&self) -> Self {
+        Self::new(self.end, self.start)
+    }
+
+    #[allow(dead_code)]
+    pub fn build(&self, text: &str, target: TargetGround) -> String {
+        let delta = 1.0 / text.len() as f32;
+        let mut result = text.char_indices().fold(String::new(), |mut acc, (i, c)| {
+            let temp = format!(
+                "\x1B[{}m{}",
+                self.at(i as f32 * delta).ansi_color_code(target),
+                c
+            );
+            acc.push_str(&temp);
+            acc
+        });
+
+        result.push_str("\x1B[0m");
+        result
+    }
+}
+
+#[allow(dead_code)]
+pub fn build_all_gradient_text(text: &str, foreground: Gradient, background: Gradient) -> String {
+    let delta = 1.0 / text.len() as f32;
+    let mut result = text.char_indices().fold(String::new(), |mut acc, (i, c)| {
+        let step = i as f32 * delta;
+        let temp = format!(
+            "\x1B[{};{}m{}",
+            foreground
+                .at(step)
+                .ansi_color_code(TargetGround::Foreground),
+            background
+                .at(step)
+                .ansi_color_code(TargetGround::Background),
+            c
+        );
+        acc.push_str(&temp);
+        acc
+    });
+
+    result.push_str("\x1B[0m");
+    result
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum TargetGround {
+    Foreground,
+    Background,
+}
+
+impl TargetGround {
+    #[inline]
+    pub const fn code(&self) -> u8 {
+        match self {
+            Self::Foreground => 30,
+            Self::Background => 40,
+        }
+    }
+}
+
+pub trait ANSIColorCode {
+    fn ansi_color_code(&self, target: TargetGround) -> String;
+}

crates/nu-ansi-term/src/lib.rs

@@ -121,13 +121,13 @@
 //! `Fixed` colors instead, but there’s nothing to be gained by doing so
 //! either.
 //!
-//! You can also access full 24-bit color by using the `Color::RGB` variant,
+//! You can also access full 24-bit color by using the `Color::Rgb` variant,
 //! which takes separate `u8` arguments for red, green, and blue:
 //!
 //! ```
-//! use nu_ansi_term::Color::RGB;
+//! use nu_ansi_term::Color::Rgb;
 //!
-//! RGB(70, 130, 180).paint("Steel blue");
+//! Rgb(70, 130, 180).paint("Steel blue");
 //! ```
 //!
 //! ## Combining successive colored strings
@@ -233,7 +233,7 @@
 #![crate_type = "rlib"]
 #![crate_type = "dylib"]
 #![warn(missing_copy_implementations)]
-#![warn(missing_docs)]
+// #![warn(missing_docs)]
 #![warn(trivial_casts, trivial_numeric_casts)]
 // #![warn(unused_extern_crates, unused_qualifications)]
 
@@ -265,3 +265,9 @@ mod util;
 pub use util::*;
 
 mod debug;
+
+pub mod gradient;
+pub use gradient::*;
+
+mod rgb;
+pub use rgb::*;

crates/nu-ansi-term/src/rgb.rs

@@ -0,0 +1,173 @@
+// Code liberally borrowed from here
+// https://github.com/navierr/coloriz
+use std::ops;
+use std::u32;
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub struct Rgb {
+    /// Red
+    pub r: u8,
+    /// Green
+    pub g: u8,
+    /// Blue
+    pub b: u8,
+}
+
+impl Rgb {
+    /// Creates a new [Rgb] color
+    #[inline]
+    pub const fn new(r: u8, g: u8, b: u8) -> Self {
+        Self { r, g, b }
+    }
+
+    /// Creates a new [Rgb] color with a hex code
+    #[inline]
+    pub const fn from_hex(hex: u32) -> Self {
+        Self::new((hex >> 16) as u8, (hex >> 8) as u8, hex as u8)
+    }
+
+    pub fn from_hex_string(hex: String) -> Self {
+        if hex.chars().count() == 8 && hex.starts_with("0x") {
+            // eprintln!("hex:{:?}", hex);
+            let (_, value_string) = hex.split_at(2);
+            // eprintln!("value_string:{:?}", value_string);
+            let int_val = u64::from_str_radix(value_string, 16);
+            match int_val {
+                Ok(num) => Self::new(
+                    ((num & 0xff0000) >> 16) as u8,
+                    ((num & 0xff00) >> 8) as u8,
+                    (num & 0xff) as u8,
+                ),
+                // Don't fail, just make the color black
+                // Should we fail?
+                _ => Self::new(0, 0, 0),
+            }
+        } else {
+            // Don't fail, just make the color black.
+            // Should we fail?
+            Self::new(0, 0, 0)
+        }
+    }
+
+    /// Creates a new [Rgb] color with three [f32] values
+    pub fn from_f32(r: f32, g: f32, b: f32) -> Self {
+        Self::new(
+            (r.clamp(0.0, 1.0) * 255.0) as u8,
+            (g.clamp(0.0, 1.0) * 255.0) as u8,
+            (b.clamp(0.0, 1.0) * 255.0) as u8,
+        )
+    }
+
+    /// Creates a grayscale [Rgb] color
+    #[inline]
+    pub const fn gray(x: u8) -> Self {
+        Self::new(x, x, x)
+    }
+
+    /// Creates a grayscale [Rgb] color with a [f32] value
+    pub fn gray_f32(x: f32) -> Self {
+        Self::from_f32(x, x, x)
+    }
+
+    /// Creates a new [Rgb] color from a [HSL] color
+    // pub fn from_hsl(hsl: HSL) -> Self {
+    //     if hsl.s == 0.0 {
+    //         return Self::gray_f32(hsl.l);
+    //     }
+
+    //     let q = if hsl.l < 0.5 {
+    //         hsl.l * (1.0 + hsl.s)
+    //     } else {
+    //         hsl.l + hsl.s - hsl.l * hsl.s
+    //     };
+    //     let p = 2.0 * hsl.l - q;
+    //     let h2c = |t: f32| {
+    //         let t = t.clamp(0.0, 1.0);
+    //         if 6.0 * t < 1.0 {
+    //             p + 6.0 * (q - p) * t
+    //         } else if t < 0.5 {
+    //             q
+    //         } else if 1.0 < 1.5 * t {
+    //             p + 6.0 * (q - p) * (1.0 / 1.5 - t)
+    //         } else {
+    //             p
+    //         }
+    //     };
+
+    //     Self::from_f32(h2c(hsl.h + 1.0 / 3.0), h2c(hsl.h), h2c(hsl.h - 1.0 / 3.0))
+    // }
+
+    /// Computes the linear interpolation between `self` and `other` for `t`
+    pub fn lerp(&self, other: Self, t: f32) -> Self {
+        let t = t.clamp(0.0, 1.0);
+        self * (1.0 - t) + other * t
+    }
+}
+
+impl From<(u8, u8, u8)> for Rgb {
+    fn from((r, g, b): (u8, u8, u8)) -> Self {
+        Self::new(r, g, b)
+    }
+}
+
+impl From<(f32, f32, f32)> for Rgb {
+    fn from((r, g, b): (f32, f32, f32)) -> Self {
+        Self::from_f32(r, g, b)
+    }
+}
+
+use crate::ANSIColorCode;
+use crate::TargetGround;
+impl ANSIColorCode for Rgb {
+    fn ansi_color_code(&self, target: TargetGround) -> String {
+        format!("{};2;{};{};{}", target.code() + 8, self.r, self.g, self.b)
+    }
+}
+
+overload::overload!(
+    (lhs: ?Rgb) + (rhs: ?Rgb) -> Rgb {
+        Rgb::new(
+            lhs.r.saturating_add(rhs.r),
+            lhs.g.saturating_add(rhs.g),
+            lhs.b.saturating_add(rhs.b)
+        )
+    }
+);
+
+overload::overload!(
+    (lhs: ?Rgb) - (rhs: ?Rgb) -> Rgb {
+        Rgb::new(
+            lhs.r.saturating_sub(rhs.r),
+            lhs.g.saturating_sub(rhs.g),
+            lhs.b.saturating_sub(rhs.b)
+        )
+    }
+);
+
+overload::overload!(
+    (lhs: ?Rgb) * (rhs: ?f32) -> Rgb {
+        Rgb::new(
+            (lhs.r as f32 * rhs.clamp(0.0, 1.0)) as u8,
+            (lhs.g as f32 * rhs.clamp(0.0, 1.0)) as u8,
+            (lhs.b as f32 * rhs.clamp(0.0, 1.0)) as u8
+        )
+    }
+);
+
+overload::overload!(
+    (lhs: ?f32) * (rhs: ?Rgb) -> Rgb {
+        Rgb::new(
+            (rhs.r as f32 * lhs.clamp(0.0, 1.0)) as u8,
+            (rhs.g as f32 * lhs.clamp(0.0, 1.0)) as u8,
+            (rhs.b as f32 * lhs.clamp(0.0, 1.0)) as u8
+        )
+    }
+);
+
+overload::overload!(
+    -(rgb: ?Rgb) -> Rgb {
+        Rgb::new(
+            255 - rgb.r,
+            255 - rgb.g,
+            255 - rgb.b)
+    }
+);

crates/nu-ansi-term/src/style.rs

@@ -364,10 +364,16 @@ pub enum Color {
     /// [cc]: https://upload.wikimedia.org/wikipedia/commons/1/15/Xterm_256color_chart.svg
     Fixed(u8),
 
-    /// A 24-bit RGB color, as specified by ISO-8613-3.
+    /// A 24-bit Rgb color, as specified by ISO-8613-3.
     Rgb(u8, u8, u8),
 }
 
+impl Default for Color {
+    fn default() -> Self {
+        Color::White
+    }
+}
+
 impl Color {
     /// Returns a `Style` with the foreground color set to this color.
     ///
@@ -546,7 +552,7 @@ impl Color {
     /// ```
     /// use nu_ansi_term::Color;
     ///
-    /// let style = Color::RGB(31, 31, 31).on(Color::White);
+    /// let style = Color::Rgb(31, 31, 31).on(Color::White);
     /// println!("{}", style.paint("eyyyy"));
     /// ```
     pub fn on(self, background: Color) -> Style {
@@ -584,13 +590,13 @@ mod serde_json_tests {
         let colors = &[
             Color::Red,
             Color::Blue,
-            Color::RGB(123, 123, 123),
+            Color::Rgb(123, 123, 123),
             Color::Fixed(255),
         ];
 
         assert_eq!(
             serde_json::to_string(&colors).unwrap(),
-            String::from("[\"Red\",\"Blue\",{\"RGB\":[123,123,123]},{\"Fixed\":255}]")
+            String::from("[\"Red\",\"Blue\",{\"Rgb\":[123,123,123]},{\"Fixed\":255}]")
         );
     }
 
@@ -599,11 +605,11 @@ mod serde_json_tests {
         let colors = &[
             Color::Red,
             Color::Blue,
-            Color::RGB(123, 123, 123),
+            Color::Rgb(123, 123, 123),
             Color::Fixed(255),
         ];
 
-        for color in colors.into_iter() {
+        for color in colors.iter() {
             let serialized = serde_json::to_string(&color).unwrap();
             let deserialized: Color = serde_json::from_str(&serialized).unwrap();
 

crates/nu-ansi-term/src/util.rs

@@ -43,7 +43,7 @@ pub fn unstyle(strs: &AnsiStrings) -> String {
     let mut s = String::new();
 
     for i in strs.0.iter() {
-        s += &i.deref();
+        s += i.deref();
     }
 
     s

crates/nu-cli/Cargo.toml

@@ -1,134 +1,42 @@
 [package]
 authors = ["The Nu Project Contributors"]
-build = "build.rs"
 description = "CLI for nushell"
 edition = "2018"
 license = "MIT"
 name = "nu-cli"
-version = "0.32.0"
+version = "0.36.0"
+build = "build.rs"
 
 [lib]
 doctest = false
 
 [dependencies]
-nu-command = { version = "0.32.0", path = "../nu-command" }
+nu-completion = { version = "0.36.0", path="../nu-completion" }
-nu-data = { version = "0.32.0", path = "../nu-data" }
+nu-command = { version = "0.36.0", path="../nu-command" }
-nu-engine = { version = "0.32.0", path = "../nu-engine" }
+nu-data = { version = "0.36.0", path="../nu-data" }
-nu-errors = { version = "0.32.0", path = "../nu-errors" }
+nu-engine = { version = "0.36.0", path="../nu-engine" }
-nu-json = { version = "0.32.0", path = "../nu-json" }
+nu-errors = { version = "0.36.0", path="../nu-errors" }
-nu-parser = { version = "0.32.0", path = "../nu-parser" }
+nu-parser = { version = "0.36.0", path="../nu-parser" }
-nu-plugin = { version = "0.32.0", path = "../nu-plugin" }
+nu-protocol = { version = "0.36.0", path="../nu-protocol" }
-nu-protocol = { version = "0.32.0", path = "../nu-protocol" }
+nu-source = { version = "0.36.0", path="../nu-source" }
-nu-source = { version = "0.32.0", path = "../nu-source" }
+nu-stream = { version = "0.36.0", path="../nu-stream" }
-nu-stream = { version = "0.32.0", path = "../nu-stream" }
+nu-ansi-term = { version = "0.36.0", path="../nu-ansi-term" }
-nu-table = { version = "0.32.0", path = "../nu-table" }
-nu-test-support = { version = "0.32.0", path = "../nu-test-support" }
-nu-value-ext = { version = "0.32.0", path = "../nu-value-ext" }
-nu-ansi-term = { version = "0.32.0", path = "../nu-ansi-term" }
-nu-pretty-hex = { version = "0.32.0", path = "../nu-pretty-hex" }
 
-Inflector = "0.11"
+indexmap ="1.6.1"
-arboard = { version = "1.1.0", optional = true }
-async-recursion = "0.3.2"
-async-trait = "0.1.42"
-base64 = "0.13.0"
-bigdecimal = { version = "0.2.0", features = ["serde"] }
-byte-unit = "4.0.9"
-bytes = "1.0.1"
-calamine = "0.17.0"
-chrono = { version = "0.4.19", features = ["serde"] }
-chrono-tz = "0.5.3"
-clap = "2.33.3"
-codespan-reporting = "0.11.0"
-csv = "1.1.5"
-ctrlc = { version = "3.1.7", optional = true }
-derive-new = "0.5.8"
-directories-next = { version = "2.0.0", optional = true }
-dirs-next = { version = "2.0.0", optional = true }
-dtparse = "1.2.0"
-dunce = "1.0.1"
-eml-parser = "0.1.0"
-encoding_rs = "0.8.28"
-filesize = "0.2.0"
-fs_extra = "1.2.0"
-futures = { version = "0.3.12", features = ["compat", "io-compat"] }
-futures-util = "0.3.12"
-futures_codec = "0.4.1"
-getset = "0.1.1"
-glob = "0.3.0"
-htmlescape = "0.3.1"
-ical = "0.7.0"
-indexmap = { version = "1.6.1", features = ["serde-1"] }
-itertools = "0.10.0"
-lazy_static = "1.*"
 log = "0.4.14"
-meval = "0.2.0"
+pretty_env_logger = "0.4.0"
-num-bigint = { version = "0.3.1", features = ["serde"] }
-num-format = { version = "0.4.0", features = ["with-num-bigint"] }
-num-traits = "0.2.14"
-parking_lot = "0.11.1"
-pin-utils = "0.1.0"
-ptree = { version = "0.3.1", optional = true }
-query_interface = "0.3.5"
-quick-xml = "0.21.0"
-rand = "0.8.3"
-rayon = "1.5.0"
-regex = "1.4.3"
-roxmltree = "0.14.0"
-rust-embed = "5.9.0"
-rustyline = { version = "8.1.0", optional = true }
-serde = { version = "1.0.123", features = ["derive"] }
-serde_bytes = "0.11.5"
-serde_ini = "0.2.0"
-serde_json = "1.0.61"
-serde_urlencoded = "0.7.0"
-serde_yaml = "0.8.16"
-sha2 = "0.9.3"
-shellexpand = "2.1.0"
 strip-ansi-escapes = "0.1.0"
-sxd-document = "0.3.2"
+rustyline = { version="9.0.0", optional=true }
-sxd-xpath = "0.4.2"
+ctrlc = { version="3.1.7", optional=true }
-tempfile = "3.2.0"
+shadow-rs = { version="0.6", default-features=false, optional=true }
-term = { version = "0.7.0", optional = true }
+serde = { version="1.0.123", features=["derive"] }
-term_size = "0.3.2"
+serde_yaml = "0.8.16"
-termcolor = "1.1.2"
+lazy_static = "1.4.0"
-titlecase = "1.1.0"
-toml = "0.5.8"
-trash = { version = "1.3.0", optional = true }
-unicode-segmentation = "1.7.1"
-url = "2.1.1"
-uuid_crate = { package = "uuid", version = "0.8.2", features = ["v4"], optional = true }
-which = { version = "4.0.2", optional = true }
-zip = { version = "0.5.9", optional = true }
-shadow-rs = { version = "0.5", default-features = false, optional = true }
-
-[target.'cfg(unix)'.dependencies]
-umask = "1.0.0"
-users = "0.11.0"
-
-# TODO this will be possible with new dependency resolver
-#   (currently on nightly behind -Zfeatures=itarget):
-#   https://github.com/rust-lang/cargo/issues/7914
-#[target.'cfg(not(windows))'.dependencies]
-#num-format = {version = "0.4", features = ["with-system-locale"]}
-
-[dependencies.rusqlite]
-features = ["bundled", "blob"]
-optional = true
-version = "0.25.3"
 
 [build-dependencies]
-shadow-rs = "0.5"
+shadow-rs = "0.6"
-
-[dev-dependencies]
-quickcheck = "1.0.3"
-quickcheck_macros = "1.0.0"
 
 [features]
 default = ["shadow-rs"]
-clipboard-cli = ["arboard"]
 rustyline-support = ["rustyline", "nu-engine/rustyline-support"]
 stable = []
-trash-support = ["trash"]
-dirs = ["dirs-next"]
-directories = ["directories-next"]

crates/nu-cli/README.md

@@ -0,0 +1,4 @@
+# nu-cli
+
+This crate provides the fundamental needs when creating the Nushell interactive REPL. In it, you'll find features for interacting with the line editor (the piece which writes the prompt and takes input from the user), keybindings, handlers for the commandline arguments passed to the REPL as it starts up, and more.
+

crates/nu-cli/src/app.rs

@@ -0,0 +1,632 @@
+mod logger;
+mod options;
+mod options_parser;
+pub mod stopwatch;
+
+use self::stopwatch::Stopwatch;
+use lazy_static::lazy_static;
+use nu_command::{commands::NuSignature as Nu, utils::test_bins as binaries};
+use nu_engine::{get_full_help, EvaluationContext};
+use nu_errors::ShellError;
+use nu_protocol::hir::{Call, Expression, SpannedExpression, Synthetic};
+use nu_protocol::{Primitive, UntaggedValue};
+use nu_source::{Span, Tag};
+use nu_stream::InputStream;
+pub use options::{CliOptions, NuScript, Options};
+use options_parser::{NuParser, OptionsParser};
+use std::sync::Mutex;
+
+lazy_static! {
+    pub static ref STOPWATCH: Mutex<Stopwatch> = {
+        let mut sw = Stopwatch::default();
+        sw.start();
+        sw.stop();
+        Mutex::new(sw)
+    };
+}
+
+pub struct App {
+    parser: Box<dyn OptionsParser>,
+    pub options: Options,
+}
+
+impl App {
+    pub fn new(parser: Box<dyn OptionsParser>, options: Options) -> Self {
+        Self { parser, options }
+    }
+
+    pub fn run(args: &[String]) -> Result<(), ShellError> {
+        let nu = Box::new(NuParser::new());
+        let options = Options::default();
+        let ui = App::new(nu, options);
+
+        ui.main(args)
+    }
+
+    pub fn main(&self, argv: &[String]) -> Result<(), ShellError> {
+        if self.perf() {
+            // start the stopwatch running
+            STOPWATCH
+                .lock()
+                .expect("unable to lock the stopwatch")
+                .start();
+        }
+
+        let argv = quote_positionals(argv).join(" ");
+
+        if let Err(cause) = self.parse(&argv) {
+            self.parser
+                .context()
+                .host()
+                .lock()
+                .print_err(cause, &nu_source::Text::from(argv));
+            std::process::exit(1);
+        }
+
+        if self.help() {
+            let context = self.parser.context();
+            let stream = nu_stream::OutputStream::one(
+                UntaggedValue::string(get_full_help(&Nu, &context.scope))
+                    .into_value(nu_source::Tag::unknown()),
+            );
+
+            consume(context, stream)?;
+
+            if self.perf() {
+                // stop the stopwatch since we're exiting
+                STOPWATCH
+                    .lock()
+                    .expect("unable to lock the stopwatch")
+                    .stop();
+                eprintln!(
+                    "help {:?}",
+                    STOPWATCH
+                        .lock()
+                        .expect("unable to lock the stopwatch")
+                        .elapsed()
+                );
+            }
+
+            std::process::exit(0);
+        }
+
+        if self.version() {
+            let context = self.parser.context();
+
+            let stream = nu_command::commands::version(nu_engine::CommandArgs {
+                context: context.clone(),
+                call_info: nu_engine::UnevaluatedCallInfo {
+                    args: Call::new(
+                        Box::new(SpannedExpression::new(
+                            Expression::Synthetic(Synthetic::String("version".to_string())),
+                            Span::unknown(),
+                        )),
+                        Span::unknown(),
+                    ),
+                    name_tag: Tag::unknown(),
+                },
+                input: InputStream::empty(),
+            })?;
+
+            let stream = {
+                let command = context
+                    .get_command("pivot")
+                    .expect("could not find version command");
+
+                context.run_command(
+                    command,
+                    Tag::unknown(),
+                    Call::new(
+                        Box::new(SpannedExpression::new(
+                            Expression::Synthetic(Synthetic::String("pivot".to_string())),
+                            Span::unknown(),
+                        )),
+                        Span::unknown(),
+                    ),
+                    stream,
+                )?
+            };
+
+            consume(context, stream)?;
+
+            if self.perf() {
+                // stop the stopwatch since we're exiting
+                STOPWATCH
+                    .lock()
+                    .expect("unable to lock the stopwatch")
+                    .stop();
+                eprintln!(
+                    "version {:?}",
+                    STOPWATCH
+                        .lock()
+                        .expect("unable to lock the stopwatch")
+                        .elapsed()
+                );
+            }
+
+            std::process::exit(0);
+        }
+
+        if let Some(bin) = self.testbin() {
+            match bin.as_deref() {
+                Ok("echo_env") => binaries::echo_env(),
+                Ok("cococo") => binaries::cococo(),
+                Ok("meow") => binaries::meow(),
+                Ok("iecho") => binaries::iecho(),
+                Ok("fail") => binaries::fail(),
+                Ok("nonu") => binaries::nonu(),
+                Ok("chop") => binaries::chop(),
+                Ok("repeater") => binaries::repeater(),
+                _ => unreachable!(),
+            }
+
+            return Ok(());
+        }
+
+        let mut opts = CliOptions::new();
+        opts.config = self.config().map(std::ffi::OsString::from);
+        opts.stdin = self.takes_stdin();
+        opts.save_history = self.save_history();
+        opts.perf = self.perf();
+
+        use logger::{configure, debug_filters, logger, trace_filters};
+
+        logger(|builder| {
+            configure(self, builder)?;
+            trace_filters(self, builder)?;
+            debug_filters(self, builder)?;
+
+            Ok(())
+        })?;
+
+        if self.perf() {
+            // start a new split
+            STOPWATCH
+                .lock()
+                .expect("unable to lock the stopwatch")
+                .start()
+        }
+
+        if let Some(commands) = self.commands() {
+            let commands = commands?;
+            let script = NuScript::code(&commands)?;
+            opts.scripts = vec![script];
+            let context = crate::create_default_context(false)?;
+            return crate::run_script_file(context, opts);
+        }
+
+        if self.perf() {
+            // start a new spit
+            eprintln!(
+                "commands using -c at launch: {:?}",
+                STOPWATCH
+                    .lock()
+                    .expect("unable to lock the stopwatch")
+                    .elapsed_split()
+            );
+            STOPWATCH
+                .lock()
+                .expect("unable to lock the stopwatch")
+                .start();
+        }
+
+        if let Some(scripts) = self.scripts() {
+            let mut source_files = vec![];
+            for script in scripts {
+                let script_name = script?;
+                let path = std::ffi::OsString::from(&script_name);
+
+                match NuScript::source_file(path.as_os_str()) {
+                    Ok(file) => source_files.push(file),
+                    Err(_) => {
+                        eprintln!("File not found: {}", script_name);
+                        return Ok(());
+                    }
+                }
+            }
+
+            for file in source_files {
+                let mut opts = opts.clone();
+                opts.scripts = vec![file];
+
+                let context = crate::create_default_context(false)?;
+                crate::run_script_file(context, opts)?;
+            }
+
+            return Ok(());
+        }
+
+        if self.perf() {
+            // start a new split
+            eprintln!(
+                "script file(s) passed in: {:?}",
+                STOPWATCH
+                    .lock()
+                    .expect("unable to lock the stopwatch")
+                    .elapsed_split()
+            );
+            STOPWATCH
+                .lock()
+                .expect("unable to lock the stopwatch")
+                .start();
+        }
+
+        let context = crate::create_default_context(true)?;
+
+        if !self.skip_plugins() {
+            let _ = crate::register_plugins(&context);
+        }
+
+        if self.perf() {
+            // start a new split
+            eprintln!(
+                "plugins registered: {:?}",
+                STOPWATCH
+                    .lock()
+                    .expect("unable to lock the stopwatch")
+                    .elapsed_split()
+            );
+        }
+
+        #[cfg(feature = "rustyline-support")]
+        {
+            crate::cli(context, opts)?;
+        }
+
+        #[cfg(not(feature = "rustyline-support"))]
+        {
+            println!("Nushell needs the 'rustyline-support' feature for CLI support");
+        }
+
+        Ok(())
+    }
+
+    pub fn commands(&self) -> Option<Result<String, ShellError>> {
+        self.options.get("commands").map(|v| match v.value {
+            UntaggedValue::Error(err) => Err(err),
+            UntaggedValue::Primitive(Primitive::String(name)) => Ok(name),
+            _ => Err(ShellError::untagged_runtime_error("Unsupported option")),
+        })
+    }
+
+    pub fn perf(&self) -> bool {
+        self.options
+            .get("perf")
+            .map(|v| matches!(v.as_bool(), Ok(true)))
+            .unwrap_or(false)
+    }
+
+    pub fn help(&self) -> bool {
+        self.options
+            .get("help")
+            .map(|v| matches!(v.as_bool(), Ok(true)))
+            .unwrap_or(false)
+    }
+
+    pub fn version(&self) -> bool {
+        self.options
+            .get("version")
+            .map(|v| matches!(v.as_bool(), Ok(true)))
+            .unwrap_or(false)
+    }
+
+    pub fn scripts(&self) -> Option<Vec<Result<String, ShellError>>> {
+        self.options.get("args").map(|v| {
+            v.table_entries()
+                .map(|v| match &v.value {
+                    UntaggedValue::Error(err) => Err(err.clone()),
+                    UntaggedValue::Primitive(Primitive::FilePath(path)) => {
+                        Ok(path.display().to_string())
+                    }
+                    UntaggedValue::Primitive(Primitive::String(name)) => Ok(name.clone()),
+                    _ => Err(ShellError::untagged_runtime_error("Unsupported option")),
+                })
+                .collect()
+        })
+    }
+
+    pub fn takes_stdin(&self) -> bool {
+        self.options
+            .get("stdin")
+            .map(|v| matches!(v.as_bool(), Ok(true)))
+            .unwrap_or(false)
+    }
+
+    pub fn config(&self) -> Option<String> {
+        self.options
+            .get("config-file")
+            .map(|v| v.as_string().expect("not a string"))
+    }
+
+    pub fn develop(&self) -> Option<Vec<Result<String, ShellError>>> {
+        self.options.get("develop").map(|v| {
+            let mut values = vec![];
+
+            match v.value {
+                UntaggedValue::Error(err) => values.push(Err(err)),
+                UntaggedValue::Primitive(Primitive::String(filters)) => {
+                    values.extend(filters.split(',').map(|filter| Ok(filter.to_string())));
+                }
+                _ => values.push(Err(ShellError::untagged_runtime_error(
+                    "Unsupported option",
+                ))),
+            };
+
+            values
+        })
+    }
+
+    pub fn debug(&self) -> Option<Vec<Result<String, ShellError>>> {
+        self.options.get("debug").map(|v| {
+            let mut values = vec![];
+
+            match v.value {
+                UntaggedValue::Error(err) => values.push(Err(err)),
+                UntaggedValue::Primitive(Primitive::String(filters)) => {
+                    values.extend(filters.split(',').map(|filter| Ok(filter.to_string())));
+                }
+                _ => values.push(Err(ShellError::untagged_runtime_error(
+                    "Unsupported option",
+                ))),
+            };
+
+            values
+        })
+    }
+
+    pub fn loglevel(&self) -> Option<Result<String, ShellError>> {
+        self.options.get("loglevel").map(|v| match v.value {
+            UntaggedValue::Error(err) => Err(err),
+            UntaggedValue::Primitive(Primitive::String(name)) => Ok(name),
+            _ => Err(ShellError::untagged_runtime_error("Unsupported option")),
+        })
+    }
+
+    pub fn testbin(&self) -> Option<Result<String, ShellError>> {
+        self.options.get("testbin").map(|v| match v.value {
+            UntaggedValue::Error(err) => Err(err),
+            UntaggedValue::Primitive(Primitive::String(name)) => Ok(name),
+            _ => Err(ShellError::untagged_runtime_error("Unsupported option")),
+        })
+    }
+
+    pub fn skip_plugins(&self) -> bool {
+        self.options
+            .get("skip-plugins")
+            .map(|v| matches!(v.as_bool(), Ok(true)))
+            .unwrap_or(false)
+    }
+
+    pub fn save_history(&self) -> bool {
+        self.options
+            .get("no-history")
+            .map(|v| !matches!(v.as_bool(), Ok(true)))
+            .unwrap_or(true)
+    }
+
+    pub fn parse(&self, args: &str) -> Result<(), ShellError> {
+        self.parser.parse(args).map(|options| {
+            self.options.swap(&options);
+        })
+    }
+}
+
+fn quote_positionals(parameters: &[String]) -> Vec<String> {
+    parameters
+        .iter()
+        .cloned()
+        .map(|arg| {
+            if arg.contains(' ') {
+                format!("\"{}\"", arg)
+            } else {
+                arg
+            }
+        })
+        .collect::<Vec<_>>()
+}
+
+fn consume(context: &EvaluationContext, stream: InputStream) -> Result<(), ShellError> {
+    let autoview_cmd = context
+        .get_command("autoview")
+        .expect("could not find autoview command");
+
+    let stream = context.run_command(
+        autoview_cmd,
+        Tag::unknown(),
+        Call::new(
+            Box::new(SpannedExpression::new(
+                Expression::Synthetic(Synthetic::String("autoview".to_string())),
+                Span::unknown(),
+            )),
+            Span::unknown(),
+        ),
+        stream,
+    )?;
+
+    for _ in stream {}
+
+    Ok(())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn cli_app() -> App {
+        let parser = Box::new(NuParser::new());
+        let options = Options::default();
+
+        App::new(parser, options)
+    }
+
+    #[test]
+    fn default_options() -> Result<(), ShellError> {
+        let ui = cli_app();
+
+        ui.parse("nu")?;
+        assert!(!ui.version());
+        assert!(!ui.help());
+        assert!(!ui.takes_stdin());
+        assert!(ui.save_history());
+        assert!(!ui.skip_plugins());
+        assert_eq!(ui.config(), None);
+        assert_eq!(ui.loglevel(), None);
+        assert_eq!(ui.debug(), None);
+        assert_eq!(ui.develop(), None);
+        assert_eq!(ui.testbin(), None);
+        assert_eq!(ui.commands(), None);
+        assert_eq!(ui.scripts(), None);
+        Ok(())
+    }
+
+    #[test]
+    fn reports_errors_on_unsupported_flags() -> Result<(), ShellError> {
+        let ui = cli_app();
+
+        assert!(ui.parse("nu --coonfig-file /path/to/config.toml").is_err());
+        assert!(ui.config().is_none());
+        Ok(())
+    }
+
+    #[test]
+    fn configures_debug_trace_level_with_filters() -> Result<(), ShellError> {
+        let ui = cli_app();
+        ui.parse("nu --develop=cli,parser")?;
+        assert_eq!(ui.develop().unwrap()[0], Ok("cli".to_string()));
+        assert_eq!(ui.develop().unwrap()[1], Ok("parser".to_string()));
+        Ok(())
+    }
+
+    #[test]
+    fn configures_debug_level_with_filters() -> Result<(), ShellError> {
+        let ui = cli_app();
+        ui.parse("nu --debug=cli,run")?;
+        assert_eq!(ui.debug().unwrap()[0], Ok("cli".to_string()));
+        assert_eq!(ui.debug().unwrap()[1], Ok("run".to_string()));
+        Ok(())
+    }
+
+    #[test]
+    fn can_use_loglevels() -> Result<(), ShellError> {
+        for level in &["error", "warn", "info", "debug", "trace"] {
+            let ui = cli_app();
+            let args = format!("nu --loglevel={}", *level);
+            ui.parse(&args)?;
+            assert_eq!(ui.loglevel().unwrap(), Ok(level.to_string()));
+
+            let ui = cli_app();
+            let args = format!("nu -l {}", *level);
+            ui.parse(&args)?;
+            assert_eq!(ui.loglevel().unwrap(), Ok(level.to_string()));
+        }
+
+        let ui = cli_app();
+        ui.parse("nu --loglevel=nada")?;
+        assert_eq!(
+            ui.loglevel().unwrap(),
+            Err(ShellError::untagged_runtime_error("nada is not supported."))
+        );
+
+        Ok(())
+    }
+
+    #[test]
+    fn can_be_passed_nu_scripts() -> Result<(), ShellError> {
+        let ui = cli_app();
+        ui.parse("nu code.nu bootstrap.nu")?;
+        assert_eq!(ui.scripts().unwrap()[0], Ok("code.nu".into()));
+        assert_eq!(ui.scripts().unwrap()[1], Ok("bootstrap.nu".into()));
+        Ok(())
+    }
+
+    #[test]
+    fn can_use_test_binaries() -> Result<(), ShellError> {
+        for binarie_name in &[
+            "echo_env", "cococo", "iecho", "fail", "nonu", "chop", "repeater", "meow",
+        ] {
+            let ui = cli_app();
+            let args = format!("nu --testbin={}", *binarie_name);
+            ui.parse(&args)?;
+            assert_eq!(ui.testbin().unwrap(), Ok(binarie_name.to_string()));
+        }
+
+        let ui = cli_app();
+        ui.parse("nu --testbin=andres")?;
+        assert_eq!(
+            ui.testbin().unwrap(),
+            Err(ShellError::untagged_runtime_error(
+                "andres is not supported."
+            ))
+        );
+
+        Ok(())
+    }
+
+    #[test]
+    fn has_version() -> Result<(), ShellError> {
+        let ui = cli_app();
+
+        ui.parse("nu --version")?;
+        assert!(ui.version());
+        Ok(())
+    }
+
+    #[test]
+    fn has_help() -> Result<(), ShellError> {
+        let ui = cli_app();
+
+        ui.parse("nu --help")?;
+        assert!(ui.help());
+        Ok(())
+    }
+
+    #[test]
+    fn can_take_stdin() -> Result<(), ShellError> {
+        let ui = cli_app();
+
+        ui.parse("nu --stdin")?;
+        assert!(ui.takes_stdin());
+        Ok(())
+    }
+
+    #[test]
+    fn can_opt_to_avoid_saving_history() -> Result<(), ShellError> {
+        let ui = cli_app();
+
+        ui.parse("nu --no-history")?;
+        assert!(!ui.save_history());
+        Ok(())
+    }
+
+    #[test]
+    fn can_opt_to_skip_plugins() -> Result<(), ShellError> {
+        let ui = cli_app();
+
+        ui.parse("nu --skip-plugins")?;
+        assert!(ui.skip_plugins());
+        Ok(())
+    }
+
+    #[test]
+    fn understands_commands_need_to_be_run() -> Result<(), ShellError> {
+        let ui = cli_app();
+
+        ui.parse("nu -c \"ls | get name\"")?;
+        assert_eq!(ui.commands().unwrap(), Ok(String::from("ls | get name")));
+
+        let ui = cli_app();
+
+        ui.parse("nu -c \"echo 'hola'\"")?;
+        assert_eq!(ui.commands().unwrap(), Ok(String::from("echo 'hola'")));
+        Ok(())
+    }
+
+    #[test]
+    fn knows_custom_configurations() -> Result<(), ShellError> {
+        let ui = cli_app();
+
+        ui.parse("nu --config-file /path/to/config.toml")?;
+        assert_eq!(ui.config().unwrap(), String::from("/path/to/config.toml"));
+        Ok(())
+    }
+}

crates/nu-cli/src/app/logger.rs

@@ -0,0 +1,52 @@
+use super::App;
+use log::LevelFilter;
+use nu_errors::ShellError;
+use pretty_env_logger::env_logger::Builder;
+
+pub fn logger(f: impl FnOnce(&mut Builder) -> Result<(), ShellError>) -> Result<(), ShellError> {
+    let mut builder = pretty_env_logger::formatted_builder();
+    f(&mut builder)?;
+    let _ = builder.try_init();
+    Ok(())
+}
+
+pub fn configure(app: &App, logger: &mut Builder) -> Result<(), ShellError> {
+    if let Some(level) = app.loglevel() {
+        let level = match level.as_deref() {
+            Ok("error") => LevelFilter::Error,
+            Ok("warn") => LevelFilter::Warn,
+            Ok("info") => LevelFilter::Info,
+            Ok("debug") => LevelFilter::Debug,
+            Ok("trace") => LevelFilter::Trace,
+            Ok(_) | Err(_) => LevelFilter::Warn,
+        };
+
+        logger.filter_module("nu", level);
+    };
+
+    if let Ok(s) = std::env::var("RUST_LOG") {
+        logger.parse_filters(&s);
+    }
+
+    Ok(())
+}
+
+pub fn trace_filters(app: &App, logger: &mut Builder) -> Result<(), ShellError> {
+    if let Some(filters) = app.develop() {
+        filters.into_iter().filter_map(Result::ok).for_each(|name| {
+            logger.filter_module(&name, LevelFilter::Trace);
+        })
+    }
+
+    Ok(())
+}
+
+pub fn debug_filters(app: &App, logger: &mut Builder) -> Result<(), ShellError> {
+    if let Some(filters) = app.debug() {
+        filters.into_iter().filter_map(Result::ok).for_each(|name| {
+            logger.filter_module(&name, LevelFilter::Debug);
+        })
+    }
+
+    Ok(())
+}

crates/nu-cli/src/app/options.rs

@@ -0,0 +1,102 @@
+use indexmap::IndexMap;
+use nu_errors::ShellError;
+use nu_protocol::{UntaggedValue, Value};
+use std::cell::RefCell;
+use std::ffi::{OsStr, OsString};
+
+#[derive(Debug, Clone)]
+pub struct CliOptions {
+    pub config: Option<OsString>,
+    pub stdin: bool,
+    pub scripts: Vec<NuScript>,
+    pub save_history: bool,
+    pub perf: bool,
+}
+
+impl Default for CliOptions {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl CliOptions {
+    pub fn new() -> Self {
+        Self {
+            config: None,
+            stdin: false,
+            scripts: vec![],
+            save_history: true,
+            perf: false,
+        }
+    }
+}
+
+#[derive(Debug)]
+pub struct Options {
+    inner: RefCell<IndexMap<String, Value>>,
+}
+
+impl Options {
+    pub fn default() -> Self {
+        Self {
+            inner: RefCell::new(IndexMap::default()),
+        }
+    }
+
+    pub fn get(&self, key: &str) -> Option<Value> {
+        self.inner.borrow().get(key).map(Clone::clone)
+    }
+
+    pub fn put(&self, key: &str, value: Value) {
+        self.inner.borrow_mut().insert(key.into(), value);
+    }
+
+    pub fn shift(&self) {
+        if let Some(Value {
+            value: UntaggedValue::Table(ref mut args),
+            ..
+        }) = self.inner.borrow_mut().get_mut("args")
+        {
+            args.remove(0);
+        }
+    }
+
+    pub fn swap(&self, other: &Options) {
+        self.inner.swap(&other.inner);
+    }
+}
+
+#[derive(Debug, Clone)]
+pub struct NuScript {
+    pub filepath: Option<OsString>,
+    pub contents: String,
+}
+
+impl NuScript {
+    pub fn code(content: &str) -> Result<Self, ShellError> {
+        Ok(Self {
+            filepath: None,
+            contents: content.to_string(),
+        })
+    }
+
+    pub fn get_code(&self) -> &str {
+        &self.contents
+    }
+
+    pub fn source_file(path: &OsStr) -> Result<Self, ShellError> {
+        use std::fs::File;
+        use std::io::Read;
+
+        let path = path.to_os_string();
+        let mut file = File::open(&path)?;
+        let mut buffer = String::new();
+
+        file.read_to_string(&mut buffer)?;
+
+        Ok(Self {
+            filepath: Some(path),
+            contents: buffer,
+        })
+    }
+}

crates/nu-cli/src/app/options_parser.rs

@@ -0,0 +1,143 @@
+use super::Options;
+
+use nu_command::commands::{loglevels, testbins, NuSignature as Nu};
+use nu_command::commands::{Autoview, Pivot, Table, Version as NuVersion};
+use nu_engine::{whole_stream_command, EvaluationContext};
+use nu_errors::ShellError;
+use nu_protocol::hir::{ClassifiedCommand, InternalCommand, NamedValue};
+use nu_protocol::UntaggedValue;
+use nu_source::Tag;
+
+pub struct NuParser {
+    context: EvaluationContext,
+}
+
+pub trait OptionsParser {
+    fn parse(&self, input: &str) -> Result<Options, ShellError>;
+    fn context(&self) -> &EvaluationContext;
+}
+
+impl NuParser {
+    pub fn new() -> Self {
+        let context = EvaluationContext::basic();
+        context.add_commands(vec![
+            whole_stream_command(Nu {}),
+            whole_stream_command(NuVersion {}),
+            whole_stream_command(Autoview {}),
+            whole_stream_command(Pivot {}),
+            whole_stream_command(Table {}),
+        ]);
+
+        Self { context }
+    }
+}
+
+impl OptionsParser for NuParser {
+    fn context(&self) -> &EvaluationContext {
+        &self.context
+    }
+
+    fn parse(&self, input: &str) -> Result<Options, ShellError> {
+        let options = Options::default();
+        let (lite_result, _err) = nu_parser::lex(input, 0, nu_parser::NewlineMode::Normal);
+        let (lite_result, _err) = nu_parser::parse_block(lite_result);
+
+        let (parsed, err) = nu_parser::classify_block(&lite_result, &self.context.scope);
+
+        if let Some(reason) = err {
+            return Err(reason.into());
+        }
+
+        match parsed.block[0].pipelines[0].list[0] {
+            ClassifiedCommand::Internal(InternalCommand { ref args, .. }) => {
+                if let Some(ref params) = args.named {
+                    params.iter().for_each(|(k, v)| {
+                        let value = match v {
+                            NamedValue::AbsentSwitch => {
+                                Some(UntaggedValue::from(false).into_untagged_value())
+                            }
+                            NamedValue::PresentSwitch(span) => {
+                                Some(UntaggedValue::from(true).into_value(Tag::from(span)))
+                            }
+                            NamedValue::AbsentValue => None,
+                            NamedValue::Value(span, exprs) => {
+                                let value = nu_engine::evaluate_baseline_expr(exprs, &self.context)
+                                    .expect("value");
+                                Some(value.value.into_value(Tag::from(span)))
+                            }
+                        };
+
+                        let value =
+                            value
+                                .map(|v| match k.as_ref() {
+                                    "testbin" => {
+                                        if let Ok(name) = v.as_string() {
+                                            if testbins().iter().any(|n| name == *n) {
+                                                Some(v)
+                                            } else {
+                                                Some(
+                                                    UntaggedValue::Error(
+                                                        ShellError::untagged_runtime_error(
+                                                            format!("{} is not supported.", name),
+                                                        ),
+                                                    )
+                                                    .into_value(v.tag),
+                                                )
+                                            }
+                                        } else {
+                                            Some(v)
+                                        }
+                                    }
+                                    "loglevel" => {
+                                        if let Ok(name) = v.as_string() {
+                                            if loglevels().iter().any(|n| name == *n) {
+                                                Some(v)
+                                            } else {
+                                                Some(
+                                                    UntaggedValue::Error(
+                                                        ShellError::untagged_runtime_error(
+                                                            format!("{} is not supported.", name),
+                                                        ),
+                                                    )
+                                                    .into_value(v.tag),
+                                                )
+                                            }
+                                        } else {
+                                            Some(v)
+                                        }
+                                    }
+                                    _ => Some(v),
+                                })
+                                .flatten();
+
+                        if let Some(value) = value {
+                            options.put(k, value);
+                        }
+                    });
+                }
+
+                let mut positional_args = vec![];
+
+                if let Some(positional) = &args.positional {
+                    for pos in positional {
+                        let result = nu_engine::evaluate_baseline_expr(pos, &self.context)?;
+                        positional_args.push(result);
+                    }
+                }
+
+                if !positional_args.is_empty() {
+                    options.put(
+                        "args",
+                        UntaggedValue::Table(positional_args).into_untagged_value(),
+                    );
+                }
+            }
+            ClassifiedCommand::Error(ref reason) => {
+                return Err(reason.clone().into());
+            }
+            _ => return Err(ShellError::untagged_runtime_error("unrecognized command")),
+        }
+
+        Ok(options)
+    }
+}

crates/nu-cli/src/app/stopwatch.rs

@@ -0,0 +1,118 @@
+#![allow(dead_code)]
+use std::default::Default;
+use std::fmt;
+use std::time::{Duration, Instant};
+
+#[derive(Clone, Copy)]
+pub struct Stopwatch {
+    /// The time the stopwatch was started last, if ever.
+    start_time: Option<Instant>,
+    /// The time the stopwatch was split last, if ever.
+    split_time: Option<Instant>,
+    /// The time elapsed while the stopwatch was running (between start() and stop()).
+    elapsed: Duration,
+}
+
+impl Default for Stopwatch {
+    fn default() -> Stopwatch {
+        Stopwatch {
+            start_time: None,
+            split_time: None,
+            elapsed: Duration::from_secs(0),
+        }
+    }
+}
+
+impl fmt::Display for Stopwatch {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        return write!(f, "{}ms", self.elapsed_ms());
+    }
+}
+
+impl Stopwatch {
+    /// Returns a new stopwatch.
+    pub fn new() -> Stopwatch {
+        let sw: Stopwatch = Default::default();
+        sw
+    }
+
+    /// Returns a new stopwatch which will immediately be started.
+    pub fn start_new() -> Stopwatch {
+        let mut sw = Stopwatch::new();
+        sw.start();
+        sw
+    }
+
+    /// Starts the stopwatch.
+    pub fn start(&mut self) {
+        self.start_time = Some(Instant::now());
+    }
+
+    /// Stops the stopwatch.
+    pub fn stop(&mut self) {
+        self.elapsed = self.elapsed();
+        self.start_time = None;
+        self.split_time = None;
+    }
+
+    /// Resets all counters and stops the stopwatch.
+    pub fn reset(&mut self) {
+        self.elapsed = Duration::from_secs(0);
+        self.start_time = None;
+        self.split_time = None;
+    }
+
+    /// Resets and starts the stopwatch again.
+    pub fn restart(&mut self) {
+        self.reset();
+        self.start();
+    }
+
+    /// Returns whether the stopwatch is running.
+    pub fn is_running(&self) -> bool {
+        self.start_time.is_some()
+    }
+
+    /// Returns the elapsed time since the start of the stopwatch.
+    pub fn elapsed(&self) -> Duration {
+        match self.start_time {
+            // stopwatch is running
+            Some(t1) => t1.elapsed() + self.elapsed,
+            // stopwatch is not running
+            None => self.elapsed,
+        }
+    }
+
+    /// Returns the elapsed time since the start of the stopwatch in milliseconds.
+    pub fn elapsed_ms(&self) -> i64 {
+        let dur = self.elapsed();
+        (dur.as_secs() * 1000 + dur.subsec_millis() as u64) as i64
+    }
+
+    /// Returns the elapsed time since last split or start/restart.
+    ///
+    /// If the stopwatch is in stopped state this will always return a zero Duration.
+    pub fn elapsed_split(&mut self) -> Duration {
+        match self.start_time {
+            // stopwatch is running
+            Some(start) => {
+                let res = match self.split_time {
+                    Some(split) => split.elapsed(),
+                    None => start.elapsed(),
+                };
+                self.split_time = Some(Instant::now());
+                res
+            }
+            // stopwatch is not running
+            None => Duration::from_secs(0),
+        }
+    }
+
+    /// Returns the elapsed time since last split or start/restart in milliseconds.
+    ///
+    /// If the stopwatch is in stopped state this will always return zero.
+    pub fn elapsed_split_ms(&mut self) -> i64 {
+        let dur = self.elapsed_split();
+        (dur.as_secs() * 1000 + dur.subsec_millis() as u64) as i64
+    }
+}

crates/nu-cli/src/cli.rs

@@ -1,3 +1,4 @@
+use crate::app::STOPWATCH;
 use crate::line_editor::configure_ctrl_c;
 use nu_ansi_term::Color;
 use nu_engine::{maybe_print_errors, run_block, script::run_script_standalone, EvaluationContext};
@@ -15,7 +16,6 @@ use crate::line_editor::{
 use nu_data::config;
 use nu_source::{Tag, Text};
 use nu_stream::InputStream;
-use std::ffi::{OsStr, OsString};
 #[allow(unused_imports)]
 use std::sync::atomic::Ordering;
 
@@ -31,72 +31,12 @@ use std::error::Error;
 use std::iter::Iterator;
 use std::path::PathBuf;
 
-pub struct Options {
+// Name of environment variable where the prompt could be stored
-    pub config: Option<OsString>,
+#[cfg(feature = "rustyline-support")]
-    pub stdin: bool,
+const PROMPT_STRING: &str = "PROMPT_STRING";
-    pub scripts: Vec<NuScript>,
-    pub save_history: bool,
-}
-
-impl Default for Options {
-    fn default() -> Self {
-        Self::new()
-    }
-}
-
-impl Options {
-    pub fn new() -> Self {
-        Self {
-            config: None,
-            stdin: false,
-            scripts: vec![],
-            save_history: true,
-        }
-    }
-}
-
-pub struct NuScript {
-    pub filepath: Option<OsString>,
-    pub contents: String,
-}
-
-impl NuScript {
-    pub fn code<'a>(content: impl Iterator<Item = &'a str>) -> Result<Self, ShellError> {
-        let text = content
-            .map(|x| x.to_string())
-            .collect::<Vec<String>>()
-            .join("\n");
-
-        Ok(Self {
-            filepath: None,
-            contents: text,
-        })
-    }
-
-    pub fn get_code(&self) -> &str {
-        &self.contents
-    }
-
-    pub fn source_file(path: &OsStr) -> Result<Self, ShellError> {
-        use std::fs::File;
-        use std::io::Read;
-
-        let path = path.to_os_string();
-        let mut file = File::open(&path)?;
-        let mut buffer = String::new();
-
-        file.read_to_string(&mut buffer)?;
-
-        Ok(Self {
-            filepath: Some(path),
-            contents: buffer,
-        })
-    }
-}
 
 pub fn search_paths() -> Vec<std::path::PathBuf> {
     use std::env;
-
     let mut search_paths = Vec::new();
 
     // Automatically add path `nu` is in as a search path
@@ -123,7 +63,10 @@ pub fn search_paths() -> Vec<std::path::PathBuf> {
     search_paths
 }
 
-pub fn run_script_file(context: EvaluationContext, options: Options) -> Result<(), Box<dyn Error>> {
+pub fn run_script_file(
+    context: EvaluationContext,
+    options: super::app::CliOptions,
+) -> Result<(), ShellError> {
     if let Some(cfg) = options.config {
         load_cfg_as_global_cfg(&context, PathBuf::from(cfg));
     } else {
@@ -144,7 +87,70 @@ pub fn run_script_file(context: EvaluationContext, options: Options) -> Result<(
 }
 
 #[cfg(feature = "rustyline-support")]
-pub fn cli(context: EvaluationContext, options: Options) -> Result<(), Box<dyn Error>> {
+fn default_prompt_string(cwd: &str) -> String {
+    format!(
+        "{}{}{}{}{}{}> ",
+        Color::Green.bold().prefix().to_string(),
+        cwd,
+        nu_ansi_term::ansi::RESET,
+        Color::Cyan.bold().prefix().to_string(),
+        current_branch(),
+        nu_ansi_term::ansi::RESET
+    )
+}
+
+#[cfg(feature = "rustyline-support")]
+fn evaluate_prompt_string(prompt_line: &str, context: &EvaluationContext, cwd: &str) -> String {
+    context.scope.enter_scope();
+    let (prompt_block, err) = nu_parser::parse(prompt_line, 0, &context.scope);
+
+    if err.is_some() {
+        context.scope.exit_scope();
+        default_prompt_string(cwd)
+    } else {
+        let run_result = run_block(
+            &prompt_block,
+            context,
+            InputStream::empty(),
+            ExternalRedirection::Stdout,
+        );
+        context.scope.exit_scope();
+
+        match run_result {
+            Ok(result) => match result.collect_string(Tag::unknown()) {
+                Ok(string_result) => {
+                    let errors = context.get_errors();
+                    maybe_print_errors(context, Text::from(prompt_line));
+                    context.clear_errors();
+
+                    if !errors.is_empty() {
+                        "> ".into()
+                    } else {
+                        string_result.item
+                    }
+                }
+                Err(e) => {
+                    context.host().lock().print_err(e, &Text::from(prompt_line));
+                    context.clear_errors();
+
+                    "> ".into()
+                }
+            },
+            Err(e) => {
+                context.host().lock().print_err(e, &Text::from(prompt_line));
+                context.clear_errors();
+
+                "> ".into()
+            }
+        }
+    }
+}
+
+#[cfg(feature = "rustyline-support")]
+pub fn cli(
+    context: EvaluationContext,
+    options: super::app::CliOptions,
+) -> Result<(), Box<dyn Error>> {
     let _ = configure_ctrl_c(&context);
 
     // start time for running startup scripts (this metric includes loading of the cfg, but w/e)
@@ -155,19 +161,30 @@ pub fn cli(context: EvaluationContext, options: Options) -> Result<(), Box<dyn E
     } else {
         load_global_cfg(&context);
     }
+
     // Store cmd duration in an env var
     context.scope.add_env_var(
-        "CMD_DURATION",
+        "CMD_DURATION_MS",
-        format!("{:?}", startup_commands_start_time.elapsed()),
+        format!("{}", startup_commands_start_time.elapsed().as_millis()),
-    );
-    trace!(
-        "startup commands took {:?}",
-        startup_commands_start_time.elapsed()
     );
 
+    if options.perf {
+        eprintln!(
+            "config loaded: {:?}",
+            STOPWATCH
+                .lock()
+                .expect("unable to lock the stopwatch")
+                .elapsed_split()
+        );
+        STOPWATCH
+            .lock()
+            .expect("unable to lock the stopwatch")
+            .start();
+    }
+
     //Configure rustyline
     let mut rl = default_rustyline_editor_configuration();
-    let history_path = if let Some(cfg) = &context.configs.lock().global_config {
+    let history_path = if let Some(cfg) = &context.configs().lock().global_config {
         let _ = configure_rustyline_editor(&mut rl, cfg);
         let helper = Some(nu_line_editor_helper(&context, cfg));
         rl.set_helper(helper);
@@ -176,13 +193,42 @@ pub fn cli(context: EvaluationContext, options: Options) -> Result<(), Box<dyn E
         nu_data::config::path::default_history_path()
     };
 
+    if options.perf {
+        eprintln!(
+            "rustyline configuration: {:?}",
+            STOPWATCH
+                .lock()
+                .expect("unable to lock the stopwatch")
+                .elapsed_split()
+        );
+        STOPWATCH
+            .lock()
+            .expect("unable to lock the stopwatch")
+            .start();
+    }
+
     // Don't load history if it's not necessary
     if options.save_history {
         let _ = rl.load_history(&history_path);
     }
 
+    if options.perf {
+        eprintln!(
+            "history load: {:?}",
+            STOPWATCH
+                .lock()
+                .expect("unable to lock the stopwatch")
+                .elapsed_split()
+        );
+        STOPWATCH
+            .lock()
+            .expect("unable to lock the stopwatch")
+            .start();
+    }
+
     //set vars from cfg if present
-    let (skip_welcome_message, prompt) = if let Some(cfg) = &context.configs.lock().global_config {
+    let (skip_welcome_message, prompt) = if let Some(cfg) = &context.configs().lock().global_config
+    {
         (
             cfg.var("skip_welcome_message")
                 .map(|x| x.is_true())
@@ -193,6 +239,20 @@ pub fn cli(context: EvaluationContext, options: Options) -> Result<(), Box<dyn E
         (false, None)
     };
 
+    if options.perf {
+        eprintln!(
+            "load custom prompt: {:?}",
+            STOPWATCH
+                .lock()
+                .expect("unable to lock the stopwatch")
+                .elapsed_split()
+        );
+        STOPWATCH
+            .lock()
+            .expect("unable to lock the stopwatch")
+            .start();
+    }
+
     //Check whether dir we start in contains local cfg file and if so load it.
     load_local_cfg_if_present(&context);
 
@@ -205,7 +265,7 @@ pub fn cli(context: EvaluationContext, options: Options) -> Result<(), Box<dyn E
     if !skip_welcome_message {
         println!(
             "Welcome to Nushell {} (type 'help' for more info)",
-            clap::crate_version!()
+            nu_command::commands::core_version()
         );
     }
 
@@ -216,80 +276,39 @@ pub fn cli(context: EvaluationContext, options: Options) -> Result<(), Box<dyn E
 
     let mut ctrlcbreak = false;
 
+    if options.perf {
+        eprintln!(
+            "timing stopped. starting run loop: {:?}",
+            STOPWATCH
+                .lock()
+                .expect("unable to lock the stopwatch")
+                .elapsed_split()
+        );
+        STOPWATCH
+            .lock()
+            .expect("unable to lock the stopwatch")
+            .stop();
+    }
+
     loop {
-        if context.ctrl_c.load(Ordering::SeqCst) {
+        if context.ctrl_c().load(Ordering::SeqCst) {
-            context.ctrl_c.store(false, Ordering::SeqCst);
+            context.ctrl_c().store(false, Ordering::SeqCst);
             continue;
         }
 
-        let cwd = context.shell_manager.path();
+        let cwd = context.shell_manager().path();
 
-        let colored_prompt = {
+        // Check if the PROMPT_STRING env variable is set. This env variable
-            if let Some(prompt) = &prompt {
+        // contains nu code that is used to overwrite the prompt
-                let prompt_line = prompt.as_string()?;
+        let colored_prompt = match context.scope.get_env(PROMPT_STRING) {
-
+            Some(env_prompt) => evaluate_prompt_string(&env_prompt, &context, &cwd),
-                context.scope.enter_scope();
+            None => {
-                let (prompt_block, err) = nu_parser::parse(&prompt_line, 0, &context.scope);
+                if let Some(prompt) = &prompt {
-
+                    let prompt_line = prompt.as_string()?;
-                if err.is_some() {
+                    evaluate_prompt_string(&prompt_line, &context, &cwd)
-                    context.scope.exit_scope();
-
-                    format!(
-                        "{}{}{}{}{}{}> ",
-                        Color::Green.bold().prefix().to_string(),
-                        cwd,
-                        nu_ansi_term::ansi::RESET,
-                        Color::Cyan.bold().prefix().to_string(),
-                        current_branch(),
-                        nu_ansi_term::ansi::RESET
-                    )
                 } else {
-                    let run_result = run_block(
+                    default_prompt_string(&cwd)
-                        &prompt_block,
-                        &context,
-                        InputStream::empty(),
-                        ExternalRedirection::Stdout,
-                    );
-                    context.scope.exit_scope();
-
-                    match run_result {
-                        Ok(result) => match result.collect_string(Tag::unknown()) {
-                            Ok(string_result) => {
-                                let errors = context.get_errors();
-                                maybe_print_errors(&context, Text::from(prompt_line));
-                                context.clear_errors();
-
-                                if !errors.is_empty() {
-                                    "> ".to_string()
-                                } else {
-                                    string_result.item
-                                }
-                            }
-                            Err(e) => {
-                                context.host.lock().print_err(e, &Text::from(prompt_line));
-                                context.clear_errors();
-
-                                "> ".to_string()
-                            }
-                        },
-                        Err(e) => {
-                            context.host.lock().print_err(e, &Text::from(prompt_line));
-                            context.clear_errors();
-
-                            "> ".to_string()
-                        }
-                    }
                 }
-            } else {
-                format!(
-                    "{}{}{}{}{}{}> ",
-                    Color::Green.bold().prefix().to_string(),
-                    cwd,
-                    nu_ansi_term::ansi::RESET,
-                    Color::Cyan.bold().prefix().to_string(),
-                    current_branch(),
-                    nu_ansi_term::ansi::RESET
-                )
             }
         };
 
@@ -307,7 +326,7 @@ pub fn cli(context: EvaluationContext, options: Options) -> Result<(), Box<dyn E
         let mut initial_command = Some(String::new());
         let mut readline = Err(ReadlineError::Eof);
         while let Some(ref cmd) = initial_command {
-            readline = rl.readline_with_initial(&prompt, (&cmd, ""));
+            readline = rl.readline_with_initial(&prompt, (cmd, ""));
             initial_command = None;
         }
 
@@ -332,9 +351,10 @@ pub fn cli(context: EvaluationContext, options: Options) -> Result<(), Box<dyn E
         };
 
         // Store cmd duration in an env var
-        context
+        context.scope.add_env_var(
-            .scope
+            "CMD_DURATION_MS",
-            .add_env_var("CMD_DURATION", format!("{:?}", cmd_start_time.elapsed()));
+            format!("{}", cmd_start_time.elapsed().as_millis()),
+        );
 
         match line {
             LineResult::Success(line) => {
@@ -359,7 +379,7 @@ pub fn cli(context: EvaluationContext, options: Options) -> Result<(), Box<dyn E
                 }
 
                 context
-                    .host
+                    .host()
                     .lock()
                     .print_err(err, &Text::from(session_text.clone()));
 
@@ -373,7 +393,7 @@ pub fn cli(context: EvaluationContext, options: Options) -> Result<(), Box<dyn E
 
             LineResult::CtrlC => {
                 let config_ctrlc_exit = context
-                    .configs
+                    .configs()
                     .lock()
                     .global_config
                     .as_ref()
@@ -399,8 +419,8 @@ pub fn cli(context: EvaluationContext, options: Options) -> Result<(), Box<dyn E
             }
 
             LineResult::CtrlD => {
-                context.shell_manager.remove_at_current();
+                context.shell_manager().remove_at_current();
-                if context.shell_manager.is_empty() {
+                if context.shell_manager().is_empty() {
                     break;
                 }
             }
@@ -420,17 +440,18 @@ pub fn cli(context: EvaluationContext, options: Options) -> Result<(), Box<dyn E
     Ok(())
 }
 
+#[cfg(feature = "rustyline-support")]
 pub fn load_local_cfg_if_present(context: &EvaluationContext) {
     trace!("Loading local cfg if present");
-    match config::loadable_cfg_exists_in_dir(PathBuf::from(context.shell_manager.path())) {
+    match config::loadable_cfg_exists_in_dir(PathBuf::from(context.shell_manager().path())) {
         Ok(Some(cfg_path)) => {
             if let Err(err) = context.load_config(&ConfigPath::Local(cfg_path)) {
-                context.host.lock().print_err(err, &Text::from(""))
+                context.host().lock().print_err(err, &Text::from(""))
             }
         }
         Err(e) => {
             //Report error while checking for local cfg file
-            context.host.lock().print_err(e, &Text::from(""))
+            context.host().lock().print_err(e, &Text::from(""))
         }
         Ok(None) => {
             //No local cfg file present in start dir
@@ -440,7 +461,7 @@ pub fn load_local_cfg_if_present(context: &EvaluationContext) {
 
 fn load_cfg_as_global_cfg(context: &EvaluationContext, path: PathBuf) {
     if let Err(err) = context.load_config(&ConfigPath::Global(path)) {
-        context.host.lock().print_err(err, &Text::from(""));
+        context.host().lock().print_err(err, &Text::from(""));
     }
 }
 
@@ -450,7 +471,7 @@ pub fn load_global_cfg(context: &EvaluationContext) {
             load_cfg_as_global_cfg(context, path);
         }
         Err(e) => {
-            context.host.lock().print_err(e, &Text::from(""));
+            context.host().lock().print_err(e, &Text::from(""));
         }
     }
 }
@@ -478,7 +499,7 @@ pub fn parse_and_eval(line: &str, ctx: &EvaluationContext) -> Result<String, She
 
     // TODO ensure the command whose examples we're testing is actually in the pipeline
     ctx.scope.enter_scope();
-    let (classified_block, err) = nu_parser::parse(&line, 0, &ctx.scope);
+    let (classified_block, err) = nu_parser::parse(line, 0, &ctx.scope);
     if let Some(err) = err {
         ctx.scope.exit_scope();
         return Err(err.into());
@@ -512,19 +533,3 @@ fn current_branch() -> String {
         "".to_string()
     }
 }
-
-#[cfg(test)]
-mod tests {
-    use nu_engine::EvaluationContext;
-
-    #[quickcheck]
-    fn quickcheck_parse(data: String) -> bool {
-        let (tokens, err) = nu_parser::lex(&data, 0);
-        let (lite_block, err2) = nu_parser::parse_block(tokens);
-        if err.is_none() && err2.is_none() {
-            let context = EvaluationContext::basic();
-            let _ = nu_parser::classify_block(&lite_block, &context.scope);
-        }
-        true
-    }
-}

crates/nu-cli/src/completion/mod.rs

@@ -1,37 +0,0 @@
-pub(crate) mod command;
-pub(crate) mod engine;
-pub(crate) mod flag;
-pub(crate) mod matchers;
-pub(crate) mod path;
-
-use matchers::Matcher;
-use nu_engine::EvaluationContext;
-
-#[derive(Debug, Eq, PartialEq)]
-pub struct Suggestion {
-    pub display: String,
-    pub replacement: String,
-}
-
-pub struct CompletionContext<'a>(&'a EvaluationContext);
-
-impl<'a> CompletionContext<'a> {
-    pub fn new(a: &'a EvaluationContext) -> CompletionContext<'a> {
-        CompletionContext(a)
-    }
-}
-
-impl<'a> AsRef<EvaluationContext> for CompletionContext<'a> {
-    fn as_ref(&self) -> &EvaluationContext {
-        self.0
-    }
-}
-
-pub trait Completer {
-    fn complete(
-        &self,
-        ctx: &CompletionContext<'_>,
-        partial: &str,
-        matcher: &dyn Matcher,
-    ) -> Vec<Suggestion>;
-}

crates/nu-cli/src/completion/path.rs

@@ -1,89 +0,0 @@
-use std::path::PathBuf;
-
-use super::matchers::Matcher;
-use crate::completion::{Completer, CompletionContext, Suggestion};
-
-const SEP: char = std::path::MAIN_SEPARATOR;
-
-pub struct PathCompleter;
-
-pub struct PathSuggestion {
-    pub(crate) path: PathBuf,
-    pub(crate) suggestion: Suggestion,
-}
-
-impl PathCompleter {
-    pub fn path_suggestions(&self, partial: &str, matcher: &dyn Matcher) -> Vec<PathSuggestion> {
-        let expanded = nu_parser::expand_ndots(partial);
-        let expanded = expanded.replace(std::path::is_separator, &SEP.to_string());
-        let expanded: &str = expanded.as_ref();
-
-        let (base_dir_name, partial) = match expanded.rfind(SEP) {
-            Some(pos) => expanded.split_at(pos + SEP.len_utf8()),
-            None => ("", expanded),
-        };
-
-        let base_dir = if base_dir_name.is_empty() {
-            PathBuf::from(".")
-        } else {
-            #[cfg(feature = "directories")]
-            {
-                let home_prefix = format!("~{}", SEP);
-                if base_dir_name.starts_with(&home_prefix) {
-                    let mut home_dir = dirs_next::home_dir().unwrap_or_else(|| PathBuf::from("~"));
-                    home_dir.push(&base_dir_name[2..]);
-                    home_dir
-                } else {
-                    PathBuf::from(base_dir_name)
-                }
-            }
-            #[cfg(not(feature = "directories"))]
-            {
-                PathBuf::from(base_dir_name)
-            }
-        };
-
-        if let Ok(result) = base_dir.read_dir() {
-            result
-                .filter_map(|entry| {
-                    entry.ok().and_then(|entry| {
-                        let mut file_name = entry.file_name().to_string_lossy().into_owned();
-                        if matcher.matches(partial, file_name.as_str()) {
-                            let mut path = format!("{}{}", base_dir_name, file_name);
-                            if entry.file_type().map(|ft| ft.is_dir()).unwrap_or(false) {
-                                path.push(std::path::MAIN_SEPARATOR);
-                                file_name.push(std::path::MAIN_SEPARATOR);
-                            }
-
-                            Some(PathSuggestion {
-                                path: entry.path(),
-                                suggestion: Suggestion {
-                                    replacement: path,
-                                    display: file_name,
-                                },
-                            })
-                        } else {
-                            None
-                        }
-                    })
-                })
-                .collect()
-        } else {
-            Vec::new()
-        }
-    }
-}
-
-impl Completer for PathCompleter {
-    fn complete(
-        &self,
-        _ctx: &CompletionContext<'_>,
-        partial: &str,
-        matcher: &dyn Matcher,
-    ) -> Vec<Suggestion> {
-        self.path_suggestions(partial, matcher)
-            .into_iter()
-            .map(|ps| ps.suggestion)
-            .collect()
-    }
-}

crates/nu-cli/src/format.rs

@@ -1,6 +0,0 @@
-use crate::prelude::*;
-use nu_errors::ShellError;
-
-pub(crate) trait RenderView {
-    fn render_view(&self, host: &mut dyn Host) -> Result<(), ShellError>;
-}

crates/nu-cli/src/keybinding.rs

@@ -155,14 +155,14 @@ fn convert_cmd(cmd: Cmd) -> rustyline::Cmd {
 fn convert_keybinding(keybinding: Keybinding) -> (rustyline::KeyEvent, rustyline::Cmd) {
     let rusty_modifiers = match keybinding.modifiers {
         Some(mods) => match mods {
-            NuModifiers::CTRL => Some(Modifiers::CTRL),
+            NuModifiers::Ctrl => Some(Modifiers::CTRL),
-            NuModifiers::ALT => Some(Modifiers::ALT),
+            NuModifiers::Alt => Some(Modifiers::ALT),
-            NuModifiers::SHIFT => Some(Modifiers::SHIFT),
+            NuModifiers::Shift => Some(Modifiers::SHIFT),
-            NuModifiers::NONE => Some(Modifiers::NONE),
+            NuModifiers::None => Some(Modifiers::NONE),
-            NuModifiers::CTRL_SHIFT => Some(Modifiers::CTRL_SHIFT),
+            NuModifiers::CtrlShift => Some(Modifiers::CTRL_SHIFT),
-            NuModifiers::ALT_SHIFT => Some(Modifiers::ALT_SHIFT),
+            NuModifiers::AltShift => Some(Modifiers::ALT_SHIFT),
-            NuModifiers::CTRL_ALT => Some(Modifiers::CTRL_ALT),
+            NuModifiers::CtrlAlt => Some(Modifiers::CTRL_ALT),
-            NuModifiers::CTRL_ALT_SHIFT => Some(Modifiers::CTRL_ALT_SHIFT),
+            NuModifiers::CtrlAltShift => Some(Modifiers::CTRL_ALT_SHIFT),
             // _ => None,
         },
         None => None,
@@ -410,32 +410,39 @@ pub enum CharSearch {
 }
 
 /// The set of modifier keys that were triggered along with a key press.
-#[derive(Serialize, Deserialize)]
+#[derive(Debug, Serialize, Deserialize)]
 #[allow(non_camel_case_types)]
-#[allow(clippy::clippy::upper_case_acronyms)]
 pub enum NuModifiers {
     /// Control modifier
-    CTRL = 8,
+    #[serde(alias = "CTRL")]
+    Ctrl = 8,
     /// Escape or Alt modifier
-    ALT = 4,
+    #[serde(alias = "ALT")]
+    Alt = 4,
     /// Shift modifier
-    SHIFT = 2,
+    #[serde(alias = "SHIFT")]
+    Shift = 2,
     /// No modifier
-    NONE = 0,
+    #[serde(alias = "NONE")]
+    None = 0,
     /// Ctrl + Shift
-    CTRL_SHIFT = 10,
+    #[serde(alias = "CTRL_SHIFT")]
+    CtrlShift = 10,
     /// Alt + Shift
-    ALT_SHIFT = 6,
+    #[serde(alias = "ALT_SHIFT")]
+    AltShift = 6,
     /// Ctrl + Alt
-    CTRL_ALT = 12,
+    #[serde(alias = "CTRL_ALT")]
+    CtrlAlt = 12,
     /// Ctrl + Alt + Shift
-    CTRL_ALT_SHIFT = 14,
+    #[serde(alias = "CTRL_ALT_SHIFT")]
+    CtrlAltShift = 14,
 }
 
 /// The number of times one command should be repeated.
 pub type RepeatCount = usize;
 
-#[derive(Serialize, Deserialize)]
+#[derive(Debug, Serialize, Deserialize)]
 pub struct Keybinding {
     key: KeyCode,
     modifiers: Option<NuModifiers>,
@@ -453,9 +460,10 @@ pub(crate) fn load_keybindings(
     // Silently fail if there is no file there
     if let Ok(contents) = contents {
         let keybindings: Keybindings = serde_yaml::from_str(&contents)?;
-        // eprint!("{}{}{}", keybindings.key, keybindings.mo);
+        // eprintln!("{:#?}", keybindings);
         for keybinding in keybindings.into_iter() {
             let (k, b) = convert_keybinding(keybinding);
+            // eprintln!("{:?} {:?}", k, b);
 
             rl.bind_sequence(k, b);
         }

crates/nu-cli/src/lib.rs

@@ -1,38 +1,15 @@
-#![recursion_limit = "2048"]
+pub mod app;
-
-#[macro_use]
-mod prelude;
-
-#[cfg(test)]
-extern crate quickcheck;
-#[cfg(test)]
-#[macro_use(quickcheck)]
-extern crate quickcheck_macros;
-
 mod cli;
 #[cfg(feature = "rustyline-support")]
-mod completion;
-mod format;
-#[cfg(feature = "rustyline-support")]
 mod keybinding;
 mod line_editor;
+#[cfg(feature = "rustyline-support")]
 mod shell;
-pub mod types;
 
 #[cfg(feature = "rustyline-support")]
 pub use crate::cli::cli;
 
+pub use crate::app::App;
 pub use crate::cli::{parse_and_eval, register_plugins, run_script_file};
-pub use crate::cli::{NuScript, Options};
 
-pub use nu_command::commands::default_context::create_default_context;
+pub use nu_command::create_default_context;
-pub use nu_data::config;
-pub use nu_data::dict::TaggedListBuilder;
-pub use nu_data::primitive;
-pub use nu_data::value;
-pub use nu_stream::{ActionStream, InputStream, InterruptibleStream};
-pub use nu_value_ext::ValueExt;
-pub use num_traits::cast::ToPrimitive;
-
-// TODO: Temporary redirect
-pub use nu_protocol::{did_you_mean, TaggedDictBuilder};

crates/nu-cli/src/line_editor.rs

@@ -1,8 +1,9 @@
 use nu_engine::EvaluationContext;
+use nu_errors::ShellError;
 use std::error::Error;
 
 #[allow(unused_imports)]
-use crate::prelude::*;
+use std::sync::atomic::Ordering;
 
 #[allow(unused_imports)]
 use nu_engine::script::LineResult;
@@ -31,7 +32,7 @@ pub fn convert_rustyline_result_to_string(input: Result<String, ReadlineError>)
         Err(ReadlineError::Interrupted) => LineResult::CtrlC,
         Err(ReadlineError::Eof) => LineResult::CtrlD,
         Err(err) => {
-            outln!("Error: {:?}", err);
+            eprintln!("Error: {:?}", err);
             LineResult::Break
         }
     }
@@ -75,6 +76,8 @@ pub fn default_rustyline_editor_configuration() -> Editor<Helper> {
     let config = Config::builder()
         .check_cursor_position(true)
         .color_mode(ColorMode::Forced)
+        .history_ignore_dups(false)
+        .max_history_size(10_000)
         .build();
     let mut rl: Editor<_> = Editor::with_config(config);
 
@@ -246,7 +249,7 @@ pub fn rustyline_hinter(
 ) -> Option<rustyline::hint::HistoryHinter> {
     if let Some(line_editor_vars) = config.var("line_editor") {
         for (idx, value) in line_editor_vars.row_entries() {
-            if idx == "show_hints" && value.expect_string() == "false" {
+            if idx == "show_hints" && value.as_bool() == Ok(false) {
                 return None;
             }
         }
@@ -258,14 +261,14 @@ pub fn rustyline_hinter(
 pub fn configure_ctrl_c(_context: &EvaluationContext) -> Result<(), Box<dyn Error>> {
     #[cfg(feature = "ctrlc")]
     {
-        let cc = _context.ctrl_c.clone();
+        let cc = _context.ctrl_c().clone();
 
         ctrlc::set_handler(move || {
             cc.store(true, Ordering::SeqCst);
         })?;
 
-        if _context.ctrl_c.load(Ordering::SeqCst) {
+        if _context.ctrl_c().load(Ordering::SeqCst) {
-            _context.ctrl_c.store(false, Ordering::SeqCst);
+            _context.ctrl_c().store(false, Ordering::SeqCst);
         }
     }
 

crates/nu-cli/src/prelude.rs

@@ -1,59 +0,0 @@
-#[macro_export]
-macro_rules! return_err {
-    ($expr:expr) => {
-        match $expr {
-            Err(_) => return,
-            Ok(expr) => expr,
-        };
-    };
-}
-
-#[macro_export]
-macro_rules! trace_out_stream {
-    (target: $target:tt, $desc:tt = $expr:expr) => {{
-        if log::log_enabled!(target: $target, log::Level::Trace) {
-            let objects = $expr.inspect(move |o| {
-                trace!(
-                    target: $target,
-                    "{} = {}",
-                    $desc,
-                    match o {
-                        Err(err) => format!("{:?}", err),
-                        Ok(value) => value.display(),
-                    }
-                );
-            });
-
-            nu_stream::OutputStream::new(objects)
-        } else {
-            $expr
-        }
-    }};
-}
-
-pub(crate) use nu_engine::Host;
-#[allow(unused_imports)]
-pub(crate) use nu_errors::ShellError;
-#[allow(unused_imports)]
-pub(crate) use nu_protocol::outln;
-pub(crate) use nu_stream::ActionStream;
-#[allow(unused_imports)]
-pub(crate) use nu_value_ext::ValueExt;
-#[allow(unused_imports)]
-pub(crate) use std::sync::atomic::Ordering;
-
-#[allow(clippy::clippy::wrong_self_convention)]
-pub trait FromInputStream {
-    fn from_input_stream(self) -> ActionStream;
-}
-
-impl<T> FromInputStream for T
-where
-    T: Iterator<Item = nu_protocol::Value> + Send + Sync + 'static,
-{
-    fn from_input_stream(self) -> ActionStream {
-        ActionStream {
-            values: Box::new(self.map(nu_protocol::ReturnSuccess::value)),
-        }
-    }
-}

crates/nu-cli/src/shell.rs

@@ -1,9 +1,234 @@
-#![allow(clippy::module_inception)]
+use nu_ansi_term::Color;
+use nu_completion::NuCompleter;
+use nu_engine::{DefaultPalette, EvaluationContext, Painter};
+use nu_source::{Tag, Tagged};
+use std::borrow::Cow::{self, Owned};
 
-#[cfg(feature = "rustyline-support")]
+pub struct Helper {
-pub(crate) mod completer;
+    completer: NuCompleter,
-#[cfg(feature = "rustyline-support")]
+    hinter: Option<rustyline::hint::HistoryHinter>,
-pub(crate) mod helper;
+    context: EvaluationContext,
+    pub colored_prompt: String,
+    validator: NuValidator,
+}
 
-#[cfg(feature = "rustyline-support")]
+impl Helper {
-pub(crate) use helper::Helper;
+    pub(crate) fn new(
+        context: EvaluationContext,
+        hinter: Option<rustyline::hint::HistoryHinter>,
+    ) -> Helper {
+        Helper {
+            completer: NuCompleter {},
+            hinter,
+            context,
+            colored_prompt: String::new(),
+            validator: NuValidator {},
+        }
+    }
+}
+
+use nu_protocol::{SignatureRegistry, VariableRegistry};
+struct CompletionContext<'a>(&'a EvaluationContext);
+
+impl<'a> nu_completion::CompletionContext for CompletionContext<'a> {
+    fn signature_registry(&self) -> &dyn SignatureRegistry {
+        &self.0.scope
+    }
+
+    fn scope(&self) -> &dyn nu_parser::ParserScope {
+        &self.0.scope
+    }
+
+    fn source(&self) -> &EvaluationContext {
+        self.as_ref()
+    }
+
+    fn variable_registry(&self) -> &dyn VariableRegistry {
+        self.0
+    }
+}
+
+impl<'a> AsRef<EvaluationContext> for CompletionContext<'a> {
+    fn as_ref(&self) -> &EvaluationContext {
+        self.0
+    }
+}
+
+pub struct CompletionSuggestion(nu_completion::Suggestion);
+
+impl rustyline::completion::Candidate for CompletionSuggestion {
+    fn display(&self) -> &str {
+        &self.0.display
+    }
+
+    fn replacement(&self) -> &str {
+        &self.0.replacement
+    }
+}
+
+impl rustyline::completion::Completer for Helper {
+    type Candidate = CompletionSuggestion;
+
+    fn complete(
+        &self,
+        line: &str,
+        pos: usize,
+        _ctx: &rustyline::Context<'_>,
+    ) -> Result<(usize, Vec<Self::Candidate>), rustyline::error::ReadlineError> {
+        let ctx = CompletionContext(&self.context);
+        let (position, suggestions) = self.completer.complete(line, pos, &ctx);
+        let suggestions = suggestions.into_iter().map(CompletionSuggestion).collect();
+        Ok((position, suggestions))
+    }
+
+    fn update(&self, line: &mut rustyline::line_buffer::LineBuffer, start: usize, elected: &str) {
+        let end = line.pos();
+        line.replace(start..end, elected)
+    }
+}
+
+impl rustyline::hint::Hinter for Helper {
+    type Hint = String;
+    fn hint(&self, line: &str, pos: usize, ctx: &rustyline::Context<'_>) -> Option<String> {
+        match &self.hinter {
+            Some(the_hinter) => the_hinter.hint(line, pos, ctx),
+            None => Some("".to_string()),
+        }
+    }
+}
+
+impl rustyline::highlight::Highlighter for Helper {
+    fn highlight_prompt<'b, 's: 'b, 'p: 'b>(
+        &'s self,
+        prompt: &'p str,
+        default: bool,
+    ) -> Cow<'b, str> {
+        use std::borrow::Cow::Borrowed;
+
+        if default {
+            Borrowed(&self.colored_prompt)
+        } else {
+            Borrowed(prompt)
+        }
+    }
+
+    fn highlight_hint<'h>(&self, hint: &'h str) -> Cow<'h, str> {
+        Owned(Color::DarkGray.prefix().to_string() + hint + nu_ansi_term::ansi::RESET)
+    }
+
+    fn highlight<'l>(&self, line: &'l str, _pos: usize) -> Cow<'l, str> {
+        let cfg = &self.context.configs().lock();
+        if let Some(palette) = &cfg.syntax_config {
+            Painter::paint_string(line, &self.context.scope, palette)
+        } else {
+            Painter::paint_string(line, &self.context.scope, &DefaultPalette {})
+        }
+    }
+
+    fn highlight_char(&self, _line: &str, _pos: usize) -> bool {
+        true
+    }
+}
+
+impl rustyline::validate::Validator for Helper {
+    fn validate(
+        &self,
+        ctx: &mut rustyline::validate::ValidationContext,
+    ) -> rustyline::Result<rustyline::validate::ValidationResult> {
+        self.validator.validate(ctx)
+    }
+
+    fn validate_while_typing(&self) -> bool {
+        self.validator.validate_while_typing()
+    }
+}
+
+struct NuValidator {}
+
+impl rustyline::validate::Validator for NuValidator {
+    fn validate(
+        &self,
+        ctx: &mut rustyline::validate::ValidationContext,
+    ) -> rustyline::Result<rustyline::validate::ValidationResult> {
+        let src = ctx.input();
+
+        let (tokens, err) = nu_parser::lex(src, 0, nu_parser::NewlineMode::Normal);
+        if let Some(err) = err {
+            if let nu_errors::ParseErrorReason::Eof { .. } = err.reason() {
+                return Ok(rustyline::validate::ValidationResult::Incomplete);
+            }
+        }
+
+        let (_, err) = nu_parser::parse_block(tokens);
+
+        if let Some(err) = err {
+            if let nu_errors::ParseErrorReason::Eof { .. } = err.reason() {
+                return Ok(rustyline::validate::ValidationResult::Incomplete);
+            }
+        }
+
+        Ok(rustyline::validate::ValidationResult::Valid(None))
+    }
+}
+
+#[allow(unused)]
+fn vec_tag<T>(input: Vec<Tagged<T>>) -> Option<Tag> {
+    let mut iter = input.iter();
+    let first = iter.next()?.tag.clone();
+    let last = iter.last();
+
+    Some(match last {
+        None => first,
+        Some(last) => first.until(&last.tag),
+    })
+}
+
+impl rustyline::Helper for Helper {}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use nu_engine::EvaluationContext;
+    use rustyline::completion::Completer;
+    use rustyline::line_buffer::LineBuffer;
+
+    #[ignore]
+    #[test]
+    fn closing_quote_should_replaced() {
+        let text = "cd \"folder with spaces\\subdirectory\\\"";
+        let replacement = "\"folder with spaces\\subdirectory\\subsubdirectory\\\"";
+
+        let mut buffer = LineBuffer::with_capacity(256);
+        buffer.insert_str(0, text);
+        buffer.set_pos(text.len() - 1);
+
+        let helper = Helper::new(EvaluationContext::basic(), None);
+
+        helper.update(&mut buffer, "cd ".len(), replacement);
+
+        assert_eq!(
+            buffer.as_str(),
+            "cd \"folder with spaces\\subdirectory\\subsubdirectory\\\""
+        );
+    }
+
+    #[ignore]
+    #[test]
+    fn replacement_with_cursor_in_text() {
+        let text = "cd \"folder with spaces\\subdirectory\\\"";
+        let replacement = "\"folder with spaces\\subdirectory\\subsubdirectory\\\"";
+
+        let mut buffer = LineBuffer::with_capacity(256);
+        buffer.insert_str(0, text);
+        buffer.set_pos(text.len() - 30);
+
+        let helper = Helper::new(EvaluationContext::basic(), None);
+
+        helper.update(&mut buffer, "cd ".len(), replacement);
+
+        assert_eq!(
+            buffer.as_str(),
+            "cd \"folder with spaces\\subdirectory\\subsubdirectory\\\""
+        );
+    }
+}

crates/nu-cli/src/shell/helper.rs

@@ -1,196 +0,0 @@
-use crate::completion;
-use crate::shell::completer::NuCompleter;
-use nu_ansi_term::Color;
-use nu_engine::{DefaultPalette, EvaluationContext, Painter};
-use nu_source::{Tag, Tagged};
-use std::borrow::Cow::{self, Owned};
-
-pub struct Helper {
-    completer: NuCompleter,
-    hinter: Option<rustyline::hint::HistoryHinter>,
-    context: EvaluationContext,
-    pub colored_prompt: String,
-    validator: NuValidator,
-}
-
-impl Helper {
-    pub(crate) fn new(
-        context: EvaluationContext,
-        hinter: Option<rustyline::hint::HistoryHinter>,
-    ) -> Helper {
-        Helper {
-            completer: NuCompleter {},
-            hinter,
-            context,
-            colored_prompt: String::new(),
-            validator: NuValidator {},
-        }
-    }
-}
-
-impl rustyline::completion::Candidate for completion::Suggestion {
-    fn display(&self) -> &str {
-        &self.display
-    }
-
-    fn replacement(&self) -> &str {
-        &self.replacement
-    }
-}
-
-impl rustyline::completion::Completer for Helper {
-    type Candidate = completion::Suggestion;
-
-    fn complete(
-        &self,
-        line: &str,
-        pos: usize,
-        _ctx: &rustyline::Context<'_>,
-    ) -> Result<(usize, Vec<Self::Candidate>), rustyline::error::ReadlineError> {
-        let ctx = completion::CompletionContext::new(&self.context);
-        Ok(self.completer.complete(line, pos, &ctx))
-    }
-
-    fn update(&self, line: &mut rustyline::line_buffer::LineBuffer, start: usize, elected: &str) {
-        let end = line.pos();
-        line.replace(start..end, elected)
-    }
-}
-
-impl rustyline::hint::Hinter for Helper {
-    type Hint = String;
-    fn hint(&self, line: &str, pos: usize, ctx: &rustyline::Context<'_>) -> Option<String> {
-        self.hinter.as_ref().and_then(|h| h.hint(line, pos, &ctx))
-    }
-}
-
-impl rustyline::highlight::Highlighter for Helper {
-    fn highlight_prompt<'b, 's: 'b, 'p: 'b>(
-        &'s self,
-        prompt: &'p str,
-        default: bool,
-    ) -> Cow<'b, str> {
-        use std::borrow::Cow::Borrowed;
-
-        if default {
-            Borrowed(&self.colored_prompt)
-        } else {
-            Borrowed(prompt)
-        }
-    }
-
-    fn highlight_hint<'h>(&self, hint: &'h str) -> Cow<'h, str> {
-        Owned(Color::DarkGray.prefix().to_string() + hint + nu_ansi_term::ansi::RESET)
-    }
-
-    fn highlight<'l>(&self, line: &'l str, _pos: usize) -> Cow<'l, str> {
-        Painter::paint_string(line, &self.context.scope, &DefaultPalette {})
-    }
-
-    fn highlight_char(&self, _line: &str, _pos: usize) -> bool {
-        true
-    }
-}
-
-impl rustyline::validate::Validator for Helper {
-    fn validate(
-        &self,
-        ctx: &mut rustyline::validate::ValidationContext,
-    ) -> rustyline::Result<rustyline::validate::ValidationResult> {
-        self.validator.validate(ctx)
-    }
-
-    fn validate_while_typing(&self) -> bool {
-        self.validator.validate_while_typing()
-    }
-}
-
-struct NuValidator {}
-
-impl rustyline::validate::Validator for NuValidator {
-    fn validate(
-        &self,
-        ctx: &mut rustyline::validate::ValidationContext,
-    ) -> rustyline::Result<rustyline::validate::ValidationResult> {
-        let src = ctx.input();
-
-        let (tokens, err) = nu_parser::lex(src, 0);
-        if let Some(err) = err {
-            if let nu_errors::ParseErrorReason::Eof { .. } = err.reason() {
-                return Ok(rustyline::validate::ValidationResult::Incomplete);
-            }
-        }
-
-        let (_, err) = nu_parser::parse_block(tokens);
-
-        if let Some(err) = err {
-            if let nu_errors::ParseErrorReason::Eof { .. } = err.reason() {
-                return Ok(rustyline::validate::ValidationResult::Incomplete);
-            }
-        }
-
-        Ok(rustyline::validate::ValidationResult::Valid(None))
-    }
-}
-
-#[allow(unused)]
-fn vec_tag<T>(input: Vec<Tagged<T>>) -> Option<Tag> {
-    let mut iter = input.iter();
-    let first = iter.next()?.tag.clone();
-    let last = iter.last();
-
-    Some(match last {
-        None => first,
-        Some(last) => first.until(&last.tag),
-    })
-}
-
-impl rustyline::Helper for Helper {}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-    use nu_engine::EvaluationContext;
-    use rustyline::completion::Completer;
-    use rustyline::line_buffer::LineBuffer;
-
-    #[ignore]
-    #[test]
-    fn closing_quote_should_replaced() {
-        let text = "cd \"folder with spaces\\subdirectory\\\"";
-        let replacement = "\"folder with spaces\\subdirectory\\subsubdirectory\\\"";
-
-        let mut buffer = LineBuffer::with_capacity(256);
-        buffer.insert_str(0, text);
-        buffer.set_pos(text.len() - 1);
-
-        let helper = Helper::new(EvaluationContext::basic(), None);
-
-        helper.update(&mut buffer, "cd ".len(), &replacement);
-
-        assert_eq!(
-            buffer.as_str(),
-            "cd \"folder with spaces\\subdirectory\\subsubdirectory\\\""
-        );
-    }
-
-    #[ignore]
-    #[test]
-    fn replacement_with_cursor_in_text() {
-        let text = "cd \"folder with spaces\\subdirectory\\\"";
-        let replacement = "\"folder with spaces\\subdirectory\\subsubdirectory\\\"";
-
-        let mut buffer = LineBuffer::with_capacity(256);
-        buffer.insert_str(0, text);
-        buffer.set_pos(text.len() - 30);
-
-        let helper = Helper::new(EvaluationContext::basic(), None);
-
-        helper.update(&mut buffer, "cd ".len(), &replacement);
-
-        assert_eq!(
-            buffer.as_str(),
-            "cd \"folder with spaces\\subdirectory\\subsubdirectory\\\""
-        );
-    }
-}

crates/nu-command/Cargo.toml

@@ -5,104 +5,105 @@ description = "CLI for nushell"
 edition = "2018"
 license = "MIT"
 name = "nu-command"
-version = "0.32.0"
+version = "0.36.0"
 
 [lib]
 doctest = false
 
 [dependencies]
-nu-data = { version = "0.32.0", path = "../nu-data" }
+nu-data = { version = "0.36.0", path="../nu-data" }
-nu-engine = { version = "0.32.0", path = "../nu-engine" }
+nu-engine = { version = "0.36.0", path="../nu-engine" }
-nu-errors = { version = "0.32.0", path = "../nu-errors" }
+nu-errors = { version = "0.36.0", path="../nu-errors" }
-nu-json = { version = "0.32.0", path = "../nu-json" }
+nu-json = { version = "0.36.0", path="../nu-json" }
-nu-parser = { version = "0.32.0", path = "../nu-parser" }
+nu-path = { version = "0.36.0", path="../nu-path" }
-nu-plugin = { version = "0.32.0", path = "../nu-plugin" }
+nu-parser = { version = "0.36.0", path="../nu-parser" }
-nu-protocol = { version = "0.32.0", path = "../nu-protocol" }
+nu-plugin = { version = "0.36.0", path="../nu-plugin" }
-nu-source = { version = "0.32.0", path = "../nu-source" }
+nu-protocol = { version = "0.36.0", path="../nu-protocol" }
-nu-stream = { version = "0.32.0", path = "../nu-stream" }
+nu-serde = { version = "0.36.0", path="../nu-serde" }
-nu-table = { version = "0.32.0", path = "../nu-table" }
+nu-source = { version = "0.36.0", path="../nu-source" }
-nu-test-support = { version = "0.32.0", path = "../nu-test-support" }
+nu-stream = { version = "0.36.0", path="../nu-stream" }
-nu-value-ext = { version = "0.32.0", path = "../nu-value-ext" }
+nu-table = { version = "0.36.0", path="../nu-table" }
-nu-ansi-term = { version = "0.32.0", path = "../nu-ansi-term" }
+nu-test-support = { version = "0.36.0", path="../nu-test-support" }
-nu-pretty-hex = { version = "0.32.0", path = "../nu-pretty-hex" }
+nu-value-ext = { version = "0.36.0", path="../nu-value-ext" }
+nu-ansi-term = { version = "0.36.0", path="../nu-ansi-term" }
+nu-pretty-hex = { version = "0.36.0", path="../nu-pretty-hex" }
 
 Inflector = "0.11"
-arboard = { version = "1.1.0", optional = true }
+arboard = { version="1.1.0", optional=true }
 base64 = "0.13.0"
-bigdecimal = { version = "0.2.0", features = ["serde"] }
+bigdecimal = { package = "bigdecimal-rs", version = "0.2.1", features = ["serde"] }
 byte-unit = "4.0.9"
 bytes = "1.0.1"
-calamine = "0.17.0"
+calamine = "0.18.0"
-chrono = { version = "0.4.19", features = ["serde"] }
+chrono = { version="0.4.19", features=["serde"] }
 chrono-tz = "0.5.3"
-clap = "2.33.3"
 codespan-reporting = "0.11.0"
-crossterm = { version = "0.19.0", optional = true }
+crossterm = { version="0.19.0", optional=true }
 csv = "1.1.3"
-ctrlc = { version = "3.1.7", optional = true }
+ctrlc = { version="3.1.7", optional=true }
 derive-new = "0.5.8"
-directories-next = { version = "2.0.0", optional = true }
+directories-next = "2.0.0"
-dirs-next = { version = "2.0.0", optional = true }
+dirs-next = "2.0.0"
 dtparse = "1.2.0"
 dunce = "1.0.1"
 eml-parser = "0.1.0"
 encoding_rs = "0.8.28"
 filesize = "0.2.0"
 fs_extra = "1.2.0"
-futures = { version = "0.3.12", features = ["compat", "io-compat"] }
+futures = { version="0.3.12", features=["compat", "io-compat"] }
 getset = "0.1.1"
 glob = "0.3.0"
 htmlescape = "0.3.1"
 ical = "0.7.0"
-indexmap = { version = "1.6.1", features = ["serde-1"] }
+indexmap = { version="1.7", features=["serde-1"] }
 itertools = "0.10.0"
 lazy_static = "1.*"
 log = "0.4.14"
-md5 = "0.7.0"
+md-5 = "0.9.1"
 meval = "0.2.0"
-minus = { version = "3.3.0", optional = true, features = ["async_std_lib", "search"] }
+minus = { version="3.4.0", optional=true, features=["async_std_lib", "search"] }
-num-bigint = { version = "0.3.1", features = ["serde"] }
+num-bigint = { version="0.3.1", features=["serde"] }
-num-format = { version = "0.4.0", features = ["with-num-bigint"] }
+num-format = { version="0.4.0", features=["with-num-bigint"] }
 num-traits = "0.2.14"
 parking_lot = "0.11.1"
 pin-utils = "0.1.0"
-ptree = { version = "0.3.1", optional = true }
 query_interface = "0.3.5"
-quick-xml = "0.21.0"
+quick-xml = "0.22"
-rand = "0.7.3"
+rand = "0.8"
 rayon = "1.5.0"
 regex = "1.4.3"
 roxmltree = "0.14.0"
 rust-embed = "5.9.0"
-rustyline = { version = "8.1.0", optional = true }
+rustyline = { version="9.0.0", optional=true }
-serde = { version = "1.0.123", features = ["derive"] }
+serde = { version="1.0.123", features=["derive"] }
 serde_bytes = "0.11.5"
 serde_ini = "0.2.0"
 serde_json = "1.0.61"
 serde_urlencoded = "0.7.0"
 serde_yaml = "0.8.16"
 sha2 = "0.9.3"
-shellexpand = "2.1.0"
 strip-ansi-escapes = "0.1.0"
 sxd-document = "0.3.2"
 sxd-xpath = "0.4.2"
+thiserror = "1.0.26"
 tempfile = "3.2.0"
-term = { version = "0.7.0", optional = true }
+term = { version="0.7.0", optional=true }
 term_size = "0.3.2"
 termcolor = "1.1.2"
 titlecase = "1.1.0"
 toml = "0.5.8"
-trash = { version = "1.3.0", optional = true }
+trash = { version="1.3.0", optional=true }
-unicode-segmentation = "1.7.1"
+unicode-segmentation = "1.8"
 url = "2.2.0"
-uuid_crate = { package = "uuid", version = "0.8.2", features = ["v4"], optional = true }
+uuid_crate = { package="uuid", version="0.8.2", features=["v4"], optional=true }
-which = { version = "4.1.0", optional = true }
+which = { version="4.1.0", optional=true }
-zip = { version = "0.5.9", optional = true }
+zip = { version="0.5.9", optional=true }
+digest = "0.9.0"
 
 [dependencies.polars]
-version = "0.13.4"
+version = "0.15.1"
 optional = true
-features = ["parquet", "json", "random"]
+features = ["parquet", "json", "random", "pivot", "strings", "is_in", "temporal"]
 
 [target.'cfg(unix)'.dependencies]
 umask = "1.0.0"
@@ -120,7 +121,7 @@ optional = true
 version = "0.25.3"
 
 [build-dependencies]
-shadow-rs = "0.5"
+shadow-rs = "0.6"
 
 [dev-dependencies]
 quickcheck = "1.0.3"
@@ -132,7 +133,5 @@ clipboard-cli = ["arboard"]
 rustyline-support = ["rustyline"]
 stable = []
 trash-support = ["trash"]
-directories = ["directories-next"]
-dirs = ["dirs-next"]
 table-pager = ["minus", "crossterm"]
 dataframe = ["nu-protocol/dataframe", "polars"]

crates/nu-command/README.md

@@ -0,0 +1,7 @@
+# nu-command
+
+The Nu command crate contains the full set of internal commands, that is, the commands that can be form the set of built-in commands in a Nushell engine.
+
+The default set of commands that Nushell ships with can be found in the [default context](src/default_context.rs).
+
+The commands themselves live in the [commands module](src/commands/).

crates/nu-command/src/classified/external.rs

@@ -5,7 +5,6 @@ use nu_test_support::NATIVE_PATH_ENV_VAR;
 use parking_lot::Mutex;
 
 use std::io::Write;
-use std::ops::Deref;
 use std::process::{Command, Stdio};
 use std::sync::mpsc;
 use std::{borrow::Cow, io::BufReader};
@@ -27,7 +26,7 @@ pub(crate) fn run_external_command(
     trace!(target: "nu::run::external", "-> {}", command.name);
 
     context.sync_path_to_env();
-    if !context.host.lock().is_external_cmd(&command.name) {
+    if !context.host().lock().is_external_cmd(&command.name) {
         return Err(ShellError::labeled_error(
             "Command not found",
             format!("command {} not found", &command.name),
@@ -38,13 +37,28 @@ pub(crate) fn run_external_command(
     run_with_stdin(command, context, input, external_redirection)
 }
 
+#[allow(unused)]
+fn trim_double_quotes(input: &str) -> String {
+    let mut chars = input.chars();
+
+    match (chars.next(), chars.next_back()) {
+        (Some('"'), Some('"')) => chars.collect(),
+        _ => input.to_string(),
+    }
+}
+
+#[allow(unused)]
+fn escape_where_needed(input: &str) -> String {
+    input.split(' ').join("\\ ").split('\'').join("\\'")
+}
+
 fn run_with_stdin(
     command: ExternalCommand,
     context: &mut EvaluationContext,
     input: InputStream,
     external_redirection: ExternalRedirection,
 ) -> Result<InputStream, ShellError> {
-    let path = context.shell_manager.path();
+    let path = context.shell_manager().path();
 
     let mut command_args = vec![];
     for arg in command.args.iter() {
@@ -81,6 +95,7 @@ fn run_with_stdin(
             }
             _ => {
                 let trimmed_value_string = value.as_string()?.trim_end_matches('\n').to_string();
+                //let trimmed_value_string = trim_quotes(&trimmed_value_string);
                 command_args.push((trimmed_value_string, is_literal));
             }
         }
@@ -89,18 +104,7 @@ fn run_with_stdin(
     let process_args = command_args
         .iter()
         .map(|(arg, _is_literal)| {
-            let home_dir;
+            let arg = nu_path::expand_tilde_string(Cow::Borrowed(arg));
-
-            #[cfg(feature = "dirs")]
-            {
-                home_dir = dirs_next::home_dir;
-            }
-            #[cfg(not(feature = "dirs"))]
-            {
-                home_dir = || Some(std::path::PathBuf::from("/"));
-            }
-
-            let arg = expand_tilde(arg.deref(), home_dir);
 
             #[cfg(not(windows))]
             {
@@ -108,7 +112,12 @@ fn run_with_stdin(
                     let escaped = escape_double_quotes(&arg);
                     add_double_quotes(&escaped)
                 } else {
-                    arg.as_ref().to_string()
+                    let trimmed = trim_double_quotes(&arg);
+                    if trimmed != arg {
+                        escape_where_needed(&trimmed)
+                    } else {
+                        trimmed
+                    }
                 }
             }
             #[cfg(windows)]
@@ -116,7 +125,7 @@ fn run_with_stdin(
                 if let Some(unquoted) = remove_quotes(&arg) {
                     unquoted.to_string()
                 } else {
-                    arg.as_ref().to_string()
+                    arg.to_string()
                 }
             }
         })
@@ -242,7 +251,10 @@ fn spawn(
                                             "Received unexpected type from pipeline ({})",
                                             unsupported.type_name()
                                         ),
-                                        "expected a string",
+                                        format!(
+                                            "expected a string, got {} as input",
+                                            unsupported.type_name()
+                                        ),
                                         stdin_name_tag.clone(),
                                     )),
                                     tag: stdin_name_tag,
@@ -430,7 +442,7 @@ fn spawn(
                         }
                     }
                     let _ = stdout_read_tx.send(Ok(Value {
-                        value: UntaggedValue::Error(ShellError::external_non_zero()),
+                        value: UntaggedValue::nothing(),
                         tag: stdout_name_tag,
                     }));
                 }
@@ -439,7 +451,7 @@ fn spawn(
             });
 
             let stream = ChannelReceiver::new(rx);
-            Ok(stream.to_input_stream())
+            Ok(stream.into_input_stream())
         }
         Err(e) => Err(ShellError::labeled_error(
             format!("{}", e),
@@ -473,15 +485,6 @@ impl Iterator for ChannelReceiver {
     }
 }
 
-fn expand_tilde<SI: ?Sized, P, HD>(input: &SI, home_dir: HD) -> std::borrow::Cow<str>
-where
-    SI: AsRef<str>,
-    P: AsRef<std::path::Path>,
-    HD: FnOnce() -> Option<P>,
-{
-    shellexpand::tilde_with_context(input, home_dir)
-}
-
 fn argument_is_quoted(argument: &str) -> bool {
     if argument.len() < 2 {
         return false;
@@ -530,9 +533,7 @@ fn shell_os_paths() -> Vec<std::path::PathBuf> {
 
 #[cfg(test)]
 mod tests {
-    use super::{
+    use super::{add_double_quotes, argument_is_quoted, escape_double_quotes, remove_quotes};
-        add_double_quotes, argument_is_quoted, escape_double_quotes, expand_tilde, remove_quotes,
-    };
     #[cfg(feature = "which")]
     use super::{run_external_command, InputStream};
 
@@ -604,26 +605,26 @@ mod tests {
 
     #[test]
     fn checks_quotes_from_argument_to_be_passed_in() {
-        assert_eq!(argument_is_quoted(""), false);
+        assert!(!argument_is_quoted(""));
 
-        assert_eq!(argument_is_quoted("'"), false);
+        assert!(!argument_is_quoted("'"));
-        assert_eq!(argument_is_quoted("'a"), false);
+        assert!(!argument_is_quoted("'a"));
-        assert_eq!(argument_is_quoted("a"), false);
+        assert!(!argument_is_quoted("a"));
-        assert_eq!(argument_is_quoted("a'"), false);
+        assert!(!argument_is_quoted("a'"));
-        assert_eq!(argument_is_quoted("''"), true);
+        assert!(argument_is_quoted("''"));
 
-        assert_eq!(argument_is_quoted(r#"""#), false);
+        assert!(!argument_is_quoted(r#"""#));
-        assert_eq!(argument_is_quoted(r#""a"#), false);
+        assert!(!argument_is_quoted(r#""a"#));
-        assert_eq!(argument_is_quoted(r#"a"#), false);
+        assert!(!argument_is_quoted(r#"a"#));
-        assert_eq!(argument_is_quoted(r#"a""#), false);
+        assert!(!argument_is_quoted(r#"a""#));
-        assert_eq!(argument_is_quoted(r#""""#), true);
+        assert!(argument_is_quoted(r#""""#));
 
-        assert_eq!(argument_is_quoted("'andrés"), false);
+        assert!(!argument_is_quoted("'andrés"));
-        assert_eq!(argument_is_quoted("andrés'"), false);
+        assert!(!argument_is_quoted("andrés'"));
-        assert_eq!(argument_is_quoted(r#""andrés"#), false);
+        assert!(!argument_is_quoted(r#""andrés"#));
-        assert_eq!(argument_is_quoted(r#"andrés""#), false);
+        assert!(!argument_is_quoted(r#"andrés""#));
-        assert_eq!(argument_is_quoted("'andrés'"), true);
+        assert!(argument_is_quoted("'andrés'"));
-        assert_eq!(argument_is_quoted(r#""andrés""#), true);
+        assert!(argument_is_quoted(r#""andrés""#));
     }
 
     #[test]
@@ -654,20 +655,4 @@ mod tests {
         assert_eq!(remove_quotes("'andrés'"), Some("andrés"));
         assert_eq!(remove_quotes(r#""andrés""#), Some("andrés"));
     }
-
-    #[test]
-    fn expands_tilde_if_starts_with_tilde_character() {
-        assert_eq!(
-            expand_tilde("~", || Some(std::path::Path::new("the_path_to_nu_light"))),
-            "the_path_to_nu_light"
-        );
-    }
-
-    #[test]
-    fn does_not_expand_tilde_if_tilde_is_not_first_character() {
-        assert_eq!(
-            expand_tilde("1~1", || Some(std::path::Path::new("the_path_to_nu_light"))),
-            "1~1"
-        );
-    }
 }

crates/nu-command/src/commands.rs

@@ -1,385 +0,0 @@
-#[macro_use]
-pub(crate) mod macros;
-
-mod from_delimited_data;
-mod to_delimited_data;
-
-pub(crate) mod all;
-pub(crate) mod ansi;
-pub(crate) mod any;
-pub(crate) mod append;
-pub(crate) mod args;
-pub mod autoenv;
-pub(crate) mod autoenv_trust;
-pub(crate) mod autoenv_untrust;
-pub(crate) mod autoview;
-pub(crate) mod benchmark;
-pub(crate) mod build_string;
-pub(crate) mod cal;
-pub(crate) mod cd;
-pub(crate) mod char_;
-pub(crate) mod chart;
-pub(crate) mod classified;
-#[cfg(feature = "clipboard-cli")]
-pub(crate) mod clip;
-pub(crate) mod compact;
-pub(crate) mod config;
-pub(crate) mod constants;
-pub(crate) mod cp;
-#[cfg(feature = "dataframe")]
-pub(crate) mod dataframe;
-pub(crate) mod date;
-pub(crate) mod debug;
-pub(crate) mod def;
-pub(crate) mod default;
-pub mod default_context;
-pub(crate) mod describe;
-pub(crate) mod do_;
-pub(crate) mod drop;
-pub(crate) mod du;
-pub(crate) mod each;
-pub(crate) mod echo;
-pub(crate) mod empty;
-pub(crate) mod enter;
-pub(crate) mod every;
-pub(crate) mod exec;
-pub(crate) mod exit;
-pub(crate) mod first;
-pub(crate) mod flatten;
-pub(crate) mod for_in;
-pub(crate) mod format;
-pub(crate) mod from;
-pub(crate) mod from_csv;
-pub(crate) mod from_eml;
-pub(crate) mod from_ics;
-pub(crate) mod from_ini;
-pub(crate) mod from_json;
-pub(crate) mod from_ods;
-pub(crate) mod from_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 group_by_date;
-pub(crate) mod hash_;
-pub(crate) mod headers;
-pub(crate) mod help;
-pub(crate) mod histogram;
-pub(crate) mod history;
-pub(crate) mod if_;
-pub(crate) mod insert;
-pub(crate) mod into;
-pub(crate) mod keep;
-pub(crate) mod last;
-pub(crate) mod length;
-pub(crate) mod let_;
-pub(crate) mod let_env;
-pub(crate) mod lines;
-pub(crate) mod load_env;
-pub(crate) mod ls;
-pub(crate) mod math;
-pub(crate) mod merge;
-pub(crate) mod mkdir;
-pub(crate) mod move_;
-pub(crate) mod next;
-pub(crate) mod nth;
-pub(crate) mod nu;
-pub(crate) mod open;
-pub(crate) mod parse;
-pub(crate) mod path;
-pub(crate) mod pivot;
-pub(crate) mod prepend;
-pub(crate) mod prev;
-pub(crate) mod pwd;
-pub(crate) mod random;
-pub(crate) mod range;
-pub(crate) mod reduce;
-pub(crate) mod reject;
-pub(crate) mod rename;
-pub(crate) mod reverse;
-pub(crate) mod rm;
-pub(crate) mod roll;
-pub(crate) mod rotate;
-pub(crate) mod run_external;
-pub(crate) mod save;
-pub(crate) mod select;
-pub(crate) mod seq;
-pub(crate) mod seq_dates;
-pub(crate) mod shells;
-pub(crate) mod shuffle;
-pub(crate) mod size;
-pub(crate) mod skip;
-pub(crate) mod sleep;
-pub(crate) mod sort_by;
-pub(crate) mod source;
-pub(crate) mod split;
-pub(crate) mod split_by;
-pub(crate) mod str_;
-pub(crate) mod table;
-pub(crate) mod tags;
-pub(crate) mod termsize;
-pub(crate) mod to;
-pub(crate) mod to_csv;
-pub(crate) mod to_html;
-pub(crate) mod to_json;
-pub(crate) mod to_md;
-pub(crate) mod to_toml;
-pub(crate) mod to_tsv;
-pub(crate) mod to_url;
-pub(crate) mod to_xml;
-pub(crate) mod to_yaml;
-pub(crate) mod uniq;
-pub(crate) mod update;
-pub(crate) mod url_;
-pub(crate) mod version;
-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 ansi::Ansi;
-pub(crate) use ansi::AnsiStrip;
-pub(crate) use append::Command as Append;
-pub(crate) use autoenv::Autoenv;
-pub(crate) use autoenv_trust::AutoenvTrust;
-pub(crate) use autoenv_untrust::AutoenvUnTrust;
-pub(crate) use benchmark::Benchmark;
-pub(crate) use build_string::BuildString;
-pub(crate) use cal::Cal;
-pub(crate) use char_::Char;
-pub(crate) use chart::Chart;
-pub(crate) use compact::Compact;
-pub(crate) use config::{
-    Config, ConfigClear, ConfigGet, ConfigPath, ConfigRemove, ConfigSet, ConfigSetInto,
-};
-pub(crate) use cp::Cpy;
-pub(crate) use date::{Date, DateFormat, DateListTimeZone, DateNow, DateToTable, DateToTimeZone};
-pub(crate) use debug::Debug;
-pub(crate) use def::Def;
-pub(crate) use default::Default;
-pub(crate) use describe::Describe;
-pub(crate) use do_::Do;
-pub(crate) use drop::{Drop, DropColumn};
-pub(crate) use du::Du;
-pub(crate) use each::Each;
-pub(crate) use each::EachGroup;
-pub(crate) use each::EachWindow;
-pub(crate) use echo::Echo;
-pub(crate) use empty::Command as Empty;
-pub(crate) use for_in::ForIn;
-pub(crate) use if_::If;
-pub(crate) use into::Into;
-pub(crate) use into::IntoBinary;
-pub(crate) use into::IntoInt;
-pub(crate) use into::IntoString;
-pub(crate) use nu::NuPlugin;
-pub(crate) use update::Command as Update;
-pub(crate) mod kill;
-pub(crate) use kill::Kill;
-pub(crate) mod clear;
-pub(crate) use clear::Clear;
-pub(crate) mod touch;
-pub(crate) use all::Command as All;
-pub(crate) use any::Command as Any;
-#[cfg(feature = "dataframe")]
-pub(crate) use dataframe::{
-    DataFrame, DataFrameAggregate, DataFrameConvert, DataFrameDTypes, DataFrameDrop,
-    DataFrameGroupBy, DataFrameJoin, DataFrameList, DataFrameLoad, DataFrameSample,
-    DataFrameSelect, DataFrameShow,
-};
-pub(crate) use enter::Enter;
-pub(crate) use every::Every;
-pub(crate) use exec::Exec;
-pub(crate) use exit::Exit;
-pub(crate) use first::First;
-pub(crate) use flatten::Command as Flatten;
-pub(crate) use format::{FileSize, Format};
-pub(crate) use from::From;
-pub(crate) use from_csv::FromCsv;
-pub(crate) use from_eml::FromEml;
-pub(crate) use from_ics::FromIcs;
-pub(crate) use from_ini::FromIni;
-pub(crate) use from_json::FromJson;
-pub(crate) use from_ods::FromOds;
-pub(crate) use from_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::Command as Get;
-pub(crate) use group_by::Command as GroupBy;
-pub(crate) use group_by_date::GroupByDate;
-pub(crate) use hash_::{Hash, HashBase64, HashMd5};
-pub(crate) use headers::Headers;
-pub(crate) use help::Help;
-pub(crate) use histogram::Histogram;
-pub(crate) use history::History;
-pub(crate) use insert::Command as Insert;
-pub(crate) use keep::{Keep, KeepUntil, KeepWhile};
-pub(crate) use last::Last;
-pub(crate) use length::Length;
-pub(crate) use let_::Let;
-pub(crate) use let_env::LetEnv;
-pub(crate) use lines::Lines;
-pub(crate) use load_env::LoadEnv;
-pub(crate) use ls::Ls;
-pub(crate) use math::{
-    Math, MathAbs, MathAverage, MathCeil, MathEval, MathFloor, MathMaximum, MathMedian,
-    MathMinimum, MathMode, MathProduct, MathRound, MathSqrt, MathStddev, MathSummation,
-    MathVariance,
-};
-pub(crate) use merge::Merge;
-pub(crate) use mkdir::Mkdir;
-pub(crate) use move_::{Move, Mv};
-pub(crate) use next::Next;
-pub(crate) use nth::Nth;
-pub(crate) use open::Open;
-pub(crate) use parse::Parse;
-pub(crate) use path::{
-    PathBasename, PathCommand, PathDirname, PathExists, PathExpand, PathJoin, PathParse,
-    PathRelativeTo, PathSplit, PathType,
-};
-pub(crate) use pivot::Pivot;
-pub(crate) use prepend::Prepend;
-pub(crate) use prev::Previous;
-pub(crate) use pwd::Pwd;
-#[cfg(feature = "uuid_crate")]
-pub(crate) use random::RandomUUID;
-pub(crate) use random::{
-    Random, RandomBool, RandomChars, RandomDecimal, RandomDice, RandomInteger,
-};
-pub(crate) use range::Range;
-pub(crate) use reduce::Reduce;
-pub(crate) use reject::Reject;
-pub(crate) use rename::Rename;
-pub(crate) use reverse::Reverse;
-pub(crate) use rm::Remove;
-pub(crate) use roll::{Roll, RollColumn, RollUp};
-pub(crate) use rotate::{Rotate, RotateCounterClockwise};
-pub(crate) use run_external::RunExternalCommand;
-pub(crate) use save::Save;
-pub(crate) use select::Command as Select;
-pub(crate) use seq::Seq;
-pub(crate) use seq_dates::SeqDates;
-pub(crate) use shells::Shells;
-pub(crate) use shuffle::Shuffle;
-pub(crate) use size::Size;
-pub(crate) use skip::{Skip, SkipUntil, SkipWhile};
-pub(crate) use sleep::Sleep;
-pub(crate) use sort_by::SortBy;
-pub(crate) use source::Source;
-pub(crate) use split::{Split, SplitChars, SplitColumn, SplitRow};
-pub(crate) use split_by::SplitBy;
-pub(crate) use str_::{
-    Str, StrCamelCase, StrCapitalize, StrCollect, StrContains, StrDowncase, StrEndsWith,
-    StrFindReplace, StrIndexOf, StrKebabCase, StrLPad, StrLength, StrPascalCase, StrRPad,
-    StrReverse, StrScreamingSnakeCase, StrSnakeCase, StrStartsWith, StrSubstring, StrToDatetime,
-    StrToDecimal, StrToInteger, StrTrim, StrTrimLeft, StrTrimRight, StrUpcase,
-};
-pub(crate) use table::Table;
-pub(crate) use tags::Tags;
-pub(crate) use termsize::TermSize;
-pub(crate) use to::To;
-pub(crate) use to_csv::ToCsv;
-pub(crate) use to_html::ToHtml;
-pub(crate) use to_json::ToJson;
-pub(crate) use to_md::Command as ToMarkdown;
-pub(crate) use to_toml::ToToml;
-pub(crate) use to_tsv::ToTsv;
-pub(crate) use to_url::ToUrl;
-pub(crate) use to_xml::ToXml;
-pub(crate) use to_yaml::ToYaml;
-pub(crate) use touch::Touch;
-pub(crate) use uniq::Uniq;
-pub(crate) use url_::{UrlCommand, UrlHost, UrlPath, UrlQuery, UrlScheme};
-pub(crate) use version::Version;
-pub(crate) use where_::Command as Where;
-pub(crate) use which_::Which;
-pub(crate) use with_env::WithEnv;
-pub(crate) use wrap::Wrap;
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-    use crate::examples::{test_anchors, test_examples};
-    use nu_engine::{whole_stream_command, Command};
-    use nu_errors::ShellError;
-
-    fn full_tests() -> Vec<Command> {
-        vec![
-            whole_stream_command(Append),
-            whole_stream_command(GroupBy),
-            whole_stream_command(Insert),
-            whole_stream_command(Move),
-            whole_stream_command(Update),
-            whole_stream_command(Empty),
-            // whole_stream_command(Select),
-            // whole_stream_command(Get),
-            // Str Command Suite
-            whole_stream_command(Str),
-            whole_stream_command(StrToDecimal),
-            whole_stream_command(StrToInteger),
-            whole_stream_command(StrDowncase),
-            whole_stream_command(StrUpcase),
-            whole_stream_command(StrCapitalize),
-            whole_stream_command(StrFindReplace),
-            whole_stream_command(StrSubstring),
-            whole_stream_command(StrToDatetime),
-            whole_stream_command(StrContains),
-            whole_stream_command(StrIndexOf),
-            whole_stream_command(StrTrim),
-            whole_stream_command(StrTrimLeft),
-            whole_stream_command(StrTrimRight),
-            whole_stream_command(StrStartsWith),
-            whole_stream_command(StrEndsWith),
-            //whole_stream_command(StrCollect),
-            whole_stream_command(StrLength),
-            whole_stream_command(StrLPad),
-            whole_stream_command(StrReverse),
-            whole_stream_command(StrRPad),
-            whole_stream_command(StrCamelCase),
-            whole_stream_command(StrPascalCase),
-            whole_stream_command(StrKebabCase),
-            whole_stream_command(StrSnakeCase),
-            whole_stream_command(StrScreamingSnakeCase),
-            whole_stream_command(ToMarkdown),
-        ]
-    }
-
-    fn only_examples() -> Vec<Command> {
-        let mut commands = full_tests();
-        commands.extend(vec![whole_stream_command(Flatten)]);
-        commands
-    }
-
-    #[test]
-    fn examples_work_as_expected() -> Result<(), ShellError> {
-        for cmd in only_examples() {
-            println!("cmd: {}", cmd.name());
-            test_examples(cmd)?;
-        }
-
-        Ok(())
-    }
-
-    #[test]
-    fn tracks_metadata() -> Result<(), ShellError> {
-        for cmd in full_tests() {
-            test_anchors(cmd)?;
-        }
-
-        Ok(())
-    }
-}

crates/nu-command/src/commands/charting/histogram.rs

@@ -59,21 +59,10 @@ impl WholeStreamCommand for Histogram {
 
 pub fn histogram(args: CommandArgs) -> Result<ActionStream, ShellError> {
     let name = args.call_info.name_tag.clone();
-    let (input, args) = args.evaluate_once()?.parts();
 
-    let values: Vec<Value> = input.collect();
+    let mut columns = args.rest::<ColumnPath>(0)?;
-
+    let evaluate_with = args.get_flag::<ColumnPath>("use")?.map(evaluator);
-    let mut columns = args
+    let values: Vec<Value> = args.input.collect();
-        .positional_iter()
-        .map(|c| c.as_column_path())
-        .filter_map(Result::ok)
-        .collect::<Vec<_>>();
-
-    let evaluate_with = if let Some(path) = args.get("use") {
-        Some(evaluator(path.as_column_path()?.item))
-    } else {
-        None
-    };
 
     let column_grouper = if !columns.is_empty() {
         columns
@@ -160,16 +149,19 @@ pub fn histogram(args: CommandArgs) -> Result<ActionStream, ShellError> {
                 "{}%",
                 // Some(2) < the number of digits
                 // true < group the digits
-                crate::commands::into::string::action(&percentage, &name, Some(2), true)?
+                crate::commands::conversions::into::string::action(
-                    .as_string()?
+                    &percentage,
+                    &name,
+                    Some(2),
+                    true
+                )?
+                .as_string()?
             );
             fact.insert_untagged("percentage", UntaggedValue::string(fmt_percentage));
 
-            let string = std::iter::repeat("*")
+            let string = "*".repeat(percentage.as_u64().map_err(|_| {
-                .take(percentage.as_u64().map_err(|_| {
+                ShellError::labeled_error("expected a number", "expected a number", &name)
-                    ShellError::labeled_error("expected a number", "expected a number", &name)
+            })? as usize);
-                })? as usize)
-                .collect::<String>();
 
             fact.insert_untagged(&frequency_column_name, UntaggedValue::string(string));
 
@@ -177,7 +169,7 @@ pub fn histogram(args: CommandArgs) -> Result<ActionStream, ShellError> {
 
             ReturnSuccess::value(fact.into_value())
         })
-        .to_action_stream())
+        .into_action_stream())
 }
 
 fn evaluator(by: ColumnPath) -> Box<dyn Fn(usize, &Value) -> Result<Value, ShellError> + Send> {
@@ -209,7 +201,7 @@ fn splitter(
                 )),
             }
         }),
-        None => Box::new(move |_, row: &Value| nu_value_ext::as_string(&row)),
+        None => Box::new(move |_, row: &Value| nu_value_ext::as_string(row)),
     }
 }
 

crates/nu-command/src/commands/charting/mod.rs

@@ -0,0 +1,5 @@
+mod chart;
+mod histogram;
+
+pub use chart::Chart;
+pub use histogram::Histogram;

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

@@ -33,7 +33,7 @@ impl WholeStreamCommand for SubCommand {
 
 pub fn clear(args: CommandArgs) -> Result<OutputStream, ShellError> {
     let name = args.call_info.name_tag.clone();
-    let ctx = EvaluationContext::from_args(&args);
+    let ctx = &args.context;
 
     let result = if let Some(global_cfg) = &mut args.configs().lock().global_config {
         global_cfg.vars.clear();

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

@@ -37,14 +37,13 @@ impl WholeStreamCommand for SubCommand {
 
 pub fn get(args: CommandArgs) -> Result<OutputStream, ShellError> {
     let name = args.call_info.name_tag.clone();
-    let ctx = EvaluationContext::from_args(&args);
+    let ctx = &args.context;
-    let args = args.evaluate_once()?;
 
     let column_path = args.req(0)?;
 
-    let result = if let Some(global_cfg) = &ctx.configs.lock().global_config {
+    let result = if let Some(global_cfg) = &ctx.configs().lock().global_config {
         let result = UntaggedValue::row(global_cfg.vars.clone()).into_value(&name);
-        let value = crate::commands::get::get_column_path(&column_path, &result)?;
+        let value = crate::commands::filters::get::get_column_path(&column_path, &result)?;
         Ok(match value {
             Value {
                 value: UntaggedValue::Table(list),

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

@@ -38,13 +38,12 @@ impl WholeStreamCommand for SubCommand {
 
 pub fn remove(args: CommandArgs) -> Result<OutputStream, ShellError> {
     let name = args.call_info.name_tag.clone();
-    let ctx = EvaluationContext::from_args(&args);
+    let ctx = &args.context;
-    let args = args.evaluate_once()?;
     let remove: Tagged<String> = args.req(0)?;
 
     let key = remove.to_string();
 
-    let result = if let Some(global_cfg) = &mut ctx.configs.lock().global_config {
+    let result = if let Some(global_cfg) = &mut ctx.configs().lock().global_config {
         if global_cfg.vars.contains_key(&key) {
             global_cfg.vars.swap_remove(&key);
             global_cfg.write()?;

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

@@ -52,13 +52,12 @@ impl WholeStreamCommand for SubCommand {
 
 pub fn set(args: CommandArgs) -> Result<OutputStream, ShellError> {
     let name = args.call_info.name_tag.clone();
-    let ctx = EvaluationContext::from_args(&args);
+    let ctx = &args.context;
-    let args = args.evaluate_once()?;
 
     let column_path = args.req(0)?;
     let mut value: Value = args.req(1)?;
 
-    let result = if let Some(global_cfg) = &mut ctx.configs.lock().global_config {
+    let result = if let Some(global_cfg) = &mut ctx.configs().lock().global_config {
         let configuration = UntaggedValue::row(global_cfg.vars.clone()).into_value(&name);
 
         if let UntaggedValue::Table(rows) = &value.value {

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

@@ -38,15 +38,14 @@ impl WholeStreamCommand for SubCommand {
 
 pub fn set_into(args: CommandArgs) -> Result<OutputStream, ShellError> {
     let name = args.call_info.name_tag.clone();
-    let ctx = EvaluationContext::from_args(&args);
+    let ctx = &args.context;
-    let args = args.evaluate_once()?;
 
     let set_into: Tagged<String> = args.req(0)?;
 
     let rows: Vec<Value> = args.input.collect();
     let key = set_into.to_string();
 
-    let result = if let Some(global_cfg) = &mut ctx.configs.lock().global_config {
+    let result = if let Some(global_cfg) = &mut ctx.configs().lock().global_config {
         if rows.is_empty() {
             return Err(ShellError::labeled_error(
                 "No values given for set_into",

crates/nu-command/src/commands/conversions/into/binary.rs

@@ -12,23 +12,10 @@ impl WholeStreamCommand for SubCommand {
     }
 
     fn signature(&self) -> Signature {
-        Signature::build("into binary")
+        Signature::build("into binary").rest(
-            .rest(
+            SyntaxShape::ColumnPath,
-                SyntaxShape::ColumnPath,
+            "column paths to convert to binary (for table input)",
-                "column paths to convert to binary (for table input)",
+        )
-            )
-            .named(
-                "skip",
-                SyntaxShape::Int,
-                "skip x number of bytes",
-                Some('s'),
-            )
-            .named(
-                "bytes",
-                SyntaxShape::Int,
-                "show y number of bytes",
-                Some('b'),
-            )
     }
 
     fn usage(&self) -> &str {
@@ -53,43 +40,21 @@ impl WholeStreamCommand for SubCommand {
                 )
                 .into()]),
             },
-            Example {
-                description: "convert string to a nushell binary primitive",
-                example:
-                    "echo 'This is a string that is exactly 52 characters long.' | into binary --skip 10",
-                result: Some(vec![UntaggedValue::binary(
-                    "string that is exactly 52 characters long."
-                        .to_string()
-                        .as_bytes()
-                        .to_vec(),
-                )
-                .into()]),
-            },
-            Example {
-                description: "convert string to a nushell binary primitive",
-                example:
-                    "echo 'This is a string that is exactly 52 characters long.' | into binary --skip 10 --bytes 10",
-                result: Some(vec![UntaggedValue::binary(
-                    "string tha"
-                        .to_string()
-                        .as_bytes()
-                        .to_vec(),
-                )
-                .into()]),
-            },
             Example {
                 description: "convert a number to a nushell binary primitive",
                 example: "echo 1 | into binary",
-                result: Some(vec![
+                result: Some(vec![UntaggedValue::binary(
-                    UntaggedValue::binary(i64::from(1).to_le_bytes().to_vec()).into()
+                    i64::from(1).to_le_bytes().to_vec(),
-                ]),
+                )
+                .into()]),
             },
             Example {
                 description: "convert a boolean to a nushell binary primitive",
                 example: "echo $true | into binary",
-                result: Some(vec![
+                result: Some(vec![UntaggedValue::binary(
-                    UntaggedValue::binary(i64::from(1).to_le_bytes().to_vec()).into()
+                    i64::from(1).to_le_bytes().to_vec(),
-                ]),
+                )
+                .into()]),
             },
             Example {
                 description: "convert a filesize to a nushell binary primitive",
@@ -113,83 +78,50 @@ impl WholeStreamCommand for SubCommand {
 }
 
 fn into_binary(args: CommandArgs) -> Result<OutputStream, ShellError> {
-    let args = args.evaluate_once()?;
-    let skip: Option<Value> = args.get_flag("skip")?;
-    let bytes: Option<Value> = args.get_flag("bytes")?;
     let column_paths: Vec<ColumnPath> = args.rest(0)?;
 
     Ok(args
         .input
         .map(move |v| {
             if column_paths.is_empty() {
-                action(&v, v.tag(), &skip, &bytes)
+                action(&v, v.tag())
             } else {
                 let mut ret = v;
                 for path in &column_paths {
-                    let skip_clone = skip.clone();
-                    let bytes_clone = bytes.clone();
                     ret = ret.swap_data_by_column_path(
                         path,
-                        Box::new(move |old| action(old, old.tag(), &skip_clone, &bytes_clone)),
+                        Box::new(move |old| action(old, old.tag())),
                     )?;
                 }
 
                 Ok(ret)
             }
         })
-        .to_input_stream())
+        .into_input_stream())
 }
 
 fn int_to_endian(n: i64) -> Vec<u8> {
     if cfg!(target_endian = "little") {
-        // eprintln!("Little Endian");
         n.to_le_bytes().to_vec()
     } else {
-        // eprintln!("Big Endian");
         n.to_be_bytes().to_vec()
     }
 }
 
 fn bigint_to_endian(n: &BigInt) -> Vec<u8> {
     if cfg!(target_endian = "little") {
-        // eprintln!("Little Endian");
         n.to_bytes_le().1
     } else {
-        // eprintln!("Big Endian");
         n.to_bytes_be().1
     }
 }
 
-pub fn action(
+pub fn action(input: &Value, tag: impl Into<Tag>) -> Result<Value, ShellError> {
-    input: &Value,
-    tag: impl Into<Tag>,
-    skip: &Option<Value>,
-    bytes: &Option<Value>,
-) -> Result<Value, ShellError> {
     let tag = tag.into();
-    let skip_bytes = match skip {
-        Some(s) => s.as_usize().unwrap_or(0),
-        None => 0usize,
-    };
-
-    let num_bytes = match bytes {
-        Some(b) => b.as_usize().unwrap_or(0),
-        None => 0usize,
-    };
 
     match &input.value {
         UntaggedValue::Primitive(prim) => Ok(UntaggedValue::binary(match prim {
-            Primitive::Binary(b) => {
+            Primitive::Binary(b) => b.to_vec(),
-                if num_bytes == 0usize {
-                    b.to_vec().into_iter().skip(skip_bytes).collect()
-                } else {
-                    b.to_vec()
-                        .into_iter()
-                        .skip(skip_bytes)
-                        .take(num_bytes)
-                        .collect()
-                }
-            }
             Primitive::Int(n_ref) => int_to_endian(*n_ref),
             Primitive::BigInt(n_ref) => bigint_to_endian(n_ref),
             Primitive::Decimal(dec) => match dec.to_bigint() {
@@ -208,25 +140,7 @@ pub fn action(
                     ));
                 }
             },
-            Primitive::String(a_string) => {
+            Primitive::String(a_string) => a_string.as_bytes().to_vec(),
-                // a_string.as_bytes().to_vec()
-                if num_bytes == 0usize {
-                    a_string
-                        .as_bytes()
-                        .to_vec()
-                        .into_iter()
-                        .skip(skip_bytes)
-                        .collect()
-                } else {
-                    a_string
-                        .as_bytes()
-                        .to_vec()
-                        .into_iter()
-                        .skip(skip_bytes)
-                        .take(num_bytes)
-                        .collect()
-                }
-            }
             Primitive::Boolean(a_bool) => match a_bool {
                 false => int_to_endian(0),
                 true => int_to_endian(1),

crates/nu-command/src/commands/conversions/into/filepath.rs

@@ -0,0 +1,126 @@
+use std::path::PathBuf;
+
+use crate::prelude::*;
+use nu_engine::WholeStreamCommand;
+use nu_errors::ShellError;
+use nu_protocol::{ColumnPath, Primitive, Signature, SyntaxShape, UntaggedValue, Value};
+
+pub struct SubCommand;
+
+impl WholeStreamCommand for SubCommand {
+    fn name(&self) -> &str {
+        "into path"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("into path").rest(
+            SyntaxShape::ColumnPath,
+            "column paths to convert to filepath (for table input)",
+        )
+    }
+
+    fn usage(&self) -> &str {
+        "Convert value to filepath"
+    }
+
+    fn run(&self, args: CommandArgs) -> Result<OutputStream, ShellError> {
+        into_filepath(args)
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![
+            Example {
+                description: "Convert string to filepath in table",
+                example: "echo [[name]; ['/dev/null'] ['C:\\Program Files'] ['../../Cargo.toml']] | into path name",
+                result: Some(vec![
+                    UntaggedValue::row(indexmap! {
+                        "name".to_string() => UntaggedValue::filepath("/dev/null").into(),
+                    })
+                    .into(),
+                    UntaggedValue::row(indexmap! {
+                        "name".to_string() => UntaggedValue::filepath("C:\\Program Files").into(),
+                    })
+                    .into(),
+                    UntaggedValue::row(indexmap! {
+                        "name".to_string() => UntaggedValue::filepath("../../Cargo.toml").into(),
+                    })
+                    .into(),
+                ]),
+            },
+            Example {
+                description: "Convert string to filepath",
+                example: "echo 'Cargo.toml' | into path",
+                result: Some(vec![UntaggedValue::filepath("Cargo.toml").into()]),
+            },
+        ]
+    }
+}
+
+fn into_filepath(args: CommandArgs) -> Result<OutputStream, ShellError> {
+    let column_paths: Vec<ColumnPath> = args.rest(0)?;
+
+    Ok(args
+        .input
+        .map(move |v| {
+            if column_paths.is_empty() {
+                action(&v, v.tag())
+            } else {
+                let mut ret = v;
+                for path in &column_paths {
+                    ret = ret.swap_data_by_column_path(
+                        path,
+                        Box::new(move |old| action(old, old.tag())),
+                    )?;
+                }
+
+                Ok(ret)
+            }
+        })
+        .into_input_stream())
+}
+
+pub fn action(input: &Value, tag: impl Into<Tag>) -> Result<Value, ShellError> {
+    let tag = tag.into();
+    match &input.value {
+        UntaggedValue::Primitive(prim) => Ok(UntaggedValue::filepath(match prim {
+            Primitive::String(a_string) => match filepath_from_string(a_string, &tag) {
+                Ok(n) => n,
+                Err(e) => {
+                    return Err(e);
+                }
+            },
+            Primitive::FilePath(a_filepath) => a_filepath.clone(),
+            _ => {
+                return Err(ShellError::unimplemented(
+                    "'into path' for non-string primitives",
+                ))
+            }
+        })
+        .into_value(&tag)),
+        UntaggedValue::Row(_) => Err(ShellError::labeled_error(
+            "specify column name to use, with 'into path COLUMN'",
+            "found table",
+            tag,
+        )),
+        _ => Err(ShellError::unimplemented(
+            "'into path' for unsupported type",
+        )),
+    }
+}
+
+fn filepath_from_string(a_string: &str, _tag: &Tag) -> Result<PathBuf, ShellError> {
+    Ok(PathBuf::from(a_string))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::ShellError;
+    use super::SubCommand;
+
+    #[test]
+    fn examples_work_as_expected() -> Result<(), ShellError> {
+        use crate::examples::test as test_examples;
+
+        test_examples(SubCommand {})
+    }
+}

crates/nu-command/src/commands/conversions/into/int.rs

@@ -79,7 +79,6 @@ impl WholeStreamCommand for SubCommand {
 }
 
 fn into_int(args: CommandArgs) -> Result<OutputStream, ShellError> {
-    let args = args.evaluate_once()?;
     let column_paths: Vec<ColumnPath> = args.rest(0)?;
 
     Ok(args
@@ -99,7 +98,7 @@ fn into_int(args: CommandArgs) -> Result<OutputStream, ShellError> {
                 Ok(ret)
             }
         })
-        .to_input_stream())
+        .into_input_stream())
 }
 
 pub fn action(input: &Value, tag: impl Into<Tag>) -> Result<Value, ShellError> {

crates/nu-command/src/commands/conversions/into/mod.rs

@@ -1,9 +1,11 @@
 mod binary;
 mod command;
+mod filepath;
 mod int;
 pub mod string;
 
 pub use binary::SubCommand as IntoBinary;
 pub use command::Command as Into;
+pub use filepath::SubCommand as IntoFilepath;
 pub use int::SubCommand as IntoInt;
 pub use string::SubCommand as IntoString;

crates/nu-command/src/commands/conversions/into/string.rs

@@ -81,8 +81,6 @@ impl WholeStreamCommand for SubCommand {
 }
 
 fn into_string(args: CommandArgs) -> Result<OutputStream, ShellError> {
-    let args = args.evaluate_once()?;
-
     let decimals: Option<Tagged<u64>> = args.get_flag("decimals")?;
     let column_paths: Vec<ColumnPath> = args.rest(0)?;
 
@@ -106,7 +104,7 @@ fn into_string(args: CommandArgs) -> Result<OutputStream, ShellError> {
                 Ok(ret)
             }
         })
-        .to_input_stream())
+        .into_input_stream())
 }
 
 pub fn action(

crates/nu-command/src/commands/conversions/mod.rs

@@ -0,0 +1,3 @@
+pub(crate) mod into;
+
+pub use into::*;

crates/nu-command/src/commands/core_commands/alias.rs

@@ -0,0 +1,52 @@
+use crate::prelude::*;
+use nu_engine::WholeStreamCommand;
+
+use nu_errors::ShellError;
+use nu_protocol::{Signature, SyntaxShape, UntaggedValue};
+
+pub struct Alias;
+
+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("equals", SyntaxShape::String, "the equals sign")
+            .rest(SyntaxShape::Any, "the expansion for the alias")
+    }
+
+    fn usage(&self) -> &str {
+        "Alias a command to an expansion."
+    }
+
+    fn run(&self, args: CommandArgs) -> Result<OutputStream, ShellError> {
+        alias(args)
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![Example {
+            description: "Alias ll to ls -l",
+            example: "alias ll = ls -l",
+            result: None,
+        }]
+    }
+}
+
+pub fn alias(args: CommandArgs) -> Result<OutputStream, ShellError> {
+    // TODO: is there a better way of checking whether no arguments were passed?
+    if args.nth(0).is_none() {
+        let aliases = UntaggedValue::string(
+            &args
+                .scope()
+                .get_aliases()
+                .iter()
+                .map(|val| format!("{} = '{}'", val.0, val.1.iter().map(|x| &x.item).join(" ")))
+                .join("\n"),
+        );
+        return Ok(OutputStream::one(aliases));
+    }
+    Ok(OutputStream::empty())
+}

crates/nu-command/src/commands/core_commands/debug.rs

@@ -5,11 +5,6 @@ use nu_protocol::{ReturnSuccess, Signature, UntaggedValue};
 
 pub struct Debug;
 
-#[derive(Deserialize)]
-pub struct DebugArgs {
-    raw: bool,
-}
-
 impl WholeStreamCommand for Debug {
     fn name(&self) -> &str {
         "debug"
@@ -29,7 +24,9 @@ impl WholeStreamCommand for Debug {
 }
 
 fn debug_value(args: CommandArgs) -> Result<ActionStream, ShellError> {
-    let (DebugArgs { raw }, input) = args.process()?;
+    let raw = args.has_flag("raw");
+    let input = args.input;
+
     Ok(input
         .map(move |v| {
             if raw {
@@ -40,7 +37,7 @@ fn debug_value(args: CommandArgs) -> Result<ActionStream, ShellError> {
                 ReturnSuccess::debug_value(v)
             }
         })
-        .to_action_stream())
+        .into_action_stream())
 }
 
 #[cfg(test)]

crates/nu-command/src/commands/core_commands/describe.rs

@@ -31,12 +31,12 @@ pub fn describe(args: CommandArgs) -> Result<ActionStream, ShellError> {
     Ok(args
         .input
         .map(|row| {
-            let name = value::format_type(&row, 100);
+            let name = value::plain_type(&row, 100);
             ReturnSuccess::value(
                 UntaggedValue::string(name).into_value(Tag::unknown_anchor(row.tag.span)),
             )
         })
-        .to_action_stream())
+        .into_action_stream())
 }
 
 #[cfg(test)]

crates/nu-command/src/commands/core_commands/do_.rs

@@ -59,11 +59,10 @@ impl WholeStreamCommand for Do {
     }
 }
 
-fn do_(raw_args: CommandArgs) -> Result<OutputStream, ShellError> {
+fn do_(args: CommandArgs) -> Result<OutputStream, ShellError> {
-    let external_redirection = raw_args.call_info.args.external_redirection;
+    let external_redirection = args.call_info.args.external_redirection;
 
-    let context = EvaluationContext::from_args(&raw_args);
+    let context = args.context().clone();
-    let args = raw_args.evaluate_once()?;
     let do_args = DoArgs {
         block: args.req(0)?,
         ignore_errors: args.has_flag("ignore-errors"),
@@ -119,12 +118,12 @@ fn do_(raw_args: CommandArgs) -> Result<OutputStream, ShellError> {
             Ok(mut stream) => {
                 let output = stream.drain_vec();
                 context.clear_errors();
-                Ok(output.into_iter().to_output_stream())
+                Ok(output.into_iter().into_output_stream())
             }
             Err(_) => Ok(OutputStream::empty()),
         }
     } else {
-        result.map(|x| x.to_output_stream())
+        result.map(|x| x.into_output_stream())
     }
 }
 

crates/nu-command/src/commands/core_commands/echo.rs

@@ -54,7 +54,6 @@ pub fn expand_value_to_stream(v: Value) -> InputStream {
 }
 
 fn echo(args: CommandArgs) -> Result<InputStream, ShellError> {
-    let args = args.evaluate_once()?;
     let rest: Vec<Value> = args.rest(0)?;
 
     let stream = rest.into_iter().map(|i| match i.as_string() {

crates/nu-command/src/commands/core_commands/help.rs

@@ -1,30 +1,30 @@
 use crate::prelude::*;
 use crate::TaggedListBuilder;
-use nu_engine::documentation::generate_docs;
+use nu_engine::{documentation::generate_docs, Command, WholeStreamCommand};
-use nu_engine::{Command, WholeStreamCommand};
 use nu_errors::ShellError;
 use nu_protocol::{
-    NamedType, PositionalType, ReturnSuccess, Signature, SyntaxShape, TaggedDictBuilder,
+    Dictionary, NamedType, PositionalType, ReturnSuccess, Signature, SyntaxShape,
-    UntaggedValue, Value,
+    TaggedDictBuilder, UntaggedValue, Value,
 };
-use nu_source::Tag;
+use nu_source::{SpannedItem, Tag, Tagged};
-use nu_source::{SpannedItem, Tagged};
 use nu_value_ext::ValueExt;
 
 pub struct Help;
 
-#[derive(Deserialize)]
-pub struct HelpArgs {
-    rest: Vec<Tagged<String>>,
-}
-
 impl WholeStreamCommand for Help {
     fn name(&self) -> &str {
         "help"
     }
 
     fn signature(&self) -> Signature {
-        Signature::build("help").rest(SyntaxShape::String, "the name of command to get help on")
+        Signature::build("help")
+            .rest(SyntaxShape::String, "the name of command to get help on")
+            .named(
+                "find",
+                SyntaxShape::String,
+                "string to find in command usage",
+                Some('f'),
+            )
     }
 
     fn usage(&self) -> &str {
@@ -34,12 +34,80 @@ impl WholeStreamCommand for Help {
     fn run_with_actions(&self, args: CommandArgs) -> Result<ActionStream, ShellError> {
         help(args)
     }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![
+            Example {
+                description: "show all commands and sub-commands",
+                example: "help commands",
+                result: None,
+            },
+            Example {
+                description: "generate documentation",
+                example: "help generate_docs",
+                result: None,
+            },
+            Example {
+                description: "show help for single command",
+                example: "help match",
+                result: None,
+            },
+            Example {
+                description: "show help for single sub-command",
+                example: "help str lpad",
+                result: None,
+            },
+            Example {
+                description: "search for string in command usage",
+                example: "help --find char",
+                result: None,
+            },
+        ]
+    }
 }
 
 fn help(args: CommandArgs) -> Result<ActionStream, ShellError> {
     let name = args.call_info.name_tag.clone();
     let scope = args.scope().clone();
-    let (HelpArgs { rest }, ..) = args.process()?;
+    let find: Option<Tagged<String>> = args.get_flag("find")?;
+    let rest: Vec<Tagged<String>> = args.rest(0)?;
+
+    if let Some(f) = find {
+        let search_string = f.item;
+        let full_commands = scope.get_commands_info();
+        let mut found_cmds_vec = Vec::new();
+
+        for (key, cmd) in full_commands {
+            let mut indexmap = IndexMap::new();
+
+            let c = cmd.usage().to_string();
+            let e = cmd.extra_usage().to_string();
+            if key.to_lowercase().contains(&search_string)
+                || c.to_lowercase().contains(&search_string)
+                || e.to_lowercase().contains(&search_string)
+            {
+                indexmap.insert(
+                    "name".to_string(),
+                    UntaggedValue::string(key).into_value(&name),
+                );
+
+                indexmap.insert(
+                    "usage".to_string(),
+                    UntaggedValue::string(cmd.usage().to_string()).into_value(&name),
+                );
+
+                indexmap.insert(
+                    "extra_usage".to_string(),
+                    UntaggedValue::string(cmd.extra_usage().to_string()).into_value(&name),
+                );
+
+                found_cmds_vec
+                    .push(UntaggedValue::Row(Dictionary::from(indexmap)).into_value(&name));
+            }
+        }
+
+        return Ok(found_cmds_vec.into_iter().into_action_stream());
+    }
 
     if !rest.is_empty() {
         if rest[0].item == "commands" {
@@ -48,11 +116,11 @@ fn help(args: CommandArgs) -> Result<ActionStream, ShellError> {
 
             let (mut subcommand_names, command_names) = sorted_names
                 .into_iter()
-                // Internal only commands shouldn't be displayed
+                // private only commands shouldn't be displayed
                 .filter(|cmd_name| {
                     scope
-                        .get_command(&cmd_name)
+                        .get_command(cmd_name)
-                        .filter(|command| !command.is_internal())
+                        .filter(|command| !command.is_private())
                         .is_some()
                 })
                 .partition::<Vec<_>, _>(|cmd_name| cmd_name.contains(' '));
@@ -66,7 +134,7 @@ fn help(args: CommandArgs) -> Result<ActionStream, ShellError> {
             ) -> Result<(), ShellError> {
                 let document_tag = rest[0].tag.clone();
                 let value = command_dict(
-                    scope.get_command(&cmd_name).ok_or_else(|| {
+                    scope.get_command(cmd_name).ok_or_else(|| {
                         ShellError::labeled_error(
                             format!("Could not load {}", cmd_name),
                             "could not load command",
@@ -154,7 +222,7 @@ fn help(args: CommandArgs) -> Result<ActionStream, ShellError> {
                         ReturnSuccess::value(short_desc.into_value())
                     });
 
-            Ok(iterator.to_action_stream())
+            Ok(iterator.into_action_stream())
         } else if rest[0].item == "generate_docs" {
             Ok(ActionStream::one(ReturnSuccess::value(generate_docs(
                 &scope,

crates/nu-command/src/commands/core_commands/history.rs

@@ -0,0 +1,74 @@
+use crate::prelude::*;
+use nu_engine::WholeStreamCommand;
+use nu_errors::ShellError;
+use nu_protocol::{ReturnSuccess, Signature, UntaggedValue};
+use std::fs::File;
+use std::io::{BufRead, BufReader};
+
+pub struct History;
+
+impl WholeStreamCommand for History {
+    fn name(&self) -> &str {
+        "history"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("history").switch("clear", "Clears out the history entries", Some('c'))
+    }
+
+    fn usage(&self) -> &str {
+        "Display command history."
+    }
+
+    fn run_with_actions(&self, args: CommandArgs) -> Result<ActionStream, ShellError> {
+        history(args)
+    }
+}
+
+fn history(args: CommandArgs) -> Result<ActionStream, ShellError> {
+    let tag = args.call_info.name_tag.clone();
+    let ctx = &args.context;
+
+    let clear = args.has_flag("clear");
+
+    let path = if let Some(global_cfg) = &ctx.configs().lock().global_config {
+        nu_data::config::path::history_path_or_default(global_cfg)
+    } else {
+        nu_data::config::path::default_history_path()
+    };
+
+    if clear {
+        // This is a NOOP, the logic to clear is handled in cli.rs
+        Ok(ActionStream::empty())
+    } else if let Ok(file) = File::open(path) {
+        let reader = BufReader::new(file);
+        // Skips the first line, which is a Rustyline internal
+        let output = reader.lines().skip(1).filter_map(move |line| match line {
+            Ok(line) => Some(ReturnSuccess::value(
+                UntaggedValue::string(line).into_value(tag.clone()),
+            )),
+            Err(_) => None,
+        });
+
+        Ok(output.into_action_stream())
+    } else {
+        Err(ShellError::labeled_error(
+            "Could not open history",
+            "history file could not be opened",
+            tag,
+        ))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::History;
+    use super::ShellError;
+
+    #[test]
+    fn examples_work_as_expected() -> Result<(), ShellError> {
+        use crate::examples::test as test_examples;
+
+        test_examples(History {})
+    }
+}

crates/nu-command/src/commands/core_commands/if_.rs

@@ -57,12 +57,11 @@ impl WholeStreamCommand for If {
         ]
     }
 }
-fn if_command(raw_args: CommandArgs) -> Result<OutputStream, ShellError> {
+fn if_command(args: CommandArgs) -> Result<OutputStream, ShellError> {
-    let tag = raw_args.call_info.name_tag.clone();
+    let tag = args.call_info.name_tag.clone();
-    let external_redirection = raw_args.call_info.args.external_redirection;
+    let external_redirection = args.call_info.args.external_redirection;
-    let context = Arc::new(EvaluationContext::from_args(&raw_args));
+    let context = Arc::new(args.context.clone());
 
-    let args = raw_args.evaluate_once()?;
     let condition: CapturedBlock = args.req(0)?;
     let then_case: CapturedBlock = args.req(1)?;
     let else_case: CapturedBlock = args.req(2)?;
@@ -101,7 +100,7 @@ fn if_command(raw_args: CommandArgs) -> Result<OutputStream, ShellError> {
     context.scope.add_vars(&condition.captured.entries);
 
     //FIXME: should we use the scope that's brought in as well?
-    let condition = evaluate_baseline_expr(&cond, &*context);
+    let condition = evaluate_baseline_expr(cond, &*context);
     match condition {
         Ok(condition) => match condition.as_bool() {
             Ok(b) => {

crates/nu-command/src/commands/core_commands/ignore.rs

@@ -0,0 +1,49 @@
+extern crate unicode_segmentation;
+
+use crate::prelude::*;
+use nu_engine::WholeStreamCommand;
+use nu_errors::ShellError;
+use nu_protocol::Signature;
+
+pub struct Ignore;
+
+impl WholeStreamCommand for Ignore {
+    fn name(&self) -> &str {
+        "ignore"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("ignore")
+    }
+
+    fn usage(&self) -> &str {
+        "Ignore the output of the previous command in the pipeline"
+    }
+
+    fn run(&self, args: CommandArgs) -> Result<OutputStream, ShellError> {
+        let _: Vec<_> = args.input.collect();
+
+        Ok(OutputStream::empty())
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![Example {
+            description: "Ignore the output of an echo command",
+            example: r#"echo done | ignore"#,
+            result: None,
+        }]
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::Ignore;
+    use super::ShellError;
+
+    #[test]
+    fn examples_work_as_expected() -> Result<(), ShellError> {
+        use crate::examples::test as test_examples;
+
+        test_examples(Ignore {})
+    }
+}

crates/nu-command/src/commands/core_commands/let_.rs

@@ -55,7 +55,7 @@ impl WholeStreamCommand for Let {
 }
 
 pub fn letcmd(args: CommandArgs) -> Result<ActionStream, ShellError> {
-    let ctx = EvaluationContext::from_args(&args);
+    let ctx = &args.context;
     let positional = args
         .call_info
         .args
@@ -63,7 +63,7 @@ pub fn letcmd(args: CommandArgs) -> Result<ActionStream, ShellError> {
         .expect("Internal error: type checker should require args");
 
     let var_name = positional[0].var_name()?;
-    let rhs_raw = evaluate_baseline_expr(&positional[2], &ctx)?;
+    let rhs_raw = evaluate_baseline_expr(&positional[2], ctx)?;
     let tag: Tag = positional[2].span.into();
 
     let rhs: CapturedBlock = FromValue::from_value(&rhs_raw)?;
@@ -98,7 +98,7 @@ pub fn letcmd(args: CommandArgs) -> Result<ActionStream, ShellError> {
     };
 
     ctx.scope.enter_scope();
-    let value = evaluate_baseline_expr(&expr, &ctx);
+    let value = evaluate_baseline_expr(expr, ctx);
     ctx.scope.exit_scope();
 
     let value = value?;

crates/nu-command/src/commands/core_commands/mod.rs

@@ -0,0 +1,39 @@
+mod alias;
+mod debug;
+mod def;
+mod describe;
+mod do_;
+pub(crate) mod echo;
+mod help;
+mod history;
+mod if_;
+mod ignore;
+mod let_;
+mod nu_plugin;
+mod nu_signature;
+mod source;
+mod tags;
+mod tutor;
+mod unalias;
+mod version;
+
+pub use self::nu_plugin::SubCommand as NuPlugin;
+pub use self::nu_signature::{
+    loglevels, testbins, version as core_version, Command as NuSignature,
+};
+pub use alias::Alias;
+pub use debug::Debug;
+pub use def::Def;
+pub use describe::Describe;
+pub use do_::Do;
+pub use echo::Echo;
+pub use help::Help;
+pub use history::History;
+pub use if_::If;
+pub use ignore::Ignore;
+pub use let_::Let;
+pub use source::Source;
+pub use tags::Tags;
+pub use tutor::Tutor;
+pub use unalias::Unalias;
+pub use version::{version, Version};

crates/nu-command/src/commands/core_commands/nu_plugin.rs

@@ -1,10 +1,10 @@
 use std::path::PathBuf;
 
 use crate::prelude::*;
-use nu_engine::filesystem::path::canonicalize;
 use nu_engine::WholeStreamCommand;
 
 use nu_errors::ShellError;
+use nu_path::canonicalize;
 use nu_protocol::{CommandAction, ReturnSuccess, Signature, SyntaxShape, UntaggedValue};
 use nu_source::Tagged;
 
@@ -48,7 +48,8 @@ impl WholeStreamCommand for SubCommand {
     fn run_with_actions(&self, args: CommandArgs) -> Result<ActionStream, ShellError> {
         let scope = args.scope().clone();
         let shell_manager = args.shell_manager();
-        let (Arguments { load_path }, _) = args.process()?;
+
+        let load_path: Option<Tagged<PathBuf>> = args.get_flag("load")?;
 
         if let Some(Tagged {
             item: load_path,

crates/nu-command/src/commands/core_commands/nu_signature.rs

@@ -0,0 +1,70 @@
+use nu_engine::WholeStreamCommand;
+use nu_protocol::{Signature, SyntaxShape};
+
+pub struct Command;
+
+impl WholeStreamCommand for Command {
+    fn name(&self) -> &str {
+        "nu"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("nu")
+            .switch("version", "Display Nu version", Some('v'))
+            .switch("stdin", "redirect stdin", None)
+            .switch("skip-plugins", "do not load plugins", None)
+            .switch("no-history", "don't save history", None)
+            .switch("perf", "show startup performance metrics", None)
+            .named(
+                "commands",
+                SyntaxShape::String,
+                "commands to run",
+                Some('c'),
+            )
+            .named(
+                "testbin",
+                SyntaxShape::String,
+                "test bin: echo_env, cococo, iecho, fail, nonu, chop, repeater, meow",
+                None,
+            )
+            .named("develop", SyntaxShape::String, "trace mode", None)
+            .named("debug", SyntaxShape::String, "debug mode", None)
+            .named(
+                "loglevel",
+                SyntaxShape::String,
+                "LEVEL: error, warn, info, debug, trace",
+                Some('l'),
+            )
+            .named(
+                "config-file",
+                SyntaxShape::FilePath,
+                "custom configuration source file",
+                None,
+            )
+            .rest(SyntaxShape::String, "source file(s) to run")
+    }
+
+    fn usage(&self) -> &str {
+        "Nu - A new type of shell."
+    }
+}
+
+pub fn version() -> &'static str {
+    env!("CARGO_PKG_VERSION")
+}
+
+pub fn testbins() -> Vec<String> {
+    vec![
+        "echo_env", "cococo", "iecho", "fail", "nonu", "chop", "repeater", "meow",
+    ]
+    .into_iter()
+    .map(String::from)
+    .collect()
+}
+
+pub fn loglevels() -> Vec<String> {
+    vec!["error", "warn", "info", "debug", "trace"]
+        .into_iter()
+        .map(String::from)
+        .collect()
+}

crates/nu-command/src/commands/core_commands/source.rs

@@ -2,10 +2,12 @@ use crate::prelude::*;
 use nu_engine::{script, WholeStreamCommand};
 
 use nu_errors::ShellError;
-use nu_parser::expand_path;
+use nu_path::expand_path;
 use nu_protocol::{Signature, SyntaxShape};
 use nu_source::Tagged;
 
+use std::{borrow::Cow, path::Path};
+
 pub struct Source;
 
 #[derive(Deserialize)]
@@ -21,7 +23,7 @@ impl WholeStreamCommand for Source {
     fn signature(&self) -> Signature {
         Signature::build("source").required(
             "filename",
-            SyntaxShape::String,
+            SyntaxShape::FilePath,
             "the filepath to the script file to source",
         )
     }
@@ -40,19 +42,19 @@ impl WholeStreamCommand for Source {
 }
 
 pub fn source(args: CommandArgs) -> Result<ActionStream, ShellError> {
-    let ctx = EvaluationContext::from_args(&args);
+    let ctx = &args.context;
-    let (SourceArgs { filename }, _) = args.process()?;
+    let filename: Tagged<String> = args.req(0)?;
 
     // Note: this is a special case for setting the context from a command
     // In this case, if we don't set it now, we'll lose the scope that this
     // variable should be set into.
-    let contents = std::fs::read_to_string(expand_path(&filename.item).into_owned());
+    let contents = std::fs::read_to_string(&expand_path(Cow::Borrowed(Path::new(&filename.item))));
     match contents {
         Ok(contents) => {
-            let result = script::run_script_standalone(contents, true, &ctx, false);
+            let result = script::run_script_standalone(contents, true, ctx, false);
 
             if let Err(err) = result {
-                ctx.error(err.into());
+                ctx.error(err);
             }
             Ok(ActionStream::empty())
         }

crates/nu-command/src/commands/core_commands/tags.rs

@@ -48,7 +48,7 @@ fn tags(args: CommandArgs) -> ActionStream {
 
             tags.into_value()
         })
-        .to_action_stream()
+        .into_action_stream()
 }
 
 #[cfg(test)]

crates/nu-command/src/commands/core_commands/tutor.rs

@@ -0,0 +1,407 @@
+use crate::prelude::*;
+use nu_engine::WholeStreamCommand;
+use nu_errors::ShellError;
+use nu_protocol::{Signature, SyntaxShape, UntaggedValue};
+
+pub struct Tutor;
+
+impl WholeStreamCommand for Tutor {
+    fn name(&self) -> &str {
+        "tutor"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("tutor")
+            .optional(
+                "search",
+                SyntaxShape::String,
+                "item to search for, or 'list' to list available tutorials",
+            )
+            .named(
+                "find",
+                SyntaxShape::String,
+                "Search tutorial for a phrase",
+                Some('f'),
+            )
+    }
+
+    fn usage(&self) -> &str {
+        "Run the tutorial. To begin, run: tutor"
+    }
+
+    fn run(&self, args: CommandArgs) -> Result<OutputStream, ShellError> {
+        tutor(args)
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![
+            Example {
+                description: "Begin the tutorial",
+                example: "tutor begin",
+                result: None,
+            },
+            Example {
+                description: "Search a tutorial by phrase",
+                example: "tutor -f \"$in\"",
+                result: None,
+            },
+        ]
+    }
+}
+
+fn tutor(args: CommandArgs) -> Result<OutputStream, ShellError> {
+    let tag = args.name_tag();
+    let scope = args.scope().clone();
+
+    let search: Option<String> = args.opt(0).unwrap_or(None);
+    let find: Option<String> = args.get_flag("find")?;
+
+    let search_space = vec![
+        (vec!["begin"], begin_tutor()),
+        (
+            vec!["table", "tables", "row", "rows", "column", "columns"],
+            table_tutor(),
+        ),
+        (vec!["cell", "cells"], cell_tutor()),
+        (
+            vec![
+                "expr",
+                "exprs",
+                "expressions",
+                "subexpression",
+                "subexpressions",
+                "sub-expression",
+                "sub-expressions",
+            ],
+            expression_tutor(),
+        ),
+        (vec!["echo"], echo_tutor()),
+        (vec!["each", "iteration", "iter"], each_tutor()),
+        (
+            vec!["var", "vars", "variable", "variables"],
+            variable_tutor(),
+        ),
+        (vec!["block", "blocks"], block_tutor()),
+        (vec!["shorthand", "shorthands"], shorthand_tutor()),
+    ];
+
+    if let Some(find) = find {
+        let mut results = vec![];
+        for search_group in search_space {
+            if search_group.1.contains(&find.as_str()) {
+                results.push(search_group.0[0].to_string())
+            }
+        }
+
+        let message = format!("You can find '{}' in the following topics:\n{}\n\nYou can learn about a topic using `tutor` followed by the name of the topic.\nFor example: `tutor table` to open the table topic.\n\n",
+            find,
+            results.into_iter().map(|x| format!("- {}", x)).join("\n")
+        );
+
+        return Ok(display(tag, &scope, &message));
+    } else if let Some(search) = search {
+        for search_group in search_space {
+            if search_group.0.contains(&search.as_str()) {
+                return Ok(display(tag, &scope, search_group.1));
+            }
+        }
+    }
+    Ok(display(tag, &scope, default_tutor()))
+}
+
+fn default_tutor() -> &'static str {
+    r#"
+Welcome to the Nushell tutorial!
+
+With the `tutor` command, you'll be able to learn a lot about how Nushell
+works along with many fun tips and tricks to speed up everyday tasks.
+
+To get started, you can use `tutor begin`.
+
+"#
+}
+
+fn begin_tutor() -> &'static str {
+    r#"
+Nushell is a structured shell and programming language. One way to begin
+using it is to try a few of the commands.
+
+The first command to try is `ls`. The `ls` command will show you a list
+of the files in the current directory. Notice that these files are shown
+as a table. Each column of this table not only tells us what is being
+shown, but also gives us a way to work with the data.
+
+You can combine the `ls` command with other commands using the pipeline
+symbol '|'. This allows data to flow from one command to the next.
+
+For example, if we only wanted the name column, we could do:
+```
+ls | select name
+```
+Notice that we still get a table, but this time it only has one column:
+the name column.
+
+You can continue to learn more about tables by running:
+```
+tutor tables
+```
+If at any point, you'd like to restart this tutorial, you can run:
+```
+tutor begin
+```
+"#
+}
+
+fn table_tutor() -> &'static str {
+    r#"
+The most common form of data in Nushell is the table. Tables contain rows and
+columns of data. In each cell of the table, there is data that you can access
+using Nushell commands.
+
+To get the 3rd row in the table, you can use the `nth` command:
+```
+ls | nth 2
+```
+This will get the 3rd (note that `nth` is zero-based) row in the table created
+by the `ls` command. You can use `nth` on any table created by other commands
+as well.
+
+You can also access the column of data in one of two ways. If you want to want
+to keep the column as part of a new table, you can use `select`.
+```
+ls | select name
+```
+This runs `ls` and returns only the "name" column of the table.
+
+If, instead, you'd like to get access to the values inside of the column, you
+can use the `get` command.
+```
+ls | get name
+```
+This allows us to get to the list of strings that are the filenames rather
+than having a full table. In some cases, this can make the names easier to 
+work with.
+
+You can continue to learn more about working with cells of the table by
+running:
+```
+tutor cells
+```
+"#
+}
+
+fn cell_tutor() -> &'static str {
+    r#"
+Working with cells of data in the table is a key part of working with data in
+Nushell. Because of this, there is a rich list of commands to work with cells
+as well as handy shorthands for accessing cells.
+
+Cells can hold simple values like strings and numbers, or more complex values
+like lists and tables.
+
+To reach a cell of data from a table, you can combine a row operation and a
+column operation.
+```
+ls | nth 4 | get name
+```
+You can combine these operations into one step using a shortcut.
+```
+(ls).4.name
+```
+Names/strings represent columns names and numbers represent row numbers.
+
+The `(ls)` is a form of expression. You can continue to learn more about
+expressions by running:
+```
+tutor expressions
+```
+You can also learn about these cell shorthands by running:
+```
+tutor shorthands
+```
+"#
+}
+
+fn expression_tutor() -> &'static str {
+    r#"
+Expressions give you the power to mix calls to commands with math. The
+simplest expression is a single value like a string or number.
+```
+3
+```
+Expressions can also include math operations like addition or division.
+```
+10 / 2
+```
+Normally, an expression is one type of operation: math or commands. You can
+mix these types by using subexpressions. Subexpressions are just like
+expressions, but they're wrapped in parentheses `()`.
+```
+10 * (3 + 4)
+```
+Here we use parentheses to create a higher math precedence in the math 
+expression.
+```
+echo (2 + 3)
+```
+You can continue to learn more about the `echo` command by running:
+```
+tutor echo
+```
+"#
+}
+
+fn echo_tutor() -> &'static str {
+    r#"
+The `echo` command in Nushell is a powerful tool for not only seeing values,
+but also for creating new ones.
+```
+echo "Hello"
+```
+You can echo output. This output, if it's not redirected using a "|" pipeline
+will be displayed to the screen.
+```
+echo 1..10
+```
+You can also use echo to work with individual values of a range. In this
+example, `echo` will create the values from 1 to 10 as a list.
+```
+echo 1 2 3 4 5
+```
+You can also create lists of values by passing `echo` multiple arguments.
+This can be helpful if you want to later processes these values.
+
+The `echo` command can pair well with the `each` command which can run
+code on each row, or item, of input.
+
+You can continue to learn more about the `echo` command by running:
+```
+tutor each
+```
+"#
+}
+
+fn each_tutor() -> &'static str {
+    r#"
+The `each` command gives us a way of working with each individual row or
+element of a list one at a time. It reads these in from the pipeline and
+runs a block on each element. A block is a group of pipelines.
+```
+echo 1 2 3 | each { $it + 10}
+```
+This example iterates over each element sent by `echo`, giving us three new
+values that are the original value + 10. Here, the `$it` is a variable that
+is the name given to the block's parameter by default.
+
+You can learn more about blocks by running:
+```
+tutor blocks
+```
+You can also learn more about variables by running:
+```
+tutor variables
+```
+"#
+}
+
+fn variable_tutor() -> &'static str {
+    r#"
+Variables are an important way to store values to be used later. To create a
+variable, you can use the `let` keyword. The `let` command will create a
+variable and then assign it a value in one step.
+```
+let $x = 3
+```
+Once created, we can refer to this variable by name.
+```
+$x
+```
+Nushell also comes with built-in variables. The `$nu` variable is a reserved
+variable that contains a lot of information about the currently running
+instance of Nushell. The `$it` variable is the name given to block parameters
+if you don't specify one. And `$in` is the variable that allows you to work
+with all of the data coming in from the pipeline in one place.
+
+"#
+}
+
+fn block_tutor() -> &'static str {
+    r#"
+Blocks are a special form of expression that hold code to be run at a later
+time. Often, you'll see blocks as one of the arguments given to commands
+like `each` and `if`.
+```
+ls | each {|x| $x.name}
+```
+The above will create a list of the filenames in the directory.
+```
+if $true { echo "it's true" } { echo "it's not true" }
+```
+This `if` call will run the first block if the expression is true, or the
+second block if the expression is false.
+
+"#
+}
+
+fn shorthand_tutor() -> &'static str {
+    r#"
+You can access cells in a table using a shorthand notation sometimes called a
+"column path" or "cell path". These paths allow you to go from a table to
+rows, columns, or cells inside of the table.
+
+Shorthand paths are made from rows numbers, column names, or both. You can use
+them on any variable or subexpression.
+```
+$nu.cwd
+```
+The above accesses the built-in `$nu` variable, gets its table, and then uses
+the shorthand path to retrieve only the cell data inside the "cwd" column.
+```
+(ls).name.4
+```
+This will retrieve the cell data in the "name" column on the 5th row (note: 
+row numbers are zero-based).
+
+Rows and columns don't need to come in any specific order. You can get the
+same value using:
+```
+(ls).4.name
+```
+"#
+}
+
+fn display(tag: Tag, scope: &Scope, help: &str) -> OutputStream {
+    let help = help.split('`');
+
+    let mut build = String::new();
+    let mut code_mode = false;
+    let palette = nu_engine::DefaultPalette {};
+
+    for item in help {
+        if code_mode {
+            code_mode = false;
+
+            //TODO: support no-color mode
+            let colored_example = nu_engine::Painter::paint_string(item, scope, &palette);
+            build.push_str(&format!("{}", colored_example));
+        } else {
+            code_mode = true;
+            build.push_str(item);
+        }
+    }
+
+    OutputStream::one(UntaggedValue::string(build).into_value(tag))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::ShellError;
+    use super::Tutor;
+
+    #[test]
+    fn examples_work_as_expected() -> Result<(), ShellError> {
+        use crate::examples::test as test_examples;
+
+        test_examples(Tutor {})
+    }
+}

crates/nu-command/src/commands/core_commands/unalias.rs

@@ -0,0 +1,37 @@
+use crate::prelude::*;
+use nu_engine::WholeStreamCommand;
+
+use nu_errors::ShellError;
+use nu_protocol::{Signature, SyntaxShape};
+
+pub struct Unalias;
+
+impl WholeStreamCommand for Unalias {
+    fn name(&self) -> &str {
+        "unalias"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("unalias").required("name", SyntaxShape::String, "the name of the alias")
+    }
+
+    fn usage(&self) -> &str {
+        "Removes an alias"
+    }
+
+    fn run(&self, args: CommandArgs) -> Result<OutputStream, ShellError> {
+        unalias(args)
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![Example {
+            description: "Remove the 'v' alias",
+            example: "unalias v",
+            result: None,
+        }]
+    }
+}
+
+pub fn unalias(_: CommandArgs) -> Result<OutputStream, ShellError> {
+    Ok(OutputStream::empty())
+}

crates/nu-command/src/commands/core_commands/version.rs

@@ -23,7 +23,7 @@ impl WholeStreamCommand for Version {
         "Display Nu version."
     }
 
-    fn run_with_actions(&self, args: CommandArgs) -> Result<ActionStream, ShellError> {
+    fn run(&self, args: CommandArgs) -> Result<OutputStream, ShellError> {
         version(args)
     }
 
@@ -36,14 +36,14 @@ impl WholeStreamCommand for Version {
     }
 }
 
-pub fn version(args: CommandArgs) -> Result<ActionStream, ShellError> {
+pub fn version(args: CommandArgs) -> Result<OutputStream, ShellError> {
     let tag = args.call_info.args.span;
 
     let mut indexmap = IndexMap::with_capacity(4);
 
     indexmap.insert(
         "version".to_string(),
-        UntaggedValue::string(clap::crate_version!()).into_value(&tag),
+        UntaggedValue::string(super::nu_signature::version()).into_value(&tag),
     );
 
     let branch: Option<&str> = Some(shadow::BRANCH).filter(|x| !x.is_empty());
@@ -140,33 +140,57 @@ pub fn version(args: CommandArgs) -> Result<ActionStream, ShellError> {
         features_enabled().join(", ").to_string_value_create_tag(),
     );
 
+    // Manually create a list of all possible plugin names
+    let all_plugins = vec![
+        "fetch",
+        "inc",
+        "match",
+        "post",
+        "ps",
+        "sys",
+        "textview",
+        "binaryview",
+        "chart bar",
+        "chart line",
+        "from bson",
+        "from sqlite",
+        "query json",
+        "s3",
+        "selector",
+        "start",
+        "to bson",
+        "to sqlite",
+        "tree",
+        "xpath",
+    ];
+
+    // Get a list of command names and check for plugins
+    let installed_plugins = args
+        .scope()
+        .get_command_names()
+        .into_iter()
+        .filter(|cmd| all_plugins.contains(&cmd.as_str()))
+        .collect::<Vec<_>>();
+
+    indexmap.insert(
+        "installed_plugins".to_string(),
+        installed_plugins.join(", ").to_string_value_create_tag(),
+    );
+
     let value = UntaggedValue::Row(Dictionary::from(indexmap)).into_value(&tag);
-    Ok(ActionStream::one(value))
+    Ok(OutputStream::one(value))
 }
 
 fn features_enabled() -> Vec<String> {
     let mut names = vec!["default".to_string()];
 
+    // NOTE: There should be another way to know
+    // features on.
     #[cfg(feature = "ctrlc")]
     {
         names.push("ctrlc".to_string());
     }
 
-    #[cfg(feature = "dirs")]
-    {
-        names.push("dirs".to_string());
-    }
-
-    #[cfg(feature = "directories")]
-    {
-        names.push("directories".to_string());
-    }
-
-    #[cfg(feature = "ptree")]
-    {
-        names.push("ptree".to_string());
-    }
-
     // #[cfg(feature = "rich-benchmark")]
     // {
     //     names.push("rich-benchmark".to_string());
@@ -207,6 +231,16 @@ fn features_enabled() -> Vec<String> {
         names.push("trash".to_string());
     }
 
+    #[cfg(feature = "dataframe")]
+    {
+        names.push("dataframe".to_string());
+    }
+
+    #[cfg(feature = "table-pager")]
+    {
+        names.push("table-pager".to_string());
+    }
+
     // #[cfg(feature = "binaryview")]
     // {
     //     names.push("binaryview".to_string());

crates/nu-command/src/commands/dataframe/aggregate.rs

@@ -1,14 +1,12 @@
-use crate::prelude::*;
+use crate::{commands::dataframe::utils::parse_polars_error, prelude::*};
 use nu_engine::WholeStreamCommand;
 use nu_errors::ShellError;
 use nu_protocol::{
-    dataframe::{NuDataFrame, PolarsData},
+    dataframe::{Column, FrameStruct, NuDataFrame},
-    Signature, SyntaxShape, UntaggedValue, Value,
+    Signature, SyntaxShape, UntaggedValue,
 };
 use nu_source::Tagged;
-use polars::frame::groupby::GroupBy;
+use polars::{frame::groupby::GroupBy, prelude::PolarsError};
-
-use super::utils::convert_columns;
 
 enum Operation {
     Mean,
@@ -66,7 +64,7 @@ impl Operation {
                 "Operation not fount",
                 "Operation does not exist",
                 &name.tag,
-                "Perhaps you want: mean, sum, min, max, first, last, nunique, quantile, median, count",
+                "Perhaps you want: mean, sum, min, max, first, last, nunique, quantile, median, var, std, or count",
                 &name.tag,
             )),
         }
@@ -77,106 +75,126 @@ pub struct DataFrame;
 
 impl WholeStreamCommand for DataFrame {
     fn name(&self) -> &str {
-        "pls aggregate"
+        "dataframe aggregate"
     }
 
     fn usage(&self) -> &str {
-        "Performs an aggregation operation on a groupby object"
+        "[DataFrame, GroupBy, Series] Performs an aggregation operation on a dataframe, groupby or series object"
     }
 
     fn signature(&self) -> Signature {
-        Signature::build("pls aggregate")
+        Signature::build("dataframe aggregate")
             .required("operation", SyntaxShape::String, "aggregate operation")
-            .optional(
-                "selection",
-                SyntaxShape::Table,
-                "columns to perform aggregation",
-            )
             .named(
                 "quantile",
                 SyntaxShape::Number,
                 "quantile value for quantile operation",
                 Some('q'),
             )
+            .switch(
+                "explicit",
+                "returns explicit names for groupby aggregations",
+                Some('e'),
+            )
     }
 
     fn run(&self, args: CommandArgs) -> Result<OutputStream, ShellError> {
-        aggregate(args)
+        command(args)
     }
 
     fn examples(&self) -> Vec<Example> {
-        vec![Example {
+        vec![
-            description: "Aggregate sum by grouping by column a and summing on col b",
+            Example {
-            example:
+                description: "Aggregate sum by grouping by column a and summing on col b",
-                "echo [[a b]; [one 1] [one 2]] | pls convert | pls groupby [a] | pls aggregate sum",
+                example:
-            result: None,
+                    "[[a b]; [one 1] [one 2]] | dataframe to-df | dataframe group-by a | dataframe aggregate sum",
-        }]
+                result: Some(vec![NuDataFrame::try_from_columns(
+                    vec![
+                        Column::new("a".to_string(), vec![UntaggedValue::string("one").into()]),
+                        Column::new("b".to_string(), vec![UntaggedValue::int(3).into()]),
+                    ],
+                    &Span::default(),
+                )
+                .expect("simple df for test should not fail")
+                .into_value(Tag::default())]),
+            },
+            Example {
+                description: "Aggregate sum in dataframe columns",
+                example: "[[a b]; [4 1] [5 2]] | dataframe to-df | dataframe aggregate sum",
+                result: Some(vec![NuDataFrame::try_from_columns(
+                    vec![
+                        Column::new("a".to_string(), vec![UntaggedValue::int(9).into()]),
+                        Column::new("b".to_string(), vec![UntaggedValue::int(3).into()]),
+                    ],
+                    &Span::default(),
+                )
+                .expect("simple df for test should not fail")
+                .into_value(Tag::default())]),
+            },
+            Example {
+                description: "Aggregate sum in series",
+                example: "[4 1 5 6] | dataframe to-df | dataframe aggregate sum",
+                result: Some(vec![NuDataFrame::try_from_columns(
+                    vec![
+                        Column::new("0".to_string(), vec![UntaggedValue::int(16).into()]),
+                    ],
+                    &Span::default(),
+                )
+                .expect("simple df for test should not fail")
+                .into_value(Tag::default())]),
+            },
+        ]
     }
 }
 
-fn aggregate(args: CommandArgs) -> Result<OutputStream, ShellError> {
+fn command(mut args: CommandArgs) -> Result<OutputStream, ShellError> {
     let tag = args.call_info.name_tag.clone();
-    let mut args = args.evaluate_once()?;
 
     let quantile: Option<Tagged<f64>> = args.get_flag("quantile")?;
     let operation: Tagged<String> = args.req(0)?;
     let op = Operation::from_tagged(&operation, quantile)?;
 
-    // Extracting the selection columns of the columns to perform the aggregation
+    let value = args.input.next().ok_or_else(|| {
-    let agg_cols: Option<Vec<Value>> = args.opt(1)?;
+        ShellError::labeled_error("Empty stream", "No value found in the stream", &tag)
-    let (selection, agg_span) = match agg_cols {
+    })?;
-        Some(cols) => {
-            let (agg_string, agg_span) = convert_columns(&cols, &tag)?;
-            (Some(agg_string), agg_span)
-        }
-        None => (None, Span::unknown()),
-    };
 
-    // The operation is only done in one dataframe. Only one input is
+    match value.value {
-    // expected from the InputStream
+        UntaggedValue::FrameStruct(FrameStruct::GroupBy(nu_groupby)) => {
-    match args.input.next() {
+            let groupby = nu_groupby.to_groupby()?;
-        None => Err(ShellError::labeled_error(
+
-            "No input received",
+            let res = perform_groupby_aggregation(
-            "missing dataframe input from stream",
+                groupby,
-            &tag,
+                op,
+                &operation.tag,
+                &tag.span,
+                args.has_flag("explicit"),
+            )?;
+
+            Ok(OutputStream::one(NuDataFrame::dataframe_to_value(res, tag)))
+        }
+        UntaggedValue::DataFrame(df) => {
+            let df = df.as_ref();
+
+            let res = perform_dataframe_aggregation(df, op, &operation.tag)?;
+
+            Ok(OutputStream::one(NuDataFrame::dataframe_to_value(res, tag)))
+        }
+        _ => Err(ShellError::labeled_error(
+            "No groupby, dataframe or series in stream",
+            "no groupby, dataframe or series found in input stream",
+            &value.tag.span,
         )),
-        Some(value) => {
-            if let UntaggedValue::DataFrame(PolarsData::GroupBy(nu_groupby)) = value.value {
-                let groupby = nu_groupby.to_groupby()?;
-
-                let groupby = match &selection {
-                    Some(cols) => groupby.select(cols),
-                    None => groupby,
-                };
-
-                let res = perform_aggregation(groupby, op, &operation.tag, &agg_span)?;
-
-                let final_df = Value {
-                    tag,
-                    value: UntaggedValue::DataFrame(PolarsData::EagerDataFrame(NuDataFrame::new(
-                        res,
-                    ))),
-                };
-
-                Ok(OutputStream::one(final_df))
-            } else {
-                Err(ShellError::labeled_error(
-                    "No groupby in stream",
-                    "no groupby found in input stream",
-                    &tag,
-                ))
-            }
-        }
     }
 }
 
-fn perform_aggregation(
+fn perform_groupby_aggregation(
     groupby: GroupBy,
     operation: Operation,
     operation_tag: &Tag,
     agg_span: &Span,
+    explicit: bool,
 ) -> Result<polars::prelude::DataFrame, ShellError> {
-    match operation {
+    let mut res = match operation {
         Operation::Mean => groupby.mean(),
         Operation::Sum => groupby.sum(),
         Operation::Min => groupby.min(),
@@ -191,12 +209,85 @@ fn perform_aggregation(
         Operation::Count => groupby.count(),
     }
     .map_err(|e| {
-        let span = if e.to_string().contains("Not found") {
+        let span = match &e {
-            agg_span
+            PolarsError::NotFound(_) => agg_span,
-        } else {
+            _ => &operation_tag.span,
-            &operation_tag.span
         };
 
-        ShellError::labeled_error("Aggregation error", format!("{}", e), span)
+        parse_polars_error::<&str>(&e, span, None)
-    })
+    })?;
+
+    if !explicit {
+        let col_names = res
+            .get_column_names()
+            .iter()
+            .map(|name| name.to_string())
+            .collect::<Vec<String>>();
+
+        for col in col_names {
+            let from = match operation {
+                Operation::Mean => "_mean",
+                Operation::Sum => "_sum",
+                Operation::Min => "_min",
+                Operation::Max => "_max",
+                Operation::First => "_first",
+                Operation::Last => "_last",
+                Operation::Nunique => "_n_unique",
+                Operation::Quantile(_) => "_quantile",
+                Operation::Median => "_median",
+                Operation::Var => "_agg_var",
+                Operation::Std => "_agg_std",
+                Operation::Count => "_count",
+            };
+
+            let new_col = match col.find(from) {
+                Some(index) => &col[..index],
+                None => &col[..],
+            };
+
+            res.rename(col.as_str(), new_col)
+                .expect("Column is always there. Looping with known names");
+        }
+    }
+
+    Ok(res)
+}
+
+fn perform_dataframe_aggregation(
+    dataframe: &polars::prelude::DataFrame,
+    operation: Operation,
+    operation_tag: &Tag,
+) -> Result<polars::prelude::DataFrame, ShellError> {
+    match operation {
+        Operation::Mean => Ok(dataframe.mean()),
+        Operation::Sum => Ok(dataframe.sum()),
+        Operation::Min => Ok(dataframe.min()),
+        Operation::Max => Ok(dataframe.max()),
+        Operation::Quantile(quantile) => dataframe
+            .quantile(quantile)
+            .map_err(|e| parse_polars_error::<&str>(&e, &operation_tag.span, None)),
+        Operation::Median => Ok(dataframe.median()),
+        Operation::Var => Ok(dataframe.var()),
+        Operation::Std => Ok(dataframe.std()),
+        _ => Err(ShellError::labeled_error_with_secondary(
+            "Not valid operation",
+            "operation not valid for dataframe",
+            &operation_tag.span,
+            "Perhaps you want: mean, sum, min, max, quantile, median, var, or std",
+            &operation_tag.span,
+        )),
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::DataFrame;
+    use super::ShellError;
+
+    #[test]
+    fn examples_work_as_expected() -> Result<(), ShellError> {
+        use crate::examples::test_dataframe as test_examples;
+
+        test_examples(DataFrame {})
+    }
 }

crates/nu-command/src/commands/dataframe/append.rs

@@ -0,0 +1,138 @@
+use crate::prelude::*;
+use nu_engine::WholeStreamCommand;
+use nu_errors::ShellError;
+use nu_protocol::{
+    dataframe::{Axis, Column, NuDataFrame},
+    Signature, SyntaxShape, UntaggedValue, Value,
+};
+use nu_source::Tagged;
+
+pub struct DataFrame;
+
+impl WholeStreamCommand for DataFrame {
+    fn name(&self) -> &str {
+        "dataframe append"
+    }
+
+    fn usage(&self) -> &str {
+        "[DataFrame] Appends a new dataframe"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("dataframe append")
+            .required_named(
+                "other",
+                SyntaxShape::Any,
+                "dataframe to be appended",
+                Some('o'),
+            )
+            .required_named(
+                "axis",
+                SyntaxShape::String,
+                "row or col axis orientation",
+                Some('a'),
+            )
+    }
+
+    fn run(&self, args: CommandArgs) -> Result<OutputStream, ShellError> {
+        command(args)
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![
+            Example {
+                description: "Appends a dataframe as new columns",
+                example: r#"let a = ([[a b]; [1 2] [3 4]] | dataframe to-df);
+    $a | dataframe append -o $a -a row"#,
+                result: Some(vec![NuDataFrame::try_from_columns(
+                    vec![
+                        Column::new(
+                            "a".to_string(),
+                            vec![UntaggedValue::int(1).into(), UntaggedValue::int(3).into()],
+                        ),
+                        Column::new(
+                            "b".to_string(),
+                            vec![UntaggedValue::int(2).into(), UntaggedValue::int(4).into()],
+                        ),
+                        Column::new(
+                            "a_x".to_string(),
+                            vec![UntaggedValue::int(1).into(), UntaggedValue::int(3).into()],
+                        ),
+                        Column::new(
+                            "b_x".to_string(),
+                            vec![UntaggedValue::int(2).into(), UntaggedValue::int(4).into()],
+                        ),
+                    ],
+                    &Span::default(),
+                )
+                .expect("simple df for test should not fail")
+                .into_value(Tag::default())]),
+            },
+            Example {
+                description: "Appends a dataframe merging at the end of columns",
+                example: r#"let a = ([[a b]; [1 2] [3 4]] | dataframe to-df);
+    $a | dataframe append -o $a -a col"#,
+                result: Some(vec![NuDataFrame::try_from_columns(
+                    vec![
+                        Column::new(
+                            "a".to_string(),
+                            vec![
+                                UntaggedValue::int(1).into(),
+                                UntaggedValue::int(3).into(),
+                                UntaggedValue::int(1).into(),
+                                UntaggedValue::int(3).into(),
+                            ],
+                        ),
+                        Column::new(
+                            "b".to_string(),
+                            vec![
+                                UntaggedValue::int(2).into(),
+                                UntaggedValue::int(4).into(),
+                                UntaggedValue::int(2).into(),
+                                UntaggedValue::int(4).into(),
+                            ],
+                        ),
+                    ],
+                    &Span::default(),
+                )
+                .expect("simple df for test should not fail")
+                .into_value(Tag::default())]),
+            },
+        ]
+    }
+}
+
+fn command(mut args: CommandArgs) -> Result<OutputStream, ShellError> {
+    let tag = args.call_info.name_tag.clone();
+    let other: Value = args.req_named("other")?;
+    let axis: Tagged<String> = args.req_named("axis")?;
+
+    let axis = Axis::try_from_str(axis.item.as_str(), &axis.tag.span)?;
+
+    let df_other = match other.value {
+        UntaggedValue::DataFrame(df) => Ok(df),
+        _ => Err(ShellError::labeled_error(
+            "Incorrect type",
+            "can only append a dataframe to a dataframe",
+            other.tag.span,
+        )),
+    }?;
+
+    let (df, _) = NuDataFrame::try_from_stream(&mut args.input, &tag.span)?;
+
+    let df_new = df.append_df(&df_other, axis, &tag.span)?;
+    Ok(OutputStream::one(df_new.into_value(tag)))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::DataFrame;
+    use super::ShellError;
+
+    #[test]
+    fn examples_work_as_expected() -> Result<(), ShellError> {
+        use crate::examples::test_dataframe as test_examples;
+
+        test_examples(DataFrame {})
+    }
+}

crates/nu-command/src/commands/dataframe/column.rs

@@ -0,0 +1,74 @@
+use crate::prelude::*;
+use nu_engine::WholeStreamCommand;
+use nu_errors::ShellError;
+use nu_protocol::{
+    dataframe::{Column, NuDataFrame},
+    Signature, SyntaxShape, UntaggedValue,
+};
+
+use nu_source::Tagged;
+
+use super::utils::parse_polars_error;
+pub struct DataFrame;
+
+impl WholeStreamCommand for DataFrame {
+    fn name(&self) -> &str {
+        "dataframe column"
+    }
+
+    fn usage(&self) -> &str {
+        "[DataFrame] Returns the selected column as Series"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("dataframe column").required("column", SyntaxShape::String, "column name")
+    }
+
+    fn run(&self, args: CommandArgs) -> Result<OutputStream, ShellError> {
+        command(args)
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![Example {
+            description: "Returns the selected column as series",
+            example: "[[a b]; [1 2] [3 4]] | dataframe to-df | dataframe column a",
+            result: Some(vec![NuDataFrame::try_from_columns(
+                vec![Column::new(
+                    "a".to_string(),
+                    vec![UntaggedValue::int(1).into(), UntaggedValue::int(3).into()],
+                )],
+                &Span::default(),
+            )
+            .expect("simple df for test should not fail")
+            .into_value(Tag::default())]),
+        }]
+    }
+}
+
+fn command(mut args: CommandArgs) -> Result<OutputStream, ShellError> {
+    let tag = args.call_info.name_tag.clone();
+    let column: Tagged<String> = args.req(0)?;
+
+    let (df, df_tag) = NuDataFrame::try_from_stream(&mut args.input, &tag.span)?;
+
+    let res = df
+        .as_ref()
+        .column(column.item.as_ref())
+        .map_err(|e| parse_polars_error::<&str>(&e, &column.tag.span, None))?;
+
+    let df = NuDataFrame::try_from_series(vec![res.clone()], &tag.span)?;
+    Ok(OutputStream::one(df.into_value(df_tag)))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::DataFrame;
+    use super::ShellError;
+
+    #[test]
+    fn examples_work_as_expected() -> Result<(), ShellError> {
+        use crate::examples::test_dataframe as test_examples;
+
+        test_examples(DataFrame {})
+    }
+}

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

@@ -7,7 +7,7 @@ pub struct Command;
 
 impl WholeStreamCommand for Command {
     fn name(&self) -> &str {
-        "pls"
+        "dataframe"
     }
 
     fn usage(&self) -> &str {
@@ -15,7 +15,7 @@ impl WholeStreamCommand for Command {
     }
 
     fn signature(&self) -> Signature {
-        Signature::build("pls")
+        Signature::build("dataframe")
     }
 
     fn run(&self, args: CommandArgs) -> Result<OutputStream, ShellError> {

crates/nu-command/src/commands/dataframe/convert.rs

@@ -1,43 +0,0 @@
-use crate::prelude::*;
-use nu_engine::WholeStreamCommand;
-use nu_errors::ShellError;
-use nu_protocol::{
-    dataframe::{NuDataFrame, PolarsData},
-    Signature, UntaggedValue,
-};
-
-pub struct DataFrame;
-
-impl WholeStreamCommand for DataFrame {
-    fn name(&self) -> &str {
-        "pls convert"
-    }
-
-    fn usage(&self) -> &str {
-        "Converts a pipelined Table or List into a polars dataframe"
-    }
-
-    fn signature(&self) -> Signature {
-        Signature::build("pls convert")
-    }
-
-    fn run(&self, args: CommandArgs) -> Result<OutputStream, ShellError> {
-        let tag = args.call_info.name_tag.clone();
-        let args = args.evaluate_once()?;
-
-        let df = NuDataFrame::try_from_iter(args.input, &tag)?;
-        let init = InputStream::one(
-            UntaggedValue::DataFrame(PolarsData::EagerDataFrame(df)).into_value(&tag),
-        );
-
-        Ok(init.to_output_stream())
-    }
-
-    fn examples(&self) -> Vec<Example> {
-        vec![Example {
-            description: "Takes an input stream and converts it to a polars dataframe",
-            example: "echo [[a b];[1 2] [3 4]] | pls convert",
-            result: None,
-        }]
-    }
-}

crates/nu-command/src/commands/dataframe/describe.rs

@@ -0,0 +1,232 @@
+use crate::prelude::*;
+use nu_engine::WholeStreamCommand;
+use nu_errors::ShellError;
+use nu_protocol::{
+    dataframe::{Column, NuDataFrame},
+    Signature, UntaggedValue,
+};
+use polars::{
+    chunked_array::ChunkedArray,
+    prelude::{
+        AnyValue, DataFrame as PolarsDF, DataType, Float64Type, IntoSeries, NewChunkedArray,
+        Series, Utf8Type,
+    },
+};
+
+use super::utils::parse_polars_error;
+
+pub struct DataFrame;
+
+impl WholeStreamCommand for DataFrame {
+    fn name(&self) -> &str {
+        "dataframe describe"
+    }
+
+    fn usage(&self) -> &str {
+        "[DataFrame] Describes dataframes numeric columns"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("dataframe describe")
+    }
+
+    fn run(&self, args: CommandArgs) -> Result<OutputStream, ShellError> {
+        command(args)
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![Example {
+            description: "Describes dataframe",
+            example: "[[a b]; [1 1] [1 1]] | dataframe to-df | dataframe describe",
+            result: Some(vec![NuDataFrame::try_from_columns(
+                vec![
+                    Column::new(
+                        "descriptor".to_string(),
+                        vec![
+                            UntaggedValue::string("count").into(),
+                            UntaggedValue::string("sum").into(),
+                            UntaggedValue::string("mean").into(),
+                            UntaggedValue::string("median").into(),
+                            UntaggedValue::string("std").into(),
+                            UntaggedValue::string("min").into(),
+                            UntaggedValue::string("25%").into(),
+                            UntaggedValue::string("50%").into(),
+                            UntaggedValue::string("75%").into(),
+                            UntaggedValue::string("max").into(),
+                        ],
+                    ),
+                    Column::new(
+                        "a (i64)".to_string(),
+                        vec![
+                            UntaggedValue::decimal_from_float(2.0, Span::default()).into(),
+                            UntaggedValue::decimal_from_float(2.0, Span::default()).into(),
+                            UntaggedValue::decimal_from_float(1.0, Span::default()).into(),
+                            UntaggedValue::decimal_from_float(1.0, Span::default()).into(),
+                            UntaggedValue::decimal_from_float(0.0, Span::default()).into(),
+                            UntaggedValue::decimal_from_float(1.0, Span::default()).into(),
+                            UntaggedValue::decimal_from_float(1.0, Span::default()).into(),
+                            UntaggedValue::decimal_from_float(1.0, Span::default()).into(),
+                            UntaggedValue::decimal_from_float(1.0, Span::default()).into(),
+                            UntaggedValue::decimal_from_float(1.0, Span::default()).into(),
+                        ],
+                    ),
+                    Column::new(
+                        "b (i64)".to_string(),
+                        vec![
+                            UntaggedValue::decimal_from_float(2.0, Span::default()).into(),
+                            UntaggedValue::decimal_from_float(2.0, Span::default()).into(),
+                            UntaggedValue::decimal_from_float(1.0, Span::default()).into(),
+                            UntaggedValue::decimal_from_float(1.0, Span::default()).into(),
+                            UntaggedValue::decimal_from_float(0.0, Span::default()).into(),
+                            UntaggedValue::decimal_from_float(1.0, Span::default()).into(),
+                            UntaggedValue::decimal_from_float(1.0, Span::default()).into(),
+                            UntaggedValue::decimal_from_float(1.0, Span::default()).into(),
+                            UntaggedValue::decimal_from_float(1.0, Span::default()).into(),
+                            UntaggedValue::decimal_from_float(1.0, Span::default()).into(),
+                        ],
+                    ),
+                ],
+                &Span::default(),
+            )
+            .expect("simple df for test should not fail")
+            .into_value(Tag::default())]),
+        }]
+    }
+}
+
+fn command(mut args: CommandArgs) -> Result<OutputStream, ShellError> {
+    let tag = args.call_info.name_tag.clone();
+
+    let (df, _) = NuDataFrame::try_from_stream(&mut args.input, &tag.span)?;
+
+    let names = ChunkedArray::<Utf8Type>::new_from_opt_slice(
+        "descriptor",
+        &[
+            Some("count"),
+            Some("sum"),
+            Some("mean"),
+            Some("median"),
+            Some("std"),
+            Some("min"),
+            Some("25%"),
+            Some("50%"),
+            Some("75%"),
+            Some("max"),
+        ],
+    )
+    .into_series();
+
+    let head = std::iter::once(names);
+
+    let tail = df.as_ref().get_columns().iter().map(|col| {
+        let count = col.len() as f64;
+
+        let sum = match col.sum_as_series().cast_with_dtype(&DataType::Float64) {
+            Ok(ca) => match ca.get(0) {
+                AnyValue::Float64(v) => Some(v),
+                _ => None,
+            },
+            Err(_) => None,
+        };
+
+        let mean = match col.mean_as_series().get(0) {
+            AnyValue::Float64(v) => Some(v),
+            _ => None,
+        };
+
+        let median = match col.median_as_series().get(0) {
+            AnyValue::Float64(v) => Some(v),
+            _ => None,
+        };
+
+        let std = match col.std_as_series().get(0) {
+            AnyValue::Float64(v) => Some(v),
+            _ => None,
+        };
+
+        let min = match col.min_as_series().cast_with_dtype(&DataType::Float64) {
+            Ok(ca) => match ca.get(0) {
+                AnyValue::Float64(v) => Some(v),
+                _ => None,
+            },
+            Err(_) => None,
+        };
+
+        let q_25 = match col.quantile_as_series(0.25) {
+            Ok(ca) => match ca.cast_with_dtype(&DataType::Float64) {
+                Ok(ca) => match ca.get(0) {
+                    AnyValue::Float64(v) => Some(v),
+                    _ => None,
+                },
+                Err(_) => None,
+            },
+            Err(_) => None,
+        };
+
+        let q_50 = match col.quantile_as_series(0.50) {
+            Ok(ca) => match ca.cast_with_dtype(&DataType::Float64) {
+                Ok(ca) => match ca.get(0) {
+                    AnyValue::Float64(v) => Some(v),
+                    _ => None,
+                },
+                Err(_) => None,
+            },
+            Err(_) => None,
+        };
+
+        let q_75 = match col.quantile_as_series(0.75) {
+            Ok(ca) => match ca.cast_with_dtype(&DataType::Float64) {
+                Ok(ca) => match ca.get(0) {
+                    AnyValue::Float64(v) => Some(v),
+                    _ => None,
+                },
+                Err(_) => None,
+            },
+            Err(_) => None,
+        };
+
+        let max = match col.max_as_series().cast_with_dtype(&DataType::Float64) {
+            Ok(ca) => match ca.get(0) {
+                AnyValue::Float64(v) => Some(v),
+                _ => None,
+            },
+            Err(_) => None,
+        };
+
+        let name = format!("{} ({})", col.name(), col.dtype());
+        ChunkedArray::<Float64Type>::new_from_opt_slice(
+            name.as_str(),
+            &[
+                Some(count),
+                sum,
+                mean,
+                median,
+                std,
+                min,
+                q_25,
+                q_50,
+                q_75,
+                max,
+            ],
+        )
+        .into_series()
+    });
+
+    let res = head.chain(tail).collect::<Vec<Series>>();
+    let df = PolarsDF::new(res).map_err(|e| parse_polars_error::<&str>(&e, &tag.span, None))?;
+    let df = NuDataFrame::dataframe_to_value(df, tag);
+    Ok(OutputStream::one(df))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::DataFrame;
+    use super::ShellError;
+
+    #[test]
+    fn examples_work_as_expected() -> Result<(), ShellError> {
+        use crate::examples::test_dataframe as test_examples;
+
+        test_examples(DataFrame {})
+    }
+}

crates/nu-command/src/commands/dataframe/drop.rs

@@ -2,96 +2,88 @@ use crate::prelude::*;
 use nu_engine::WholeStreamCommand;
 use nu_errors::ShellError;
 use nu_protocol::{
-    dataframe::{NuDataFrame, PolarsData},
+    dataframe::{Column, NuDataFrame},
     Signature, SyntaxShape, UntaggedValue, Value,
 };
 
-use super::utils::convert_columns;
+use super::utils::{convert_columns, parse_polars_error};
 
 pub struct DataFrame;
 
 impl WholeStreamCommand for DataFrame {
     fn name(&self) -> &str {
-        "pls drop"
+        "dataframe drop"
     }
 
     fn usage(&self) -> &str {
-        "Creates a new dataframe by dropping the selected columns"
+        "[DataFrame] Creates a new dataframe by dropping the selected columns"
     }
 
     fn signature(&self) -> Signature {
-        Signature::build("pls drop").required(
+        Signature::build("dataframe drop").rest(SyntaxShape::Any, "column names to be dropped")
-            "columns",
-            SyntaxShape::Table,
-            "column names to be dropped",
-        )
     }
 
     fn run(&self, args: CommandArgs) -> Result<OutputStream, ShellError> {
-        drop(args)
+        command(args)
     }
 
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "drop column a",
-            example: "echo [[a b]; [1 2] [3 4]] | pls convert | pls drop [a]",
+            example: "[[a b]; [1 2] [3 4]] | dataframe to-df | dataframe drop a",
-            result: None,
+            result: Some(vec![NuDataFrame::try_from_columns(
+                vec![Column::new(
+                    "b".to_string(),
+                    vec![UntaggedValue::int(2).into(), UntaggedValue::int(4).into()],
+                )],
+                &Span::default(),
+            )
+            .expect("simple df for test should not fail")
+            .into_value(Tag::default())]),
         }]
     }
 }
 
-fn drop(args: CommandArgs) -> Result<OutputStream, ShellError> {
+fn command(mut args: CommandArgs) -> Result<OutputStream, ShellError> {
     let tag = args.call_info.name_tag.clone();
-    let mut args = args.evaluate_once()?;
-
-    let columns: Vec<Value> = args.req(0)?;
 
+    let columns: Vec<Value> = args.rest(0)?;
     let (col_string, col_span) = convert_columns(&columns, &tag)?;
 
-    match args.input.next() {
+    let (df, _) = NuDataFrame::try_from_stream(&mut args.input, &tag.span)?;
+
+    let new_df = match col_string.get(0) {
+        Some(col) => df
+            .as_ref()
+            .drop(col)
+            .map_err(|e| parse_polars_error::<&str>(&e, &col_span, None)),
         None => Err(ShellError::labeled_error(
-            "No input received",
+            "Empty names list",
-            "missing dataframe input from stream",
+            "No column names where found",
-            &tag,
+            &col_span,
         )),
-        Some(value) => {
+    }?;
-            if let UntaggedValue::DataFrame(PolarsData::EagerDataFrame(NuDataFrame {
-                dataframe: Some(ref df),
-                ..
-            })) = value.value
-            {
-                let new_df = match col_string.iter().next() {
-                    Some(col) => df.drop(col).map_err(|e| {
-                        ShellError::labeled_error("Join error", format!("{}", e), &col_span)
-                    }),
-                    None => Err(ShellError::labeled_error(
-                        "Empty names list",
-                        "No column names where found",
-                        &col_span,
-                    )),
-                }?;
 
-                let res = col_string.iter().skip(1).try_fold(new_df, |new_df, col| {
+    // If there are more columns in the drop selection list, these
-                    new_df.drop(col).map_err(|e| {
+    // are added from the resulting dataframe
-                        ShellError::labeled_error("Drop error", format!("{}", e), &col_span)
+    let res = col_string.iter().skip(1).try_fold(new_df, |new_df, col| {
-                    })
+        new_df
-                })?;
+            .drop(col)
+            .map_err(|e| parse_polars_error::<&str>(&e, &col_span, None))
+    })?;
 
-                let value = Value {
+    Ok(OutputStream::one(NuDataFrame::dataframe_to_value(res, tag)))
-                    value: UntaggedValue::DataFrame(PolarsData::EagerDataFrame(NuDataFrame::new(
+}
-                        res,
-                    ))),
-                    tag: tag.clone(),
-                };
 
-                Ok(OutputStream::one(value))
+#[cfg(test)]
-            } else {
+mod tests {
-                Err(ShellError::labeled_error(
+    use super::DataFrame;
-                    "No dataframe in stream",
+    use super::ShellError;
-                    "no dataframe found in input stream",
+
-                    &tag,
+    #[test]
-                ))
+    fn examples_work_as_expected() -> Result<(), ShellError> {
-            }
+        use crate::examples::test_dataframe as test_examples;
-        }
+
+        test_examples(DataFrame {})
     }
 }

crates/nu-command/src/commands/dataframe/drop_duplicates.rs

@@ -0,0 +1,95 @@
+use crate::prelude::*;
+use nu_engine::WholeStreamCommand;
+use nu_errors::ShellError;
+use nu_protocol::{
+    dataframe::{Column, NuDataFrame},
+    Signature, SyntaxShape, UntaggedValue, Value,
+};
+
+use super::utils::{convert_columns, parse_polars_error};
+
+pub struct DataFrame;
+
+impl WholeStreamCommand for DataFrame {
+    fn name(&self) -> &str {
+        "dataframe drop-duplicates"
+    }
+
+    fn usage(&self) -> &str {
+        "[DataFrame] Drops duplicate values in dataframe"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("dataframe drop-duplicates")
+            .optional(
+                "subset",
+                SyntaxShape::Table,
+                "subset of columns to drop duplicates",
+            )
+            .switch("maintain", "maintain order", Some('m'))
+    }
+
+    fn run(&self, args: CommandArgs) -> Result<OutputStream, ShellError> {
+        command(args)
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![Example {
+            description: "drop duplicates",
+            example: "[[a b]; [1 2] [3 4] [1 2]] | dataframe to-df | dataframe drop-duplicates",
+            result: Some(vec![NuDataFrame::try_from_columns(
+                vec![
+                    Column::new(
+                        "a".to_string(),
+                        vec![UntaggedValue::int(1).into(), UntaggedValue::int(3).into()],
+                    ),
+                    Column::new(
+                        "b".to_string(),
+                        vec![UntaggedValue::int(2).into(), UntaggedValue::int(4).into()],
+                    ),
+                ],
+                &Span::default(),
+            )
+            .expect("simple df for test should not fail")
+            .into_value(Tag::default())]),
+        }]
+    }
+}
+
+fn command(mut args: CommandArgs) -> Result<OutputStream, ShellError> {
+    let tag = args.call_info.name_tag.clone();
+
+    // Extracting the selection columns of the columns to perform the aggregation
+    let columns: Option<Vec<Value>> = args.opt(0)?;
+    let (subset, col_span) = match columns {
+        Some(cols) => {
+            let (agg_string, col_span) = convert_columns(&cols, &tag)?;
+            (Some(agg_string), col_span)
+        }
+        None => (None, Span::unknown()),
+    };
+
+    let (df, _) = NuDataFrame::try_from_stream(&mut args.input, &tag.span)?;
+
+    let subset_slice = subset.as_ref().map(|cols| &cols[..]);
+
+    let res = df
+        .as_ref()
+        .drop_duplicates(args.has_flag("maintain"), subset_slice)
+        .map_err(|e| parse_polars_error::<&str>(&e, &col_span, None))?;
+
+    Ok(OutputStream::one(NuDataFrame::dataframe_to_value(res, tag)))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::DataFrame;
+    use super::ShellError;
+
+    #[test]
+    fn examples_work_as_expected() -> Result<(), ShellError> {
+        use crate::examples::test_dataframe as test_examples;
+
+        test_examples(DataFrame {})
+    }
+}

crates/nu-command/src/commands/dataframe/drop_nulls.rs

@@ -0,0 +1,132 @@
+use crate::prelude::*;
+use nu_engine::WholeStreamCommand;
+use nu_errors::ShellError;
+use nu_protocol::{
+    dataframe::{Column, NuDataFrame},
+    Signature, SyntaxShape, UntaggedValue, Value,
+};
+
+use super::utils::{convert_columns, parse_polars_error};
+
+pub struct DataFrame;
+
+impl WholeStreamCommand for DataFrame {
+    fn name(&self) -> &str {
+        "dataframe drop-nulls"
+    }
+
+    fn usage(&self) -> &str {
+        "[DataFrame, Series] Drops null values in dataframe"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("dataframe drop-nulls").optional(
+            "subset",
+            SyntaxShape::Table,
+            "subset of columns to drop duplicates",
+        )
+    }
+
+    fn run(&self, args: CommandArgs) -> Result<OutputStream, ShellError> {
+        command(args)
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![
+            Example {
+                description: "drop null values in dataframe",
+                example: r#"let df = ([[a b]; [1 2] [3 0] [1 2]] | dataframe to-df);
+    let res = ($df.b / $df.b);
+    let df = ($df | dataframe with-column $res --name res);
+    $df | dataframe drop-nulls"#,
+                result: Some(vec![NuDataFrame::try_from_columns(
+                    vec![
+                        Column::new(
+                            "a".to_string(),
+                            vec![UntaggedValue::int(1).into(), UntaggedValue::int(1).into()],
+                        ),
+                        Column::new(
+                            "b".to_string(),
+                            vec![UntaggedValue::int(2).into(), UntaggedValue::int(2).into()],
+                        ),
+                        Column::new(
+                            "res".to_string(),
+                            vec![UntaggedValue::int(1).into(), UntaggedValue::int(1).into()],
+                        ),
+                    ],
+                    &Span::default(),
+                )
+                .expect("simple df for test should not fail")
+                .into_value(Tag::default())]),
+            },
+            Example {
+                description: "drop null values in dataframe",
+                example: r#"let s = ([1 2 0 0 3 4] | dataframe to-df);
+    ($s / $s) | dataframe drop-nulls"#,
+                result: Some(vec![NuDataFrame::try_from_columns(
+                    vec![Column::new(
+                        "div_0_0".to_string(),
+                        vec![
+                            UntaggedValue::int(1).into(),
+                            UntaggedValue::int(1).into(),
+                            UntaggedValue::int(1).into(),
+                            UntaggedValue::int(1).into(),
+                        ],
+                    )],
+                    &Span::default(),
+                )
+                .expect("simple df for test should not fail")
+                .into_value(Tag::default())]),
+            },
+        ]
+    }
+}
+
+fn command(mut args: CommandArgs) -> Result<OutputStream, ShellError> {
+    let tag = args.call_info.name_tag.clone();
+
+    let value = args.input.next().ok_or_else(|| {
+        ShellError::labeled_error("Empty stream", "No value found in stream", &tag.span)
+    })?;
+
+    match value.value {
+        UntaggedValue::DataFrame(df) => {
+            // Extracting the selection columns of the columns to perform the aggregation
+            let columns: Option<Vec<Value>> = args.opt(0)?;
+            let (subset, col_span) = match columns {
+                Some(cols) => {
+                    let (agg_string, col_span) = convert_columns(&cols, &tag)?;
+                    (Some(agg_string), col_span)
+                }
+                None => (None, Span::unknown()),
+            };
+
+            let subset_slice = subset.as_ref().map(|cols| &cols[..]);
+
+            let res = df
+                .as_ref()
+                .drop_nulls(subset_slice)
+                .map_err(|e| parse_polars_error::<&str>(&e, &col_span, None))?;
+
+            Ok(OutputStream::one(NuDataFrame::dataframe_to_value(res, tag)))
+        }
+        _ => Err(ShellError::labeled_error(
+            "Incorrect type",
+            "drop nulls cannot be done with this value",
+            &value.tag.span,
+        )),
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::DataFrame;
+    use super::ShellError;
+
+    #[test]
+    fn examples_work_as_expected() -> Result<(), ShellError> {
+        use crate::examples::test_dataframe as test_examples;
+
+        test_examples(DataFrame {})
+    }
+}

crates/nu-command/src/commands/dataframe/dtypes.rs

@@ -2,80 +2,105 @@ use crate::prelude::*;
 use nu_engine::WholeStreamCommand;
 use nu_errors::ShellError;
 use nu_protocol::{
-    dataframe::{NuDataFrame, PolarsData},
+    dataframe::{Column, NuDataFrame},
-    Signature, TaggedDictBuilder, UntaggedValue,
+    Signature, UntaggedValue, Value,
 };
 
 pub struct DataFrame;
 
 impl WholeStreamCommand for DataFrame {
     fn name(&self) -> &str {
-        "pls dtypes"
+        "dataframe dtypes"
     }
 
     fn usage(&self) -> &str {
-        "Show dataframe data types"
+        "[DataFrame] Show dataframe data types"
     }
 
     fn signature(&self) -> Signature {
-        Signature::build("pls dtypes")
+        Signature::build("dataframe dtypes")
     }
 
     fn run(&self, args: CommandArgs) -> Result<OutputStream, ShellError> {
-        dtypes(args)
+        command(args)
     }
 
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "drop column a",
-            example: "echo [[a b]; [1 2] [3 4]] | pls convert | pls dtypes",
+            example: "[[a b]; [1 2] [3 4]] | dataframe to-df | dataframe dtypes",
-            result: None,
+            result: Some(vec![NuDataFrame::try_from_columns(
+                vec![
+                    Column::new(
+                        "column".to_string(),
+                        vec![
+                            UntaggedValue::string("a").into(),
+                            UntaggedValue::string("b").into(),
+                        ],
+                    ),
+                    Column::new(
+                        "dtype".to_string(),
+                        vec![
+                            UntaggedValue::string("i64").into(),
+                            UntaggedValue::string("i64").into(),
+                        ],
+                    ),
+                ],
+                &Span::default(),
+            )
+            .expect("simple df for test should not fail")
+            .into_value(Tag::default())]),
         }]
     }
 }
 
-fn dtypes(args: CommandArgs) -> Result<OutputStream, ShellError> {
+#[allow(clippy::needless_collect)]
+fn command(mut args: CommandArgs) -> Result<OutputStream, ShellError> {
     let tag = args.call_info.name_tag.clone();
-    let mut args = args.evaluate_once()?;
 
-    match args.input.next() {
+    let (df, _) = NuDataFrame::try_from_stream(&mut args.input, &tag.span)?;
-        None => Err(ShellError::labeled_error(
-            "No input received",
-            "missing dataframe input from stream",
-            &tag,
-        )),
-        Some(value) => {
-            if let UntaggedValue::DataFrame(PolarsData::EagerDataFrame(NuDataFrame {
-                dataframe: Some(df),
-                ..
-            })) = value.value
-            {
-                let col_names = df
-                    .get_column_names()
-                    .iter()
-                    .map(|v| v.to_string())
-                    .collect::<Vec<String>>();
 
-                let values =
+    let mut dtypes: Vec<Value> = Vec::new();
-                    df.dtypes()
+    let names: Vec<Value> = df
-                        .into_iter()
+        .as_ref()
-                        .zip(col_names.into_iter())
+        .get_column_names()
-                        .map(move |(dtype, name)| {
+        .iter()
-                            let mut data = TaggedDictBuilder::new(tag.clone());
+        .map(|v| {
-                            data.insert_value("column", name.as_ref());
+            let dtype = df
-                            data.insert_value("dtype", format!("{}", dtype));
+                .as_ref()
+                .column(v)
+                .expect("using name from list of names from dataframe")
+                .dtype();
 
-                            data.into_value()
+            let dtype_str = format!("{}", dtype);
-                        });
+            dtypes.push(Value {
+                value: dtype_str.into(),
+                tag: Tag::default(),
+            });
 
-                Ok(OutputStream::from_stream(values))
+            Value {
-            } else {
+                value: v.to_string().into(),
-                Err(ShellError::labeled_error(
+                tag: Tag::default(),
-                    "No dataframe in stream",
-                    "no dataframe found in input stream",
-                    &tag,
-                ))
             }
-        }
+        })
+        .collect();
+
+    let names_col = Column::new("column".to_string(), names);
+    let dtypes_col = Column::new("dtype".to_string(), dtypes);
+
+    let df = NuDataFrame::try_from_columns(vec![names_col, dtypes_col], &tag.span)?;
+    Ok(OutputStream::one(df.into_value(tag)))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::DataFrame;
+    use super::ShellError;
+
+    #[test]
+    fn examples_work_as_expected() -> Result<(), ShellError> {
+        use crate::examples::test_dataframe as test_examples;
+
+        test_examples(DataFrame {})
     }
 }

crates/nu-command/src/commands/dataframe/dummies.rs

@@ -0,0 +1,142 @@
+use crate::prelude::*;
+use nu_engine::WholeStreamCommand;
+use nu_errors::ShellError;
+use nu_protocol::{
+    dataframe::{Column, NuDataFrame},
+    Signature, UntaggedValue,
+};
+
+use super::utils::parse_polars_error;
+
+pub struct DataFrame;
+
+impl WholeStreamCommand for DataFrame {
+    fn name(&self) -> &str {
+        "dataframe to-dummies"
+    }
+
+    fn usage(&self) -> &str {
+        "[DataFrame] Creates a new dataframe with dummy variables"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("dataframe to-dummies")
+    }
+
+    fn run(&self, args: CommandArgs) -> Result<OutputStream, ShellError> {
+        command(args)
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![
+            Example {
+                description: "Create new dataframe with dummy variables from a dataframe",
+                example: "[[a b]; [1 2] [3 4]] | dataframe to-df | dataframe to-dummies",
+                result: Some(vec![NuDataFrame::try_from_columns(
+                    vec![
+                        Column::new(
+                            "a_1".to_string(),
+                            vec![UntaggedValue::int(1).into(), UntaggedValue::int(0).into()],
+                        ),
+                        Column::new(
+                            "a_3".to_string(),
+                            vec![UntaggedValue::int(0).into(), UntaggedValue::int(1).into()],
+                        ),
+                        Column::new(
+                            "b_2".to_string(),
+                            vec![UntaggedValue::int(1).into(), UntaggedValue::int(0).into()],
+                        ),
+                        Column::new(
+                            "b_4".to_string(),
+                            vec![UntaggedValue::int(0).into(), UntaggedValue::int(1).into()],
+                        ),
+                    ],
+                    &Span::default(),
+                )
+                .expect("simple df for test should not fail")
+                .into_value(Tag::default())]),
+            },
+            Example {
+                description: "Create new dataframe with dummy variables from a series",
+                example: "[1 2 2 3 3] | dataframe to-df | dataframe to-dummies",
+                result: Some(vec![NuDataFrame::try_from_columns(
+                    vec![
+                        Column::new(
+                            "0_1".to_string(),
+                            vec![
+                                UntaggedValue::int(1).into(),
+                                UntaggedValue::int(0).into(),
+                                UntaggedValue::int(0).into(),
+                                UntaggedValue::int(0).into(),
+                                UntaggedValue::int(0).into(),
+                            ],
+                        ),
+                        Column::new(
+                            "0_2".to_string(),
+                            vec![
+                                UntaggedValue::int(0).into(),
+                                UntaggedValue::int(1).into(),
+                                UntaggedValue::int(1).into(),
+                                UntaggedValue::int(0).into(),
+                                UntaggedValue::int(0).into(),
+                            ],
+                        ),
+                        Column::new(
+                            "0_3".to_string(),
+                            vec![
+                                UntaggedValue::int(0).into(),
+                                UntaggedValue::int(0).into(),
+                                UntaggedValue::int(0).into(),
+                                UntaggedValue::int(1).into(),
+                                UntaggedValue::int(1).into(),
+                            ],
+                        ),
+                    ],
+                    &Span::default(),
+                )
+                .expect("simple df for test should not fail")
+                .into_value(Tag::default())]),
+            },
+        ]
+    }
+}
+
+fn command(mut args: CommandArgs) -> Result<OutputStream, ShellError> {
+    let tag = args.call_info.name_tag.clone();
+
+    let value = args.input.next().ok_or_else(|| {
+        ShellError::labeled_error("Empty stream", "No value found in stream", &tag.span)
+    })?;
+
+    match value.value {
+        UntaggedValue::DataFrame(df) => {
+            let res = df.as_ref().to_dummies().map_err(|e| {
+                parse_polars_error(
+                    &e,
+                    &tag.span,
+                    Some("The only allowed column types for dummies are String or Int"),
+                )
+            })?;
+
+            Ok(OutputStream::one(NuDataFrame::dataframe_to_value(res, tag)))
+        }
+        _ => Err(ShellError::labeled_error(
+            "Incorrect type",
+            "dummies cannot be done with this value",
+            &value.tag.span,
+        )),
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::DataFrame;
+    use super::ShellError;
+
+    #[test]
+    fn examples_work_as_expected() -> Result<(), ShellError> {
+        use crate::examples::test_dataframe as test_examples;
+
+        test_examples(DataFrame {})
+    }
+}

crates/nu-command/src/commands/dataframe/filter.rs

@@ -0,0 +1,102 @@
+use crate::prelude::*;
+use nu_engine::WholeStreamCommand;
+use nu_errors::ShellError;
+use nu_protocol::{
+    dataframe::{Column, NuDataFrame},
+    Signature, SyntaxShape, UntaggedValue, Value,
+};
+
+use super::utils::parse_polars_error;
+pub struct DataFrame;
+
+impl WholeStreamCommand for DataFrame {
+    fn name(&self) -> &str {
+        "dataframe filter-with"
+    }
+
+    fn usage(&self) -> &str {
+        "[DataFrame] Filters dataframe using a mask as reference"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("dataframe filter-with").required(
+            "mask",
+            SyntaxShape::Any,
+            "boolean mask used to filter data",
+        )
+    }
+
+    fn run(&self, args: CommandArgs) -> Result<OutputStream, ShellError> {
+        command(args)
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![
+            Example {
+                description: "Filter dataframe using a bool mask",
+                example: r#"let mask = ([$true $false] | dataframe to-df);
+    [[a b]; [1 2] [3 4]] | dataframe to-df | dataframe filter-with $mask"#,
+                result: Some(vec![NuDataFrame::try_from_columns(
+                    vec![
+                        Column::new("a".to_string(), vec![UntaggedValue::int(1).into()]),
+                        Column::new("b".to_string(), vec![UntaggedValue::int(2).into()]),
+                    ],
+                    &Span::default(),
+                )
+                .expect("simple df for test should not fail")
+                .into_value(Tag::default())]),
+            },
+            Example {
+                description: "Filter dataframe by creating a mask from operation",
+                example: r#"let mask = (([5 6] | dataframe to-df) > 5);
+    [[a b]; [1 2] [3 4]] | dataframe to-df | dataframe filter-with $mask"#,
+                result: None,
+            },
+        ]
+    }
+}
+
+fn command(mut args: CommandArgs) -> Result<OutputStream, ShellError> {
+    let tag = args.call_info.name_tag.clone();
+    let value: Value = args.req(0)?;
+
+    let series_span = value.tag.span;
+    let df = match value.value {
+        UntaggedValue::DataFrame(df) => Ok(df),
+        _ => Err(ShellError::labeled_error(
+            "Incorrect type",
+            "can only add a series to a dataframe",
+            value.tag.span,
+        )),
+    }?;
+    let series = df.as_series(&series_span)?;
+    let casted = series.bool().map_err(|e| {
+        parse_polars_error(
+            &e,
+            &series_span,
+            Some("Perhaps you want to use a series with booleans as mask"),
+        )
+    })?;
+
+    let (df, df_tag) = NuDataFrame::try_from_stream(&mut args.input, &tag.span)?;
+
+    let res = df
+        .as_ref()
+        .filter(casted)
+        .map_err(|e| parse_polars_error::<&str>(&e, &df_tag.span, None))?;
+
+    Ok(OutputStream::one(NuDataFrame::dataframe_to_value(res, tag)))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::DataFrame;
+    use super::ShellError;
+
+    #[test]
+    fn examples_work_as_expected() -> Result<(), ShellError> {
+        use crate::examples::test_dataframe as test_examples;
+
+        test_examples(DataFrame {})
+    }
+}

crates/nu-command/src/commands/dataframe/first.rs

@@ -0,0 +1,77 @@
+use crate::prelude::*;
+use nu_engine::WholeStreamCommand;
+use nu_errors::ShellError;
+use nu_protocol::{
+    dataframe::{Column, NuDataFrame},
+    Signature, SyntaxShape, UntaggedValue,
+};
+
+use nu_source::Tagged;
+
+pub struct DataFrame;
+
+impl WholeStreamCommand for DataFrame {
+    fn name(&self) -> &str {
+        "dataframe first"
+    }
+
+    fn usage(&self) -> &str {
+        "[DataFrame] Creates new dataframe with first rows"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("dataframe select").optional(
+            "rows",
+            SyntaxShape::Number,
+            "Number of rows for head",
+        )
+    }
+
+    fn run(&self, args: CommandArgs) -> Result<OutputStream, ShellError> {
+        command(args)
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![Example {
+            description: "Create new dataframe with head rows",
+            example: "[[a b]; [1 2] [3 4]] | dataframe to-df | dataframe first 1",
+            result: Some(vec![NuDataFrame::try_from_columns(
+                vec![
+                    Column::new("a".to_string(), vec![UntaggedValue::int(1).into()]),
+                    Column::new("b".to_string(), vec![UntaggedValue::int(2).into()]),
+                ],
+                &Span::default(),
+            )
+            .expect("simple df for test should not fail")
+            .into_value(Tag::default())]),
+        }]
+    }
+}
+
+fn command(mut args: CommandArgs) -> Result<OutputStream, ShellError> {
+    let tag = args.call_info.name_tag.clone();
+    let rows: Option<Tagged<usize>> = args.opt(0)?;
+
+    let rows = match rows {
+        Some(val) => val.item,
+        None => 5,
+    };
+
+    let (df, _) = NuDataFrame::try_from_stream(&mut args.input, &tag.span)?;
+    let res = df.as_ref().head(Some(rows));
+
+    Ok(OutputStream::one(NuDataFrame::dataframe_to_value(res, tag)))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::DataFrame;
+    use super::ShellError;
+
+    #[test]
+    fn examples_work_as_expected() -> Result<(), ShellError> {
+        use crate::examples::test_dataframe as test_examples;
+
+        test_examples(DataFrame {})
+    }
+}

crates/nu-command/src/commands/dataframe/get.rs

@@ -0,0 +1,73 @@
+use crate::prelude::*;
+use nu_engine::WholeStreamCommand;
+use nu_errors::ShellError;
+use nu_protocol::{
+    dataframe::{Column, NuDataFrame},
+    Signature, SyntaxShape, UntaggedValue, Value,
+};
+
+use super::utils::{convert_columns, parse_polars_error};
+pub struct DataFrame;
+
+impl WholeStreamCommand for DataFrame {
+    fn name(&self) -> &str {
+        "dataframe get"
+    }
+
+    fn usage(&self) -> &str {
+        "[DataFrame] Creates dataframe with the selected columns"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("dataframe get").rest(SyntaxShape::Any, "column names to sort dataframe")
+    }
+
+    fn run(&self, args: CommandArgs) -> Result<OutputStream, ShellError> {
+        command(args)
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![Example {
+            description: "Creates dataframe with selected columns",
+            example: "[[a b]; [1 2] [3 4]] | dataframe to-df | dataframe get a",
+            result: Some(vec![NuDataFrame::try_from_columns(
+                vec![Column::new(
+                    "a".to_string(),
+                    vec![UntaggedValue::int(1).into(), UntaggedValue::int(3).into()],
+                )],
+                &Span::default(),
+            )
+            .expect("simple df for test should not fail")
+            .into_value(Tag::default())]),
+        }]
+    }
+}
+
+fn command(mut args: CommandArgs) -> Result<OutputStream, ShellError> {
+    let tag = args.call_info.name_tag.clone();
+    let columns: Vec<Value> = args.rest(0)?;
+
+    let (col_string, col_span) = convert_columns(&columns, &tag)?;
+
+    let (df, _) = NuDataFrame::try_from_stream(&mut args.input, &tag.span)?;
+
+    let res = df
+        .as_ref()
+        .select(&col_string)
+        .map_err(|e| parse_polars_error::<&str>(&e, &col_span, None))?;
+
+    Ok(OutputStream::one(NuDataFrame::dataframe_to_value(res, tag)))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::DataFrame;
+    use super::ShellError;
+
+    #[test]
+    fn examples_work_as_expected() -> Result<(), ShellError> {
+        use crate::examples::test_dataframe as test_examples;
+
+        test_examples(DataFrame {})
+    }
+}

crates/nu-command/src/commands/dataframe/groupby.rs

@@ -1,8 +1,8 @@
-use crate::prelude::*;
+use crate::{commands::dataframe::utils::parse_polars_error, prelude::*};
 use nu_engine::WholeStreamCommand;
 use nu_errors::ShellError;
 use nu_protocol::{
-    dataframe::{NuDataFrame, NuGroupBy, PolarsData},
+    dataframe::{FrameStruct, NuDataFrame, NuGroupBy},
     Signature, SyntaxShape, UntaggedValue, Value,
 };
 
@@ -12,83 +12,57 @@ pub struct DataFrame;
 
 impl WholeStreamCommand for DataFrame {
     fn name(&self) -> &str {
-        "pls groupby"
+        "dataframe group-by"
     }
 
     fn usage(&self) -> &str {
-        "Creates a groupby object that can be used for other aggregations"
+        "[DataFrame] Creates a groupby object that can be used for other aggregations"
     }
 
     fn signature(&self) -> Signature {
-        Signature::build("pls groupby").required(
+        Signature::build("dataframe group-by").rest(SyntaxShape::Any, "groupby columns")
-            "by columns",
-            SyntaxShape::Table,
-            "groupby columns",
-        )
     }
 
     fn run(&self, args: CommandArgs) -> Result<OutputStream, ShellError> {
-        groupby(args)
+        command(args)
     }
 
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Grouping by column a",
-            example: "echo [[a b]; [one 1] [one 2]] | pls convert | pls groupby [a]",
+            example: "[[a b]; [one 1] [one 2]] | dataframe to-df | dataframe group-by a",
             result: None,
         }]
     }
 }
 
-fn groupby(args: CommandArgs) -> Result<OutputStream, ShellError> {
+fn command(mut args: CommandArgs) -> Result<OutputStream, ShellError> {
     let tag = args.call_info.name_tag.clone();
-    let mut args = args.evaluate_once()?;
 
     // Extracting the names of the columns to perform the groupby
-    let by_columns: Vec<Value> = args.req(0)?;
+    let by_columns: Vec<Value> = args.rest(0)?;
     let (columns_string, col_span) = convert_columns(&by_columns, &tag)?;
 
-    // The operation is only done in one dataframe. Only one input is
+    let (df, _) = NuDataFrame::try_from_stream(&mut args.input, &tag.span)?;
-    // expected from the InputStream
-    match args.input.next() {
-        None => Err(ShellError::labeled_error(
-            "No input received",
-            "missing dataframe input from stream",
-            &tag,
-        )),
-        Some(value) => {
-            if let UntaggedValue::DataFrame(PolarsData::EagerDataFrame(nu_df)) = value.value {
-                let df = match nu_df.dataframe {
-                    Some(df) => df,
-                    None => unreachable!("No dataframe in nu_dataframe"),
-                };
 
-                // This is the expensive part of the groupby; to create the
+    // This is the expensive part of the groupby; to create the
-                // groups that will be used for grouping the data in the
+    // groups that will be used for grouping the data in the
-                // dataframe. Once it has been done these values can be stored
+    // dataframe. Once it has been done these values can be stored
-                // in the NuGroupBy
+    // in a NuGroupBy
-                let groupby = df.groupby(&columns_string).map_err(|e| {
+    let groupby = df
-                    ShellError::labeled_error("Groupby error", format!("{}", e), col_span)
+        .as_ref()
-                })?;
+        .groupby(&columns_string)
+        .map_err(|e| parse_polars_error::<&str>(&e, &col_span, None))?;
 
-                let groups = groupby.get_groups().to_vec();
+    let groups = groupby.get_groups().to_vec();
-                let groupby = Value {
+    let groupby = Value {
-                    tag: value.tag,
+        tag,
-                    value: UntaggedValue::DataFrame(PolarsData::GroupBy(NuGroupBy::new(
+        value: UntaggedValue::FrameStruct(FrameStruct::GroupBy(NuGroupBy::new(
-                        NuDataFrame::new_with_name(df, nu_df.name),
+            NuDataFrame::new(df.as_ref().clone()),
-                        columns_string,
+            columns_string,
-                        groups,
+            groups,
-                    ))),
+        ))),
-                };
+    };
 
-                Ok(OutputStream::one(groupby))
+    Ok(OutputStream::one(groupby))
-            } else {
-                Err(ShellError::labeled_error(
-                    "No dataframe in stream",
-                    "no dataframe found in input stream",
-                    &tag,
-                ))
-            }
-        }
-    }
 }

crates/nu-command/src/commands/dataframe/join.rs

@@ -2,11 +2,11 @@ use crate::prelude::*;
 use nu_engine::WholeStreamCommand;
 use nu_errors::ShellError;
 use nu_protocol::{
-    dataframe::{NuDataFrame, PolarsData},
+    dataframe::{Column, NuDataFrame},
     Signature, SyntaxShape, UntaggedValue, Value,
 };
 
-use super::utils::convert_columns;
+use super::utils::{convert_columns, parse_polars_error};
 
 use polars::prelude::JoinType;
 
@@ -16,25 +16,27 @@ pub struct DataFrame;
 
 impl WholeStreamCommand for DataFrame {
     fn name(&self) -> &str {
-        "pls join"
+        "dataframe join"
     }
 
     fn usage(&self) -> &str {
-        "Joins a dataframe using columns as reference"
+        "[DataFrame] Joins a dataframe using columns as reference"
     }
 
     fn signature(&self) -> Signature {
-        Signature::build("pls join")
+        Signature::build("dataframe join")
             .required("dataframe", SyntaxShape::Any, "right dataframe to join")
-            .required(
+            .required_named(
-                "l_columns",
+                "left",
                 SyntaxShape::Table,
                 "left column names to perform join",
+                Some('l'),
             )
-            .required(
+            .required_named(
-                "r_columns",
+                "right",
                 SyntaxShape::Table,
                 "right column names to perform join",
+                Some('r'),
             )
             .named(
                 "type",
@@ -45,33 +47,63 @@ impl WholeStreamCommand for DataFrame {
     }
 
     fn run(&self, args: CommandArgs) -> Result<OutputStream, ShellError> {
-        join(args)
+        command(args)
     }
 
     fn examples(&self) -> Vec<Example> {
-        vec![
+        vec![Example {
-            Example {
+            description: "inner join dataframe",
-                description: "inner join dataframe",
+            example: r#"let right = ([[a b c]; [1 2 5] [3 4 5] [5 6 6]] | dataframe to-df);
-                example: "echo [[a b]; [1 2] [3 4]] | pls convert | pls join $right [a] [a]",
+    $right | dataframe join $right -l [a b] -r [a b]"#,
-                result: None,
+            result: Some(vec![NuDataFrame::try_from_columns(
-            },
+                vec![
-            Example {
+                    Column::new(
-                description: "right join dataframe",
+                        "a".to_string(),
-                example:
+                        vec![
-                    "echo [[a b]; [1 2] [3 4] [5 6]] | pls convert | pls join $right [b] [b] -t right",
+                            UntaggedValue::int(1).into(),
-                result: None,
+                            UntaggedValue::int(3).into(),
-            },
+                            UntaggedValue::int(5).into(),
-        ]
+                        ],
+                    ),
+                    Column::new(
+                        "b".to_string(),
+                        vec![
+                            UntaggedValue::int(2).into(),
+                            UntaggedValue::int(4).into(),
+                            UntaggedValue::int(6).into(),
+                        ],
+                    ),
+                    Column::new(
+                        "c".to_string(),
+                        vec![
+                            UntaggedValue::int(5).into(),
+                            UntaggedValue::int(5).into(),
+                            UntaggedValue::int(6).into(),
+                        ],
+                    ),
+                    Column::new(
+                        "c_right".to_string(),
+                        vec![
+                            UntaggedValue::int(5).into(),
+                            UntaggedValue::int(5).into(),
+                            UntaggedValue::int(6).into(),
+                        ],
+                    ),
+                ],
+                &Span::default(),
+            )
+            .expect("simple df for test should not fail")
+            .into_value(Tag::default())]),
+        }]
     }
 }
 
-fn join(args: CommandArgs) -> Result<OutputStream, ShellError> {
+fn command(mut args: CommandArgs) -> Result<OutputStream, ShellError> {
     let tag = args.call_info.name_tag.clone();
-    let mut args = args.evaluate_once()?;
 
     let r_df: Value = args.req(0)?;
-    let l_col: Vec<Value> = args.req(1)?;
+    let l_col: Vec<Value> = args.req_named("left")?;
-    let r_col: Vec<Value> = args.req(2)?;
+    let r_col: Vec<Value> = args.req_named("right")?;
     let join_type_op: Option<Tagged<String>> = args.get_flag("type")?;
 
     let join_type = match join_type_op {
@@ -95,69 +127,37 @@ fn join(args: CommandArgs) -> Result<OutputStream, ShellError> {
     let (l_col_string, l_col_span) = convert_columns(&l_col, &tag)?;
     let (r_col_string, r_col_span) = convert_columns(&r_col, &tag)?;
 
-    match args.input.next() {
+    let (df, _) = NuDataFrame::try_from_stream(&mut args.input, &tag.span)?;
-        None => Err(ShellError::labeled_error(
-            "No input received",
-            "missing dataframe input from stream",
-            &tag,
-        )),
-        Some(value) => {
-            if let UntaggedValue::DataFrame(PolarsData::EagerDataFrame(NuDataFrame {
-                dataframe: Some(ref df),
-                ..
-            })) = value.value
-            {
-                let res = match r_df.value {
-                    UntaggedValue::DataFrame(PolarsData::EagerDataFrame(NuDataFrame {
-                        dataframe: Some(r_df),
-                        ..
-                    })) => {
-                        // Checking the column types before performing the join
-                        check_column_datatypes(
-                            df,
-                            &l_col_string,
-                            &l_col_span,
-                            &r_col_string,
-                            &r_col_span,
-                        )?;
 
-                        df.join(&r_df, &l_col_string, &r_col_string, join_type)
+    let res = match r_df.value {
-                            .map_err(|e| {
+        UntaggedValue::DataFrame(r_df) => {
-                                ShellError::labeled_error(
+            // Checking the column types before performing the join
-                                    "Join error",
+            check_column_datatypes(
-                                    format!("{}", e),
+                df.as_ref(),
-                                    &l_col_span,
+                r_df.as_ref(),
-                                )
+                &l_col_string,
-                            })
+                &l_col_span,
-                    }
+                &r_col_string,
-                    _ => Err(ShellError::labeled_error(
+                &r_col_span,
-                        "Not a dataframe",
+            )?;
-                        "not a dataframe type value",
-                        &r_df.tag,
-                    )),
-                }?;
 
-                let value = Value {
+            df.as_ref()
-                    value: UntaggedValue::DataFrame(PolarsData::EagerDataFrame(NuDataFrame::new(
+                .join(r_df.as_ref(), &l_col_string, &r_col_string, join_type)
-                        res,
+                .map_err(|e| parse_polars_error::<&str>(&e, &l_col_span, None))
-                    ))),
-                    tag: tag.clone(),
-                };
-
-                Ok(OutputStream::one(value))
-            } else {
-                Err(ShellError::labeled_error(
-                    "No dataframe in stream",
-                    "no dataframe found in input stream",
-                    &tag,
-                ))
-            }
         }
-    }
+        _ => Err(ShellError::labeled_error(
+            "Not a dataframe",
+            "not a dataframe type value",
+            &r_df.tag,
+        )),
+    }?;
+
+    Ok(OutputStream::one(NuDataFrame::dataframe_to_value(res, tag)))
 }
 
 fn check_column_datatypes<T: AsRef<str>>(
-    df: &polars::prelude::DataFrame,
+    df_l: &polars::prelude::DataFrame,
+    df_r: &polars::prelude::DataFrame,
     l_cols: &[T],
     l_col_span: &Span,
     r_cols: &[T],
@@ -178,13 +178,13 @@ fn check_column_datatypes<T: AsRef<str>>(
     }
 
     for (l, r) in l_cols.iter().zip(r_cols.iter()) {
-        let l_series = df
+        let l_series = df_l
             .column(l.as_ref())
-            .map_err(|e| ShellError::labeled_error("Join error", format!("{}", e), l_col_span))?;
+            .map_err(|e| parse_polars_error::<&str>(&e, l_col_span, None))?;
 
-        let r_series = df
+        let r_series = df_r
             .column(r.as_ref())
-            .map_err(|e| ShellError::labeled_error("Join error", format!("{}", e), r_col_span))?;
+            .map_err(|e| parse_polars_error::<&str>(&e, r_col_span, None))?;
 
         if l_series.dtype() != r_series.dtype() {
             return Err(ShellError::labeled_error_with_secondary(
@@ -203,3 +203,16 @@ fn check_column_datatypes<T: AsRef<str>>(
 
     Ok(())
 }
+
+#[cfg(test)]
+mod tests {
+    use super::DataFrame;
+    use super::ShellError;
+
+    #[test]
+    fn examples_work_as_expected() -> Result<(), ShellError> {
+        use crate::examples::test_dataframe as test_examples;
+
+        test_examples(DataFrame {})
+    }
+}

crates/nu-command/src/commands/dataframe/last.rs

@@ -0,0 +1,77 @@
+use crate::prelude::*;
+use nu_engine::WholeStreamCommand;
+use nu_errors::ShellError;
+use nu_protocol::{
+    dataframe::{Column, NuDataFrame},
+    Signature, SyntaxShape, UntaggedValue,
+};
+
+use nu_source::Tagged;
+pub struct DataFrame;
+
+impl WholeStreamCommand for DataFrame {
+    fn name(&self) -> &str {
+        "dataframe last"
+    }
+
+    fn usage(&self) -> &str {
+        "[DataFrame] Creates new dataframe with tail rows"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("dataframe last").optional(
+            "n_rows",
+            SyntaxShape::Number,
+            "Number of rows for tail",
+        )
+    }
+
+    fn run(&self, args: CommandArgs) -> Result<OutputStream, ShellError> {
+        command(args)
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![Example {
+            description: "Create new dataframe with last rows",
+            example: "[[a b]; [1 2] [3 4]] | dataframe to-df | dataframe last 1",
+            result: Some(vec![NuDataFrame::try_from_columns(
+                vec![
+                    Column::new("a".to_string(), vec![UntaggedValue::int(3).into()]),
+                    Column::new("b".to_string(), vec![UntaggedValue::int(4).into()]),
+                ],
+                &Span::default(),
+            )
+            .expect("simple df for test should not fail")
+            .into_value(Tag::default())]),
+        }]
+    }
+}
+
+fn command(mut args: CommandArgs) -> Result<OutputStream, ShellError> {
+    let tag = args.call_info.name_tag.clone();
+    let rows: Option<Tagged<usize>> = args.opt(0)?;
+
+    let rows = match rows {
+        Some(val) => val.item,
+        None => 5,
+    };
+
+    let (df, _) = NuDataFrame::try_from_stream(&mut args.input, &tag.span)?;
+
+    let res = df.as_ref().tail(Some(rows));
+
+    Ok(OutputStream::one(NuDataFrame::dataframe_to_value(res, tag)))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::DataFrame;
+    use super::ShellError;
+
+    #[test]
+    fn examples_work_as_expected() -> Result<(), ShellError> {
+        use crate::examples::test_dataframe as test_examples;
+
+        test_examples(DataFrame {})
+    }
+}

crates/nu-command/src/commands/dataframe/list.rs

@@ -2,15 +2,15 @@ use crate::prelude::*;
 use nu_engine::WholeStreamCommand;
 use nu_errors::ShellError;
 use nu_protocol::{
-    dataframe::{NuDataFrame, PolarsData},
+    dataframe::{Column, NuDataFrame},
-    Signature, TaggedDictBuilder, UntaggedValue,
+    Signature, UntaggedValue, Value,
 };
 
 pub struct DataFrame;
 
 impl WholeStreamCommand for DataFrame {
     fn name(&self) -> &str {
-        "pls list"
+        "dataframe list"
     }
 
     fn usage(&self) -> &str {
@@ -18,47 +18,98 @@ impl WholeStreamCommand for DataFrame {
     }
 
     fn signature(&self) -> Signature {
-        Signature::build("pls list")
+        Signature::build("dataframe list")
     }
 
     fn run(&self, args: CommandArgs) -> Result<OutputStream, ShellError> {
-        let args = args.evaluate_once()?;
+        let data = args
-
-        let values = args
             .context
             .scope
             .get_vars()
             .into_iter()
             .filter_map(|(name, value)| {
-                if let UntaggedValue::DataFrame(PolarsData::EagerDataFrame(NuDataFrame {
+                if let UntaggedValue::DataFrame(df) = &value.value {
-                    dataframe: Some(df),
+                    let rows = Value {
-                    name: file_name,
+                        value: (df.as_ref().height() as i64).into(),
-                })) = &value.value
+                        tag: Tag::default(),
-                {
+                    };
-                    let mut data = TaggedDictBuilder::new(value.tag.clone());
 
-                    let rows = df.height();
+                    let cols = Value {
-                    let cols = df.width();
+                        value: (df.as_ref().width() as i64).into(),
+                        tag: Tag::default(),
+                    };
 
-                    data.insert_value("name", name.as_ref());
+                    let location = match value.tag.anchor {
-                    data.insert_value("file", file_name.as_ref());
+                        Some(AnchorLocation::File(name)) => name,
-                    data.insert_value("rows", format!("{}", rows));
+                        Some(AnchorLocation::Url(name)) => name,
-                    data.insert_value("columns", format!("{}", cols));
+                        Some(AnchorLocation::Source(text)) => text.slice(0..text.end).text,
+                        None => "stream".to_string(),
+                    };
 
-                    Some(data.into_value())
+                    let location = Value {
+                        value: location.into(),
+                        tag: Tag::default(),
+                    };
+
+                    let name = Value {
+                        value: name.into(),
+                        tag: Tag::default(),
+                    };
+
+                    Some((name, rows, cols, location))
                 } else {
                     None
                 }
             });
 
-        Ok(OutputStream::from_stream(values))
+        let mut name = Column::new_empty("name".to_string());
+        let mut rows = Column::new_empty("rows".to_string());
+        let mut cols = Column::new_empty("columns".to_string());
+        let mut location = Column::new_empty("location".to_string());
+
+        for tuple in data {
+            name.push(tuple.0);
+            rows.push(tuple.1);
+            cols.push(tuple.2);
+            location.push(tuple.3);
+        }
+
+        let tag = args.call_info.name_tag;
+        let df = NuDataFrame::try_from_columns(vec![name, rows, cols, location], &tag.span)?;
+        Ok(OutputStream::one(df.into_value(tag)))
     }
 
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Lists loaded dataframes in current scope",
-            example: "pls list",
+            example: "let a = ([[a b];[1 2] [3 4]] | dataframe to-df); dataframe list",
-            result: None,
+            result: Some(vec![NuDataFrame::try_from_columns(
+                vec![
+                    Column::new("name".to_string(), vec![UntaggedValue::string("$a").into()]),
+                    Column::new("rows".to_string(), vec![UntaggedValue::int(2).into()]),
+                    Column::new("columns".to_string(), vec![UntaggedValue::int(2).into()]),
+                    Column::new(
+                        "location".to_string(),
+                        vec![UntaggedValue::string("stream").into()],
+                    ),
+                ],
+                &Span::default(),
+            )
+            .expect("simple df for test should not fail")
+            .into_value(Tag::default())]),
         }]
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::DataFrame;
+    use super::ShellError;
+
+    #[test]
+    fn examples_work_as_expected() -> Result<(), ShellError> {
+        use crate::examples::test_dataframe as test_examples;
+
+        test_examples(DataFrame {})
+    }
+}

crates/nu-command/src/commands/dataframe/melt.rs

@@ -0,0 +1,178 @@
+use crate::{commands::dataframe::utils::parse_polars_error, prelude::*};
+use nu_engine::WholeStreamCommand;
+use nu_errors::ShellError;
+use nu_protocol::{
+    dataframe::{Column, NuDataFrame},
+    Signature, SyntaxShape, UntaggedValue, Value,
+};
+
+use super::utils::convert_columns;
+
+pub struct DataFrame;
+
+impl WholeStreamCommand for DataFrame {
+    fn name(&self) -> &str {
+        "dataframe melt"
+    }
+
+    fn usage(&self) -> &str {
+        "[DataFrame] Unpivot a DataFrame from wide to long format"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("dataframe melt")
+            .required_named(
+                "columns",
+                SyntaxShape::Table,
+                "column names for melting",
+                Some('c'),
+            )
+            .required_named(
+                "values",
+                SyntaxShape::Table,
+                "column names used as value columns",
+                Some('v'),
+            )
+    }
+
+    fn run(&self, args: CommandArgs) -> Result<OutputStream, ShellError> {
+        command(args)
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![Example {
+            description: "melt dataframe",
+            example:
+                "[[a b c d]; [x 1 4 a] [y 2 5 b] [z 3 6 c]] | dataframe to-df | dataframe melt -c [b c] -v [a d]",
+            result: Some(vec![NuDataFrame::try_from_columns(
+                vec![
+                    Column::new(
+                        "b".to_string(),
+                        vec![
+                            UntaggedValue::int(1).into(),
+                            UntaggedValue::int(2).into(),
+                            UntaggedValue::int(3).into(),
+                            UntaggedValue::int(1).into(),
+                            UntaggedValue::int(2).into(),
+                            UntaggedValue::int(3).into(),
+                        ],
+                    ),
+                    Column::new(
+                        "c".to_string(),
+                        vec![
+                            UntaggedValue::int(4).into(),
+                            UntaggedValue::int(5).into(),
+                            UntaggedValue::int(6).into(),
+                            UntaggedValue::int(4).into(),
+                            UntaggedValue::int(5).into(),
+                            UntaggedValue::int(6).into(),
+                        ],
+                    ),
+                    Column::new(
+                        "variable".to_string(),
+                        vec![
+                            UntaggedValue::string("a").into(),
+                            UntaggedValue::string("a").into(),
+                            UntaggedValue::string("a").into(),
+                            UntaggedValue::string("d").into(),
+                            UntaggedValue::string("d").into(),
+                            UntaggedValue::string("d").into(),
+                        ],
+                    ),
+                    Column::new(
+                        "value".to_string(),
+                        vec![
+                            UntaggedValue::string("x").into(),
+                            UntaggedValue::string("y").into(),
+                            UntaggedValue::string("z").into(),
+                            UntaggedValue::string("a").into(),
+                            UntaggedValue::string("b").into(),
+                            UntaggedValue::string("c").into(),
+                        ],
+                    ),
+                ],
+                &Span::default(),
+            )
+            .expect("simple df for test should not fail")
+            .into_value(Tag::default())]),
+        }]
+    }
+}
+
+fn command(mut args: CommandArgs) -> Result<OutputStream, ShellError> {
+    let tag = args.call_info.name_tag.clone();
+
+    let id_col: Vec<Value> = args.req_named("columns")?;
+    let val_col: Vec<Value> = args.req_named("values")?;
+
+    let (id_col_string, id_col_span) = convert_columns(&id_col, &tag)?;
+    let (val_col_string, val_col_span) = convert_columns(&val_col, &tag)?;
+
+    let (df, _) = NuDataFrame::try_from_stream(&mut args.input, &tag.span)?;
+
+    check_column_datatypes(df.as_ref(), &id_col_string, &id_col_span)?;
+    check_column_datatypes(df.as_ref(), &val_col_string, &val_col_span)?;
+
+    let res = df
+        .as_ref()
+        .melt(&id_col_string, &val_col_string)
+        .map_err(|e| parse_polars_error::<&str>(&e, &tag.span, None))?;
+
+    Ok(OutputStream::one(NuDataFrame::dataframe_to_value(res, tag)))
+}
+
+fn check_column_datatypes<T: AsRef<str>>(
+    df: &polars::prelude::DataFrame,
+    cols: &[T],
+    col_span: &Span,
+) -> Result<(), ShellError> {
+    if cols.is_empty() {
+        return Err(ShellError::labeled_error(
+            "Merge error",
+            "empty column list",
+            col_span,
+        ));
+    }
+
+    // Checking if they are same type
+    if cols.len() > 1 {
+        for w in cols.windows(2) {
+            let l_series = df
+                .column(w[0].as_ref())
+                .map_err(|e| parse_polars_error::<&str>(&e, col_span, None))?;
+
+            let r_series = df
+                .column(w[1].as_ref())
+                .map_err(|e| parse_polars_error::<&str>(&e, col_span, None))?;
+
+            if l_series.dtype() != r_series.dtype() {
+                return Err(ShellError::labeled_error_with_secondary(
+                    "Merge error",
+                    "found different column types in list",
+                    col_span,
+                    format!(
+                        "datatypes {} and {} are incompatible",
+                        l_series.dtype(),
+                        r_series.dtype()
+                    ),
+                    col_span,
+                ));
+            }
+        }
+    }
+
+    Ok(())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::DataFrame;
+    use super::ShellError;
+
+    #[test]
+    fn examples_work_as_expected() -> Result<(), ShellError> {
+        use crate::examples::test_dataframe as test_examples;
+
+        test_examples(DataFrame {})
+    }
+}