add bytes starts-with command (#5950)

* refactor operate, make it generic

* refactor operate, add starts with command

* add comment

* remove useless file

.github/pull_request_template.md

@@ -4,6 +4,12 @@
 
 # Tests
 
+Make sure you've done the following:
+
+- [ ] Add tests that cover your changes, either in the command examples, the crate/tests folder, or in the /tests folder.
+- [ ] Try to think about corner cases and various ways how your changes could break. Cover them with tests.
+- [ ] If adding tests is not possible, please document in the PR body a minimal example with steps on how to reproduce so one can verify your change works.
+
 Make sure you've run and fixed any issues with these commands:
 
 - [ ] `cargo fmt --all -- --check` to check standard code formatting (`cargo fmt --all` applies these changes)

.github/workflows/release-pkg.nu

@@ -102,8 +102,8 @@ if $os in ['ubuntu-latest', 'macos-latest'] {
     let releaseStem = $'($bin)-($version)-($target)'
 
     $'(char nl)Download less related stuffs...'; hr-line
-    curl https://github.com/jftuga/less-Windows/releases/download/less-v590/less.exe -o $'($dist)\less.exe'
+    aria2c https://github.com/jftuga/less-Windows/releases/download/less-v590/less.exe -o less.exe
-    curl https://raw.githubusercontent.com/jftuga/less-Windows/master/LICENSE -o $'($dist)\LICENSE-for-less.txt'
+    aria2c https://raw.githubusercontent.com/jftuga/less-Windows/master/LICENSE -o LICENSE-for-less.txt
 
     # Create Windows msi release package
     if (get-env _EXTRA_) == 'msi' {

.github/workflows/winget-submission.yml

@@ -1,4 +1,4 @@
-name: Submit Nushell package to Windows Package Manager Community Repository 
+name: Submit Nushell package to Windows Package Manager Community Repository
 
 on:
   workflow_dispatch:
@@ -15,5 +15,5 @@ jobs:
         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
+          $installerUrl = $github.release.assets | Where-Object -Property name -match 'windows-msvc.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.lock

@@ -80,9 +80,9 @@ dependencies = [
 
 [[package]]
 name = "ansi-str"
-version = "0.1.1"
+version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "90cb0ceb8c444d026166795e474e9dfe54b443bdc07cc21bd6c5073f5e637482"
+checksum = "e04d04a41a1463228d6eed971b9cdadd86b5577c69c09fd2379c57fe5e159071"
 dependencies = [
  "ansi-parser",
 ]
@@ -131,9 +131,9 @@ checksum = "8da52d66c7071e2e3fa2a1e5c6d088fec47b593032b254f5e980de8ea54454d6"
 
 [[package]]
 name = "arrow-format"
-version = "0.4.0"
+version = "0.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2333f8ccf0d597ba779863c57a0b61f635721187fb2fdeabae92691d7d582fe5"
+checksum = "216249afef413d7e9e9b4b543e73b3e371ace3a812380af98f1c871521572cdd"
 dependencies = [
  "planus",
  "serde",
@@ -141,26 +141,24 @@ dependencies = [
 
 [[package]]
 name = "arrow2"
-version = "0.11.2"
+version = "0.12.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b040061368d1314b0fd8b8f1fde0671eba1afc63a1c61a4dafaf2d4fc10c96f9"
+checksum = "5feafd6df4e3f577529e6aa2b9b7cdb3c9fe8e8f66ebc8dc29abbe71a7e968f0"
 dependencies = [
  "arrow-format",
  "base64",
  "bytemuck",
  "chrono",
- "csv-core",
  "either",
  "fallible-streaming-iterator",
  "futures",
  "hash_hasher",
  "indexmap",
+ "json-deserializer",
  "lexical-core",
  "multiversion",
  "num-traits",
  "parquet2",
- "serde",
- "serde_json",
  "simdutf8",
  "streaming-iterator",
  "strength_reduce",
@@ -1875,6 +1873,12 @@ dependencies = [
  "wasm-bindgen",
 ]
 
+[[package]]
+name = "json-deserializer"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "47631885425c482fcf2dc4b182fc973c3c5b81a8f43a028055559bd24cccfa6e"
+
 [[package]]
 name = "kernel32-sys"
 version = "0.2.2"
@@ -2199,13 +2203,13 @@ dependencies = [
 
 [[package]]
 name = "miette"
-version = "4.7.1"
+version = "5.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1c90329e44f9208b55f45711f9558cec15d7ef8295cc65ecd6d4188ae8edc58c"
+checksum = "6ec753a43fd71bb5f28751c9ec17fbe89d6d26ca8282d1e1f82f5ac3dbd5581e"
 dependencies = [
  "atty",
  "backtrace",
- "miette-derive 4.7.1",
+ "miette-derive 5.1.0",
  "once_cell",
  "owo-colors",
  "supports-color",
@@ -2230,9 +2234,9 @@ dependencies = [
 
 [[package]]
 name = "miette-derive"
-version = "4.7.1"
+version = "5.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6b5bc45b761bcf1b5e6e6c4128cd93b84c218721a8d9b894aa0aff4ed180174c"
+checksum = "fdfc33ea15c5446600f91d319299dd40301614afff7143cdfa9bf4c09da3ca64"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -2470,7 +2474,7 @@ dependencies = [
 
 [[package]]
 name = "nu"
-version = "0.64.0"
+version = "0.65.0"
 dependencies = [
  "assert_cmd",
  "chrono",
@@ -2480,7 +2484,7 @@ dependencies = [
  "is_executable",
  "itertools",
  "log",
- "miette 4.7.1",
+ "miette 5.1.0",
  "nu-ansi-term",
  "nu-cli",
  "nu-color-config",
@@ -2521,14 +2525,14 @@ dependencies = [
 
 [[package]]
 name = "nu-cli"
-version = "0.64.0"
+version = "0.65.0"
 dependencies = [
  "chrono",
  "crossterm",
  "fuzzy-matcher",
  "is_executable",
  "log",
- "miette 4.7.1",
+ "miette 5.1.0",
  "nu-ansi-term",
  "nu-color-config",
  "nu-command",
@@ -2545,7 +2549,7 @@ dependencies = [
 
 [[package]]
 name = "nu-color-config"
-version = "0.64.0"
+version = "0.65.0"
 dependencies = [
  "nu-ansi-term",
  "nu-json",
@@ -2556,11 +2560,12 @@ dependencies = [
 
 [[package]]
 name = "nu-command"
-version = "0.64.0"
+version = "0.65.0"
 dependencies = [
  "Inflector",
  "alphanumeric-sort",
  "base64",
+ "byteorder",
  "bytesize",
  "calamine",
  "chrono",
@@ -2617,6 +2622,7 @@ dependencies = [
  "regex",
  "reqwest",
  "roxmltree",
+ "rstest",
  "rusqlite",
  "rust-embed",
  "serde",
@@ -2625,6 +2631,7 @@ dependencies = [
  "serde_yaml",
  "sha2 0.10.2",
  "shadow-rs",
+ "signal-hook",
  "sqlparser",
  "strip-ansi-escapes",
  "sysinfo 0.23.13",
@@ -2645,7 +2652,7 @@ dependencies = [
 
 [[package]]
 name = "nu-engine"
-version = "0.64.0"
+version = "0.65.0"
 dependencies = [
  "chrono",
  "nu-glob",
@@ -2657,7 +2664,7 @@ dependencies = [
 
 [[package]]
 name = "nu-glob"
-version = "0.64.0"
+version = "0.65.0"
 dependencies = [
  "doc-comment",
  "tempdir",
@@ -2665,7 +2672,7 @@ dependencies = [
 
 [[package]]
 name = "nu-json"
-version = "0.64.0"
+version = "0.65.0"
 dependencies = [
  "lazy_static",
  "linked-hash-map",
@@ -2678,11 +2685,12 @@ dependencies = [
 
 [[package]]
 name = "nu-parser"
-version = "0.64.0"
+version = "0.65.0"
 dependencies = [
  "chrono",
+ "itertools",
  "log",
- "miette 4.7.1",
+ "miette 5.1.0",
  "nu-path",
  "nu-plugin",
  "nu-protocol",
@@ -2692,7 +2700,7 @@ dependencies = [
 
 [[package]]
 name = "nu-path"
-version = "0.64.0"
+version = "0.65.0"
 dependencies = [
  "dirs-next",
  "dunce",
@@ -2701,7 +2709,7 @@ dependencies = [
 
 [[package]]
 name = "nu-plugin"
-version = "0.64.0"
+version = "0.65.0"
 dependencies = [
  "capnp",
  "nu-engine",
@@ -2712,7 +2720,7 @@ dependencies = [
 
 [[package]]
 name = "nu-pretty-hex"
-version = "0.64.0"
+version = "0.65.0"
 dependencies = [
  "heapless 0.7.13",
  "nu-ansi-term",
@@ -2721,13 +2729,13 @@ dependencies = [
 
 [[package]]
 name = "nu-protocol"
-version = "0.64.0"
+version = "0.65.0"
 dependencies = [
  "byte-unit",
  "chrono",
  "chrono-humanize",
  "indexmap",
- "miette 4.7.1",
+ "miette 5.1.0",
  "nu-json",
  "nu-utils",
  "num-format",
@@ -2741,7 +2749,7 @@ dependencies = [
 
 [[package]]
 name = "nu-system"
-version = "0.64.0"
+version = "0.65.0"
 dependencies = [
  "chrono",
  "errno",
@@ -2755,7 +2763,7 @@ dependencies = [
 
 [[package]]
 name = "nu-table"
-version = "0.64.0"
+version = "0.65.0"
 dependencies = [
  "ansi-str",
  "atty",
@@ -2768,7 +2776,7 @@ dependencies = [
 
 [[package]]
 name = "nu-term-grid"
-version = "0.64.0"
+version = "0.65.0"
 dependencies = [
  "strip-ansi-escapes",
  "unicode-width",
@@ -2776,7 +2784,7 @@ dependencies = [
 
 [[package]]
 name = "nu-test-support"
-version = "0.64.0"
+version = "0.65.0"
 dependencies = [
  "getset",
  "hamcrest2",
@@ -2788,14 +2796,14 @@ dependencies = [
 
 [[package]]
 name = "nu-utils"
-version = "0.64.0"
+version = "0.65.0"
 dependencies = [
  "crossterm_winapi",
 ]
 
 [[package]]
 name = "nu_plugin_example"
-version = "0.64.0"
+version = "0.65.0"
 dependencies = [
  "nu-plugin",
  "nu-protocol",
@@ -2803,7 +2811,7 @@ dependencies = [
 
 [[package]]
 name = "nu_plugin_gstat"
-version = "0.64.0"
+version = "0.65.0"
 dependencies = [
  "git2",
  "nu-engine",
@@ -2813,7 +2821,7 @@ dependencies = [
 
 [[package]]
 name = "nu_plugin_inc"
-version = "0.64.0"
+version = "0.65.0"
 dependencies = [
  "nu-plugin",
  "nu-protocol",
@@ -2822,7 +2830,7 @@ dependencies = [
 
 [[package]]
 name = "nu_plugin_query"
-version = "0.64.0"
+version = "0.65.0"
 dependencies = [
  "gjson",
  "nu-engine",
@@ -3145,9 +3153,9 @@ dependencies = [
 
 [[package]]
 name = "parquet2"
-version = "0.12.1"
+version = "0.13.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cbacca5619bdee7f942938890451dea1a61f082c682aac913d7b4e326e66d7b4"
+checksum = "73fd2690ad041f9296876daef1f2706f6347073bdbcc719090887f1691e4a09d"
 dependencies = [
  "async-stream",
  "bitpacking",
@@ -3319,9 +3327,9 @@ dependencies = [
 
 [[package]]
 name = "polars"
-version = "0.21.1"
+version = "0.22.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b140da767e129c60c41c8e1968ffab5f114bcf823182edb7fa900464a31bf421"
+checksum = "3d175c67e80ceaef7219258cfc3a8686531d9510875b0cefa25404e5b80a7933"
 dependencies = [
  "polars-core",
  "polars-io",
@@ -3332,9 +3340,9 @@ dependencies = [
 
 [[package]]
 name = "polars-arrow"
-version = "0.21.1"
+version = "0.22.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6d27df11ee28956bd6f5aed54e7e05ce87b886871995e1da501134627ec89077"
+checksum = "f66c7d3da2c10a09131294dbe7802fac792f570be639dc6ebf207bfc3e144287"
 dependencies = [
  "arrow2",
  "hashbrown 0.12.1",
@@ -3345,9 +3353,9 @@ dependencies = [
 
 [[package]]
 name = "polars-core"
-version = "0.21.1"
+version = "0.22.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fdf8d12cb7ec278516228fc86469f98c62ab81ca31e4e76d2c0ccf5a09c70491"
+checksum = "f7f15f443a90d5367c4fbbb151e203f03b5b96055c8b928c6bc30655a3644f13"
 dependencies = [
  "ahash",
  "anyhow",
@@ -3356,8 +3364,8 @@ dependencies = [
  "comfy-table",
  "hashbrown 0.12.1",
  "indexmap",
- "lazy_static",
  "num 0.4.0",
+ "once_cell",
  "polars-arrow",
  "polars-utils",
  "rand 0.8.5",
@@ -3371,20 +3379,21 @@ dependencies = [
 
 [[package]]
 name = "polars-io"
-version = "0.21.1"
+version = "0.22.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fdd4b762e5694f359ded21ca0627b5bc95b6eb49f6b330569afc1d20f0564b01"
+checksum = "058d0a847ce5009b974c69ec878ed416e306436f21b626543019f738cee12315"
 dependencies = [
  "ahash",
  "anyhow",
  "arrow2",
  "csv-core",
  "dirs",
- "lazy_static",
  "lexical",
+ "lexical-core",
  "memchr",
  "memmap2",
  "num 0.4.0",
+ "once_cell",
  "polars-arrow",
  "polars-core",
  "polars-time",
@@ -3398,9 +3407,9 @@ dependencies = [
 
 [[package]]
 name = "polars-lazy"
-version = "0.21.1"
+version = "0.22.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "eedc21001f05611e41bb7439b38d0f4ef9406aa49c17f3b289b5f57d8fa40c59"
+checksum = "dad86a4ce7e32540ff12089bce6f77270fd133a5b263328a92be61defdd6b151"
 dependencies = [
  "ahash",
  "glob",
@@ -3408,6 +3417,7 @@ dependencies = [
  "polars-arrow",
  "polars-core",
  "polars-io",
+ "polars-ops",
  "polars-time",
  "polars-utils",
  "rayon",
@@ -3416,31 +3426,33 @@ dependencies = [
 
 [[package]]
 name = "polars-ops"
-version = "0.21.1"
+version = "0.22.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "86fae68f0992955f224f09d1f15648a6fb76d8e3b962efac2f97ccc2aa58977a"
+checksum = "030ecd473be113cd0264f1bc19de39a844fa12fa565db9dc52c859cbc292cf04"
 dependencies = [
+ "polars-arrow",
  "polars-core",
 ]
 
 [[package]]
 name = "polars-time"
-version = "0.21.1"
+version = "0.22.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "be499f73749e820f96689c5f9ec59669b7cdd551d864358e2bdaebb5944e4bfb"
+checksum = "94047b20d2da3bcc55c421be187a0c6f316cf1eea7fe7ed7347c1160a32d017c"
 dependencies = [
  "chrono",
  "lexical",
  "polars-arrow",
  "polars-core",
+ "polars-utils",
  "serde",
 ]
 
 [[package]]
 name = "polars-utils"
-version = "0.21.1"
+version = "0.22.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c7f4cd569d383f5f000abbd6d5146550e6cb4e43fac30d1af98699499a440d56"
+checksum = "fcd3d0238462d5d9f7fbeaaea46e73ed4d58f6fae8b70d53cbe51d7538cc43f5"
 dependencies = [
  "parking_lot 0.12.1",
  "rayon",
@@ -3816,14 +3828,15 @@ dependencies = [
 
 [[package]]
 name = "reedline"
-version = "0.7.0"
+version = "0.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3f8163ab90fabf0b8978b824743bb7a384394501b4b40c198a146c0eb9670ca4"
+checksum = "d064ec92a21deb048c440b6461ccf0d0babdb5f2160ea9dfac451bc7b4b556e2"
 dependencies = [
  "chrono",
  "crossterm",
  "fd-lock",
  "gethostname",
+ "itertools",
  "nu-ansi-term",
  "rusqlite",
  "serde",
@@ -4224,7 +4237,6 @@ version = "1.0.81"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9b7ce2b32a1aed03c558dc61a5cd328f15aff2dbc17daad8fb8af04d2100e15c"
 dependencies = [
- "indexmap",
  "itoa 1.0.2",
  "ryu",
  "serde",

Cargo.toml

@@ -11,7 +11,7 @@ name = "nu"
 readme = "README.md"
 repository = "https://github.com/nushell/nushell"
 rust-version = "1.60"
-version = "0.64.0"
+version = "0.65.0"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
@@ -36,23 +36,23 @@ chrono = { version = "0.4.19", features = ["serde"] }
 crossterm = "0.23.0"
 ctrlc = "3.2.1"
 log = "0.4"
-miette = "4.5.0"
+miette = "5.1.0"
 nu-ansi-term = "0.46.0"
-nu-cli = { path="./crates/nu-cli", version = "0.64.0"  }
+nu-cli = { path="./crates/nu-cli", version = "0.65.0"  }
-nu-color-config = { path = "./crates/nu-color-config", version = "0.64.0"  }
+nu-color-config = { path = "./crates/nu-color-config", version = "0.65.0"  }
-nu-command = { path="./crates/nu-command", version = "0.64.0"  }
+nu-command = { path="./crates/nu-command", version = "0.65.0"  }
-nu-engine = { path="./crates/nu-engine", version = "0.64.0"  }
+nu-engine = { path="./crates/nu-engine", version = "0.65.0"  }
-nu-json = { path="./crates/nu-json", version = "0.64.0"  }
+nu-json = { path="./crates/nu-json", version = "0.65.0"  }
-nu-parser = { path="./crates/nu-parser", version = "0.64.0"  }
+nu-parser = { path="./crates/nu-parser", version = "0.65.0"  }
-nu-path = { path="./crates/nu-path", version = "0.64.0"  }
+nu-path = { path="./crates/nu-path", version = "0.65.0"  }
-nu-plugin = { path = "./crates/nu-plugin", optional = true, version = "0.64.0"  }
+nu-plugin = { path = "./crates/nu-plugin", optional = true, version = "0.65.0"  }
-nu-pretty-hex = { path = "./crates/nu-pretty-hex", version = "0.64.0"  }
+nu-pretty-hex = { path = "./crates/nu-pretty-hex", version = "0.65.0"  }
-nu-protocol = { path = "./crates/nu-protocol", version = "0.64.0"  }
+nu-protocol = { path = "./crates/nu-protocol", version = "0.65.0"  }
-nu-system = { path = "./crates/nu-system", version = "0.64.0" }
+nu-system = { path = "./crates/nu-system", version = "0.65.0" }
-nu-table = { path = "./crates/nu-table", version = "0.64.0"  }
+nu-table = { path = "./crates/nu-table", version = "0.65.0"  }
-nu-term-grid = { path = "./crates/nu-term-grid", version = "0.64.0"  }
+nu-term-grid = { path = "./crates/nu-term-grid", version = "0.65.0"  }
-nu-utils = { path = "./crates/nu-utils", version = "0.64.0"  }
+nu-utils = { path = "./crates/nu-utils", version = "0.65.0"  }
-reedline = { version = "0.7.0", features = ["bashisms", "sqlite"]}
+reedline = { version = "0.8.0", features = ["bashisms", "sqlite"]}
 pretty_env_logger = "0.4.0"
 rayon = "1.5.1"
 is_executable = "1.0.1"
@@ -63,7 +63,7 @@ openssl = { version = "0.10.38", features = ["vendored"], optional = true }
 signal-hook = { version = "0.3.14", default-features = false }
 
 [dev-dependencies]
-nu-test-support = { path="./crates/nu-test-support", version = "0.64.0"  }
+nu-test-support = { path="./crates/nu-test-support", version = "0.65.0"  }
 tempfile = "3.2.0"
 assert_cmd = "2.0.2"
 pretty_assertions = "1.0.0"

crates/nu-cli/Cargo.toml

@@ -4,24 +4,24 @@ description = "CLI-related functionality for Nushell"
 edition = "2021"
 license = "MIT"
 name = "nu-cli"
-version = "0.64.0"
+version = "0.65.0"
 
 [dev-dependencies]
-nu-test-support = { path="../nu-test-support", version = "0.64.0"  }
+nu-test-support = { path="../nu-test-support", version = "0.65.0"  }
-nu-command = { path = "../nu-command", version = "0.64.0" }
+nu-command = { path = "../nu-command", version = "0.65.0" }
 
 [dependencies]
-nu-engine = { path = "../nu-engine", version = "0.64.0"  }
+nu-engine = { path = "../nu-engine", version = "0.65.0"  }
-nu-path = { path = "../nu-path", version = "0.64.0"  }
+nu-path = { path = "../nu-path", version = "0.65.0"  }
-nu-parser = { path = "../nu-parser", version = "0.64.0"  }
+nu-parser = { path = "../nu-parser", version = "0.65.0"  }
-nu-protocol = { path = "../nu-protocol", version = "0.64.0"  }
+nu-protocol = { path = "../nu-protocol", version = "0.65.0"  }
-nu-utils = { path = "../nu-utils", version = "0.64.0"  }
+nu-utils = { path = "../nu-utils", version = "0.65.0"  }
 nu-ansi-term = "0.46.0"
-nu-color-config = { path = "../nu-color-config", version = "0.64.0"  }
+nu-color-config = { path = "../nu-color-config", version = "0.65.0"  }
-reedline = { version = "0.7.0", features = ["bashisms", "sqlite"]}
+reedline = { version = "0.8.0", features = ["bashisms", "sqlite"]}
 crossterm = "0.23.0"
-miette = { version = "4.5.0", features = ["fancy"] }
+miette = { version = "5.1.0", features = ["fancy"] }
-thiserror = "1.0.29"
+thiserror = "1.0.31"
 fuzzy-matcher = "0.3.7"
 
 log = "0.4"

crates/nu-cli/src/commands.rs

@@ -18,7 +18,7 @@ pub fn evaluate_commands(
     input: PipelineData,
     is_perf_true: bool,
     table_mode: Option<Value>,
-) -> Result<()> {
+) -> Result<Option<i64>> {
     // Run a command (or commands) given to us by the user
     let (block, delta) = {
         if let Some(ref t_mode) = table_mode {
@@ -74,7 +74,7 @@ pub fn evaluate_commands(
         std::process::exit(1);
     }
 
-    match eval_block(engine_state, stack, &block, input, false, false) {
+    let exit_code = match eval_block(engine_state, stack, &block, input, false, false) {
         Ok(pipeline_data) => {
             crate::eval_file::print_table_or_error(engine_state, stack, pipeline_data, &mut config)
         }
@@ -84,11 +84,11 @@ pub fn evaluate_commands(
             report_error(&working_set, &err);
             std::process::exit(1);
         }
-    }
+    };
 
     if is_perf_true {
         info!("evaluate {}:{}:{}", file!(), line!(), column!());
     }
 
-    Ok(())
+    Ok(exit_code)
 }

crates/nu-cli/src/completions/completer.rs

@@ -68,14 +68,10 @@ impl NuCompleter {
         for pipeline in output.pipelines.into_iter() {
             for expr in pipeline.expressions {
                 let flattened: Vec<_> = flatten_expression(&working_set, &expr);
+                let span_offset: usize = alias_offset.iter().sum();
 
                 for (flat_idx, flat) in flattened.iter().enumerate() {
-                    let alias = if alias_offset.is_empty() {
+                    if pos + span_offset >= flat.0.start && pos + span_offset < flat.0.end {
-                        0
-                    } else {
-                        alias_offset[flat_idx]
-                    };
-                    if pos >= flat.0.start - alias && pos < flat.0.end - alias {
                         // Context variables
                         let most_left_var =
                             most_left_variable(flat_idx, &working_set, flattened.clone());
@@ -84,42 +80,18 @@ impl NuCompleter {
                         let new_span = if flat_idx == 0 {
                             Span {
                                 start: flat.0.start,
-                                end: flat.0.end - 1 - alias,
+                                end: flat.0.end - 1 - span_offset,
                             }
                         } else {
                             Span {
-                                start: flat.0.start - alias,
+                                start: flat.0.start - span_offset,
-                                end: flat.0.end - 1 - alias,
+                                end: flat.0.end - 1 - span_offset,
                             }
                         };
 
                         // Parses the prefix
                         let mut prefix = working_set.get_span_contents(flat.0).to_vec();
-                        prefix.remove(pos - (flat.0.start - alias));
+                        prefix.remove(pos - (flat.0.start - span_offset));
-
-                        // Completions that depends on the previous expression (e.g: use, source)
-                        if flat_idx > 0 {
-                            if let Some(previous_expr) = flattened.get(flat_idx - 1) {
-                                // Read the content for the previous expression
-                                let prev_expr_str =
-                                    working_set.get_span_contents(previous_expr.0).to_vec();
-
-                                // Completion for .nu files
-                                if prev_expr_str == b"use" || prev_expr_str == b"source" {
-                                    let mut completer =
-                                        DotNuCompletion::new(self.engine_state.clone());
-
-                                    return self.process_completion(
-                                        &mut completer,
-                                        &working_set,
-                                        prefix,
-                                        new_span,
-                                        offset,
-                                        pos,
-                                    );
-                                }
-                            }
-                        }
 
                         // Variables completion
                         if prefix.starts_with(b"$") || most_left_var.is_some() {
@@ -153,6 +125,42 @@ impl NuCompleter {
                             );
                         }
 
+                        // Completions that depends on the previous expression (e.g: use, source)
+                        if flat_idx > 0 {
+                            if let Some(previous_expr) = flattened.get(flat_idx - 1) {
+                                // Read the content for the previous expression
+                                let prev_expr_str =
+                                    working_set.get_span_contents(previous_expr.0).to_vec();
+
+                                // Completion for .nu files
+                                if prev_expr_str == b"use" || prev_expr_str == b"source" {
+                                    let mut completer =
+                                        DotNuCompletion::new(self.engine_state.clone());
+
+                                    return self.process_completion(
+                                        &mut completer,
+                                        &working_set,
+                                        prefix,
+                                        new_span,
+                                        offset,
+                                        pos,
+                                    );
+                                } else if prev_expr_str == b"ls" {
+                                    let mut completer =
+                                        FileCompletion::new(self.engine_state.clone());
+
+                                    return self.process_completion(
+                                        &mut completer,
+                                        &working_set,
+                                        prefix,
+                                        new_span,
+                                        offset,
+                                        pos,
+                                    );
+                                }
+                            }
+                        }
+
                         // Match other types
                         match &flat.1 {
                             FlatShape::Custom(decl_id) => {
@@ -185,6 +193,18 @@ impl NuCompleter {
                                     pos,
                                 );
                             }
+                            FlatShape::Filepath | FlatShape::GlobPattern => {
+                                let mut completer = FileCompletion::new(self.engine_state.clone());
+
+                                return self.process_completion(
+                                    &mut completer,
+                                    &working_set,
+                                    prefix,
+                                    new_span,
+                                    offset,
+                                    pos,
+                                );
+                            }
                             flat_shape => {
                                 let mut completer = CommandCompletion::new(
                                     self.engine_state.clone(),
@@ -235,7 +255,7 @@ impl ReedlineCompleter for NuCompleter {
     }
 }
 
-type MatchedAlias<'a> = Vec<(&'a [u8], &'a [u8])>;
+type MatchedAlias = Vec<(Vec<u8>, Vec<u8>)>;
 
 // Handler the completion when giving lines contains at least one alias. (e.g: `g checkout`)
 // that `g` is an alias of `git`
@@ -254,6 +274,13 @@ fn try_find_alias(line: &[u8], working_set: &StateWorkingSet) -> (Vec<u8>, Vec<u
                 lens -= 1;
             }
         }
+
+        if !line.is_empty() {
+            let last = line.last().expect("input is empty");
+            if last == &b' ' {
+                output.push(b' ');
+            }
+        }
     } else {
         output = line.to_vec();
     }
@@ -261,7 +288,7 @@ fn try_find_alias(line: &[u8], working_set: &StateWorkingSet) -> (Vec<u8>, Vec<u
     (output, alias_offset)
 }
 
-fn search_alias<'a>(input: &'a [u8], working_set: &'a StateWorkingSet) -> Option<MatchedAlias<'a>> {
+fn search_alias(input: &[u8], working_set: &StateWorkingSet) -> Option<MatchedAlias> {
     let mut vec_names = vec![];
     let mut vec_alias = vec![];
     let mut pos = 0;
@@ -269,27 +296,31 @@ fn search_alias<'a>(input: &'a [u8], working_set: &'a StateWorkingSet) -> Option
     for (index, character) in input.iter().enumerate() {
         if *character == b' ' {
             let range = &input[pos..index];
-            vec_names.push(range);
+            vec_names.push(range.to_owned());
             pos = index + 1;
         }
     }
     // Push the rest to names vector.
     if pos < input.len() {
-        vec_names.push(&input[pos..]);
+        vec_names.push((&input[pos..]).to_owned());
     }
 
     for name in &vec_names {
-        if let Some(alias_id) = working_set.find_alias(name) {
+        if let Some(alias_id) = working_set.find_alias(&name[..]) {
             let alias_span = working_set.get_alias(alias_id);
+            let mut span_vec = vec![];
             is_alias = true;
             for alias in alias_span {
                 let name = working_set.get_span_contents(*alias);
                 if !name.is_empty() {
-                    vec_alias.push(name);
+                    span_vec.push(name);
                 }
             }
+            // Join span of vector together for complex alias, e.g: `f` is an alias for `git remote -v`
+            let full_aliases = span_vec.join(&[b' '][..]);
+            vec_alias.push(full_aliases);
         } else {
-            vec_alias.push(name);
+            vec_alias.push(name.to_owned());
         }
     }
 

crates/nu-cli/src/completions/variable_completions.rs

@@ -41,7 +41,7 @@ impl Completer for VariableCompletion {
         options: &CompletionOptions,
     ) -> Vec<Suggestion> {
         let mut output = vec![];
-        let builtins = ["$nu", "$in", "$config", "$env", "$nothing"];
+        let builtins = ["$nu", "$in", "$env", "$nothing"];
         let var_str = std::str::from_utf8(&self.var_context.0)
             .unwrap_or("")
             .to_lowercase();

crates/nu-cli/src/eval_file.rs

@@ -66,7 +66,7 @@ pub fn print_table_or_error(
     stack: &mut Stack,
     mut pipeline_data: PipelineData,
     config: &mut Config,
-) {
+) -> Option<i64> {
     let exit_code = match &mut pipeline_data {
         PipelineData::ExternalStream { exit_code, .. } => exit_code.take(),
         _ => None,
@@ -130,6 +130,14 @@ pub fn print_table_or_error(
 
     // Make sure everything has finished
     if let Some(exit_code) = exit_code {
-        let _: Vec<_> = exit_code.into_iter().collect();
+        let mut exit_code: Vec<_> = exit_code.into_iter().collect();
+        exit_code
+            .pop()
+            .and_then(|last_exit_code| match last_exit_code {
+                Value::Int { val: code, .. } => Some(code),
+                _ => None,
+            })
+    } else {
+        None
     }
 }

crates/nu-cli/src/print.rs

@@ -21,11 +21,19 @@ impl Command for Print {
                 "print without inserting a newline for the line ending",
                 Some('n'),
             )
+            .switch("stderr", "print to stderr instead of stdout", Some('e'))
             .category(Category::Strings)
     }
 
     fn usage(&self) -> &str {
-        "Prints the values given"
+        "Print the given values to stdout"
+    }
+
+    fn extra_usage(&self) -> &str {
+        r#"Unlike `echo`, this command does not return any value (`print | describe` will return "nothing").
+Since this command has no output, there is no point in piping it with other commands.
+
+`print` may be used inside blocks of code (e.g.: hooks) to display text during execution without interfering with the pipeline."#
     }
 
     fn search_terms(&self) -> Vec<&str> {
@@ -41,11 +49,12 @@ impl Command for Print {
     ) -> Result<PipelineData, ShellError> {
         let args: Vec<Value> = call.rest(engine_state, stack, 0)?;
         let no_newline = call.has_flag("no-newline");
+        let to_stderr = call.has_flag("stderr");
         let head = call.head;
 
         for arg in args {
             arg.into_pipeline_data()
-                .print(engine_state, stack, no_newline)?;
+                .print(engine_state, stack, no_newline, to_stderr)?;
         }
 
         Ok(PipelineData::new(head))

crates/nu-cli/src/reedline_config.rs

@@ -875,7 +875,16 @@ fn edit_from_record(
         "moveleft" => EditCommand::MoveLeft,
         "moveright" => EditCommand::MoveRight,
         "movewordleft" => EditCommand::MoveWordLeft,
+        "movebigwordleft" => EditCommand::MoveBigWordLeft,
         "movewordright" => EditCommand::MoveWordRight,
+        "movewordrightend" => EditCommand::MoveWordRightEnd,
+        "movebigwordrightend" => EditCommand::MoveBigWordRightEnd,
+        "movewordrightstart" => EditCommand::MoveWordRightStart,
+        "movebigwordrightstart" => EditCommand::MoveBigWordRightStart,
+        "movetoposition" => {
+            let value = extract_value("value", cols, vals, span)?;
+            EditCommand::MoveToPosition(value.as_integer()? as usize)
+        }
         "insertchar" => {
             let value = extract_value("value", cols, vals, span)?;
             let char = extract_char(value, config)?;
@@ -888,6 +897,7 @@ fn edit_from_record(
         "insertnewline" => EditCommand::InsertNewline,
         "backspace" => EditCommand::Backspace,
         "delete" => EditCommand::Delete,
+        "cutchar" => EditCommand::CutChar,
         "backspaceword" => EditCommand::BackspaceWord,
         "deleteword" => EditCommand::DeleteWord,
         "clear" => EditCommand::Clear,
@@ -898,7 +908,11 @@ fn edit_from_record(
         "cuttoend" => EditCommand::CutToEnd,
         "cuttolineend" => EditCommand::CutToLineEnd,
         "cutwordleft" => EditCommand::CutWordLeft,
+        "cutbigwordleft" => EditCommand::CutBigWordLeft,
         "cutwordright" => EditCommand::CutWordRight,
+        "cutbigwordright" => EditCommand::CutBigWordRight,
+        "cutwordrighttonext" => EditCommand::CutWordRightToNext,
+        "cutbigwordrighttonext" => EditCommand::CutBigWordRightToNext,
         "pastecutbufferbefore" => EditCommand::PasteCutBufferBefore,
         "pastecutbufferafter" => EditCommand::PasteCutBufferAfter,
         "uppercaseword" => EditCommand::UppercaseWord,

crates/nu-cli/src/util.rs

@@ -247,7 +247,7 @@ pub fn eval_source(
                 set_last_exit_code(stack, 0);
             }
 
-            if let Err(err) = pipeline_data.print(engine_state, stack, false) {
+            if let Err(err) = pipeline_data.print(engine_state, stack, false, false) {
                 let working_set = StateWorkingSet::new(engine_state);
 
                 report_error(&working_set, &err);

crates/nu-cli/tests/alias.rs

@@ -0,0 +1,65 @@
+pub mod support;
+
+use nu_cli::NuCompleter;
+use reedline::Completer;
+use support::{match_suggestions, new_engine};
+
+#[test]
+fn alias_of_command_and_flags() {
+    let (dir, _, mut engine, mut stack) = new_engine();
+
+    // Create an alias
+    let alias = r#"alias ll = ls -l"#;
+    assert!(support::merge_input(alias.as_bytes(), &mut engine, &mut stack, dir).is_ok());
+
+    let mut completer = NuCompleter::new(std::sync::Arc::new(engine), stack);
+
+    let suggestions = completer.complete("ll t", 4);
+    #[cfg(windows)]
+    let expected_paths: Vec<String> = vec!["test_a\\".to_string(), "test_b\\".to_string()];
+    #[cfg(not(windows))]
+    let expected_paths: Vec<String> = vec!["test_a/".to_string(), "test_b/".to_string()];
+
+    match_suggestions(expected_paths, suggestions)
+}
+
+#[test]
+fn alias_of_basic_command() {
+    let (dir, _, mut engine, mut stack) = new_engine();
+
+    // Create an alias
+    let alias = r#"alias ll = ls "#;
+    assert!(support::merge_input(alias.as_bytes(), &mut engine, &mut stack, dir).is_ok());
+
+    let mut completer = NuCompleter::new(std::sync::Arc::new(engine), stack);
+
+    let suggestions = completer.complete("ll t", 4);
+    #[cfg(windows)]
+    let expected_paths: Vec<String> = vec!["test_a\\".to_string(), "test_b\\".to_string()];
+    #[cfg(not(windows))]
+    let expected_paths: Vec<String> = vec!["test_a/".to_string(), "test_b/".to_string()];
+
+    match_suggestions(expected_paths, suggestions)
+}
+
+#[test]
+fn alias_of_another_alias() {
+    let (dir, _, mut engine, mut stack) = new_engine();
+
+    // Create an alias
+    let alias = r#"alias ll = ls -la"#;
+    assert!(support::merge_input(alias.as_bytes(), &mut engine, &mut stack, dir.clone()).is_ok());
+    // Create the second alias
+    let alias = r#"alias lf = ll -f"#;
+    assert!(support::merge_input(alias.as_bytes(), &mut engine, &mut stack, dir).is_ok());
+
+    let mut completer = NuCompleter::new(std::sync::Arc::new(engine), stack);
+
+    let suggestions = completer.complete("lf t", 4);
+    #[cfg(windows)]
+    let expected_paths: Vec<String> = vec!["test_a\\".to_string(), "test_b\\".to_string()];
+    #[cfg(not(windows))]
+    let expected_paths: Vec<String> = vec!["test_a/".to_string(), "test_b/".to_string()];
+
+    match_suggestions(expected_paths, suggestions)
+}

crates/nu-cli/tests/custom_completions.rs

@@ -14,7 +14,7 @@ fn variables_completions() {
     def my-command [animal: string@animals] { print $animal }"#;
     assert!(support::merge_input(record.as_bytes(), &mut engine, &mut stack, dir).is_ok());
 
-    // Instatiate a new completer
+    // Instantiate a new completer
     let mut completer = NuCompleter::new(std::sync::Arc::new(engine), stack);
 
     // Test completions for $nu

crates/nu-cli/tests/file_completions.rs

@@ -40,3 +40,233 @@ fn file_completions() {
     // Match the results
     match_suggestions(expected_paths, suggestions);
 }
+
+#[test]
+fn command_ls_completion() {
+    let (_, _, engine, stack) = new_engine();
+
+    let mut completer = NuCompleter::new(std::sync::Arc::new(engine), stack);
+
+    let target_dir = "ls ";
+    let suggestions = completer.complete(target_dir, target_dir.len());
+
+    #[cfg(windows)]
+    let expected_paths: Vec<String> = vec![
+        "nushell".to_string(),
+        "test_a\\".to_string(),
+        "test_b\\".to_string(),
+        "another\\".to_string(),
+        "custom_completion.nu".to_string(),
+        ".hidden_file".to_string(),
+        ".hidden_folder\\".to_string(),
+    ];
+    #[cfg(not(windows))]
+    let expected_paths: Vec<String> = vec![
+        "nushell".to_string(),
+        "test_a/".to_string(),
+        "test_b/".to_string(),
+        "another/".to_string(),
+        "custom_completion.nu".to_string(),
+        ".hidden_file".to_string(),
+        ".hidden_folder/".to_string(),
+    ];
+
+    match_suggestions(expected_paths, suggestions)
+}
+#[test]
+fn command_open_completion() {
+    let (_, _, engine, stack) = new_engine();
+
+    let mut completer = NuCompleter::new(std::sync::Arc::new(engine), stack);
+
+    let target_dir = "open ";
+    let suggestions = completer.complete(target_dir, target_dir.len());
+
+    #[cfg(windows)]
+    let expected_paths: Vec<String> = vec![
+        "nushell".to_string(),
+        "test_a\\".to_string(),
+        "test_b\\".to_string(),
+        "another\\".to_string(),
+        "custom_completion.nu".to_string(),
+        ".hidden_file".to_string(),
+        ".hidden_folder\\".to_string(),
+    ];
+    #[cfg(not(windows))]
+    let expected_paths: Vec<String> = vec![
+        "nushell".to_string(),
+        "test_a/".to_string(),
+        "test_b/".to_string(),
+        "another/".to_string(),
+        "custom_completion.nu".to_string(),
+        ".hidden_file".to_string(),
+        ".hidden_folder/".to_string(),
+    ];
+
+    match_suggestions(expected_paths, suggestions)
+}
+
+#[test]
+fn command_rm_completion() {
+    let (_, _, engine, stack) = new_engine();
+
+    let mut completer = NuCompleter::new(std::sync::Arc::new(engine), stack);
+
+    let target_dir = "rm ";
+    let suggestions = completer.complete(target_dir, target_dir.len());
+
+    #[cfg(windows)]
+    let expected_paths: Vec<String> = vec![
+        "nushell".to_string(),
+        "test_a\\".to_string(),
+        "test_b\\".to_string(),
+        "another\\".to_string(),
+        "custom_completion.nu".to_string(),
+        ".hidden_file".to_string(),
+        ".hidden_folder\\".to_string(),
+    ];
+    #[cfg(not(windows))]
+    let expected_paths: Vec<String> = vec![
+        "nushell".to_string(),
+        "test_a/".to_string(),
+        "test_b/".to_string(),
+        "another/".to_string(),
+        "custom_completion.nu".to_string(),
+        ".hidden_file".to_string(),
+        ".hidden_folder/".to_string(),
+    ];
+
+    match_suggestions(expected_paths, suggestions)
+}
+
+#[test]
+fn command_cp_completion() {
+    let (_, _, engine, stack) = new_engine();
+
+    let mut completer = NuCompleter::new(std::sync::Arc::new(engine), stack);
+
+    let target_dir = "cp ";
+    let suggestions = completer.complete(target_dir, target_dir.len());
+
+    #[cfg(windows)]
+    let expected_paths: Vec<String> = vec![
+        "nushell".to_string(),
+        "test_a\\".to_string(),
+        "test_b\\".to_string(),
+        "another\\".to_string(),
+        "custom_completion.nu".to_string(),
+        ".hidden_file".to_string(),
+        ".hidden_folder\\".to_string(),
+    ];
+    #[cfg(not(windows))]
+    let expected_paths: Vec<String> = vec![
+        "nushell".to_string(),
+        "test_a/".to_string(),
+        "test_b/".to_string(),
+        "another/".to_string(),
+        "custom_completion.nu".to_string(),
+        ".hidden_file".to_string(),
+        ".hidden_folder/".to_string(),
+    ];
+
+    match_suggestions(expected_paths, suggestions)
+}
+
+#[test]
+fn command_save_completion() {
+    let (_, _, engine, stack) = new_engine();
+
+    let mut completer = NuCompleter::new(std::sync::Arc::new(engine), stack);
+
+    let target_dir = "save ";
+    let suggestions = completer.complete(target_dir, target_dir.len());
+
+    #[cfg(windows)]
+    let expected_paths: Vec<String> = vec![
+        "nushell".to_string(),
+        "test_a\\".to_string(),
+        "test_b\\".to_string(),
+        "another\\".to_string(),
+        "custom_completion.nu".to_string(),
+        ".hidden_file".to_string(),
+        ".hidden_folder\\".to_string(),
+    ];
+    #[cfg(not(windows))]
+    let expected_paths: Vec<String> = vec![
+        "nushell".to_string(),
+        "test_a/".to_string(),
+        "test_b/".to_string(),
+        "another/".to_string(),
+        "custom_completion.nu".to_string(),
+        ".hidden_file".to_string(),
+        ".hidden_folder/".to_string(),
+    ];
+
+    match_suggestions(expected_paths, suggestions)
+}
+
+#[test]
+fn command_touch_completion() {
+    let (_, _, engine, stack) = new_engine();
+
+    let mut completer = NuCompleter::new(std::sync::Arc::new(engine), stack);
+
+    let target_dir = "touch ";
+    let suggestions = completer.complete(target_dir, target_dir.len());
+
+    #[cfg(windows)]
+    let expected_paths: Vec<String> = vec![
+        "nushell".to_string(),
+        "test_a\\".to_string(),
+        "test_b\\".to_string(),
+        "another\\".to_string(),
+        "custom_completion.nu".to_string(),
+        ".hidden_file".to_string(),
+        ".hidden_folder\\".to_string(),
+    ];
+    #[cfg(not(windows))]
+    let expected_paths: Vec<String> = vec![
+        "nushell".to_string(),
+        "test_a/".to_string(),
+        "test_b/".to_string(),
+        "another/".to_string(),
+        "custom_completion.nu".to_string(),
+        ".hidden_file".to_string(),
+        ".hidden_folder/".to_string(),
+    ];
+
+    match_suggestions(expected_paths, suggestions)
+}
+
+#[test]
+fn command_watch_completion() {
+    let (_, _, engine, stack) = new_engine();
+
+    let mut completer = NuCompleter::new(std::sync::Arc::new(engine), stack);
+
+    let target_dir = "watch ";
+    let suggestions = completer.complete(target_dir, target_dir.len());
+
+    #[cfg(windows)]
+    let expected_paths: Vec<String> = vec![
+        "nushell".to_string(),
+        "test_a\\".to_string(),
+        "test_b\\".to_string(),
+        "another\\".to_string(),
+        "custom_completion.nu".to_string(),
+        ".hidden_file".to_string(),
+        ".hidden_folder\\".to_string(),
+    ];
+    #[cfg(not(windows))]
+    let expected_paths: Vec<String> = vec![
+        "nushell".to_string(),
+        "test_a/".to_string(),
+        "test_b/".to_string(),
+        "another/".to_string(),
+        "custom_completion.nu".to_string(),
+        ".hidden_file".to_string(),
+        ".hidden_folder/".to_string(),
+    ];
+
+    match_suggestions(expected_paths, suggestions)
+}

crates/nu-color-config/Cargo.toml

@@ -4,11 +4,11 @@ description = "Color configuration code used by Nushell"
 edition = "2021"
 license = "MIT"
 name = "nu-color-config"
-version = "0.64.0"
+version = "0.65.0"
 
 [dependencies]
-nu-protocol = { path = "../nu-protocol", version = "0.64.0"  }
+nu-protocol = { path = "../nu-protocol", version = "0.65.0"  }
 nu-ansi-term = "0.46.0"
-nu-json = { path = "../nu-json", version = "0.64.0"  }
+nu-json = { path = "../nu-json", version = "0.65.0"  }
-nu-table = { path = "../nu-table", version = "0.64.0"  }
+nu-table = { path = "../nu-table", version = "0.65.0"  }
 serde = { version="1.0.123", features=["derive"] }

crates/nu-command/Cargo.toml

@@ -4,30 +4,31 @@ description = "Nushell's built-in commands"
 edition = "2021"
 license = "MIT"
 name = "nu-command"
-version = "0.64.0"
+version = "0.65.0"
 build = "build.rs"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-nu-color-config = { path = "../nu-color-config", version = "0.64.0"  }
+nu-color-config = { path = "../nu-color-config", version = "0.65.0"  }
-nu-engine = { path = "../nu-engine", version = "0.64.0"  }
+nu-engine = { path = "../nu-engine", version = "0.65.0"  }
-nu-glob = { path = "../nu-glob", version = "0.64.0" }
+nu-glob = { path = "../nu-glob", version = "0.65.0" }
-nu-json = { path = "../nu-json", version = "0.64.0"  }
+nu-json = { path = "../nu-json", version = "0.65.0"  }
-nu-parser = { path = "../nu-parser", version = "0.64.0"  }
+nu-parser = { path = "../nu-parser", version = "0.65.0"  }
-nu-path = { path = "../nu-path", version = "0.64.0"  }
+nu-path = { path = "../nu-path", version = "0.65.0"  }
-nu-pretty-hex = { path = "../nu-pretty-hex", version = "0.64.0"  }
+nu-pretty-hex = { path = "../nu-pretty-hex", version = "0.65.0"  }
-nu-protocol = { path = "../nu-protocol", version = "0.64.0"  }
+nu-protocol = { path = "../nu-protocol", version = "0.65.0"  }
-nu-system = { path = "../nu-system", version = "0.64.0"  }
+nu-system = { path = "../nu-system", version = "0.65.0"  }
-nu-table = { path = "../nu-table", version = "0.64.0"  }
+nu-table = { path = "../nu-table", version = "0.65.0"  }
-nu-term-grid = { path = "../nu-term-grid", version = "0.64.0"  }
+nu-term-grid = { path = "../nu-term-grid", version = "0.65.0"  }
-nu-test-support = { path = "../nu-test-support", version = "0.64.0"  }
+nu-test-support = { path = "../nu-test-support", version = "0.65.0"  }
-nu-utils = { path = "../nu-utils", version = "0.64.0" }
+nu-utils = { path = "../nu-utils", version = "0.65.0" }
 nu-ansi-term = "0.46.0"
 
 # Potential dependencies for extras
 alphanumeric-sort = "1.4.4"
 base64 = "0.13.0"
+byteorder = "1.4.3"
 bytesize = "1.1.0"
 calamine = "0.18.0"
 chrono = { version = "0.4.19", features = ["serde"] }
@@ -76,14 +77,14 @@ shadow-rs = { version = "0.11.0", default-features = false }
 strip-ansi-escapes = "0.1.1"
 sysinfo = "0.23.5"
 terminal_size = "0.1.17"
-thiserror = "1.0.29"
+thiserror = "1.0.31"
 titlecase = "1.1.0"
 toml = "0.5.8"
 unicode-segmentation = "1.8.0"
 url = "2.2.1"
 uuid = { version = "0.8.2", features = ["v4"] }
 which = { version = "4.2.2", optional = true }
-reedline = { version = "0.7.0", features = ["bashisms", "sqlite"]}
+reedline = { version = "0.8.0", features = ["bashisms", "sqlite"]}
 wax = { version =  "0.4.0", features = ["diagnostics"] }
 rusqlite = { version = "0.27.0", features = ["bundled"], optional = true }
 sqlparser = { version = "0.16.0", features = ["serde"], optional = true }
@@ -91,13 +92,14 @@ sqlparser = { version = "0.16.0", features = ["serde"], optional = true }
 [target.'cfg(unix)'.dependencies]
 umask = "2.0.0"
 users = "0.11.0"
+signal-hook = { version = "0.3.14", default-features = false }
 
 [target.'cfg(not(any(target_os = "android", target_os = "ios")))'.dependencies.trash]
 version = "2.1.3"
 optional = true
 
 [dependencies.polars]
-version = "0.21.1"
+version = "0.22.8"
 # path = "../../../../polars/polars"
 optional = true
 features = [
@@ -105,7 +107,7 @@ features = [
 	"object", "checked_arithmetic", "strings", "cum_agg", "is_in",
 	"rolling_window", "strings", "rows", "random",
   "dtype-datetime", "dtype-struct", "lazy", "cross_join",
-	"dynamic_groupby"
+	"dynamic_groupby", "dtype-categorical"
 ]
 
 [target.'cfg(windows)'.dependencies.windows]
@@ -132,3 +134,4 @@ hamcrest2 = "0.3.0"
 dirs-next = "2.0.0"
 quickcheck = "1.0.3"
 quickcheck_macros = "1.0.0"
+rstest = "0.12.0"

crates/nu-command/src/bytes/length.rs

@@ -0,0 +1,98 @@
+use super::{operate, BytesArgument};
+use nu_engine::CallExt;
+use nu_protocol::ast::Call;
+use nu_protocol::ast::CellPath;
+use nu_protocol::engine::{Command, EngineState, Stack};
+use nu_protocol::Category;
+use nu_protocol::{Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Value};
+
+#[derive(Clone)]
+pub struct BytesLen;
+
+struct Arguments {
+    column_paths: Option<Vec<CellPath>>,
+}
+
+impl BytesArgument for Arguments {
+    fn take_column_paths(&mut self) -> Option<Vec<CellPath>> {
+        self.column_paths.take()
+    }
+}
+
+impl Command for BytesLen {
+    fn name(&self) -> &str {
+        "bytes length"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("bytes length")
+            .rest(
+                "rest",
+                SyntaxShape::CellPath,
+                "optionally find length of binary by column paths",
+            )
+            .category(Category::Bytes)
+    }
+
+    fn usage(&self) -> &str {
+        "Output the length of any bytes in the pipeline"
+    }
+
+    fn search_terms(&self) -> Vec<&str> {
+        vec!["len", "size", "count"]
+    }
+
+    fn run(
+        &self,
+        engine_state: &EngineState,
+        stack: &mut Stack,
+        call: &Call,
+        input: PipelineData,
+    ) -> Result<PipelineData, ShellError> {
+        let column_paths: Vec<CellPath> = call.rest(engine_state, stack, 1)?;
+        let column_paths = if column_paths.is_empty() {
+            None
+        } else {
+            Some(column_paths)
+        };
+        let arg = Arguments { column_paths };
+        operate(length, arg, input, call.head, engine_state.ctrlc.clone())
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![
+            Example {
+                description: "Return the lengths of multiple strings",
+                example: "0x[1F FF AA AB] | bytes length",
+                result: Some(Value::test_int(4)),
+            },
+            Example {
+                description: "Return the lengths of multiple strings",
+                example: "[0x[1F FF AA AB] 0x[1F]] | bytes length",
+                result: Some(Value::List {
+                    vals: vec![Value::test_int(4), Value::test_int(1)],
+                    span: Span::test_data(),
+                }),
+            },
+        ]
+    }
+}
+
+fn length(input: &[u8], _arg: &Arguments, span: Span) -> Value {
+    Value::Int {
+        val: input.len() as i64,
+        span,
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn test_examples() {
+        use crate::test_examples;
+
+        test_examples(BytesLen {})
+    }
+}

crates/nu-command/src/bytes/mod.rs

@@ -0,0 +1,77 @@
+mod length;
+mod starts_with;
+use nu_protocol::ast::CellPath;
+use nu_protocol::{PipelineData, ShellError, Span, Value};
+use std::sync::atomic::AtomicBool;
+use std::sync::Arc;
+
+pub use length::BytesLen;
+pub use starts_with::BytesStartsWith;
+
+trait BytesArgument {
+    fn take_column_paths(&mut self) -> Option<Vec<CellPath>>;
+}
+
+/// map input pipeline data, for each elements, if it's Binary, invoke relative `cmd` with `arg`.
+fn operate<C, A>(
+    cmd: C,
+    mut arg: A,
+    input: PipelineData,
+    span: Span,
+    ctrlc: Option<Arc<AtomicBool>>,
+) -> Result<PipelineData, ShellError>
+where
+    A: BytesArgument + Send + Sync + 'static,
+    C: Fn(&[u8], &A, Span) -> Value + Send + Sync + 'static + Clone + Copy,
+{
+    match arg.take_column_paths() {
+        None => input.map(
+            move |v| match v {
+                Value::Binary {
+                    val,
+                    span: val_span,
+                } => cmd(&val, &arg, val_span),
+                other => Value::Error {
+                    error: ShellError::UnsupportedInput(
+                        format!(
+                            "Input's type is {}. This command only works with bytes.",
+                            other.get_type()
+                        ),
+                        span,
+                    ),
+                },
+            },
+            ctrlc,
+        ),
+        Some(column_paths) => {
+            let arg = Arc::new(arg);
+            input.map(
+                move |mut v| {
+                    for path in &column_paths {
+                        let opt = arg.clone();
+                        let r = v.update_cell_path(
+                            &path.members,
+                            Box::new(move |old| {
+                                match old {
+                                    Value::Binary {val, span: val_span} => cmd(val, &opt, *val_span),
+                                    other => Value::Error {
+                                    error: ShellError::UnsupportedInput(
+                                        format!(
+                                            "Input's type is {}. This command only works with bytes.",
+                                            other.get_type()
+                                        ),
+                                        span,
+                                 ),
+                            }}}),
+                        );
+                        if let Err(error) = r {
+                            return Value::Error { error };
+                        }
+                    }
+                    v
+                },
+                ctrlc,
+            )
+        }
+    }
+}

crates/nu-command/src/bytes/starts_with.rs

@@ -0,0 +1,122 @@
+use super::{operate, BytesArgument};
+use nu_engine::CallExt;
+use nu_protocol::ast::Call;
+use nu_protocol::ast::CellPath;
+use nu_protocol::engine::{Command, EngineState, Stack};
+use nu_protocol::Category;
+use nu_protocol::{Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Value};
+
+struct Arguments {
+    pattern: Vec<u8>,
+    column_paths: Option<Vec<CellPath>>,
+}
+
+impl BytesArgument for Arguments {
+    fn take_column_paths(&mut self) -> Option<Vec<CellPath>> {
+        self.column_paths.take()
+    }
+}
+
+#[derive(Clone)]
+
+pub struct BytesStartsWith;
+
+impl Command for BytesStartsWith {
+    fn name(&self) -> &str {
+        "bytes starts-with"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("bytes starts-with")
+            .required("pattern", SyntaxShape::Binary, "the pattern to match")
+            .rest(
+                "rest",
+                SyntaxShape::CellPath,
+                "optionally matches prefix of text by column paths",
+            )
+            .category(Category::Bytes)
+    }
+
+    fn usage(&self) -> &str {
+        "Check if bytes starts with a pattern"
+    }
+
+    fn search_terms(&self) -> Vec<&str> {
+        vec!["pattern", "match", "find", "search"]
+    }
+
+    fn run(
+        &self,
+        engine_state: &EngineState,
+        stack: &mut Stack,
+        call: &Call,
+        input: PipelineData,
+    ) -> Result<PipelineData, ShellError> {
+        let pattern: Vec<u8> = call.req(engine_state, stack, 0)?;
+        let column_paths: Vec<CellPath> = call.rest(engine_state, stack, 1)?;
+        let column_paths = if column_paths.is_empty() {
+            None
+        } else {
+            Some(column_paths)
+        };
+        let arg = Arguments {
+            pattern,
+            column_paths,
+        };
+        operate(
+            starts_with,
+            arg,
+            input,
+            call.head,
+            engine_state.ctrlc.clone(),
+        )
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![
+            Example {
+                description: "Checks if binary starts with `0x[1F FF AA]`",
+                example: "0x[1F FF AA AA] | bytes starts-with 0x[1F FF AA]",
+                result: Some(Value::Bool {
+                    val: true,
+                    span: Span::test_data(),
+                }),
+            },
+            Example {
+                description: "Checks if binary starts with `0x[1F]`",
+                example: "0x[1F FF AA AA] | bytes starts-with 0x[1F]",
+                result: Some(Value::Bool {
+                    val: true,
+                    span: Span::test_data(),
+                }),
+            },
+            Example {
+                description: "Checks if binary starts with `0x[1F]`",
+                example: "0x[1F FF AA AA] | bytes starts-with 0x[11]",
+                result: Some(Value::Bool {
+                    val: false,
+                    span: Span::test_data(),
+                }),
+            },
+        ]
+    }
+}
+
+fn starts_with(input: &[u8], Arguments { pattern, .. }: &Arguments, span: Span) -> Value {
+    Value::Bool {
+        val: input.starts_with(pattern),
+        span,
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_examples() {
+        use crate::test_examples;
+
+        test_examples(BytesStartsWith {})
+    }
+}

crates/nu-command/src/conversions/into/datetime.rs

@@ -1,3 +1,4 @@
+use crate::{generate_strftime_list, parse_date_from_string};
 use chrono::{DateTime, FixedOffset, Local, TimeZone, Utc};
 use nu_engine::CallExt;
 use nu_protocol::ast::Call;
@@ -7,9 +8,6 @@ use nu_protocol::{
     Category, Example, PipelineData, ShellError, Signature, Span, Spanned, SyntaxShape, Value,
 };
 
-use crate::generate_strftime_list;
-use crate::parse_date_from_string;
-
 struct Arguments {
     timezone: Option<Spanned<String>>,
     offset: Option<Spanned<i64>>,
@@ -148,6 +146,15 @@ impl Command for SubCommand {
                 example: "1614434140 | into datetime -o +9",
                 result: None,
             },
+            Example {
+                description:
+                    "Convert timestamps like the sqlite history t",
+                example: "1656165681720 | into datetime",
+                result: Some(Value::Date {
+                    val: Utc.timestamp_millis(1656165681720).into(),
+                    span: Span::test_data(),
+                }),
+            },
         ]
     }
 }
@@ -251,10 +258,19 @@ fn action(
 
         return match timezone {
             // default to UTC
-            None => Value::Date {
+            None => {
-                val: Utc.timestamp(ts, 0).into(),
+                // be able to convert chrono::Utc::now()
-                span: head,
+                let dt = match ts.to_string().len() {
-            },
+                    x if x > 13 => Utc.timestamp_nanos(ts).into(),
+                    x if x > 10 => Utc.timestamp_millis(ts).into(),
+                    _ => Utc.timestamp(ts, 0).into(),
+                };
+
+                Value::Date {
+                    val: dt,
+                    span: head,
+                }
+            }
             Some(Spanned { item, span }) => match item {
                 Zone::Utc => Value::Date {
                     val: Utc.timestamp(ts, 0).into(),

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

@@ -8,6 +8,7 @@ use nu_protocol::{
 struct Arguments {
     radix: Option<Value>,
     column_paths: Vec<CellPath>,
+    little_endian: bool,
 }
 
 #[derive(Clone)]
@@ -21,6 +22,7 @@ impl Command for SubCommand {
     fn signature(&self) -> Signature {
         Signature::build("into int")
             .named("radix", SyntaxShape::Number, "radix of integer", Some('r'))
+            .switch("little-endian", "use little-endian byte decoding", None)
             .rest(
                 "rest",
                 SyntaxShape::CellPath,
@@ -114,6 +116,7 @@ fn into_int(
 
     let options = Arguments {
         radix: call.get_flag(engine_state, stack, "radix")?,
+        little_endian: call.has_flag("little-endian"),
         column_paths: call.rest(engine_state, stack, 0)?,
     };
 
@@ -135,13 +138,13 @@ fn into_int(
     input.map(
         move |v| {
             if options.column_paths.is_empty() {
-                action(&v, head, radix)
+                action(&v, head, radix, options.little_endian)
             } else {
                 let mut ret = v;
                 for path in &options.column_paths {
                     let r = ret.update_cell_path(
                         &path.members,
-                        Box::new(move |old| action(old, head, radix)),
+                        Box::new(move |old| action(old, head, radix, options.little_endian)),
                     );
                     if let Err(error) = r {
                         return Value::Error { error };
@@ -155,7 +158,7 @@ fn into_int(
     )
 }
 
-pub fn action(input: &Value, span: Span, radix: u32) -> Value {
+pub fn action(input: &Value, span: Span, radix: u32, little_endian: bool) -> Value {
     match input {
         Value::Int { val: _, .. } => {
             if radix == 10 {
@@ -190,6 +193,33 @@ pub fn action(input: &Value, span: Span, radix: u32) -> Value {
             val: val.timestamp(),
             span,
         },
+        Value::Binary { val, span } => {
+            use byteorder::{BigEndian, ByteOrder, LittleEndian};
+
+            let mut val = val.to_vec();
+
+            if little_endian {
+                while val.len() < 8 {
+                    val.push(0);
+                }
+                val.resize(8, 0);
+
+                Value::Int {
+                    val: LittleEndian::read_i64(&val),
+                    span: *span,
+                }
+            } else {
+                while val.len() < 8 {
+                    val.insert(0, 0);
+                }
+                val.resize(8, 0);
+
+                Value::Int {
+                    val: BigEndian::read_i64(&val),
+                    span: *span,
+                }
+            }
+        }
         _ => Value::Error {
             error: ShellError::UnsupportedInput(
                 format!("'into int' for unsupported type '{}'", input.get_type()),
@@ -294,21 +324,21 @@ mod test {
         let word = Value::test_string("10");
         let expected = Value::test_int(10);
 
-        let actual = action(&word, Span::test_data(), 10);
+        let actual = action(&word, Span::test_data(), 10, false);
         assert_eq!(actual, expected);
     }
 
     #[test]
     fn turns_binary_to_integer() {
         let s = Value::test_string("0b101");
-        let actual = action(&s, Span::test_data(), 10);
+        let actual = action(&s, Span::test_data(), 10, false);
         assert_eq!(actual, Value::test_int(5));
     }
 
     #[test]
     fn turns_hex_to_integer() {
         let s = Value::test_string("0xFF");
-        let actual = action(&s, Span::test_data(), 16);
+        let actual = action(&s, Span::test_data(), 16, false);
         assert_eq!(actual, Value::test_int(255));
     }
 
@@ -316,7 +346,7 @@ mod test {
     fn communicates_parsing_error_given_an_invalid_integerlike_string() {
         let integer_str = Value::test_string("36anra");
 
-        let actual = action(&integer_str, Span::test_data(), 10);
+        let actual = action(&integer_str, Span::test_data(), 10, false);
 
         assert_eq!(actual.get_type(), Error)
     }

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

@@ -2,8 +2,8 @@ use nu_engine::CallExt;
 use nu_protocol::{
     ast::{Call, CellPath},
     engine::{Command, EngineState, Stack},
-    Category, Config, Example, IntoPipelineData, PipelineData, ShellError, Signature, Span,
+    into_code, Category, Config, Example, IntoPipelineData, PipelineData, ShellError, Signature,
-    SyntaxShape, Value,
+    Span, SyntaxShape, Value,
 };
 
 // TODO num_format::SystemLocale once platform-specific dependencies are stable (see Cargo.toml)
@@ -247,6 +247,15 @@ pub fn action(
             val: input.into_string(", ", config),
             span,
         },
+        Value::Error { error } => Value::String {
+            val: {
+                match into_code(error) {
+                    Some(code) => code,
+                    None => "".to_string(),
+                }
+            },
+            span,
+        },
         Value::Nothing { .. } => Value::String {
             val: "".to_string(),
             span,

crates/nu-command/src/core_commands/def_env.rs

@@ -28,7 +28,33 @@ impl Command for DefEnv {
 
     fn extra_usage(&self) -> &str {
         r#"This command is a parser keyword. For details, check:
-  https://www.nushell.sh/book/thinking_in_nushell.html"#
+  https://www.nushell.sh/book/thinking_in_nushell.html
+
+=== EXTRA NOTE ===
+All blocks are scoped, including variable definition and environment variable changes.
+
+Because of this, the following doesn't work:
+
+def-env cd_with_fallback [arg = ""] {
+    let fall_back_path = "/tmp"
+    if $arg != "" {
+        cd $arg
+    } else {
+        cd $fall_back_path
+    }
+}
+
+Instead, you have to use cd in the top level scope:
+
+def-env cd_with_fallback [arg = ""] {
+    let fall_back_path = "/tmp"
+    let path = if $arg != "" {
+        $arg
+    } else {
+        $fall_back_path
+    }
+    cd $path
+}"#
     }
 
     fn is_parser_keyword(&self) -> bool {

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

@@ -1,7 +1,9 @@
 use nu_engine::{eval_block, CallExt};
 use nu_protocol::ast::Call;
 use nu_protocol::engine::{CaptureBlock, Command, EngineState, Stack};
-use nu_protocol::{Category, Example, PipelineData, Signature, SyntaxShape, Value};
+use nu_protocol::{
+    Category, Example, IntoPipelineData, PipelineData, Signature, SyntaxShape, Value,
+};
 
 #[derive(Clone)]
 pub struct Do;
@@ -23,6 +25,11 @@ impl Command for Do {
                 "ignore errors as the block runs",
                 Some('i'),
             )
+            .switch(
+                "capture-errors",
+                "capture errors as the block runs and return it",
+                Some('c'),
+            )
             .rest("rest", SyntaxShape::Any, "the parameter(s) for the block")
             .category(Category::Core)
     }
@@ -37,6 +44,7 @@ impl Command for Do {
         let block: CaptureBlock = call.req(engine_state, stack, 0)?;
         let rest: Vec<Value> = call.rest(engine_state, stack, 1)?;
         let ignore_errors = call.has_flag("ignore-errors");
+        let capture_errors = call.has_flag("capture-errors");
 
         let mut stack = stack.captures_to_stack(&block.captures);
         let block = engine_state.get_block(block.block_id);
@@ -85,7 +93,7 @@ impl Command for Do {
             block,
             input,
             call.redirect_stdout,
-            ignore_errors,
+            ignore_errors || capture_errors,
         );
 
         if ignore_errors {
@@ -93,6 +101,11 @@ impl Command for Do {
                 Ok(x) => Ok(x),
                 Err(_) => Ok(PipelineData::new(call.head)),
             }
+        } else if capture_errors {
+            match result {
+                Ok(x) => Ok(x),
+                Err(err) => Ok((Value::Error { error: err }).into_pipeline_data()),
+            }
         } else {
             result
         }

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

@@ -23,6 +23,10 @@ impl Command for Echo {
             .category(Category::Core)
     }
 
+    fn extra_usage(&self) -> &str {
+        "Unlike `print`, this command returns an actual value that will be passed to the next command of the pipeline."
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/core_commands/error_make.rs

@@ -2,8 +2,7 @@ use nu_engine::CallExt;
 use nu_protocol::ast::Call;
 use nu_protocol::engine::{Command, EngineState, Stack};
 use nu_protocol::{
-    Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, Span, SyntaxShape,
+    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Value,
-    Value,
 };
 
 #[derive(Clone)]
@@ -16,7 +15,7 @@ impl Command for ErrorMake {
 
     fn signature(&self) -> Signature {
         Signature::build("error make")
-            .optional("error_struct", SyntaxShape::Record, "the error to create")
+            .required("error_struct", SyntaxShape::Record, "the error to create")
             .category(Category::Core)
     }
 
@@ -33,43 +32,20 @@ impl Command for ErrorMake {
         engine_state: &EngineState,
         stack: &mut Stack,
         call: &Call,
-        input: PipelineData,
+        _input: PipelineData,
     ) -> Result<nu_protocol::PipelineData, nu_protocol::ShellError> {
         let span = call.head;
-        let ctrlc = engine_state.ctrlc.clone();
+        let arg: Value = call.req(engine_state, stack, 0)?;
-        let arg: Option<Value> = call.opt(engine_state, stack, 0)?;
 
-        if let Some(arg) = arg {
+        Err(make_error(&arg, span).unwrap_or_else(|| {
-            Ok(make_error(&arg, span)
+            ShellError::GenericError(
-                .map(|err| Value::Error { error: err })
+                "Creating error value not supported.".into(),
-                .unwrap_or_else(|| Value::Error {
+                "unsupported error format".into(),
-                    error: ShellError::GenericError(
+                Some(span),
-                        "Creating error value not supported.".into(),
+                None,
-                        "unsupported error format".into(),
+                Vec::new(),
-                        Some(span),
-                        None,
-                        Vec::new(),
-                    ),
-                })
-                .into_pipeline_data())
-        } else {
-            input.map(
-                move |value| {
-                    make_error(&value, span)
-                        .map(|err| Value::Error { error: err })
-                        .unwrap_or_else(|| Value::Error {
-                            error: ShellError::GenericError(
-                                "Creating error value not supported.".into(),
-                                "unsupported error format".into(),
-                                Some(span),
-                                None,
-                                Vec::new(),
-                            ),
-                        })
-                },
-                ctrlc,
             )
-        }
+        }))
     }
 
     fn examples(&self) -> Vec<Example> {

crates/nu-command/src/core_commands/export_def_env.rs

@@ -28,7 +28,33 @@ impl Command for ExportDefEnv {
 
     fn extra_usage(&self) -> &str {
         r#"This command is a parser keyword. For details, check:
-  https://www.nushell.sh/book/thinking_in_nushell.html"#
+  https://www.nushell.sh/book/thinking_in_nushell.html
+
+=== EXTRA NOTE ===
+All blocks are scoped, including variable definition and environment variable changes.
+
+Because of this, the following doesn't work:
+
+export def-env cd_with_fallback [arg = ""] {
+    let fall_back_path = "/tmp"
+    if $arg != "" {
+        cd $arg
+    } else {
+        cd $fall_back_path
+    }
+}
+
+Instead, you have to use cd in the top level scope:
+
+export def-env cd_with_fallback [arg = ""] {
+    let fall_back_path = "/tmp"
+    let path = if $arg != "" {
+        $arg
+    } else {
+        $fall_back_path
+    }
+    cd $path
+}"#
     }
 
     fn is_parser_keyword(&self) -> bool {

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

@@ -1,131 +0,0 @@
-use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, Stack};
-use nu_protocol::{
-    Category, Example, HistoryFileFormat, IntoInterruptiblePipelineData, PipelineData, ShellError,
-    Signature, Value,
-};
-use reedline::{
-    FileBackedHistory, History as ReedlineHistory, SearchDirection, SearchQuery,
-    SqliteBackedHistory,
-};
-
-#[derive(Clone)]
-pub struct History;
-
-impl Command for History {
-    fn name(&self) -> &str {
-        "history"
-    }
-
-    fn usage(&self) -> &str {
-        "Get the command history"
-    }
-
-    fn signature(&self) -> nu_protocol::Signature {
-        Signature::build("history")
-            .switch("clear", "Clears out the history entries", Some('c'))
-            .category(Category::Core)
-    }
-
-    fn run(
-        &self,
-        engine_state: &EngineState,
-        _stack: &mut Stack,
-        call: &Call,
-        _input: PipelineData,
-    ) -> Result<nu_protocol::PipelineData, nu_protocol::ShellError> {
-        let head = call.head;
-        // todo for sqlite history this command should be an alias to `open ~/.config/nushell/history.sqlite3 | get history`
-        if let Some(config_path) = nu_path::config_dir() {
-            let clear = call.has_flag("clear");
-            let ctrlc = engine_state.ctrlc.clone();
-
-            let mut history_path = config_path;
-            history_path.push("nushell");
-            match engine_state.config.history_file_format {
-                HistoryFileFormat::Sqlite => {
-                    history_path.push("history.sqlite3");
-                }
-                HistoryFileFormat::PlainText => {
-                    history_path.push("history.txt");
-                }
-            }
-
-            if clear {
-                let _ = std::fs::remove_file(history_path);
-                // TODO: FIXME also clear the auxiliary files when using sqlite
-                Ok(PipelineData::new(head))
-            } else {
-                let history_reader: Option<Box<dyn ReedlineHistory>> =
-                    match engine_state.config.history_file_format {
-                        HistoryFileFormat::Sqlite => SqliteBackedHistory::with_file(history_path)
-                            .map(|inner| {
-                                let boxed: Box<dyn ReedlineHistory> = Box::new(inner);
-                                boxed
-                            })
-                            .ok(),
-
-                        HistoryFileFormat::PlainText => FileBackedHistory::with_file(
-                            engine_state.config.max_history_size as usize,
-                            history_path,
-                        )
-                        .map(|inner| {
-                            let boxed: Box<dyn ReedlineHistory> = Box::new(inner);
-                            boxed
-                        })
-                        .ok(),
-                    };
-
-                let data = history_reader
-                    .and_then(|h| {
-                        h.search(SearchQuery::everything(SearchDirection::Forward))
-                            .ok()
-                    })
-                    .map(move |entries| {
-                        entries
-                            .into_iter()
-                            .enumerate()
-                            .map(move |(idx, entry)| Value::Record {
-                                cols: vec!["command".to_string(), "index".to_string()],
-                                vals: vec![
-                                    Value::String {
-                                        val: entry.command_line,
-                                        span: head,
-                                    },
-                                    Value::Int {
-                                        val: idx as i64,
-                                        span: head,
-                                    },
-                                ],
-                                span: head,
-                            })
-                    })
-                    .ok_or(ShellError::FileNotFound(head))?
-                    .into_pipeline_data(ctrlc);
-                Ok(data)
-            }
-        } else {
-            Err(ShellError::FileNotFound(head))
-        }
-    }
-
-    fn examples(&self) -> Vec<Example> {
-        vec![
-            Example {
-                example: "history | length",
-                description: "Get current history length",
-                result: None,
-            },
-            Example {
-                example: "history | last 5",
-                description: "Show last 5 commands you have ran",
-                result: None,
-            },
-            Example {
-                example: "history | wrap cmd | where cmd =~ cargo",
-                description: "Search all the commands from history that contains 'cargo'",
-                result: None,
-            },
-        ]
-    }
-}

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

@@ -16,7 +16,6 @@ mod extern_;
 mod for_;
 mod help;
 mod hide;
-mod history;
 mod if_;
 mod ignore;
 mod let_;
@@ -24,7 +23,6 @@ mod metadata;
 mod module;
 pub(crate) mod overlay;
 mod source;
-mod tutor;
 mod use_;
 mod version;
 
@@ -46,7 +44,6 @@ pub use extern_::Extern;
 pub use for_::For;
 pub use help::Help;
 pub use hide::Hide;
-pub use history::History;
 pub use if_::If;
 pub use ignore::Ignore;
 pub use let_::Let;
@@ -54,7 +51,6 @@ pub use metadata::Metadata;
 pub use module::Module;
 pub use overlay::*;
 pub use source::Source;
-pub use tutor::Tutor;
 pub use use_::Use;
 pub use version::Version;
 #[cfg(feature = "plugin")]

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

@@ -1,26 +1,26 @@
-use crate::{
+use crate::SQLiteDatabase;
-    database::values::dsl::{ExprDb, SelectDb},
-    SQLiteDatabase,
-};
 use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, SyntaxShape,
+    Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, Span, SyntaxShape,
+    Type, Value,
 };
-use sqlparser::ast::{Ident, SelectItem, SetExpr, Statement, TableAlias, TableFactor};
+use sqlparser::ast::{Ident, SetExpr, Statement, TableAlias, TableFactor};
 
 #[derive(Clone)]
-pub struct AliasExpr;
+pub struct AliasDb;
 
-impl Command for AliasExpr {
+impl Command for AliasDb {
     fn name(&self) -> &str {
-        "db as"
+        "as"
     }
 
     fn signature(&self) -> Signature {
         Signature::build(self.name())
             .required("alias", SyntaxShape::String, "alias name")
+            .input_type(Type::Custom("database".into()))
+            .output_type(Type::Custom("database".into()))
             .category(Category::Custom("database".into()))
     }
 
@@ -29,11 +29,59 @@ impl Command for AliasExpr {
     }
 
     fn examples(&self) -> Vec<Example> {
-        vec![Example {
+        vec![
-            description: "Creates an alias for a column selection",
+            Example {
-            example: "db col name_a | db as new_a",
+                description: "Creates an alias for a selected table",
-            result: None,
+                example: r#"open db.mysql
-        }]
+    | into db
+    | select a
+    | from table_1
+    | as t1
+    | describe"#,
+                result: Some(Value::Record {
+                    cols: vec!["connection".into(), "query".into()],
+                    vals: vec![
+                        Value::String {
+                            val: "db.mysql".into(),
+                            span: Span::test_data(),
+                        },
+                        Value::String {
+                            val: "SELECT a FROM table_1 AS t1".into(),
+                            span: Span::test_data(),
+                        },
+                    ],
+                    span: Span::test_data(),
+                }),
+            },
+            Example {
+                description: "Creates an alias for a derived table",
+                example: r#"open db.mysql
+    | into db
+    | select a
+    | from (
+        open db.mysql
+        | into db
+        | select a b
+        | from table_a
+      )
+    | as t1
+    | describe"#,
+                result: Some(Value::Record {
+                    cols: vec!["connection".into(), "query".into()],
+                    vals: vec![
+                        Value::String {
+                            val: "db.mysql".into(),
+                            span: Span::test_data(),
+                        },
+                        Value::String {
+                            val: "SELECT a FROM (SELECT a, b FROM table_a) AS t1".into(),
+                            span: Span::test_data(),
+                        },
+                    ],
+                    span: Span::test_data(),
+                }),
+            },
+        ]
     }
 
     fn search_terms(&self) -> Vec<&str> {
@@ -48,52 +96,12 @@ impl Command for AliasExpr {
         input: PipelineData,
     ) -> Result<PipelineData, ShellError> {
         let alias: String = call.req(engine_state, stack, 0)?;
-        let value = input.into_value(call.head);
 
-        if let Ok(expr) = ExprDb::try_from_value(&value) {
+        let db = SQLiteDatabase::try_from_pipeline(input, call.head)?;
-            alias_selection(expr.into_native().into(), alias, call)
+        alias_db(db, alias, call)
-        } else if let Ok(select) = SelectDb::try_from_value(&value) {
-            alias_selection(select, alias, call)
-        } else if let Ok(db) = SQLiteDatabase::try_from_value(value.clone()) {
-            alias_db(db, alias, call)
-        } else {
-            Err(ShellError::CantConvert(
-                "expression or query".into(),
-                value.get_type().to_string(),
-                value.span()?,
-                None,
-            ))
-        }
     }
 }
 
-fn alias_selection(
-    select: SelectDb,
-    alias: String,
-    call: &Call,
-) -> Result<PipelineData, ShellError> {
-    let select = match select.into_native() {
-        SelectItem::UnnamedExpr(expr) => SelectItem::ExprWithAlias {
-            expr,
-            alias: Ident {
-                value: alias,
-                quote_style: None,
-            },
-        },
-        SelectItem::ExprWithAlias { expr, .. } => SelectItem::ExprWithAlias {
-            expr,
-            alias: Ident {
-                value: alias,
-                quote_style: None,
-            },
-        },
-        select => select,
-    };
-
-    let select: SelectDb = select.into();
-    Ok(select.into_value(call.head).into_pipeline_data())
-}
-
 fn alias_db(
     mut db: SQLiteDatabase,
     new_alias: String,
@@ -142,7 +150,7 @@ fn alias_db(
             },
             s => {
                 return Err(ShellError::GenericError(
-                    "Connection doesnt define a query".into(),
+                    "Connection doesn't define a query".into(),
                     format!("Expected a connection with query. Got {}", s),
                     Some(call.head),
                     None,
@@ -152,3 +160,19 @@ fn alias_db(
         },
     }
 }
+
+#[cfg(test)]
+mod test {
+    use super::super::{FromDb, ProjectionDb};
+    use super::*;
+    use crate::database::test_database::test_database;
+
+    #[test]
+    fn test_examples() {
+        test_database(vec![
+            Box::new(AliasDb {}),
+            Box::new(ProjectionDb {}),
+            Box::new(FromDb {}),
+        ])
+    }
+}

crates/nu-command/src/database/commands/and.rs

@@ -6,7 +6,7 @@ use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
     Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, Span, SyntaxShape,
-    Value,
+    Type, Value,
 };
 use sqlparser::ast::{BinaryOperator, Expr, Query, Select, SetExpr, Statement};
 
@@ -15,16 +15,18 @@ pub struct AndDb;
 
 impl Command for AndDb {
     fn name(&self) -> &str {
-        "db and"
+        "and"
     }
 
     fn usage(&self) -> &str {
-        "Includes an AND clause for a query or expression"
+        "Includes an AND clause for a query"
     }
 
     fn signature(&self) -> Signature {
         Signature::build(self.name())
             .required("where", SyntaxShape::Any, "Where expression on the table")
+            .input_type(Type::Custom("database".into()))
+            .output_type(Type::Custom("database".into()))
             .category(Category::Custom("database".into()))
     }
 
@@ -35,23 +37,52 @@ impl Command for AndDb {
     fn examples(&self) -> Vec<Example> {
         vec![
             Example {
-                description: "selects a column from a database with a where clause",
+                description: "Selects a column from a database with an AND clause",
-                example: r#"db open db.mysql 
+                example: r#"open db.mysql
-    | db select a 
+    | into db
-    | db from table_1 
+    | select a
-    | db where ((db col a) > 1) 
+    | from table_1
-    | db and ((db col b) == 1) 
+    | where ((field a) > 1)
-    | db describe"#,
+    | and ((field b) == 1)
-                result: None,
+    | describe"#,
+                result: Some(Value::Record {
+                    cols: vec!["connection".into(), "query".into()],
+                    vals: vec![
+                        Value::String {
+                            val: "db.mysql".into(),
+                            span: Span::test_data(),
+                        },
+                        Value::String {
+                            val: "SELECT a FROM table_1 WHERE a > 1 AND b = 1".into(),
+                            span: Span::test_data(),
+                        },
+                    ],
+                    span: Span::test_data(),
+                }),
             },
             Example {
-                description: "Creates a nested where clause",
+                description: "Creates a AND clause combined with an expression AND",
-                example: r#"db open db.mysql 
+                example: r#"open db.mysql
-    | db select a 
+    | into db
-    | db from table_1 
+    | select a
-    | db where ((db col a) > 1 | db and ((db col a) < 10)) 
+    | from table_1
-    | db describe"#,
+    | where ((field a) > 1 | and ((field a) < 10))
-                result: None,
+    | and ((field b) == 1)
+    | describe"#,
+                result: Some(Value::Record {
+                    cols: vec!["connection".into(), "query".into()],
+                    vals: vec![
+                        Value::String {
+                            val: "db.mysql".into(),
+                            span: Span::test_data(),
+                        },
+                        Value::String {
+                            val: "SELECT a FROM table_1 WHERE (a > 1 AND a < 10) AND b = 1".into(),
+                            span: Span::test_data(),
+                        },
+                    ],
+                    span: Span::test_data(),
+                }),
             },
         ]
     }
@@ -66,51 +97,32 @@ impl Command for AndDb {
         let value: Value = call.req(engine_state, stack, 0)?;
         let expr = ExprDb::try_from_value(&value)?.into_native();
 
-        let value = input.into_value(call.head);
+        let mut db = SQLiteDatabase::try_from_pipeline(input, call.head)?;
-        if let Ok(expression) = ExprDb::try_from_value(&value) {
+        match db.statement.as_mut() {
-            let expression = Expr::BinaryOp {
+            Some(statement) => match statement {
-                left: Box::new(expression.into_native()),
+                Statement::Query(query) => modify_query(query, expr, call.head)?,
-                op: BinaryOperator::And,
+                s => {
-                right: Box::new(expr),
-            };
-
-            let expression: ExprDb = Expr::Nested(Box::new(expression)).into();
-
-            Ok(expression.into_value(call.head).into_pipeline_data())
-        } else if let Ok(mut db) = SQLiteDatabase::try_from_value(value.clone()) {
-            match db.statement.as_mut() {
-                Some(statement) => match statement {
-                    Statement::Query(query) => modify_query(query, expr, call.head)?,
-                    s => {
-                        return Err(ShellError::GenericError(
-                            "Connection doesnt define a query".into(),
-                            format!("Expected a connection with query. Got {}", s),
-                            Some(call.head),
-                            None,
-                            Vec::new(),
-                        ))
-                    }
-                },
-                None => {
                     return Err(ShellError::GenericError(
-                        "Connection without statement".into(),
+                        "Connection doesn't define a query".into(),
-                        "The connection needs a statement defined".into(),
+                        format!("Expected a connection with query. Got {}", s),
                         Some(call.head),
                         None,
                         Vec::new(),
                     ))
                 }
-            };
+            },
+            None => {
+                return Err(ShellError::GenericError(
+                    "Connection without statement".into(),
+                    "The connection needs a statement defined".into(),
+                    Some(call.head),
+                    None,
+                    Vec::new(),
+                ))
+            }
+        };
 
-            Ok(db.into_value(call.head).into_pipeline_data())
+        Ok(db.into_value(call.head).into_pipeline_data())
-        } else {
-            Err(ShellError::CantConvert(
-                "expression or query".into(),
-                value.get_type().to_string(),
-                value.span()?,
-                None,
-            ))
-        }
     }
 }
 
@@ -150,3 +162,23 @@ fn modify_select(select: &mut Box<Select>, expression: Expr, span: Span) -> Resu
     select.as_mut().selection = Some(new_expression);
     Ok(())
 }
+
+#[cfg(test)]
+mod test {
+    use super::super::super::expressions::{AndExpr, FieldExpr};
+    use super::super::{FromDb, ProjectionDb, WhereDb};
+    use super::*;
+    use crate::database::test_database::test_database;
+
+    #[test]
+    fn test_examples() {
+        test_database(vec![
+            Box::new(AndDb {}),
+            Box::new(ProjectionDb {}),
+            Box::new(FromDb {}),
+            Box::new(WhereDb {}),
+            Box::new(FieldExpr {}),
+            Box::new(AndExpr {}),
+        ])
+    }
+}

crates/nu-command/src/database/commands/col.rs

@@ -1,51 +0,0 @@
-use crate::database::values::dsl::ExprDb;
-use nu_engine::CallExt;
-use nu_protocol::{
-    ast::Call,
-    engine::{Command, EngineState, Stack},
-    Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, SyntaxShape, Value,
-};
-
-#[derive(Clone)]
-pub struct ColExpr;
-
-impl Command for ColExpr {
-    fn name(&self) -> &str {
-        "db col"
-    }
-
-    fn signature(&self) -> Signature {
-        Signature::build(self.name())
-            .required("name", SyntaxShape::String, "column name")
-            .category(Category::Custom("database".into()))
-    }
-
-    fn usage(&self) -> &str {
-        "Creates column expression for database"
-    }
-
-    fn examples(&self) -> Vec<Example> {
-        vec![Example {
-            description: "Creates a named column expression",
-            example: "db col name_1",
-            result: None,
-        }]
-    }
-
-    fn search_terms(&self) -> Vec<&str> {
-        vec!["database", "column", "expression"]
-    }
-
-    fn run(
-        &self,
-        engine_state: &EngineState,
-        stack: &mut Stack,
-        call: &Call,
-        _input: PipelineData,
-    ) -> Result<PipelineData, ShellError> {
-        let value: Value = call.req(engine_state, stack, 0)?;
-        let expression = ExprDb::try_from_value(&value)?;
-
-        Ok(expression.into_value(call.head).into_pipeline_data())
-    }
-}

crates/nu-command/src/database/commands/collect.rs

@@ -1,7 +1,7 @@
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, IntoPipelineData, PipelineData, ShellError, Signature,
+    Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, Type,
 };
 
 use super::super::SQLiteDatabase;
@@ -11,21 +11,24 @@ pub struct CollectDb;
 
 impl Command for CollectDb {
     fn name(&self) -> &str {
-        "db collect"
+        "collect"
     }
 
     fn signature(&self) -> Signature {
-        Signature::build(self.name()).category(Category::Custom("database".into()))
+        Signature::build(self.name())
+            .input_type(Type::Custom("database".into()))
+            .output_type(Type::Any)
+            .category(Category::Custom("database".into()))
     }
 
     fn usage(&self) -> &str {
-        "Query a database using SQL."
+        "Collects a query from a database database connection"
     }
 
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Collect from a select query",
-            example: "open foo.db | db select a | db from table_1 | db collect",
+            example: "open foo.db | into db | select a | from table_1 | collect",
             result: None,
         }]
     }

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

@@ -1,42 +0,0 @@
-use nu_engine::get_full_help;
-use nu_protocol::{
-    ast::Call,
-    engine::{Command, EngineState, Stack},
-    Category, IntoPipelineData, PipelineData, ShellError, Signature, Value,
-};
-
-#[derive(Clone)]
-pub struct Database;
-
-impl Command for Database {
-    fn name(&self) -> &str {
-        "db"
-    }
-
-    fn usage(&self) -> &str {
-        "Database commands"
-    }
-
-    fn signature(&self) -> Signature {
-        Signature::build(self.name()).category(Category::Custom("database".into()))
-    }
-
-    fn run(
-        &self,
-        engine_state: &EngineState,
-        stack: &mut Stack,
-        call: &Call,
-        _input: PipelineData,
-    ) -> Result<PipelineData, ShellError> {
-        Ok(Value::String {
-            val: get_full_help(
-                &Database.signature(),
-                &Database.examples(),
-                engine_state,
-                stack,
-            ),
-            span: call.head,
-        }
-        .into_pipeline_data())
-    }
-}

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

@@ -1,7 +1,7 @@
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, IntoPipelineData, PipelineData, ShellError, Signature,
+    Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, Span, Type, Value,
 };
 
 use super::super::SQLiteDatabase;
@@ -11,11 +11,14 @@ pub struct DescribeDb;
 
 impl Command for DescribeDb {
     fn name(&self) -> &str {
-        "db describe"
+        "describe"
     }
 
     fn signature(&self) -> Signature {
-        Signature::build(self.name()).category(Category::Custom("database".into()))
+        Signature::build(self.name())
+            .input_type(Type::Custom("database".into()))
+            .output_type(Type::Any)
+            .category(Category::Custom("database".into()))
     }
 
     fn usage(&self) -> &str {
@@ -25,13 +28,26 @@ impl Command for DescribeDb {
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Describe SQLite database constructed query",
-            example: "db open foo.db | db select table_1 | db describe",
+            example: "open foo.db | into db | select col_1 | from table_1 | describe",
-            result: None,
+            result: Some(Value::Record {
+                cols: vec!["connection".into(), "query".into()],
+                vals: vec![
+                    Value::String {
+                        val: "foo.db".into(),
+                        span: Span::test_data(),
+                    },
+                    Value::String {
+                        val: "SELECT col_1 FROM table_1".into(),
+                        span: Span::test_data(),
+                    },
+                ],
+                span: Span::test_data(),
+            }),
         }]
     }
 
     fn search_terms(&self) -> Vec<&str> {
-        vec!["database", "SQLite"]
+        vec!["database", "SQLite", "describe"]
     }
 
     fn run(
@@ -45,3 +61,19 @@ impl Command for DescribeDb {
         Ok(db.describe(call.head).into_pipeline_data())
     }
 }
+
+#[cfg(test)]
+mod test {
+    use super::super::{FromDb, ProjectionDb};
+    use super::*;
+    use crate::database::test_database::test_database;
+
+    #[test]
+    fn test_examples() {
+        test_database(vec![
+            Box::new(DescribeDb {}),
+            Box::new(ProjectionDb {}),
+            Box::new(FromDb {}),
+        ])
+    }
+}

crates/nu-command/src/database/commands/from.rs

@@ -5,7 +5,8 @@ use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, SyntaxShape, Value,
+    Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, Span, SyntaxShape,
+    Type, Value,
 };
 use sqlparser::ast::{Ident, Query, Select, SetExpr, Statement, TableAlias, TableWithJoins};
 
@@ -14,7 +15,7 @@ pub struct FromDb;
 
 impl Command for FromDb {
     fn name(&self) -> &str {
-        "db from"
+        "from"
     }
 
     fn usage(&self) -> &str {
@@ -34,6 +35,8 @@ impl Command for FromDb {
                 "Alias for the selected table",
                 Some('a'),
             )
+            .input_type(Type::Custom("database".into()))
+            .output_type(Type::Custom("database".into()))
             .category(Category::Custom("database".into()))
     }
 
@@ -43,9 +46,22 @@ impl Command for FromDb {
 
     fn examples(&self) -> Vec<Example> {
         vec![Example {
-            description: "Selects table from database",
+            description: "Selects a table from database",
-            example: "db open db.mysql | db from table_a",
+            example: "open db.mysql | into db | from table_a | describe",
-            result: None,
+            result: Some(Value::Record {
+                cols: vec!["connection".into(), "query".into()],
+                vals: vec![
+                    Value::String {
+                        val: "db.mysql".into(),
+                        span: Span::test_data(),
+                    },
+                    Value::String {
+                        val: "SELECT  FROM table_a".into(),
+                        span: Span::test_data(),
+                    },
+                ],
+                span: Span::test_data(),
+            }),
         }]
     }
 
@@ -180,3 +196,14 @@ fn create_table(
 
     Ok(table)
 }
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    use crate::database::test_database::test_database;
+
+    #[test]
+    fn test_examples() {
+        test_database(vec![Box::new(FromDb {})])
+    }
+}

crates/nu-command/src/database/commands/function.rs

@@ -1,85 +0,0 @@
-use crate::database::values::dsl::ExprDb;
-use nu_engine::CallExt;
-use nu_protocol::{
-    ast::Call,
-    engine::{Command, EngineState, Stack},
-    Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, SyntaxShape, Value,
-};
-use sqlparser::ast::{Expr, Function, FunctionArg, FunctionArgExpr, Ident, ObjectName};
-
-#[derive(Clone)]
-pub struct FunctionExpr;
-
-impl Command for FunctionExpr {
-    fn name(&self) -> &str {
-        "db fn"
-    }
-
-    fn signature(&self) -> Signature {
-        Signature::build(self.name())
-            .required("name", SyntaxShape::String, "function name")
-            .switch("distinct", "distict values", Some('d'))
-            .rest("arguments", SyntaxShape::Any, "function arguments")
-            .category(Category::Custom("database".into()))
-    }
-
-    fn usage(&self) -> &str {
-        "Creates function expression for a select operation"
-    }
-
-    fn examples(&self) -> Vec<Example> {
-        vec![Example {
-            description: "Creates a function expression",
-            example: "db fn count name_1",
-            result: None,
-        }]
-    }
-
-    fn search_terms(&self) -> Vec<&str> {
-        vec!["database", "function", "expression"]
-    }
-
-    fn run(
-        &self,
-        engine_state: &EngineState,
-        stack: &mut Stack,
-        call: &Call,
-        _input: PipelineData,
-    ) -> Result<PipelineData, ShellError> {
-        let name: String = call.req(engine_state, stack, 0)?;
-        let vals: Vec<Value> = call.rest(engine_state, stack, 1)?;
-        let value = Value::List {
-            vals,
-            span: call.head,
-        };
-        let expressions = ExprDb::extract_exprs(value)?;
-
-        let name: Vec<Ident> = name
-            .split('.')
-            .map(|part| Ident {
-                value: part.to_string(),
-                quote_style: None,
-            })
-            .collect();
-        let name = ObjectName(name);
-
-        let args: Vec<FunctionArg> = expressions
-            .into_iter()
-            .map(|expr| {
-                let arg = FunctionArgExpr::Expr(expr);
-
-                FunctionArg::Unnamed(arg)
-            })
-            .collect();
-
-        let expression: ExprDb = Expr::Function(Function {
-            name,
-            args,
-            over: None,
-            distinct: call.has_flag("distinct"),
-        })
-        .into();
-
-        Ok(expression.into_value(call.head).into_pipeline_data())
-    }
-}

crates/nu-command/src/database/commands/group_by.rs

@@ -5,7 +5,8 @@ use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, SyntaxShape, Value,
+    Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, Span, SyntaxShape,
+    Type, Value,
 };
 use sqlparser::ast::{SetExpr, Statement};
 
@@ -14,7 +15,7 @@ pub struct GroupByDb;
 
 impl Command for GroupByDb {
     fn name(&self) -> &str {
-        "db group-by"
+        "group-by"
     }
 
     fn usage(&self) -> &str {
@@ -28,6 +29,8 @@ impl Command for GroupByDb {
                 SyntaxShape::Any,
                 "Select expression(s) on the table",
             )
+            .input_type(Type::Custom("database".into()))
+            .output_type(Type::Custom("database".into()))
             .category(Category::Custom("database".into()))
     }
 
@@ -36,15 +39,54 @@ impl Command for GroupByDb {
     }
 
     fn examples(&self) -> Vec<Example> {
-        vec![Example {
+        vec![
-            description: "orders query by a column",
+            Example {
-            example: r#"db open db.mysql 
+                description: "groups by column a and calculates the max",
-    | db from table_a 
+                example: r#"open db.mysql
-    | db select a 
+    | into db
-    | db group-by a 
+    | from table_a
-    | db describe"#,
+    | select (fn max a)
-            result: None,
+    | group-by a
-        }]
+    | describe"#,
+                result: Some(Value::Record {
+                    cols: vec!["connection".into(), "query".into()],
+                    vals: vec![
+                        Value::String {
+                            val: "db.mysql".into(),
+                            span: Span::test_data(),
+                        },
+                        Value::String {
+                            val: "SELECT max(a) FROM table_a GROUP BY a".into(),
+                            span: Span::test_data(),
+                        },
+                    ],
+                    span: Span::test_data(),
+                }),
+            },
+            Example {
+                description: "groups by column column a and counts records",
+                example: r#"open db.mysql
+    | into db
+    | from table_a
+    | select (fn count *)
+    | group-by a
+    | describe"#,
+                result: Some(Value::Record {
+                    cols: vec!["connection".into(), "query".into()],
+                    vals: vec![
+                        Value::String {
+                            val: "db.mysql".into(),
+                            span: Span::test_data(),
+                        },
+                        Value::String {
+                            val: "SELECT count(*) FROM table_a GROUP BY a".into(),
+                            span: Span::test_data(),
+                        },
+                    ],
+                    span: Span::test_data(),
+                }),
+            },
+        ]
     }
 
     fn run(
@@ -100,3 +142,24 @@ impl Command for GroupByDb {
         Ok(db.into_value(call.head).into_pipeline_data())
     }
 }
+
+#[cfg(test)]
+mod test {
+    use super::super::super::expressions::{FieldExpr, FunctionExpr, OrExpr};
+    use super::super::{FromDb, ProjectionDb, WhereDb};
+    use super::*;
+    use crate::database::test_database::test_database;
+
+    #[test]
+    fn test_examples() {
+        test_database(vec![
+            Box::new(GroupByDb {}),
+            Box::new(ProjectionDb {}),
+            Box::new(FunctionExpr {}),
+            Box::new(FromDb {}),
+            Box::new(WhereDb {}),
+            Box::new(FieldExpr {}),
+            Box::new(OrExpr {}),
+        ])
+    }
+}

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

@@ -4,7 +4,8 @@ use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, SyntaxShape, Value,
+    Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, Span, SyntaxShape,
+    Type, Value,
 };
 use sqlparser::ast::{
     Ident, Join, JoinConstraint, JoinOperator, Select, SetExpr, Statement, TableAlias,
@@ -15,7 +16,7 @@ pub struct JoinDb;
 
 impl Command for JoinDb {
     fn name(&self) -> &str {
-        "db join"
+        "join"
     }
 
     fn usage(&self) -> &str {
@@ -40,6 +41,8 @@ impl Command for JoinDb {
             .switch("right", "right outer join", Some('r'))
             .switch("outer", "full outer join", Some('o'))
             .switch("cross", "cross join", Some('c'))
+            .input_type(Type::Custom("database".into()))
+            .output_type(Type::Custom("database".into()))
             .category(Category::Custom("database".into()))
     }
 
@@ -48,11 +51,61 @@ impl Command for JoinDb {
     }
 
     fn examples(&self) -> Vec<Example> {
-        vec![Example {
+        vec![
-            description: "",
+            Example {
-            example: "",
+                description: "joins two tables on col_b",
-            result: None,
+                example: r#"open db.mysql
-        }]
+    | into db
+    | select col_a
+    | from table_1 --as t1
+    | join table_2 col_b --as t2
+    | describe"#,
+                result: Some(Value::Record {
+                    cols: vec!["connection".into(), "query".into()],
+                    vals: vec![
+                        Value::String {
+                            val: "db.mysql".into(),
+                            span: Span::test_data(),
+                        },
+                        Value::String {
+                            val: "SELECT col_a FROM table_1 AS t1 JOIN table_2 AS t2 ON col_b"
+                                .into(),
+                            span: Span::test_data(),
+                        },
+                    ],
+                    span: Span::test_data(),
+                }),
+            },
+            Example {
+                description: "joins a table with a derived table using aliases",
+                example: r#"open db.mysql
+    | into db
+    | select col_a
+    | from table_1 --as t1
+    | join (
+        open db.mysql
+        | into db
+        | select col_c
+        | from table_2
+      ) ((field t1.col_a) == (field t2.col_c)) --as t2 --right
+    | describe"#,
+                result: Some(Value::Record {
+                    cols: vec!["connection".into(), "query".into()],
+                    vals: vec![
+                        Value::String {
+                            val: "db.mysql".into(),
+                            span: Span::test_data(),
+                        },
+                        Value::String {
+                            val: "SELECT col_a FROM table_1 AS t1 RIGHT JOIN (SELECT col_c FROM table_2) AS t2 ON t1.col_a = t2.col_c"
+                                .into(),
+                            span: Span::test_data(),
+                        },
+                    ],
+                    span: Span::test_data(),
+                }),
+            },
+        ]
     }
 
     fn run(
@@ -176,3 +229,23 @@ fn modify_from(
         )),
     }
 }
+
+#[cfg(test)]
+mod test {
+    use super::super::super::expressions::{FieldExpr, OrExpr};
+    use super::super::{FromDb, ProjectionDb, WhereDb};
+    use super::*;
+    use crate::database::test_database::test_database;
+
+    #[test]
+    fn test_examples() {
+        test_database(vec![
+            Box::new(JoinDb {}),
+            Box::new(ProjectionDb {}),
+            Box::new(FromDb {}),
+            Box::new(WhereDb {}),
+            Box::new(FieldExpr {}),
+            Box::new(OrExpr {}),
+        ])
+    }
+}

crates/nu-command/src/database/commands/limit.rs

@@ -4,7 +4,8 @@ use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, SyntaxShape, Value,
+    Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, Span, SyntaxShape,
+    Type, Value,
 };
 use sqlparser::ast::Statement;
 
@@ -13,7 +14,7 @@ pub struct LimitDb;
 
 impl Command for LimitDb {
     fn name(&self) -> &str {
-        "db limit"
+        "limit"
     }
 
     fn usage(&self) -> &str {
@@ -27,6 +28,8 @@ impl Command for LimitDb {
                 SyntaxShape::Int,
                 "Number of rows to extract for query",
             )
+            .input_type(Type::Custom("database".into()))
+            .output_type(Type::Custom("database".into()))
             .category(Category::Custom("database".into()))
     }
 
@@ -37,12 +40,26 @@ impl Command for LimitDb {
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Limits selection from table",
-            example: r#"db open db.mysql 
+            example: r#"open db.mysql
-    | db from table_a 
+    | into db
-    | db select a 
+    | from table_a
-    | db limit 10 
+    | select a
-    | db describe"#,
+    | limit 10
-            result: None,
+    | describe"#,
+            result: Some(Value::Record {
+                cols: vec!["connection".into(), "query".into()],
+                vals: vec![
+                    Value::String {
+                        val: "db.mysql".into(),
+                        span: Span::test_data(),
+                    },
+                    Value::String {
+                        val: "SELECT a FROM table_a LIMIT 10".into(),
+                        span: Span::test_data(),
+                    },
+                ],
+                span: Span::test_data(),
+            }),
         }]
     }
 
@@ -84,3 +101,23 @@ impl Command for LimitDb {
         Ok(db.into_value(call.head).into_pipeline_data())
     }
 }
+
+#[cfg(test)]
+mod test {
+    use super::super::super::expressions::{FieldExpr, OrExpr};
+    use super::super::{FromDb, ProjectionDb, WhereDb};
+    use super::*;
+    use crate::database::test_database::test_database;
+
+    #[test]
+    fn test_examples() {
+        test_database(vec![
+            Box::new(LimitDb {}),
+            Box::new(ProjectionDb {}),
+            Box::new(FromDb {}),
+            Box::new(WhereDb {}),
+            Box::new(FieldExpr {}),
+            Box::new(OrExpr {}),
+        ])
+    }
+}

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

@@ -3,22 +3,19 @@ pub mod conversions;
 
 mod alias;
 mod and;
-mod col;
 mod collect;
-mod command;
 mod describe;
 mod from;
-mod function;
 mod group_by;
 mod join;
 mod limit;
 mod open;
 mod or;
 mod order_by;
-mod over;
 mod query;
 mod schema;
 mod select;
+mod to_db;
 mod where_;
 
 // Temporal module to create Query objects
@@ -27,27 +24,24 @@ use testing::TestingDb;
 
 use nu_protocol::engine::StateWorkingSet;
 
-use alias::AliasExpr;
+use alias::AliasDb;
 use and::AndDb;
-use col::ColExpr;
 use collect::CollectDb;
-use command::Database;
+pub(crate) use describe::DescribeDb;
-use describe::DescribeDb;
+pub(crate) use from::FromDb;
-use from::FromDb;
-use function::FunctionExpr;
 use group_by::GroupByDb;
 use join::JoinDb;
 use limit::LimitDb;
 use open::OpenDb;
 use or::OrDb;
 use order_by::OrderByDb;
-use over::OverExpr;
 use query::QueryDb;
 use schema::SchemaDb;
-use select::ProjectionDb;
+pub(crate) use select::ProjectionDb;
+pub(crate) use to_db::ToDataBase;
 use where_::WhereDb;
 
-pub fn add_database_decls(working_set: &mut StateWorkingSet) {
+pub fn add_commands_decls(working_set: &mut StateWorkingSet) {
     macro_rules! bind_command {
             ( $command:expr ) => {
                 working_set.add_decl(Box::new($command));
@@ -59,21 +53,18 @@ pub fn add_database_decls(working_set: &mut StateWorkingSet) {
 
     // Series commands
     bind_command!(
-        AliasExpr,
+        ToDataBase,
+        AliasDb,
         AndDb,
-        ColExpr,
         CollectDb,
-        Database,
         DescribeDb,
         FromDb,
-        FunctionExpr,
         GroupByDb,
         JoinDb,
         LimitDb,
         OpenDb,
         OrderByDb,
         OrDb,
-        OverExpr,
         QueryDb,
         ProjectionDb,
         SchemaDb,

crates/nu-command/src/database/commands/open.rs

@@ -4,6 +4,7 @@ use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
     Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, Spanned, SyntaxShape,
+    Type,
 };
 use std::path::PathBuf;
 
@@ -12,12 +13,14 @@ pub struct OpenDb;
 
 impl Command for OpenDb {
     fn name(&self) -> &str {
-        "db open"
+        "open-db"
     }
 
     fn signature(&self) -> Signature {
         Signature::build(self.name())
             .required("query", SyntaxShape::Filepath, "SQLite file to be opened")
+            .input_type(Type::Any)
+            .output_type(Type::Custom("database".into()))
             .category(Category::Custom("database".into()))
     }
 
@@ -31,8 +34,8 @@ impl Command for OpenDb {
 
     fn examples(&self) -> Vec<Example> {
         vec![Example {
-            description: "Open a sqlite file",
+            description: "Creates a connection to a sqlite database based on the file name",
-            example: r#"db open file.sqlite"#,
+            example: r#"open-db file.sqlite"#,
             result: None,
         }]
     }

crates/nu-command/src/database/commands/or.rs

@@ -6,7 +6,7 @@ use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
     Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, Span, SyntaxShape,
-    Value,
+    Type, Value,
 };
 use sqlparser::ast::{BinaryOperator, Expr, Query, Select, SetExpr, Statement};
 
@@ -15,16 +15,18 @@ pub struct OrDb;
 
 impl Command for OrDb {
     fn name(&self) -> &str {
-        "db or"
+        "or"
     }
 
     fn usage(&self) -> &str {
-        "Includes an OR clause for a query or expression"
+        "Includes an OR clause for a query"
     }
 
     fn signature(&self) -> Signature {
         Signature::build(self.name())
             .required("where", SyntaxShape::Any, "Where expression on the table")
+            .input_type(Type::Custom("database".into()))
+            .output_type(Type::Custom("database".into()))
             .category(Category::Custom("database".into()))
     }
 
@@ -35,23 +37,52 @@ impl Command for OrDb {
     fn examples(&self) -> Vec<Example> {
         vec![
             Example {
-                description: "selects a column from a database with a where clause",
+                description: "selects a column from a database with an OR clause",
-                example: r#"db open db.mysql 
+                example: r#"open db.mysql
-    | db select a 
+    | into db
-    | db from table_1 
+    | select a
-    | db where ((db col a) > 1) 
+    | from table_1
-    | db or ((db col b) == 1) 
+    | where ((field a) > 1)
-    | db describe"#,
+    | or ((field b) == 1)
-                result: None,
+    | describe"#,
+                result: Some(Value::Record {
+                    cols: vec!["connection".into(), "query".into()],
+                    vals: vec![
+                        Value::String {
+                            val: "db.mysql".into(),
+                            span: Span::test_data(),
+                        },
+                        Value::String {
+                            val: "SELECT a FROM table_1 WHERE a > 1 OR b = 1".into(),
+                            span: Span::test_data(),
+                        },
+                    ],
+                    span: Span::test_data(),
+                }),
             },
             Example {
-                description: "Creates a nested where clause",
+                description: "Creates an OR clause in the column names and a column",
-                example: r#"db open db.mysql 
+                example: r#"open db.mysql
-    | db select a 
+    | into db
-    | db from table_1 
+    | select a
-    | db where ((db col a) > 1 | db or ((db col a) < 10)) 
+    | from table_1
-    | db describe"#,
+    | where ((field a) > 1 | or ((field a) < 10))
-                result: None,
+    | or ((field b) == 1)
+    | describe"#,
+                result: Some(Value::Record {
+                    cols: vec!["connection".into(), "query".into()],
+                    vals: vec![
+                        Value::String {
+                            val: "db.mysql".into(),
+                            span: Span::test_data(),
+                        },
+                        Value::String {
+                            val: "SELECT a FROM table_1 WHERE (a > 1 OR a < 10) OR b = 1".into(),
+                            span: Span::test_data(),
+                        },
+                    ],
+                    span: Span::test_data(),
+                }),
             },
         ]
     }
@@ -66,51 +97,32 @@ impl Command for OrDb {
         let value: Value = call.req(engine_state, stack, 0)?;
         let expr = ExprDb::try_from_value(&value)?.into_native();
 
-        let value = input.into_value(call.head);
+        let mut db = SQLiteDatabase::try_from_pipeline(input, call.head)?;
-        if let Ok(expression) = ExprDb::try_from_value(&value) {
+        match db.statement {
-            let expression = Expr::BinaryOp {
+            Some(ref mut statement) => match statement {
-                left: Box::new(expression.into_native()),
+                Statement::Query(query) => modify_query(query, expr, call.head)?,
-                op: BinaryOperator::Or,
+                s => {
-                right: Box::new(expr),
-            };
-
-            let expression: ExprDb = Expr::Nested(Box::new(expression)).into();
-
-            Ok(expression.into_value(call.head).into_pipeline_data())
-        } else if let Ok(mut db) = SQLiteDatabase::try_from_value(value.clone()) {
-            match db.statement {
-                Some(ref mut statement) => match statement {
-                    Statement::Query(query) => modify_query(query, expr, call.head)?,
-                    s => {
-                        return Err(ShellError::GenericError(
-                            "Connection doesnt define a query".into(),
-                            format!("Expected a connection with query. Got {}", s),
-                            Some(call.head),
-                            None,
-                            Vec::new(),
-                        ))
-                    }
-                },
-                None => {
                     return Err(ShellError::GenericError(
-                        "Connection without statement".into(),
+                        "Connection doesnt define a query".into(),
-                        "The connection needs a statement defined".into(),
+                        format!("Expected a connection with query. Got {}", s),
                         Some(call.head),
                         None,
                         Vec::new(),
                     ))
                 }
-            };
+            },
+            None => {
+                return Err(ShellError::GenericError(
+                    "Connection without statement".into(),
+                    "The connection needs a statement defined".into(),
+                    Some(call.head),
+                    None,
+                    Vec::new(),
+                ))
+            }
+        };
 
-            Ok(db.into_value(call.head).into_pipeline_data())
+        Ok(db.into_value(call.head).into_pipeline_data())
-        } else {
-            Err(ShellError::CantConvert(
-                "expression or query".into(),
-                value.get_type().to_string(),
-                value.span()?,
-                None,
-            ))
-        }
     }
 }
 
@@ -150,3 +162,23 @@ fn modify_select(select: &mut Box<Select>, expression: Expr, span: Span) -> Resu
     select.as_mut().selection = Some(new_expression);
     Ok(())
 }
+
+#[cfg(test)]
+mod test {
+    use super::super::super::expressions::{FieldExpr, OrExpr};
+    use super::super::{FromDb, ProjectionDb, WhereDb};
+    use super::*;
+    use crate::database::test_database::test_database;
+
+    #[test]
+    fn test_examples() {
+        test_database(vec![
+            Box::new(OrDb {}),
+            Box::new(ProjectionDb {}),
+            Box::new(FromDb {}),
+            Box::new(WhereDb {}),
+            Box::new(FieldExpr {}),
+            Box::new(OrExpr {}),
+        ])
+    }
+}

crates/nu-command/src/database/commands/order_by.rs

@@ -5,7 +5,8 @@ use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, SyntaxShape, Value,
+    Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, Span, SyntaxShape,
+    Type, Value,
 };
 use sqlparser::ast::{Expr, OrderByExpr, Statement};
 
@@ -14,7 +15,7 @@ pub struct OrderByDb;
 
 impl Command for OrderByDb {
     fn name(&self) -> &str {
-        "db order-by"
+        "order-by"
     }
 
     fn usage(&self) -> &str {
@@ -30,23 +31,65 @@ impl Command for OrderByDb {
                 SyntaxShape::Any,
                 "Select expression(s) on the table",
             )
+            .input_type(Type::Custom("database".into()))
+            .output_type(Type::Custom("database".into()))
             .category(Category::Custom("database".into()))
     }
 
     fn search_terms(&self) -> Vec<&str> {
-        vec!["database", "select"]
+        vec!["database", "order-by"]
     }
 
     fn examples(&self) -> Vec<Example> {
-        vec![Example {
+        vec![
-            description: "orders query by a column",
+            Example {
-            example: r#"db open db.mysql
+                description: "orders query by a column",
-    | db from table_a
+                example: r#"open db.mysql
-    | db select a
+    | into db
-    | db order-by a
+    | from table_a
-    | db describe"#,
+    | select a
-            result: None,
+    | order-by a
-        }]
+    | describe"#,
+                result: Some(Value::Record {
+                    cols: vec!["connection".into(), "query".into()],
+                    vals: vec![
+                        Value::String {
+                            val: "db.mysql".into(),
+                            span: Span::test_data(),
+                        },
+                        Value::String {
+                            val: "SELECT a FROM table_a ORDER BY a".into(),
+                            span: Span::test_data(),
+                        },
+                    ],
+                    span: Span::test_data(),
+                }),
+            },
+            Example {
+                description: "orders query by column a ascending and by column b",
+                example: r#"open db.mysql
+    | into db
+    | from table_a
+    | select a
+    | order-by a --ascending
+    | order-by b
+    | describe"#,
+                result: Some(Value::Record {
+                    cols: vec!["connection".into(), "query".into()],
+                    vals: vec![
+                        Value::String {
+                            val: "db.mysql".into(),
+                            span: Span::test_data(),
+                        },
+                        Value::String {
+                            val: "SELECT a FROM table_a ORDER BY a ASC, b".into(),
+                            span: Span::test_data(),
+                        },
+                    ],
+                    span: Span::test_data(),
+                }),
+            },
+        ]
     }
 
     fn run(
@@ -155,3 +198,23 @@ fn update_connection(
 
     Ok(db.into_value(call.head).into_pipeline_data())
 }
+
+#[cfg(test)]
+mod test {
+    use super::super::super::expressions::{FieldExpr, OrExpr};
+    use super::super::{FromDb, ProjectionDb, WhereDb};
+    use super::*;
+    use crate::database::test_database::test_database;
+
+    #[test]
+    fn test_examples() {
+        test_database(vec![
+            Box::new(OrderByDb {}),
+            Box::new(ProjectionDb {}),
+            Box::new(FromDb {}),
+            Box::new(WhereDb {}),
+            Box::new(FieldExpr {}),
+            Box::new(OrExpr {}),
+        ])
+    }
+}

crates/nu-command/src/database/commands/over.rs

@@ -1,80 +0,0 @@
-use crate::database::values::dsl::ExprDb;
-use nu_engine::CallExt;
-use nu_protocol::{
-    ast::Call,
-    engine::{Command, EngineState, Stack},
-    Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, SyntaxShape, Value,
-};
-use sqlparser::ast::{Expr, WindowSpec};
-
-#[derive(Clone)]
-pub struct OverExpr;
-
-impl Command for OverExpr {
-    fn name(&self) -> &str {
-        "db over"
-    }
-
-    fn signature(&self) -> Signature {
-        Signature::build(self.name())
-            .rest(
-                "partition-by",
-                SyntaxShape::Any,
-                "columns to partition the window function",
-            )
-            .category(Category::Custom("database".into()))
-    }
-
-    fn usage(&self) -> &str {
-        "Adds a partition to an expression function"
-    }
-
-    fn examples(&self) -> Vec<Example> {
-        vec![Example {
-            description: "Adds a partition to a function expresssion",
-            example: "db function avg col_a | db over col_b",
-            result: None,
-        }]
-    }
-
-    fn search_terms(&self) -> Vec<&str> {
-        vec!["database", "column", "expression"]
-    }
-
-    fn run(
-        &self,
-        engine_state: &EngineState,
-        stack: &mut Stack,
-        call: &Call,
-        input: PipelineData,
-    ) -> Result<PipelineData, ShellError> {
-        let vals: Vec<Value> = call.rest(engine_state, stack, 0)?;
-        let value = Value::List {
-            vals,
-            span: call.head,
-        };
-        let partitions = ExprDb::extract_exprs(value)?;
-
-        let mut expression = ExprDb::try_from_pipeline(input, call.head)?;
-        match expression.as_mut() {
-            Expr::Function(function) => {
-                function.over = Some(WindowSpec {
-                    partition_by: partitions,
-                    order_by: Vec::new(),
-                    window_frame: None,
-                });
-            }
-            s => {
-                return Err(ShellError::GenericError(
-                    "Expression doesnt define a function".into(),
-                    format!("Expected an expression with a function. Got {}", s),
-                    Some(call.head),
-                    None,
-                    Vec::new(),
-                ))
-            }
-        };
-
-        Ok(expression.into_value(call.head).into_pipeline_data())
-    }
-}

crates/nu-command/src/database/commands/query.rs

@@ -3,6 +3,7 @@ use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
     Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, Spanned, SyntaxShape,
+    Type,
 };
 
 use super::super::SQLiteDatabase;
@@ -12,7 +13,7 @@ pub struct QueryDb;
 
 impl Command for QueryDb {
     fn name(&self) -> &str {
-        "db query"
+        "query"
     }
 
     fn signature(&self) -> Signature {
@@ -22,6 +23,8 @@ impl Command for QueryDb {
                 SyntaxShape::String,
                 "SQL to execute against the database",
             )
+            .input_type(Type::Custom("database".into()))
+            .output_type(Type::Any)
             .category(Category::Custom("database".into()))
     }
 
@@ -31,8 +34,8 @@ impl Command for QueryDb {
 
     fn examples(&self) -> Vec<Example> {
         vec![Example {
-            description: "Get 1 table out of a SQLite database",
+            description: "Execute a query statement using the database connection",
-            example: r#"db open foo.db | db query "SELECT * FROM Bar""#,
+            example: r#"open foo.db | into db | query "SELECT * FROM Bar""#,
             result: None,
         }]
     }

crates/nu-command/src/database/commands/schema.rs

@@ -3,7 +3,7 @@ use crate::database::values::definitions::{db::Db, db_row::DbRow, db_table::DbTa
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, Type, Value,
 };
 use rusqlite::Connection;
 #[derive(Clone)]
@@ -11,21 +11,24 @@ pub struct SchemaDb;
 
 impl Command for SchemaDb {
     fn name(&self) -> &str {
-        "db schema"
+        "schema"
     }
 
     fn signature(&self) -> Signature {
-        Signature::build(self.name()).category(Category::Custom("database".into()))
+        Signature::build(self.name())
+            .input_type(Type::Custom("database".into()))
+            .output_type(Type::Any)
+            .category(Category::Custom("database".into()))
     }
 
     fn usage(&self) -> &str {
-        "Show database information, including its schema."
+        "Show sqlite database information, including its schema."
     }
 
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Show the schema of a SQLite database",
-            example: r#"open foo.db | db schema"#,
+            example: r#"open foo.db | into db | schema"#,
             result: None,
         }]
     }

crates/nu-command/src/database/commands/select.rs

@@ -4,7 +4,7 @@ use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
     Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, Span, SyntaxShape,
-    Value,
+    Type, Value,
 };
 use sqlparser::ast::{Query, Select, SelectItem, SetExpr, Statement};
 
@@ -13,7 +13,7 @@ pub struct ProjectionDb;
 
 impl Command for ProjectionDb {
     fn name(&self) -> &str {
-        "db select"
+        "select"
     }
 
     fn usage(&self) -> &str {
@@ -27,6 +27,8 @@ impl Command for ProjectionDb {
                 SyntaxShape::Any,
                 "Select expression(s) on the table",
             )
+            .input_type(Type::Custom("database".into()))
+            .output_type(Type::Custom("database".into()))
             .category(Category::Custom("database".into()))
     }
 
@@ -38,13 +40,43 @@ impl Command for ProjectionDb {
         vec![
             Example {
                 description: "selects a column from a database",
-                example: "db open db.mysql | db select a | db describe",
+                example: "open db.mysql | into db | select a | describe",
-                result: None,
+                result: Some(Value::Record {
+                    cols: vec!["connection".into(), "query".into()],
+                    vals: vec![
+                        Value::String {
+                            val: "db.mysql".into(),
+                            span: Span::test_data(),
+                        },
+                        Value::String {
+                            val: "SELECT a".into(),
+                            span: Span::test_data(),
+                        },
+                    ],
+                    span: Span::test_data(),
+                }),
             },
             Example {
-                description: "selects columns from a database",
+                description: "selects columns from a database using alias",
-                example: "db open db.mysql | db select a b c | db describe",
+                example: r#"open db.mysql
-                result: None,
+    | into db
+    | select (field a | as new_a) b c
+    | from table_1
+    | describe"#,
+                result: Some(Value::Record {
+                    cols: vec!["connection".into(), "query".into()],
+                    vals: vec![
+                        Value::String {
+                            val: "db.mysql".into(),
+                            span: Span::test_data(),
+                        },
+                        Value::String {
+                            val: "SELECT a AS new_a, b, c FROM table_1".into(),
+                            span: Span::test_data(),
+                        },
+                    ],
+                    span: Span::test_data(),
+                }),
             },
         ]
     }
@@ -104,7 +136,7 @@ fn modify_statement(
             Ok(statement)
         }
         s => Err(ShellError::GenericError(
-            "Connection doesnt define a statement".into(),
+            "Connection doesn't define a statement".into(),
             format!("Expected a connection with query. Got {}", s),
             Some(span),
             None,
@@ -129,3 +161,21 @@ fn create_select(projection: Vec<SelectItem>) -> Select {
         having: None,
     }
 }
+
+#[cfg(test)]
+mod test {
+    use super::super::super::expressions::{AliasExpr, FieldExpr};
+    use super::super::FromDb;
+    use super::*;
+    use crate::database::test_database::test_database;
+
+    #[test]
+    fn test_examples() {
+        test_database(vec![
+            Box::new(ProjectionDb {}),
+            Box::new(FromDb {}),
+            Box::new(FieldExpr {}),
+            Box::new(AliasExpr {}),
+        ])
+    }
+}

crates/nu-command/src/database/commands/testing.rs

@@ -13,7 +13,7 @@ pub struct TestingDb;
 
 impl Command for TestingDb {
     fn name(&self) -> &str {
-        "db testing"
+        "testing-db"
     }
 
     fn signature(&self) -> Signature {
@@ -27,7 +27,7 @@ impl Command for TestingDb {
     }
 
     fn usage(&self) -> &str {
-        "Create query object"
+        "Temporal Command: Create query object"
     }
 
     fn examples(&self) -> Vec<Example> {

crates/nu-command/src/database/commands/to_db.rs

@@ -0,0 +1,50 @@
+use super::super::SQLiteDatabase;
+
+use nu_protocol::{
+    ast::Call,
+    engine::{Command, EngineState, Stack},
+    Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, Type,
+};
+
+#[derive(Clone)]
+pub struct ToDataBase;
+
+impl Command for ToDataBase {
+    fn name(&self) -> &str {
+        "into db"
+    }
+
+    fn usage(&self) -> &str {
+        "Converts into an open db connection"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build(self.name())
+            .input_type(Type::Any)
+            .output_type(Type::Custom("database".into()))
+            .category(Category::Custom("database".into()))
+    }
+
+    fn search_terms(&self) -> Vec<&str> {
+        vec!["database", "into", "db"]
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![Example {
+            description: "Converts an open file into a db object",
+            example: "open db.mysql | into db",
+            result: None,
+        }]
+    }
+
+    fn run(
+        &self,
+        _engine_state: &EngineState,
+        _stack: &mut Stack,
+        call: &Call,
+        input: PipelineData,
+    ) -> Result<PipelineData, ShellError> {
+        let db = SQLiteDatabase::try_from_pipeline(input, call.head)?;
+        Ok(db.into_value(call.head).into_pipeline_data())
+    }
+}

crates/nu-command/src/database/commands/where_.rs

@@ -5,7 +5,8 @@ use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, SyntaxShape, Value,
+    Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, Span, SyntaxShape,
+    Type, Value,
 };
 use sqlparser::ast::{Expr, Query, Select, SetExpr, Statement};
 
@@ -14,7 +15,7 @@ pub struct WhereDb;
 
 impl Command for WhereDb {
     fn name(&self) -> &str {
-        "db where"
+        "where"
     }
 
     fn usage(&self) -> &str {
@@ -24,6 +25,8 @@ impl Command for WhereDb {
     fn signature(&self) -> Signature {
         Signature::build(self.name())
             .required("where", SyntaxShape::Any, "Where expression on the table")
+            .input_type(Type::Custom("database".into()))
+            .output_type(Type::Custom("database".into()))
             .category(Category::Custom("database".into()))
     }
 
@@ -34,12 +37,26 @@ impl Command for WhereDb {
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "selects a column from a database with a where clause",
-            example: r#"db open db.mysql 
+            example: r#"open db.mysql
-    | db select a 
+    | into db
-    | db from table_1 
+    | select a
-    | db where ((db col a) > 1) 
+    | from table_1
-    | db describe"#,
+    | where ((field a) > 1)
-            result: None,
+    | describe"#,
+            result: Some(Value::Record {
+                cols: vec!["connection".into(), "query".into()],
+                vals: vec![
+                    Value::String {
+                        val: "db.mysql".into(),
+                        span: Span::test_data(),
+                    },
+                    Value::String {
+                        val: "SELECT a FROM table_1 WHERE a > 1".into(),
+                        span: Span::test_data(),
+                    },
+                ],
+                span: Span::test_data(),
+            }),
         }]
     }
 
@@ -111,3 +128,23 @@ fn create_select(expression: Expr) -> Select {
         having: None,
     }
 }
+
+#[cfg(test)]
+mod test {
+    use super::super::super::expressions::{FieldExpr, OrExpr};
+    use super::super::{FromDb, ProjectionDb};
+    use super::*;
+    use crate::database::test_database::test_database;
+
+    #[test]
+    fn test_examples() {
+        test_database(vec![
+            Box::new(WhereDb {}),
+            Box::new(ProjectionDb {}),
+            Box::new(FromDb {}),
+            Box::new(WhereDb {}),
+            Box::new(FieldExpr {}),
+            Box::new(OrExpr {}),
+        ])
+    }
+}

crates/nu-command/src/database/expressions/alias.rs

@@ -0,0 +1,132 @@
+use crate::database::values::dsl::{ExprDb, SelectDb};
+use nu_engine::CallExt;
+use nu_protocol::{
+    ast::Call,
+    engine::{Command, EngineState, Stack},
+    Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, Span, SyntaxShape,
+    Type, Value,
+};
+use sqlparser::ast::{Ident, SelectItem};
+
+#[derive(Clone)]
+pub struct AliasExpr;
+
+impl Command for AliasExpr {
+    fn name(&self) -> &str {
+        "as"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build(self.name())
+            .required("alias", SyntaxShape::String, "alias name")
+            .input_type(Type::Custom("db-expression".into()))
+            .output_type(Type::Custom("db-expression".into()))
+            .category(Category::Custom("db-expression".into()))
+    }
+
+    fn usage(&self) -> &str {
+        "Creates an alias for a column selection"
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![Example {
+            description: "Creates an alias for a column selection",
+            example: "field name_a | as new_a | into nu",
+            result: Some(Value::Record {
+                cols: vec!["expression".into(), "alias".into()],
+                vals: vec![
+                    Value::Record {
+                        cols: vec!["value".into(), "quoted_style".into()],
+                        vals: vec![
+                            Value::String {
+                                val: "name_a".into(),
+                                span: Span::test_data(),
+                            },
+                            Value::String {
+                                val: "None".into(),
+                                span: Span::test_data(),
+                            },
+                        ],
+                        span: Span::test_data(),
+                    },
+                    Value::Record {
+                        cols: vec!["value".into(), "quoted_style".into()],
+                        vals: vec![
+                            Value::String {
+                                val: "new_a".into(),
+                                span: Span::test_data(),
+                            },
+                            Value::String {
+                                val: "None".into(),
+                                span: Span::test_data(),
+                            },
+                        ],
+                        span: Span::test_data(),
+                    },
+                ],
+                span: Span::test_data(),
+            }),
+        }]
+    }
+
+    fn search_terms(&self) -> Vec<&str> {
+        vec!["database", "alias", "column"]
+    }
+
+    fn run(
+        &self,
+        engine_state: &EngineState,
+        stack: &mut Stack,
+        call: &Call,
+        input: PipelineData,
+    ) -> Result<PipelineData, ShellError> {
+        let alias: String = call.req(engine_state, stack, 0)?;
+
+        let value = input.into_value(call.head);
+        if let Ok(expr) = ExprDb::try_from_value(&value) {
+            alias_selection(expr.into_native().into(), alias, call)
+        } else {
+            let select = SelectDb::try_from_value(&value)?;
+            alias_selection(select, alias, call)
+        }
+    }
+}
+
+fn alias_selection(
+    select: SelectDb,
+    alias: String,
+    call: &Call,
+) -> Result<PipelineData, ShellError> {
+    let select = match select.into_native() {
+        SelectItem::UnnamedExpr(expr) => SelectItem::ExprWithAlias {
+            expr,
+            alias: Ident {
+                value: alias,
+                quote_style: None,
+            },
+        },
+        SelectItem::ExprWithAlias { expr, .. } => SelectItem::ExprWithAlias {
+            expr,
+            alias: Ident {
+                value: alias,
+                quote_style: None,
+            },
+        },
+        select => select,
+    };
+
+    let select: SelectDb = select.into();
+    Ok(select.into_value(call.head).into_pipeline_data())
+}
+
+#[cfg(test)]
+mod test {
+    use super::super::FieldExpr;
+    use super::*;
+    use crate::database::test_database::test_database;
+
+    #[test]
+    fn test_examples() {
+        test_database(vec![Box::new(AliasExpr {}), Box::new(FieldExpr {})])
+    }
+}

crates/nu-command/src/database/expressions/and.rs

@@ -0,0 +1,141 @@
+use crate::database::values::dsl::ExprDb;
+
+use nu_engine::CallExt;
+use nu_protocol::{
+    ast::Call,
+    engine::{Command, EngineState, Stack},
+    Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, Span, SyntaxShape,
+    Type, Value,
+};
+use sqlparser::ast::{BinaryOperator, Expr};
+
+#[derive(Clone)]
+pub struct AndExpr;
+
+impl Command for AndExpr {
+    fn name(&self) -> &str {
+        "and"
+    }
+
+    fn usage(&self) -> &str {
+        "Includes an AND clause for an expression"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build(self.name())
+            .required("and", SyntaxShape::Any, "AND expression")
+            .input_type(Type::Custom("db-expression".into()))
+            .output_type(Type::Custom("db-expression".into()))
+            .category(Category::Custom("db-expression".into()))
+    }
+
+    fn search_terms(&self) -> Vec<&str> {
+        vec!["database", "and", "expression"]
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![Example {
+            description: "Creates an AND expression",
+            example: r#"(field a) > 1 | and ((field a) < 10) | into nu"#,
+            result: Some(Value::Record {
+                cols: vec!["left".into(), "op".into(), "right".into()],
+                vals: vec![
+                    Value::Record {
+                        cols: vec!["left".into(), "op".into(), "right".into()],
+                        vals: vec![
+                            Value::Record {
+                                cols: vec!["value".into(), "quoted_style".into()],
+                                vals: vec![
+                                    Value::String {
+                                        val: "a".into(),
+                                        span: Span::test_data(),
+                                    },
+                                    Value::String {
+                                        val: "None".into(),
+                                        span: Span::test_data(),
+                                    },
+                                ],
+                                span: Span::test_data(),
+                            },
+                            Value::String {
+                                val: ">".into(),
+                                span: Span::test_data(),
+                            },
+                            Value::String {
+                                val: "1".into(),
+                                span: Span::test_data(),
+                            },
+                        ],
+                        span: Span::test_data(),
+                    },
+                    Value::String {
+                        val: "AND".into(),
+                        span: Span::test_data(),
+                    },
+                    Value::Record {
+                        cols: vec!["left".into(), "op".into(), "right".into()],
+                        vals: vec![
+                            Value::Record {
+                                cols: vec!["value".into(), "quoted_style".into()],
+                                vals: vec![
+                                    Value::String {
+                                        val: "a".into(),
+                                        span: Span::test_data(),
+                                    },
+                                    Value::String {
+                                        val: "None".into(),
+                                        span: Span::test_data(),
+                                    },
+                                ],
+                                span: Span::test_data(),
+                            },
+                            Value::String {
+                                val: "<".into(),
+                                span: Span::test_data(),
+                            },
+                            Value::String {
+                                val: "10".into(),
+                                span: Span::test_data(),
+                            },
+                        ],
+                        span: Span::test_data(),
+                    },
+                ],
+                span: Span::test_data(),
+            }),
+        }]
+    }
+
+    fn run(
+        &self,
+        engine_state: &EngineState,
+        stack: &mut Stack,
+        call: &Call,
+        input: PipelineData,
+    ) -> Result<PipelineData, ShellError> {
+        let value: Value = call.req(engine_state, stack, 0)?;
+        let expr = ExprDb::try_from_value(&value)?.into_native();
+
+        let expression = ExprDb::try_from_pipeline(input, call.head)?;
+        let expression = Expr::BinaryOp {
+            left: Box::new(expression.into_native()),
+            op: BinaryOperator::And,
+            right: Box::new(expr),
+        };
+
+        let expression: ExprDb = Expr::Nested(Box::new(expression)).into();
+        Ok(expression.into_value(call.head).into_pipeline_data())
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::super::FieldExpr;
+    use super::*;
+    use crate::database::test_database::test_database;
+
+    #[test]
+    fn test_examples() {
+        test_database(vec![Box::new(AndExpr {}), Box::new(FieldExpr {})])
+    }
+}

crates/nu-command/src/database/expressions/as_nu.rs

@@ -0,0 +1,76 @@
+use crate::database::values::dsl::{ExprDb, SelectDb};
+
+use nu_protocol::{
+    ast::Call,
+    engine::{Command, EngineState, Stack},
+    Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, Span, Type, Value,
+};
+
+#[derive(Clone)]
+pub struct ExprAsNu;
+
+impl Command for ExprAsNu {
+    fn name(&self) -> &str {
+        "into nu"
+    }
+
+    fn usage(&self) -> &str {
+        "Convert a db expression into a nu value for access and exploration"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build(self.name())
+            .input_type(Type::Custom("db-expression".into()))
+            .output_type(Type::Any)
+            .category(Category::Custom("db-expression".into()))
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![Example {
+            description: "Convert a col expression into a nushell value",
+            example: "field name_1 | into nu",
+            result: Some(Value::Record {
+                cols: vec!["value".into(), "quoted_style".into()],
+                vals: vec![
+                    Value::String {
+                        val: "name_1".into(),
+                        span: Span::test_data(),
+                    },
+                    Value::String {
+                        val: "None".into(),
+                        span: Span::test_data(),
+                    },
+                ],
+                span: Span::test_data(),
+            }),
+        }]
+    }
+
+    fn run(
+        &self,
+        _engine_state: &EngineState,
+        _stack: &mut Stack,
+        call: &Call,
+        input: PipelineData,
+    ) -> Result<PipelineData, ShellError> {
+        let value = input.into_value(call.head);
+        if let Ok(expr) = ExprDb::try_from_value(&value) {
+            Ok(expr.to_value(call.head).into_pipeline_data())
+        } else {
+            let select = SelectDb::try_from_value(&value)?;
+            Ok(select.to_value(call.head).into_pipeline_data())
+        }
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::super::FieldExpr;
+    use super::*;
+    use crate::database::test_database::test_database;
+
+    #[test]
+    fn test_examples() {
+        test_database(vec![Box::new(ExprAsNu {}), Box::new(FieldExpr {})])
+    }
+}

crates/nu-command/src/database/expressions/field.rs

@@ -0,0 +1,78 @@
+use crate::database::values::dsl::ExprDb;
+use nu_engine::CallExt;
+use nu_protocol::{
+    ast::Call,
+    engine::{Command, EngineState, Stack},
+    Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, Span, SyntaxShape,
+    Type, Value,
+};
+
+#[derive(Clone)]
+pub struct FieldExpr;
+
+impl Command for FieldExpr {
+    fn name(&self) -> &str {
+        "field"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build(self.name())
+            .required("name", SyntaxShape::String, "column name")
+            .input_type(Type::Any)
+            .output_type(Type::Custom("db-expression".into()))
+            .category(Category::Custom("db-expression".into()))
+    }
+
+    fn usage(&self) -> &str {
+        "Creates column expression for database"
+    }
+
+    fn search_terms(&self) -> Vec<&str> {
+        vec!["database", "column", "expression"]
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![Example {
+            description: "Creates a named field expression",
+            example: "field name_1 | into nu",
+            result: Some(Value::Record {
+                cols: vec!["value".into(), "quoted_style".into()],
+                vals: vec![
+                    Value::String {
+                        val: "name_1".into(),
+                        span: Span::test_data(),
+                    },
+                    Value::String {
+                        val: "None".into(),
+                        span: Span::test_data(),
+                    },
+                ],
+                span: Span::test_data(),
+            }),
+        }]
+    }
+
+    fn run(
+        &self,
+        engine_state: &EngineState,
+        stack: &mut Stack,
+        call: &Call,
+        _input: PipelineData,
+    ) -> Result<PipelineData, ShellError> {
+        let value: Value = call.req(engine_state, stack, 0)?;
+        let expression = ExprDb::try_from_value(&value)?;
+
+        Ok(expression.into_value(call.head).into_pipeline_data())
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    use crate::database::test_database::test_database;
+
+    #[test]
+    fn test_examples() {
+        test_database(vec![Box::new(FieldExpr {})])
+    }
+}

crates/nu-command/src/database/expressions/function.rs

@@ -0,0 +1,157 @@
+use crate::database::values::dsl::ExprDb;
+use nu_engine::CallExt;
+use nu_protocol::{
+    ast::Call,
+    engine::{Command, EngineState, Stack},
+    Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, Span, SyntaxShape,
+    Type, Value,
+};
+use sqlparser::ast::{Expr, Function, FunctionArg, FunctionArgExpr, Ident, ObjectName};
+
+#[derive(Clone)]
+pub struct FunctionExpr;
+
+impl Command for FunctionExpr {
+    fn name(&self) -> &str {
+        "fn"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build(self.name())
+            .required("name", SyntaxShape::String, "function name")
+            .switch("distinct", "distict values", Some('d'))
+            .rest("arguments", SyntaxShape::Any, "function arguments")
+            .input_type(Type::Any)
+            .output_type(Type::Custom("db-expression".into()))
+            .category(Category::Custom("db-expression".into()))
+    }
+
+    fn usage(&self) -> &str {
+        "Creates function expression for a select operation"
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![
+            Example {
+                description: "Creates a function expression",
+                example: "fn count name_1 | into nu",
+                result: Some(Value::Record {
+                    cols: vec![
+                        "name".into(),
+                        "args".into(),
+                        "over".into(),
+                        "distinct".into(),
+                    ],
+                    vals: vec![
+                        Value::String {
+                            val: "count".into(),
+                            span: Span::test_data(),
+                        },
+                        Value::List {
+                            vals: vec![Value::String {
+                                val: "name_1".into(),
+                                span: Span::test_data(),
+                            }],
+                            span: Span::test_data(),
+                        },
+                        Value::String {
+                            val: "None".into(),
+                            span: Span::test_data(),
+                        },
+                        Value::Bool {
+                            val: false,
+                            span: Span::test_data(),
+                        },
+                    ],
+                    span: Span::test_data(),
+                }),
+            },
+            Example {
+                description: "orders query by a column",
+                example: r#"open db.mysql
+    | into db
+    | select (fn lead col_a)
+    | from table_a
+    | describe"#,
+                result: Some(Value::Record {
+                    cols: vec!["connection".into(), "query".into()],
+                    vals: vec![
+                        Value::String {
+                            val: "db.mysql".into(),
+                            span: Span::test_data(),
+                        },
+                        Value::String {
+                            val: "SELECT lead(col_a) FROM table_a".into(),
+                            span: Span::test_data(),
+                        },
+                    ],
+                    span: Span::test_data(),
+                }),
+            },
+        ]
+    }
+
+    fn search_terms(&self) -> Vec<&str> {
+        vec!["database", "function", "expression"]
+    }
+
+    fn run(
+        &self,
+        engine_state: &EngineState,
+        stack: &mut Stack,
+        call: &Call,
+        _input: PipelineData,
+    ) -> Result<PipelineData, ShellError> {
+        let name: String = call.req(engine_state, stack, 0)?;
+        let vals: Vec<Value> = call.rest(engine_state, stack, 1)?;
+        let value = Value::List {
+            vals,
+            span: call.head,
+        };
+        let expressions = ExprDb::extract_exprs(value)?;
+
+        let name: Vec<Ident> = name
+            .split('.')
+            .map(|part| Ident {
+                value: part.to_string(),
+                quote_style: None,
+            })
+            .collect();
+        let name = ObjectName(name);
+
+        let args: Vec<FunctionArg> = expressions
+            .into_iter()
+            .map(|expr| {
+                let arg = FunctionArgExpr::Expr(expr);
+
+                FunctionArg::Unnamed(arg)
+            })
+            .collect();
+
+        let expression: ExprDb = Expr::Function(Function {
+            name,
+            args,
+            over: None,
+            distinct: call.has_flag("distinct"),
+        })
+        .into();
+
+        Ok(expression.into_value(call.head).into_pipeline_data())
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::super::super::commands::{FromDb, ProjectionDb};
+    use super::*;
+    use crate::database::test_database::test_database;
+
+    #[test]
+    fn test_examples() {
+        test_database(vec![
+            Box::new(FunctionExpr {}),
+            Box::new(ProjectionDb {}),
+            Box::new(FromDb {}),
+        ])
+    }
+}

crates/nu-command/src/database/expressions/mod.rs

@@ -0,0 +1,40 @@
+// Conversions between value and sqlparser objects
+mod alias;
+mod and;
+mod as_nu;
+mod field;
+mod function;
+mod or;
+mod over;
+
+use nu_protocol::engine::StateWorkingSet;
+
+pub(crate) use alias::AliasExpr;
+pub(crate) use and::AndExpr;
+pub(crate) use as_nu::ExprAsNu;
+pub(crate) use field::FieldExpr;
+pub(crate) use function::FunctionExpr;
+pub(crate) use or::OrExpr;
+pub(crate) use over::OverExpr;
+
+pub fn add_expressions_decls(working_set: &mut StateWorkingSet) {
+    macro_rules! bind_command {
+            ( $command:expr ) => {
+                working_set.add_decl(Box::new($command));
+            };
+            ( $( $command:expr ),* ) => {
+                $( working_set.add_decl(Box::new($command)); )*
+            };
+        }
+
+    // Series commands
+    bind_command!(
+        ExprAsNu,
+        AliasExpr,
+        AndExpr,
+        FieldExpr,
+        FunctionExpr,
+        OrExpr,
+        OverExpr
+    );
+}

crates/nu-command/src/database/expressions/or.rs

@@ -0,0 +1,141 @@
+use crate::database::values::dsl::ExprDb;
+
+use nu_engine::CallExt;
+use nu_protocol::{
+    ast::Call,
+    engine::{Command, EngineState, Stack},
+    Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, Span, SyntaxShape,
+    Type, Value,
+};
+use sqlparser::ast::{BinaryOperator, Expr};
+
+#[derive(Clone)]
+pub struct OrExpr;
+
+impl Command for OrExpr {
+    fn name(&self) -> &str {
+        "or"
+    }
+
+    fn usage(&self) -> &str {
+        "Includes an OR clause for an expression"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build(self.name())
+            .required("or", SyntaxShape::Any, "OR expression")
+            .input_type(Type::Custom("db-expression".into()))
+            .output_type(Type::Custom("db-expression".into()))
+            .category(Category::Custom("db-expression".into()))
+    }
+
+    fn search_terms(&self) -> Vec<&str> {
+        vec!["database", "or", "expression"]
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![Example {
+            description: "Creates an AND expression",
+            example: r#"(field a) > 1 | or ((field a) < 10) | into nu"#,
+            result: Some(Value::Record {
+                cols: vec!["left".into(), "op".into(), "right".into()],
+                vals: vec![
+                    Value::Record {
+                        cols: vec!["left".into(), "op".into(), "right".into()],
+                        vals: vec![
+                            Value::Record {
+                                cols: vec!["value".into(), "quoted_style".into()],
+                                vals: vec![
+                                    Value::String {
+                                        val: "a".into(),
+                                        span: Span::test_data(),
+                                    },
+                                    Value::String {
+                                        val: "None".into(),
+                                        span: Span::test_data(),
+                                    },
+                                ],
+                                span: Span::test_data(),
+                            },
+                            Value::String {
+                                val: ">".into(),
+                                span: Span::test_data(),
+                            },
+                            Value::String {
+                                val: "1".into(),
+                                span: Span::test_data(),
+                            },
+                        ],
+                        span: Span::test_data(),
+                    },
+                    Value::String {
+                        val: "OR".into(),
+                        span: Span::test_data(),
+                    },
+                    Value::Record {
+                        cols: vec!["left".into(), "op".into(), "right".into()],
+                        vals: vec![
+                            Value::Record {
+                                cols: vec!["value".into(), "quoted_style".into()],
+                                vals: vec![
+                                    Value::String {
+                                        val: "a".into(),
+                                        span: Span::test_data(),
+                                    },
+                                    Value::String {
+                                        val: "None".into(),
+                                        span: Span::test_data(),
+                                    },
+                                ],
+                                span: Span::test_data(),
+                            },
+                            Value::String {
+                                val: "<".into(),
+                                span: Span::test_data(),
+                            },
+                            Value::String {
+                                val: "10".into(),
+                                span: Span::test_data(),
+                            },
+                        ],
+                        span: Span::test_data(),
+                    },
+                ],
+                span: Span::test_data(),
+            }),
+        }]
+    }
+
+    fn run(
+        &self,
+        engine_state: &EngineState,
+        stack: &mut Stack,
+        call: &Call,
+        input: PipelineData,
+    ) -> Result<PipelineData, ShellError> {
+        let value: Value = call.req(engine_state, stack, 0)?;
+        let expr = ExprDb::try_from_value(&value)?.into_native();
+
+        let expression = ExprDb::try_from_pipeline(input, call.head)?;
+        let expression = Expr::BinaryOp {
+            left: Box::new(expression.into_native()),
+            op: BinaryOperator::Or,
+            right: Box::new(expr),
+        };
+
+        let expression: ExprDb = Expr::Nested(Box::new(expression)).into();
+        Ok(expression.into_value(call.head).into_pipeline_data())
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::super::FieldExpr;
+    use super::*;
+    use crate::database::test_database::test_database;
+
+    #[test]
+    fn test_examples() {
+        test_database(vec![Box::new(OrExpr {}), Box::new(FieldExpr {})])
+    }
+}

crates/nu-command/src/database/expressions/over.rs

@@ -0,0 +1,153 @@
+use crate::database::values::dsl::ExprDb;
+use nu_engine::CallExt;
+use nu_protocol::{
+    ast::Call,
+    engine::{Command, EngineState, Stack},
+    Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, Span, SyntaxShape,
+    Type, Value,
+};
+use sqlparser::ast::{Expr, WindowSpec};
+
+#[derive(Clone)]
+pub struct OverExpr;
+
+impl Command for OverExpr {
+    fn name(&self) -> &str {
+        "over"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build(self.name())
+            .rest(
+                "partition-by",
+                SyntaxShape::Any,
+                "columns to partition the window function",
+            )
+            .input_type(Type::Custom("db-expression".into()))
+            .output_type(Type::Custom("db-expression".into()))
+            .category(Category::Custom("db-expression".into()))
+    }
+
+    fn usage(&self) -> &str {
+        "Adds a partition to an expression function"
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![Example {
+            description: "Adds a partition to a function expression",
+            example: "fn avg col_a | over col_b | into nu",
+            result: Some(Value::Record {
+                cols: vec![
+                    "name".into(),
+                    "args".into(),
+                    "over".into(),
+                    "distinct".into(),
+                ],
+                vals: vec![
+                    Value::String {
+                        val: "avg".into(),
+                        span: Span::test_data(),
+                    },
+                    Value::List {
+                        vals: vec![Value::String {
+                            val: "col_a".into(),
+                            span: Span::test_data(),
+                        }],
+                        span: Span::test_data(),
+                    },
+                    Value::String {
+                        val: "Some(WindowSpec { partition_by: [Identifier(Ident { value: \"col_b\", quote_style: None })], order_by: [], window_frame: None })".into(),
+                        span: Span::test_data(),
+                    },
+                    Value::Bool {
+                        val: false,
+                        span: Span::test_data(),
+                    },
+                ],
+                span: Span::test_data(),
+            }),
+        },
+            Example {
+                description: "orders query by a column",
+                example: r#"open db.mysql
+    | into db
+    | select (fn lead col_a | over col_b)
+    | from table_a
+    | describe"#,
+                result: Some(Value::Record {
+                    cols: vec!["connection".into(), "query".into()],
+                    vals: vec![
+                        Value::String {
+                            val: "db.mysql".into(),
+                            span: Span::test_data(),
+                        },
+                        Value::String {
+                            val: "SELECT lead(col_a) OVER (PARTITION BY col_b) FROM table_a".into(),
+                            span: Span::test_data(),
+                        },
+                    ],
+                    span: Span::test_data(),
+                }),
+            },
+        ]
+    }
+
+    fn search_terms(&self) -> Vec<&str> {
+        vec!["database", "over", "expression"]
+    }
+
+    fn run(
+        &self,
+        engine_state: &EngineState,
+        stack: &mut Stack,
+        call: &Call,
+        input: PipelineData,
+    ) -> Result<PipelineData, ShellError> {
+        let vals: Vec<Value> = call.rest(engine_state, stack, 0)?;
+        let value = Value::List {
+            vals,
+            span: call.head,
+        };
+        let partitions = ExprDb::extract_exprs(value)?;
+
+        let mut expression = ExprDb::try_from_pipeline(input, call.head)?;
+        match expression.as_mut() {
+            Expr::Function(function) => {
+                function.over = Some(WindowSpec {
+                    partition_by: partitions,
+                    order_by: Vec::new(),
+                    window_frame: None,
+                });
+            }
+            s => {
+                return Err(ShellError::GenericError(
+                    "Expression doesnt define a function".into(),
+                    format!("Expected an expression with a function. Got {}", s),
+                    Some(call.head),
+                    None,
+                    Vec::new(),
+                ))
+            }
+        };
+
+        Ok(expression.into_value(call.head).into_pipeline_data())
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::super::super::commands::{FromDb, ProjectionDb};
+    use super::super::FunctionExpr;
+    use super::*;
+    use crate::database::test_database::test_database;
+
+    #[test]
+    fn test_examples() {
+        test_database(vec![
+            Box::new(OverExpr {}),
+            Box::new(FunctionExpr {}),
+            Box::new(ProjectionDb {}),
+            Box::new(FromDb {}),
+        ])
+    }
+}

crates/nu-command/src/database/mod.rs

@@ -1,8 +1,21 @@
 mod commands;
+mod expressions;
 mod values;
 
-pub use commands::add_database_decls;
+use commands::add_commands_decls;
+use expressions::add_expressions_decls;
+
 pub use values::{
     convert_sqlite_row_to_nu_value, convert_sqlite_value_to_nu_value, open_connection_in_memory,
     SQLiteDatabase,
 };
+
+use nu_protocol::engine::StateWorkingSet;
+
+pub fn add_database_decls(working_set: &mut StateWorkingSet) {
+    add_commands_decls(working_set);
+    add_expressions_decls(working_set);
+}
+
+#[cfg(test)]
+mod test_database;

crates/nu-command/src/database/test_database.rs

@@ -0,0 +1,138 @@
+use std::path::Path;
+
+use super::commands::{DescribeDb, ToDataBase};
+use super::expressions::ExprAsNu;
+use crate::SQLiteDatabase;
+use nu_engine::{eval_block, CallExt};
+use nu_parser::parse;
+use nu_protocol::{
+    engine::{Command, EngineState, Stack, StateWorkingSet},
+    Category, IntoPipelineData, PipelineData, Signature, Span, Type,
+};
+
+#[derive(Clone)]
+pub struct CustomOpen;
+
+impl Command for CustomOpen {
+    fn name(&self) -> &str {
+        "open"
+    }
+
+    fn usage(&self) -> &str {
+        "Mock open file command"
+    }
+
+    fn signature(&self) -> nu_protocol::Signature {
+        Signature::build(self.name())
+            .required(
+                "filename",
+                nu_protocol::SyntaxShape::String,
+                "the filename to use",
+            )
+            .input_type(Type::Any)
+            .output_type(Type::Custom("database".into()))
+            .category(Category::Custom("database".into()))
+    }
+
+    fn run(
+        &self,
+        engine_state: &EngineState,
+        stack: &mut Stack,
+        call: &nu_protocol::ast::Call,
+        _input: nu_protocol::PipelineData,
+    ) -> Result<nu_protocol::PipelineData, nu_protocol::ShellError> {
+        let path: String = call.req(engine_state, stack, 0)?;
+        let path = Path::new(&path);
+
+        let db = SQLiteDatabase::new(path);
+        Ok(db.into_value(call.head).into_pipeline_data())
+    }
+}
+
+pub fn test_database(cmds: Vec<Box<dyn Command + 'static>>) {
+    if cmds.is_empty() {
+        panic!("Empty commands vector")
+    }
+
+    // The first element in the cmds vector must be the one tested
+    let examples = cmds[0].examples();
+    let mut engine_state = Box::new(EngineState::new());
+
+    let delta = {
+        // Base functions that are needed for testing
+        // Try to keep this working set small to keep tests running as fast as possible
+        let mut working_set = StateWorkingSet::new(&*engine_state);
+        working_set.add_decl(Box::new(DescribeDb {}));
+        working_set.add_decl(Box::new(ToDataBase {}));
+        working_set.add_decl(Box::new(CustomOpen {}));
+        working_set.add_decl(Box::new(ExprAsNu {}));
+
+        // Adding the command that is being tested to the working set
+        for cmd in cmds {
+            working_set.add_decl(cmd);
+        }
+
+        working_set.render()
+    };
+
+    let cwd = std::env::current_dir().expect("Could not get current working directory.");
+    let _ = engine_state.merge_delta(delta, None, &cwd);
+
+    for example in examples {
+        // Skip tests that don't have results to compare to
+        if example.result.is_none() {
+            continue;
+        }
+        let start = std::time::Instant::now();
+
+        let (block, delta) = {
+            let mut working_set = StateWorkingSet::new(&*engine_state);
+            let (output, err) = parse(
+                &mut working_set,
+                None,
+                example.example.as_bytes(),
+                false,
+                &[],
+            );
+
+            if let Some(err) = err {
+                panic!("test parse error in `{}`: {:?}", example.example, err)
+            }
+
+            (output, working_set.render())
+        };
+
+        let _ = engine_state.merge_delta(delta, None, &cwd);
+
+        let mut stack = Stack::new();
+
+        match eval_block(
+            &engine_state,
+            &mut stack,
+            &block,
+            PipelineData::new(Span::test_data()),
+            true,
+            true,
+        ) {
+            Err(err) => panic!("test eval error in `{}`: {:?}", example.example, err),
+            Ok(result) => {
+                let result = result.into_value(Span::test_data());
+                println!("input: {}", example.example);
+                println!("result: {:?}", result);
+                println!("done: {:?}", start.elapsed());
+
+                // Note. Value implements PartialEq for Bool, Int, Float, String and Block
+                // If the command you are testing requires to compare another case, then
+                // you need to define its equality in the Value struct
+                if let Some(expected) = example.result {
+                    if result != expected {
+                        panic!(
+                            "the example result is different to expected value: {:?} != {:?}",
+                            result, expected
+                        )
+                    }
+                }
+            }
+        }
+    }
+}

crates/nu-command/src/database/values/dsl/expression.rs

@@ -118,6 +118,11 @@ impl CustomValue for ExprDb {
             Operator::In
             | Operator::NotIn
             | Operator::Pow
+            | Operator::BitOr
+            | Operator::BitXor
+            | Operator::BitAnd
+            | Operator::ShiftLeft
+            | Operator::ShiftRight
             | Operator::StartsWith
             | Operator::EndsWith => Err(ShellError::UnsupportedOperator(operator, op)),
         }?;

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

@@ -23,6 +23,8 @@ impl Command for AppendDF {
         Signature::build(self.name())
             .required("other", SyntaxShape::Any, "dataframe to be appended")
             .switch("col", "appends in col orientation", Some('c'))
+            .input_type(Type::Custom("dataframe".into()))
+            .output_type(Type::Custom("dataframe".into()))
             .category(Category::Custom("dataframe".into()))
     }
 
@@ -30,7 +32,7 @@ impl Command for AppendDF {
         vec![
             Example {
                 description: "Appends a dataframe as new columns",
-                example: r#"let a = ([[a b]; [1 2] [3 4]] | to-df);
+                example: r#"let a = ([[a b]; [1 2] [3 4]] | into df);
     $a | append $a"#,
                 result: Some(
                     NuDataFrame::try_from_columns(vec![
@@ -57,7 +59,7 @@ impl Command for AppendDF {
             },
             Example {
                 description: "Appends a dataframe merging at the end of columns",
-                example: r#"let a = ([[a b]; [1 2] [3 4]] | to-df);
+                example: r#"let a = ([[a b]; [1 2] [3 4]] | into df);
     $a | append $a --col"#,
                 result: Some(
                     NuDataFrame::try_from_columns(vec![
@@ -87,14 +89,6 @@ impl Command for AppendDF {
         ]
     }
 
-    fn input_type(&self) -> Type {
-        Type::Custom("dataframe".into())
-    }
-
-    fn output_type(&self) -> Type {
-        Type::Custom("dataframe".into())
-    }
-
     fn run(
         &self,
         engine_state: &EngineState,

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

@@ -29,6 +29,8 @@ impl Command for DescribeDF {
     fn signature(&self) -> Signature {
         Signature::build(self.name())
             .category(Category::Custom("dataframe".into()))
+            .input_type(Type::Custom("dataframe".into()))
+            .output_type(Type::Custom("dataframe".into()))
             .named(
                 "quantiles",
                 SyntaxShape::Table,
@@ -40,7 +42,7 @@ impl Command for DescribeDF {
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "dataframe description",
-            example: "[[a b]; [1 1] [1 1]] | to-df | describe",
+            example: "[[a b]; [1 1] [1 1]] | into df | describe",
             result: Some(
                 NuDataFrame::try_from_columns(vec![
                     Column::new(
@@ -95,14 +97,6 @@ impl Command for DescribeDF {
         }]
     }
 
-    fn input_type(&self) -> Type {
-        Type::Custom("dataframe".into())
-    }
-
-    fn output_type(&self) -> Type {
-        Type::Custom("dataframe".into())
-    }
-
     fn run(
         &self,
         engine_state: &EngineState,

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

@@ -23,13 +23,15 @@ impl Command for DropDF {
     fn signature(&self) -> Signature {
         Signature::build(self.name())
             .rest("rest", SyntaxShape::Any, "column names to be dropped")
+            .input_type(Type::Custom("dataframe".into()))
+            .output_type(Type::Custom("dataframe".into()))
             .category(Category::Custom("dataframe".into()))
     }
 
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "drop column a",
-            example: "[[a b]; [1 2] [3 4]] | to-df | drop a",
+            example: "[[a b]; [1 2] [3 4]] | into df | drop a",
             result: Some(
                 NuDataFrame::try_from_columns(vec![Column::new(
                     "b".to_string(),
@@ -41,14 +43,6 @@ impl Command for DropDF {
         }]
     }
 
-    fn input_type(&self) -> Type {
-        Type::Custom("dataframe".into())
-    }
-
-    fn output_type(&self) -> Type {
-        Type::Custom("dataframe".into())
-    }
-
     fn run(
         &self,
         engine_state: &EngineState,

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

@@ -34,13 +34,15 @@ impl Command for DropDuplicates {
                 "keeps last duplicate value (by default keeps first)",
                 Some('l'),
             )
+            .input_type(Type::Custom("dataframe".into()))
+            .output_type(Type::Custom("dataframe".into()))
             .category(Category::Custom("dataframe".into()))
     }
 
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "drop duplicates",
-            example: "[[a b]; [1 2] [3 4] [1 2]] | to-df | drop-duplicates",
+            example: "[[a b]; [1 2] [3 4] [1 2]] | into df | drop-duplicates",
             result: Some(
                 NuDataFrame::try_from_columns(vec![
                     Column::new(
@@ -58,14 +60,6 @@ impl Command for DropDuplicates {
         }]
     }
 
-    fn input_type(&self) -> Type {
-        Type::Custom("dataframe".into())
-    }
-
-    fn output_type(&self) -> Type {
-        Type::Custom("dataframe".into())
-    }
-
     fn run(
         &self,
         engine_state: &EngineState,

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

@@ -27,6 +27,8 @@ impl Command for DropNulls {
                 SyntaxShape::Table,
                 "subset of columns to drop nulls",
             )
+            .input_type(Type::Custom("dataframe".into()))
+            .output_type(Type::Custom("dataframe".into()))
             .category(Category::Custom("dataframe".into()))
     }
 
@@ -34,7 +36,7 @@ impl Command for DropNulls {
         vec![
             Example {
                 description: "drop null values in dataframe",
-                example: r#"let df = ([[a b]; [1 2] [3 0] [1 2]] | to-df);
+                example: r#"let df = ([[a b]; [1 2] [3 0] [1 2]] | into df);
     let res = ($df.b / $df.b);
     let a = ($df | with-column $res --name res);
     $a | drop-nulls"#,
@@ -59,7 +61,7 @@ impl Command for DropNulls {
             },
             Example {
                 description: "drop null values in dataframe",
-                example: r#"let s = ([1 2 0 0 3 4] | to-df);
+                example: r#"let s = ([1 2 0 0 3 4] | into df);
     ($s / $s) | drop-nulls"#,
                 result: Some(
                     NuDataFrame::try_from_columns(vec![Column::new(
@@ -78,14 +80,6 @@ impl Command for DropNulls {
         ]
     }
 
-    fn input_type(&self) -> Type {
-        Type::Custom("dataframe".into())
-    }
-
-    fn output_type(&self) -> Type {
-        Type::Custom("dataframe".into())
-    }
-
     fn run(
         &self,
         engine_state: &EngineState,

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

@@ -18,13 +18,16 @@ impl Command for DataTypes {
     }
 
     fn signature(&self) -> Signature {
-        Signature::build(self.name()).category(Category::Custom("dataframe".into()))
+        Signature::build(self.name())
+            .input_type(Type::Custom("dataframe".into()))
+            .output_type(Type::Custom("dataframe".into()))
+            .category(Category::Custom("dataframe".into()))
     }
 
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Dataframe dtypes",
-            example: "[[a b]; [1 2] [3 4]] | to-df | dtypes",
+            example: "[[a b]; [1 2] [3 4]] | into df | dtypes",
             result: Some(
                 NuDataFrame::try_from_columns(vec![
                     Column::new(
@@ -42,14 +45,6 @@ impl Command for DataTypes {
         }]
     }
 
-    fn input_type(&self) -> Type {
-        Type::Custom("dataframe".into())
-    }
-
-    fn output_type(&self) -> Type {
-        Type::Custom("dataframe".into())
-    }
-
     fn run(
         &self,
         engine_state: &EngineState,

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

@@ -11,7 +11,7 @@ pub struct Dummies;
 
 impl Command for Dummies {
     fn name(&self) -> &str {
-        "to-dummies"
+        "dummies"
     }
 
     fn usage(&self) -> &str {
@@ -19,14 +19,17 @@ impl Command for Dummies {
     }
 
     fn signature(&self) -> Signature {
-        Signature::build(self.name()).category(Category::Custom("dataframe".into()))
+        Signature::build(self.name())
+            .input_type(Type::Custom("dataframe".into()))
+            .output_type(Type::Custom("dataframe".into()))
+            .category(Category::Custom("dataframe".into()))
     }
 
     fn examples(&self) -> Vec<Example> {
         vec![
             Example {
                 description: "Create new dataframe with dummy variables from a dataframe",
-                example: "[[a b]; [1 2] [3 4]] | to-df | to-dummies",
+                example: "[[a b]; [1 2] [3 4]] | into df | dummies",
                 result: Some(
                     NuDataFrame::try_from_columns(vec![
                         Column::new(
@@ -52,7 +55,7 @@ impl Command for Dummies {
             },
             Example {
                 description: "Create new dataframe with dummy variables from a series",
-                example: "[1 2 2 3 3] | to-df | to-dummies",
+                example: "[1 2 2 3 3] | into df | dummies",
                 result: Some(
                     NuDataFrame::try_from_columns(vec![
                         Column::new(
@@ -93,14 +96,6 @@ impl Command for Dummies {
         ]
     }
 
-    fn input_type(&self) -> Type {
-        Type::Custom("dataframe".into())
-    }
-
-    fn output_type(&self) -> Type {
-        Type::Custom("dataframe".into())
-    }
-
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/eager/filter_with.rs

@@ -29,6 +29,8 @@ impl Command for FilterWith {
                 SyntaxShape::Any,
                 "boolean mask used to filter data",
             )
+            .input_type(Type::Custom("dataframe".into()))
+            .output_type(Type::Custom("dataframe".into()))
             .category(Category::Custom("dataframe or lazyframe".into()))
     }
 
@@ -36,8 +38,8 @@ impl Command for FilterWith {
         vec![
             Example {
                 description: "Filter dataframe using a bool mask",
-                example: r#"let mask = ([true false] | to-df);
+                example: r#"let mask = ([true false] | into df);
-    [[a b]; [1 2] [3 4]] | to-df | filter-with $mask"#,
+    [[a b]; [1 2] [3 4]] | into df | filter-with $mask"#,
                 result: Some(
                     NuDataFrame::try_from_columns(vec![
                         Column::new("a".to_string(), vec![Value::test_int(1)]),
@@ -49,7 +51,7 @@ impl Command for FilterWith {
             },
             Example {
                 description: "Filter dataframe using an expression",
-                example: "[[a b]; [1 2] [3 4]] | to-df | filter-with ((col a) > 1)",
+                example: "[[a b]; [1 2] [3 4]] | into df | filter-with ((col a) > 1)",
                 result: Some(
                     NuDataFrame::try_from_columns(vec![
                         Column::new("a".to_string(), vec![Value::test_int(3)]),
@@ -62,14 +64,6 @@ impl Command for FilterWith {
         ]
     }
 
-    fn input_type(&self) -> Type {
-        Type::Custom("dataframe".into())
-    }
-
-    fn output_type(&self) -> Type {
-        Type::Custom("dataframe".into())
-    }
-
     fn run(
         &self,
         engine_state: &EngineState,

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

@@ -21,13 +21,15 @@ impl Command for FirstDF {
     fn signature(&self) -> Signature {
         Signature::build(self.name())
             .optional("rows", SyntaxShape::Int, "Number of rows for head")
+            .input_type(Type::Custom("dataframe".into()))
+            .output_type(Type::Custom("dataframe".into()))
             .category(Category::Custom("dataframe".into()))
     }
 
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Create new dataframe with head rows",
-            example: "[[a b]; [1 2] [3 4]] | to-df | first 1",
+            example: "[[a b]; [1 2] [3 4]] | into df | first 1",
             result: Some(
                 NuDataFrame::try_from_columns(vec![
                     Column::new("a".to_string(), vec![Value::test_int(1)]),
@@ -39,14 +41,6 @@ impl Command for FirstDF {
         }]
     }
 
-    fn input_type(&self) -> Type {
-        Type::Custom("dataframe".into())
-    }
-
-    fn output_type(&self) -> Type {
-        Type::Custom("dataframe".into())
-    }
-
     fn run(
         &self,
         engine_state: &EngineState,

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

@@ -24,13 +24,15 @@ impl Command for GetDF {
     fn signature(&self) -> Signature {
         Signature::build(self.name())
             .rest("rest", SyntaxShape::Any, "column names to sort dataframe")
+            .input_type(Type::Custom("dataframe".into()))
+            .output_type(Type::Custom("dataframe".into()))
             .category(Category::Custom("dataframe".into()))
     }
 
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Returns the selected column",
-            example: "[[a b]; [1 2] [3 4]] | to-df | get a",
+            example: "[[a b]; [1 2] [3 4]] | into df | get a",
             result: Some(
                 NuDataFrame::try_from_columns(vec![Column::new(
                     "a".to_string(),
@@ -42,14 +44,6 @@ impl Command for GetDF {
         }]
     }
 
-    fn input_type(&self) -> Type {
-        Type::Custom("dataframe".into())
-    }
-
-    fn output_type(&self) -> Type {
-        Type::Custom("dataframe".into())
-    }
-
     fn run(
         &self,
         engine_state: &EngineState,

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

@@ -21,13 +21,15 @@ impl Command for LastDF {
     fn signature(&self) -> Signature {
         Signature::build(self.name())
             .optional("rows", SyntaxShape::Int, "Number of rows for tail")
+            .input_type(Type::Custom("dataframe".into()))
+            .output_type(Type::Custom("dataframe".into()))
             .category(Category::Custom("dataframe".into()))
     }
 
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Create new dataframe with last rows",
-            example: "[[a b]; [1 2] [3 4]] | to-df | last 1",
+            example: "[[a b]; [1 2] [3 4]] | into df | last 1",
             result: Some(
                 NuDataFrame::try_from_columns(vec![
                     Column::new("a".to_string(), vec![Value::test_int(3)]),
@@ -39,14 +41,6 @@ impl Command for LastDF {
         }]
     }
 
-    fn input_type(&self) -> Type {
-        Type::Custom("dataframe".into())
-    }
-
-    fn output_type(&self) -> Type {
-        Type::Custom("dataframe".into())
-    }
-
     fn run(
         &self,
         engine_state: &EngineState,

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

@@ -25,7 +25,7 @@ impl Command for ListDF {
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Creates a new dataframe and shows it in the dataframe list",
-            example: r#"let test = ([[a b];[1 2] [3 4]] | to-df);
+            example: r#"let test = ([[a b];[1 2] [3 4]] | into df);
     ls-df"#,
             result: None,
         }]

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

@@ -48,13 +48,16 @@ impl Command for MeltDF {
                 "optional name for value column",
                 Some('l'),
             )
+            .input_type(Type::Custom("dataframe".into()))
+            .output_type(Type::Custom("dataframe".into()))
             .category(Category::Custom("dataframe".into()))
     }
 
     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]] | to-df | melt -c [b c] -v [a d]",
+            example:
+                "[[a b c d]; [x 1 4 a] [y 2 5 b] [z 3 6 c]] | into df | melt -c [b c] -v [a d]",
             result: Some(
                 NuDataFrame::try_from_columns(vec![
                     Column::new(
@@ -108,14 +111,6 @@ impl Command for MeltDF {
         }]
     }
 
-    fn input_type(&self) -> Type {
-        Type::Custom("dataframe".into())
-    }
-
-    fn output_type(&self) -> Type {
-        Type::Custom("dataframe".into())
-    }
-
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/eager/open.rs

@@ -58,6 +58,8 @@ impl Command for OpenDataFrame {
                 "Columns to be selected from csv file. CSV and Parquet file",
                 None,
             )
+            .input_type(Type::Any)
+            .output_type(Type::Custom("dataframe".into()))
             .category(Category::Custom("dataframe".into()))
     }
 
@@ -69,14 +71,6 @@ impl Command for OpenDataFrame {
         }]
     }
 
-    fn input_type(&self) -> Type {
-        Type::Any
-    }
-
-    fn output_type(&self) -> Type {
-        Type::Custom("dataframe".into())
-    }
-
     fn run(
         &self,
         engine_state: &EngineState,
@@ -155,7 +149,7 @@ fn from_json(
     call: &Call,
 ) -> Result<polars::prelude::DataFrame, ShellError> {
     let file: Spanned<PathBuf> = call.req(engine_state, stack, 0)?;
-    let mut file = File::open(&file.item).map_err(|e| {
+    let file = File::open(&file.item).map_err(|e| {
         ShellError::GenericError(
             "Error opening file".into(),
             e.to_string(),
@@ -165,7 +159,7 @@ fn from_json(
         )
     })?;
 
-    let buf_reader = BufReader::new(&mut file);
+    let buf_reader = BufReader::new(file);
     let reader = JsonReader::new(buf_reader);
 
     reader.finish().map_err(|e| {

crates/nu-command/src/dataframe/eager/rename.rs

@@ -33,6 +33,8 @@ impl Command for RenameDF {
                 SyntaxShape::Any,
                 "New names for the selected column(s). A string or list of strings",
             )
+            .input_type(Type::Custom("dataframe".into()))
+            .output_type(Type::Custom("dataframe".into()))
             .category(Category::Custom("dataframe or lazyframe".into()))
     }
 
@@ -40,7 +42,7 @@ impl Command for RenameDF {
         vec![
             Example {
                 description: "Renames a series",
-                example: "[5 6 7 8] | to-df | rename '0' new_name",
+                example: "[5 6 7 8] | into df | rename '0' new_name",
                 result: Some(
                     NuDataFrame::try_from_columns(vec![Column::new(
                         "new_name".to_string(),
@@ -57,7 +59,7 @@ impl Command for RenameDF {
             },
             Example {
                 description: "Renames a dataframe column",
-                example: "[[a b]; [1 2] [3 4]] | to-df | rename a a_new",
+                example: "[[a b]; [1 2] [3 4]] | into df | rename a a_new",
                 result: Some(
                     NuDataFrame::try_from_columns(vec![
                         Column::new(
@@ -75,7 +77,7 @@ impl Command for RenameDF {
             },
             Example {
                 description: "Renames two dataframe columns",
-                example: "[[a b]; [1 2] [3 4]] | to-df | rename [a b] [a_new b_new]",
+                example: "[[a b]; [1 2] [3 4]] | into df | rename [a b] [a_new b_new]",
                 result: Some(
                     NuDataFrame::try_from_columns(vec![
                         Column::new(
@@ -94,14 +96,6 @@ impl Command for RenameDF {
         ]
     }
 
-    fn input_type(&self) -> Type {
-        Type::Custom("dataframe".into())
-    }
-
-    fn output_type(&self) -> Type {
-        Type::Custom("dataframe".into())
-    }
-
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/eager/sample.rs

@@ -40,6 +40,9 @@ impl Command for SampleDF {
                 Some('s'),
             )
             .switch("replace", "sample with replace", Some('e'))
+            .switch("shuffle", "shuffle sample", Some('u'))
+            .input_type(Type::Custom("dataframe".into()))
+            .output_type(Type::Custom("dataframe".into()))
             .category(Category::Custom("dataframe".into()))
     }
 
@@ -47,25 +50,17 @@ impl Command for SampleDF {
         vec![
             Example {
                 description: "Sample rows from dataframe",
-                example: "[[a b]; [1 2] [3 4]] | to-df | sample -n 1",
+                example: "[[a b]; [1 2] [3 4]] | into df | sample -n 1",
                 result: None, // No expected value because sampling is random
             },
             Example {
                 description: "Shows sample row using fraction and replace",
-                example: "[[a b]; [1 2] [3 4] [5 6]] | to-df | sample -f 0.5 -e",
+                example: "[[a b]; [1 2] [3 4] [5 6]] | into df | sample -f 0.5 -e",
                 result: None, // No expected value because sampling is random
             },
         ]
     }
 
-    fn input_type(&self) -> Type {
-        Type::Custom("dataframe".into())
-    }
-
-    fn output_type(&self) -> Type {
-        Type::Custom("dataframe".into())
-    }
-
     fn run(
         &self,
         engine_state: &EngineState,
@@ -89,22 +84,26 @@ fn command(
         .get_flag::<i64>(engine_state, stack, "seed")?
         .map(|val| val as u64);
     let replace: bool = call.has_flag("replace");
+    let shuffle: bool = call.has_flag("shuffle");
 
     let df = NuDataFrame::try_from_pipeline(input, call.head)?;
 
     match (rows, fraction) {
-        (Some(rows), None) => df.as_ref().sample_n(rows.item, replace, seed).map_err(|e| {
+        (Some(rows), None) => df
-            ShellError::GenericError(
+            .as_ref()
-                "Error creating sample".into(),
+            .sample_n(rows.item, replace, shuffle, seed)
-                e.to_string(),
+            .map_err(|e| {
-                Some(rows.span),
+                ShellError::GenericError(
-                None,
+                    "Error creating sample".into(),
-                Vec::new(),
+                    e.to_string(),
-            )
+                    Some(rows.span),
-        }),
+                    None,
+                    Vec::new(),
+                )
+            }),
         (None, Some(frac)) => df
             .as_ref()
-            .sample_frac(frac.item, replace, seed)
+            .sample_frac(frac.item, replace, shuffle, seed)
             .map_err(|e| {
                 ShellError::GenericError(
                     "Error creating sample".into(),

crates/nu-command/src/dataframe/eager/shape.rs

@@ -21,13 +21,16 @@ impl Command for ShapeDF {
     }
 
     fn signature(&self) -> Signature {
-        Signature::build(self.name()).category(Category::Custom("dataframe".into()))
+        Signature::build(self.name())
+            .input_type(Type::Custom("dataframe".into()))
+            .output_type(Type::Custom("dataframe".into()))
+            .category(Category::Custom("dataframe".into()))
     }
 
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Shows row and column shape",
-            example: "[[a b]; [1 2] [3 4]] | to-df | shape",
+            example: "[[a b]; [1 2] [3 4]] | into df | shape",
             result: Some(
                 NuDataFrame::try_from_columns(vec![
                     Column::new("rows".to_string(), vec![Value::test_int(2)]),
@@ -39,14 +42,6 @@ impl Command for ShapeDF {
         }]
     }
 
-    fn input_type(&self) -> Type {
-        Type::Custom("dataframe".into())
-    }
-
-    fn output_type(&self) -> Type {
-        Type::Custom("dataframe".into())
-    }
-
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/eager/slice.rs

@@ -25,13 +25,15 @@ impl Command for SliceDF {
         Signature::build(self.name())
             .required("offset", SyntaxShape::Int, "start of slice")
             .required("size", SyntaxShape::Int, "size of slice")
+            .input_type(Type::Custom("dataframe".into()))
+            .output_type(Type::Custom("dataframe".into()))
             .category(Category::Custom("dataframe".into()))
     }
 
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Create new dataframe from a slice of the rows",
-            example: "[[a b]; [1 2] [3 4]] | to-df | slice 0 1",
+            example: "[[a b]; [1 2] [3 4]] | into df | slice 0 1",
             result: Some(
                 NuDataFrame::try_from_columns(vec![
                     Column::new("a".to_string(), vec![Value::test_int(1)]),
@@ -43,14 +45,6 @@ impl Command for SliceDF {
         }]
     }
 
-    fn input_type(&self) -> Type {
-        Type::Custom("dataframe".into())
-    }
-
-    fn output_type(&self) -> Type {
-        Type::Custom("dataframe".into())
-    }
-
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/eager/take.rs

@@ -29,6 +29,8 @@ impl Command for TakeDF {
                 SyntaxShape::Any,
                 "list of indices used to take data",
             )
+            .input_type(Type::Custom("dataframe".into()))
+            .output_type(Type::Custom("dataframe".into()))
             .category(Category::Custom("dataframe".into()))
     }
 
@@ -36,8 +38,8 @@ impl Command for TakeDF {
         vec![
             Example {
                 description: "Takes selected rows from dataframe",
-                example: r#"let df = ([[a b]; [4 1] [5 2] [4 3]] | to-df);
+                example: r#"let df = ([[a b]; [4 1] [5 2] [4 3]] | into df);
-    let indices = ([0 2] | to-df);
+    let indices = ([0 2] | into df);
     $df | take $indices"#,
                 result: Some(
                     NuDataFrame::try_from_columns(vec![
@@ -56,8 +58,8 @@ impl Command for TakeDF {
             },
             Example {
                 description: "Takes selected rows from series",
-                example: r#"let series = ([4 1 5 2 4 3] | to-df);
+                example: r#"let series = ([4 1 5 2 4 3] | into df);
-    let indices = ([0 2] | to-df);
+    let indices = ([0 2] | into df);
     $series | take $indices"#,
                 result: Some(
                     NuDataFrame::try_from_columns(vec![Column::new(
@@ -71,14 +73,6 @@ impl Command for TakeDF {
         ]
     }
 
-    fn input_type(&self) -> Type {
-        Type::Custom("dataframe".into())
-    }
-
-    fn output_type(&self) -> Type {
-        Type::Custom("dataframe".into())
-    }
-
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/eager/to_csv.rs

@@ -15,7 +15,7 @@ pub struct ToCSV;
 
 impl Command for ToCSV {
     fn name(&self) -> &str {
-        "to-csv"
+        "to csv"
     }
 
     fn usage(&self) -> &str {
@@ -32,6 +32,8 @@ impl Command for ToCSV {
                 Some('d'),
             )
             .switch("no-header", "Indicates if file doesn't have header", None)
+            .input_type(Type::Custom("dataframe".into()))
+            .output_type(Type::Any)
             .category(Category::Custom("dataframe".into()))
     }
 
@@ -39,25 +41,17 @@ impl Command for ToCSV {
         vec![
             Example {
                 description: "Saves dataframe to csv file",
-                example: "[[a b]; [1 2] [3 4]] | to-df | to-csv test.csv",
+                example: "[[a b]; [1 2] [3 4]] | into df | to csv test.csv",
                 result: None,
             },
             Example {
                 description: "Saves dataframe to csv file using other delimiter",
-                example: "[[a b]; [1 2] [3 4]] | to-df | to-csv test.csv -d '|'",
+                example: "[[a b]; [1 2] [3 4]] | into df | to csv test.csv -d '|'",
                 result: None,
             },
         ]
     }
 
-    fn input_type(&self) -> Type {
-        Type::Custom("dataframe".into())
-    }
-
-    fn output_type(&self) -> Type {
-        Type::Any
-    }
-
     fn run(
         &self,
         engine_state: &EngineState,
@@ -99,7 +93,7 @@ fn command(
         writer.has_header(true)
     };
 
-    let writer = match delimiter {
+    let mut writer = match delimiter {
         None => writer,
         Some(d) => {
             if d.item.len() != 1 {

crates/nu-command/src/dataframe/eager/to_df.rs

@@ -11,7 +11,7 @@ pub struct ToDataFrame;
 
 impl Command for ToDataFrame {
     fn name(&self) -> &str {
-        "to-df"
+        "into df"
     }
 
     fn usage(&self) -> &str {
@@ -19,14 +19,17 @@ impl Command for ToDataFrame {
     }
 
     fn signature(&self) -> Signature {
-        Signature::build(self.name()).category(Category::Custom("dataframe".into()))
+        Signature::build(self.name())
+            .input_type(Type::Any)
+            .output_type(Type::Custom("dataframe".into()))
+            .category(Category::Custom("dataframe".into()))
     }
 
     fn examples(&self) -> Vec<Example> {
         vec![
             Example {
                 description: "Takes a dictionary and creates a dataframe",
-                example: "[[a b];[1 2] [3 4]] | to-df",
+                example: "[[a b];[1 2] [3 4]] | into df",
                 result: Some(
                     NuDataFrame::try_from_columns(vec![
                         Column::new(
@@ -44,7 +47,7 @@ impl Command for ToDataFrame {
             },
             Example {
                 description: "Takes a list of tables and creates a dataframe",
-                example: "[[1 2 a] [3 4 b] [5 6 c]] | to-df",
+                example: "[[1 2 a] [3 4 b] [5 6 c]] | into df",
                 result: Some(
                     NuDataFrame::try_from_columns(vec![
                         Column::new(
@@ -70,7 +73,7 @@ impl Command for ToDataFrame {
             },
             Example {
                 description: "Takes a list and creates a dataframe",
-                example: "[a b c] | to-df",
+                example: "[a b c] | into df",
                 result: Some(
                     NuDataFrame::try_from_columns(vec![Column::new(
                         "0".to_string(),
@@ -86,7 +89,7 @@ impl Command for ToDataFrame {
             },
             Example {
                 description: "Takes a list of booleans and creates a dataframe",
-                example: "[true true false] | to-df",
+                example: "[true true false] | into df",
                 result: Some(
                     NuDataFrame::try_from_columns(vec![Column::new(
                         "0".to_string(),
@@ -103,14 +106,6 @@ impl Command for ToDataFrame {
         ]
     }
 
-    fn input_type(&self) -> Type {
-        Type::Any
-    }
-
-    fn output_type(&self) -> Type {
-        Type::Custom("dataframe".into())
-    }
-
     fn run(
         &self,
         _engine_state: &EngineState,

crates/nu-command/src/dataframe/eager/to_nu.rs

@@ -2,7 +2,7 @@ use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, SyntaxShape, Type, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
 };
 
 use super::super::values::NuDataFrame;
@@ -12,11 +12,11 @@ pub struct ToNu;
 
 impl Command for ToNu {
     fn name(&self) -> &str {
-        "to-nu"
+        "into nu"
     }
 
     fn usage(&self) -> &str {
-        "Converts a section of the dataframe to Nushell Table"
+        "Converts a section of the dataframe into nushell Table"
     }
 
     fn signature(&self) -> Signature {
@@ -28,32 +28,49 @@ impl Command for ToNu {
                 Some('n'),
             )
             .switch("tail", "shows tail rows", Some('t'))
+            .input_type(Type::Custom("dataframe".into()))
+            .output_type(Type::Any)
             .category(Category::Custom("dataframe".into()))
     }
 
     fn examples(&self) -> Vec<Example> {
+        let cols = vec!["index".into(), "a".into(), "b".into()];
+        let rec_1 = Value::Record {
+            cols: cols.clone(),
+            vals: vec![Value::test_int(0), Value::test_int(1), Value::test_int(2)],
+            span: Span::test_data(),
+        };
+        let rec_2 = Value::Record {
+            cols: cols.clone(),
+            vals: vec![Value::test_int(1), Value::test_int(3), Value::test_int(4)],
+            span: Span::test_data(),
+        };
+        let rec_3 = Value::Record {
+            cols,
+            vals: vec![Value::test_int(2), Value::test_int(3), Value::test_int(4)],
+            span: Span::test_data(),
+        };
+
         vec![
             Example {
                 description: "Shows head rows from dataframe",
-                example: "[[a b]; [1 2] [3 4]] | to-df | to nu",
+                example: "[[a b]; [1 2] [3 4]] | into df | into nu",
-                result: None,
+                result: Some(Value::List {
+                    vals: vec![rec_1, rec_2],
+                    span: Span::test_data(),
+                }),
             },
             Example {
                 description: "Shows tail rows from dataframe",
-                example: "[[a b]; [1 2] [3 4] [5 6]] | to-df | to nu -t -n 1",
+                example: "[[a b]; [1 2] [5 6] [3 4]] | into df | into nu -t -n 1",
-                result: None,
+                result: Some(Value::List {
+                    vals: vec![rec_3],
+                    span: Span::test_data(),
+                }),
             },
         ]
     }
 
-    fn input_type(&self) -> Type {
-        Type::Custom("dataframe".into())
-    }
-
-    fn output_type(&self) -> Type {
-        Type::Any
-    }
-
     fn run(
         &self,
         engine_state: &EngineState,
@@ -71,7 +88,7 @@ fn command(
     call: &Call,
     input: PipelineData,
 ) -> Result<PipelineData, ShellError> {
-    let rows: Option<usize> = call.get_flag(engine_state, stack, "n-rows")?;
+    let rows: Option<usize> = call.get_flag(engine_state, stack, "rows")?;
     let tail: bool = call.has_flag("tail");
 
     let df = NuDataFrame::try_from_pipeline(input, call.head)?;
@@ -94,3 +111,14 @@ fn command(
 
     Ok(PipelineData::Value(value, None))
 }
+
+#[cfg(test)]
+mod test {
+    use super::super::super::test_dataframe::test_dataframe;
+    use super::*;
+
+    #[test]
+    fn test_examples() {
+        test_dataframe(vec![Box::new(ToNu {})])
+    }
+}

crates/nu-command/src/dataframe/eager/to_parquet.rs

@@ -15,7 +15,7 @@ pub struct ToParquet;
 
 impl Command for ToParquet {
     fn name(&self) -> &str {
-        "to-parquet"
+        "to parquet"
     }
 
     fn usage(&self) -> &str {
@@ -25,25 +25,19 @@ impl Command for ToParquet {
     fn signature(&self) -> Signature {
         Signature::build(self.name())
             .required("file", SyntaxShape::Filepath, "file path to save dataframe")
+            .input_type(Type::Custom("dataframe".into()))
+            .output_type(Type::Any)
             .category(Category::Custom("dataframe".into()))
     }
 
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Saves dataframe to parquet file",
-            example: "[[a b]; [1 2] [3 4]] | to-df | to-parquet test.parquet",
+            example: "[[a b]; [1 2] [3 4]] | into df | to parquet test.parquet",
             result: None,
         }]
     }
 
-    fn input_type(&self) -> Type {
-        Type::Custom("dataframe".into())
-    }
-
-    fn output_type(&self) -> Type {
-        Type::Any
-    }
-
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/eager/with_column.rs

@@ -27,6 +27,8 @@ impl Command for WithColumn {
                 SyntaxShape::Any,
                 "series to be added or expressions used to define the new columns",
             )
+            .input_type(Type::Custom("dataframe".into()))
+            .output_type(Type::Custom("dataframe".into()))
             .category(Category::Custom("dataframe or lazyframe".into()))
     }
 
@@ -35,8 +37,8 @@ impl Command for WithColumn {
             Example {
                 description: "Adds a series to the dataframe",
                 example: r#"[[a b]; [1 2] [3 4]]
-    | to-df
+    | into df
-    | with-column ([5 6] | to-df) --name c"#,
+    | with-column ([5 6] | into df) --name c"#,
                 result: Some(
                     NuDataFrame::try_from_columns(vec![
                         Column::new(
@@ -59,7 +61,7 @@ impl Command for WithColumn {
             Example {
                 description: "Adds a series to the dataframe",
                 example: r#"[[a b]; [1 2] [3 4]]
-    | to-lazy
+    | into lazy
     | with-column [
         ((col a) * 2 | as "c")
         ((col a) * 3 | as "d")
@@ -91,14 +93,6 @@ impl Command for WithColumn {
         ]
     }
 
-    fn input_type(&self) -> Type {
-        Type::Custom("dataframe".into())
-    }
-
-    fn output_type(&self) -> Type {
-        Type::Custom("dataframe".into())
-    }
-
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/expressions/alias.rs

@@ -26,13 +26,15 @@ impl Command for ExprAlias {
                 SyntaxShape::String,
                 "Alias name for the expression",
             )
+            .input_type(Type::Custom("expression".into()))
+            .output_type(Type::Custom("expression".into()))
             .category(Category::Custom("expression".into()))
     }
 
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Creates and alias expression",
-            example: "col a | as new_a | to-nu",
+            example: "col a | as new_a | into nu",
             result: {
                 let cols = vec!["expr".into(), "value".into()];
                 let expr = Value::test_string("column");
@@ -57,14 +59,6 @@ impl Command for ExprAlias {
         }]
     }
 
-    fn input_type(&self) -> Type {
-        Type::Custom("expression".into())
-    }
-
-    fn output_type(&self) -> Type {
-        Type::Custom("expression".into())
-    }
-
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/expressions/as_nu.rs

@@ -11,21 +11,24 @@ pub struct ExprAsNu;
 
 impl Command for ExprAsNu {
     fn name(&self) -> &str {
-        "to-nu"
+        "into nu"
     }
 
     fn usage(&self) -> &str {
-        "Convert expression to a nu value for access and exploration"
+        "Convert expression into a nu value for access and exploration"
     }
 
     fn signature(&self) -> Signature {
-        Signature::build(self.name()).category(Category::Custom("expression".into()))
+        Signature::build(self.name())
+            .input_type(Type::Custom("expression".into()))
+            .output_type(Type::Any)
+            .category(Category::Custom("expression".into()))
     }
 
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Convert a col expression into a nushell value",
-            example: "col a | to-nu",
+            example: "col a | into nu",
             result: Some(Value::Record {
                 cols: vec!["expr".into(), "value".into()],
                 vals: vec![
@@ -43,14 +46,6 @@ impl Command for ExprAsNu {
         }]
     }
 
-    fn input_type(&self) -> Type {
-        Type::Custom("expression".into())
-    }
-
-    fn output_type(&self) -> Type {
-        Type::Any
-    }
-
     fn run(
         &self,
         _engine_state: &EngineState,

crates/nu-command/src/dataframe/expressions/col.rs

@@ -26,13 +26,15 @@ impl Command for ExprCol {
                 SyntaxShape::String,
                 "Name of column to be used",
             )
+            .input_type(Type::Any)
+            .output_type(Type::Custom("expression".into()))
             .category(Category::Custom("expression".into()))
     }
 
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Creates a named column expression and converts it to a nu object",
-            example: "col a | to-nu",
+            example: "col a | into nu",
             result: Some(Value::Record {
                 cols: vec!["expr".into(), "value".into()],
                 vals: vec![
@@ -50,14 +52,6 @@ impl Command for ExprCol {
         }]
     }
 
-    fn input_type(&self) -> Type {
-        Type::Any
-    }
-
-    fn output_type(&self) -> Type {
-        Type::Custom("expression".into())
-    }
-
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/expressions/expressions_macro.rs

@@ -25,21 +25,16 @@ macro_rules! expr_command {
             }
 
             fn signature(&self) -> Signature {
-                Signature::build(self.name()).category(Category::Custom("expression".into()))
+                Signature::build(self.name())
+                    .input_type(Type::Custom("expression".into()))
+                    .output_type(Type::Custom("expression".into()))
+                    .category(Category::Custom("expression".into()))
             }
 
             fn examples(&self) -> Vec<Example> {
                 $examples
             }
 
-            fn input_type(&self) -> Type {
-                Type::Custom("expression".into())
-            }
-
-            fn output_type(&self) -> Type {
-                Type::Custom("expression".into())
-            }
-
             fn run(
                 &self,
                 _engine_state: &EngineState,
@@ -250,7 +245,7 @@ expr_command!(
     vec![Example {
         description: "Max aggregation for a group by",
         example: r#"[[a b]; [one 2] [one 4] [two 1]]
-    | to-df
+    | into df
     | group-by a
     | agg (col b | max)"#,
         result: Some(
@@ -281,7 +276,7 @@ expr_command!(
     vec![Example {
         description: "Min aggregation for a group by",
         example: r#"[[a b]; [one 2] [one 4] [two 1]]
-    | to-df
+    | into df
     | group-by a
     | agg (col b | min)"#,
         result: Some(
@@ -312,7 +307,7 @@ expr_command!(
     vec![Example {
         description: "Sum aggregation for a group by",
         example: r#"[[a b]; [one 2] [one 4] [two 1]]
-    | to-df
+    | into df
     | group-by a
     | agg (col b | sum)"#,
         result: Some(
@@ -343,7 +338,7 @@ expr_command!(
     vec![Example {
         description: "Mean aggregation for a group by",
         example: r#"[[a b]; [one 2] [one 4] [two 1]]
-    | to-df
+    | into df
     | group-by a
     | agg (col b | mean)"#,
         result: Some(
@@ -374,7 +369,7 @@ expr_command!(
     vec![Example {
         description: "Median aggregation for a group by",
         example: r#"[[a b]; [one 2] [one 4] [two 1]]
-    | to-df
+    | into df
     | group-by a
     | agg (col b | median)"#,
         result: Some(
@@ -405,7 +400,7 @@ expr_command!(
     vec![Example {
         description: "Std aggregation for a group by",
         example: r#"[[a b]; [one 2] [one 2] [two 1] [two 1]]
-    | to-df
+    | into df
     | group-by a
     | agg (col b | std)"#,
         result: Some(
@@ -436,7 +431,7 @@ expr_command!(
     vec![Example {
         description: "Var aggregation for a group by",
         example: r#"[[a b]; [one 2] [one 2] [two 1] [two 1]]
-    | to-df
+    | into df
     | group-by a
     | agg (col b | var)"#,
         result: Some(

crates/nu-command/src/dataframe/expressions/lit.rs

@@ -25,13 +25,15 @@ impl Command for ExprLit {
                 SyntaxShape::Any,
                 "literal to construct the expression",
             )
+            .input_type(Type::Any)
+            .output_type(Type::Custom("expression".into()))
             .category(Category::Custom("expression".into()))
     }
 
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Created a literal expression and converts it to a nu object",
-            example: "lit 2 | to-nu",
+            example: "lit 2 | into nu",
             result: Some(Value::Record {
                 cols: vec!["expr".into(), "value".into()],
                 vals: vec![
@@ -49,14 +51,6 @@ impl Command for ExprLit {
         }]
     }
 
-    fn input_type(&self) -> Type {
-        Type::Any
-    }
-
-    fn output_type(&self) -> Type {
-        Type::Custom("expression".into())
-    }
-
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/expressions/otherwise.rs

@@ -25,6 +25,8 @@ impl Command for ExprOtherwise {
                 SyntaxShape::Any,
                 "expressioini to apply when no when predicate matches",
             )
+            .input_type(Type::Any)
+            .output_type(Type::Custom("expression".into()))
             .category(Category::Custom("expression".into()))
     }
 
@@ -43,7 +45,7 @@ impl Command for ExprOtherwise {
             Example {
                 description: "Create a new column for the dataframe",
                 example: r#"[[a b]; [6 2] [1 4] [4 1]]
-   | to-lazy
+   | into lazy
    | with-column (
        when ((col a) > 2) 4 | otherwise 5 | as c
      )
@@ -77,14 +79,6 @@ impl Command for ExprOtherwise {
         ]
     }
 
-    fn input_type(&self) -> Type {
-        Type::Any
-    }
-
-    fn output_type(&self) -> Type {
-        Type::Custom("expression".into())
-    }
-
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/expressions/quantile.rs

@@ -26,6 +26,8 @@ impl Command for ExprQuantile {
                 SyntaxShape::Number,
                 "quantile value for quantile operation",
             )
+            .input_type(Type::Custom("expression".into()))
+            .output_type(Type::Custom("expression".into()))
             .category(Category::Custom("expression".into()))
     }
 
@@ -33,7 +35,7 @@ impl Command for ExprQuantile {
         vec![Example {
             description: "Quantile aggregation for a group by",
             example: r#"[[a b]; [one 2] [one 4] [two 1]]
-    | to-df
+    | into df
     | group-by a
     | agg (col b | quantile 0.5)"#,
             result: Some(
@@ -53,14 +55,6 @@ impl Command for ExprQuantile {
         }]
     }
 
-    fn input_type(&self) -> Type {
-        Type::Custom("expression".into())
-    }
-
-    fn output_type(&self) -> Type {
-        Type::Custom("expression".into())
-    }
-
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/expressions/when.rs

@@ -31,6 +31,8 @@ impl Command for ExprWhen {
                 SyntaxShape::Any,
                 "expression that will be applied when predicate is true",
             )
+            .input_type(Type::Custom("expression".into()))
+            .output_type(Type::Custom("expression".into()))
             .category(Category::Custom("expression".into()))
     }
 
@@ -49,7 +51,7 @@ impl Command for ExprWhen {
             Example {
                 description: "Create a new column for the dataframe",
                 example: r#"[[a b]; [6 2] [1 4] [4 1]]
-   | to-lazy
+   | into lazy
    | with-column (
        when ((col a) > 2) 4 | otherwise 5 | as c
      )
@@ -83,14 +85,6 @@ impl Command for ExprWhen {
         ]
     }
 
-    fn input_type(&self) -> Type {
-        Type::Custom("expression".into())
-    }
-
-    fn output_type(&self) -> Type {
-        Type::Custom("expression".into())
-    }
-
     fn run(
         &self,
         engine_state: &EngineState,

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

@@ -26,6 +26,8 @@ impl Command for LazyAggregate {
                 SyntaxShape::Any,
                 "Expression(s) that define the aggregations to be applied",
             )
+            .input_type(Type::Custom("dataframe".into()))
+            .output_type(Type::Custom("dataframe".into()))
             .category(Category::Custom("lazyframe".into()))
     }
 
@@ -34,7 +36,7 @@ impl Command for LazyAggregate {
             Example {
                 description: "Group by and perform an aggregation",
                 example: r#"[[a b]; [1 2] [1 4] [2 6] [2 4]]
-    | to-df
+    | into df
     | group-by a
     | agg [
         (col b | min | as "b_min")
@@ -67,7 +69,7 @@ impl Command for LazyAggregate {
             Example {
                 description: "Group by and perform an aggregation",
                 example: r#"[[a b]; [1 2] [1 4] [2 6] [2 4]]
-    | to-lazy
+    | into lazy
     | group-by a
     | agg [
         (col b | min | as "b_min")
@@ -101,14 +103,6 @@ impl Command for LazyAggregate {
         ]
     }
 
-    fn input_type(&self) -> Type {
-        Type::Custom("dataframe".into())
-    }
-
-    fn output_type(&self) -> Type {
-        Type::Custom("dataframe".into())
-    }
-
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/lazy/collect.rs

@@ -20,13 +20,16 @@ impl Command for LazyCollect {
     }
 
     fn signature(&self) -> Signature {
-        Signature::build(self.name()).category(Category::Custom("lazyframe".into()))
+        Signature::build(self.name())
+            .input_type(Type::Custom("dataframe".into()))
+            .output_type(Type::Custom("dataframe".into()))
+            .category(Category::Custom("lazyframe".into()))
     }
 
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "drop duplicates",
-            example: "[[a b]; [1 2] [3 4]] | to-lazy | collect",
+            example: "[[a b]; [1 2] [3 4]] | into lazy | collect",
             result: Some(
                 NuDataFrame::try_from_columns(vec![
                     Column::new(
@@ -44,14 +47,6 @@ impl Command for LazyCollect {
         }]
     }
 
-    fn input_type(&self) -> Type {
-        Type::Custom("dataframe".into())
-    }
-
-    fn output_type(&self) -> Type {
-        Type::Custom("dataframe".into())
-    }
-
     fn run(
         &self,
         _engine_state: &EngineState,

crates/nu-command/src/dataframe/lazy/fetch.rs

@@ -26,13 +26,15 @@ impl Command for LazyFetch {
                 SyntaxShape::Int,
                 "number of rows to be fetched from lazyframe",
             )
+            .input_type(Type::Custom("dataframe".into()))
+            .output_type(Type::Custom("dataframe".into()))
             .category(Category::Custom("lazyframe".into()))
     }
 
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Fetch a rows from the dataframe",
-            example: "[[a b]; [6 2] [4 2] [2 2]] | to-df | fetch 2",
+            example: "[[a b]; [6 2] [4 2] [2 2]] | into df | fetch 2",
             result: Some(
                 NuDataFrame::try_from_columns(vec![
                     Column::new(
@@ -50,14 +52,6 @@ impl Command for LazyFetch {
         }]
     }
 
-    fn input_type(&self) -> Type {
-        Type::Custom("dataframe".into())
-    }
-
-    fn output_type(&self) -> Type {
-        Type::Custom("dataframe".into())
-    }
-
     fn run(
         &self,
         engine_state: &EngineState,