Bump to 0.8.0 (#1166)

* Put a sample_data.ods file for testing

This is a copy of the sample_data.xlsx file but in ods format

* Add the from-ods command

Most of the work was doing `rg xlsx` and then copy/paste with light editing

* Add tests for the from-ods command

* Fix failing test

The problem was improper filename sorting in the test `prepares_and_decorates_filesystem_source_files`

.azure/azure-pipelines.yml

@@ -42,12 +42,18 @@ steps:
       echo "##vso[task.prependpath]$HOME/.cargo/bin"
       rustup component add rustfmt --toolchain "stable"
     displayName: Install Rust
-  - bash: RUSTFLAGS="-D warnings" cargo test --all-features
+  - bash: RUSTFLAGS="-D warnings" cargo test --all --features=stable
     condition: eq(variables['style'], 'unflagged')
     displayName: Run tests
-  - bash: NUSHELL_ENABLE_ALL_FLAGS=1 RUSTFLAGS="-D warnings" cargo test --all-features
+  - bash: RUSTFLAGS="-D warnings" cargo clippy --all --features=stable -- -D clippy::result_unwrap_used -D clippy::option_unwrap_used
+    condition: eq(variables['style'], 'unflagged')
+    displayName: Check clippy lints
+  - bash: NUSHELL_ENABLE_ALL_FLAGS=1 RUSTFLAGS="-D warnings" cargo test --all --features=stable
     condition: eq(variables['style'], 'canary')
     displayName: Run tests
+  - bash: NUSHELL_ENABLE_ALL_FLAGS=1 RUSTFLAGS="-D warnings" cargo clippy --all --features=stable -- -D clippy::result_unwrap_used -D clippy::option_unwrap_used
+    condition: eq(variables['style'], 'canary')
+    displayName: Check clippy lints
   - bash: cargo fmt --all -- --check
     condition: eq(variables['style'], 'fmt')
     displayName: Lint

.gitpod.yml

@@ -1,7 +1,7 @@
 image:
   file: .gitpod.Dockerfile
 tasks:
-  - init: cargo install nu
+  - init: cargo install nu --features=stable
     command: nu
 github:
   prebuilds:

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "nu"
-version = "0.6.1"
+version = "0.8.0"
 authors = ["Yehuda Katz <wycats@gmail.com>", "Jonathan Turner <jonathan.d.turner@gmail.com>", "Andrés N. Robalino <andres@androbtech.com>"]
 description = "A shell for the GitHub era"
 license = "MIT"
@@ -9,22 +9,64 @@ readme = "README.md"
 default-run = "nu"
 repository = "https://github.com/nushell/nushell"
 homepage = "https://www.nushell.sh"
-documentation = "https://book.nushell.sh"
+documentation = "https://www.nushell.sh/book/"
 
 [workspace]
 
-members = ["crates/nu-source"]
+members = [
+    "crates/nu-macros",
+    "crates/nu-errors",
+    "crates/nu-source",
+    "crates/nu_plugin_average",
+    "crates/nu_plugin_binaryview",
+    "crates/nu_plugin_fetch",
+    "crates/nu_plugin_inc",
+    "crates/nu_plugin_match",
+    "crates/nu_plugin_post",
+    "crates/nu_plugin_ps",
+    "crates/nu_plugin_str",
+    "crates/nu_plugin_sum",
+    "crates/nu_plugin_sys",
+    "crates/nu_plugin_textview",
+    "crates/nu_plugin_tree",
+    "crates/nu-protocol",
+    "crates/nu-plugin",
+    "crates/nu-parser",
+    "crates/nu-value-ext",
+    "crates/nu-build"
+]
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-nu-source = { version = "0.1.0", path = "./crates/nu-source" }
+nu-source = { version = "0.8.0", path = "./crates/nu-source" }
+nu-plugin = { version = "0.8.0", path = "./crates/nu-plugin" }
+nu-protocol = { version = "0.8.0", path = "./crates/nu-protocol" }
+nu-errors = { version = "0.8.0", path = "./crates/nu-errors" }
+nu-parser = { version = "0.8.0", path = "./crates/nu-parser" }
+nu-value-ext = { version = "0.8.0", path = "./crates/nu-value-ext" }
+nu_plugin_average = {version = "0.8.0", path = "./crates/nu_plugin_average", optional=true}
+nu_plugin_binaryview = {version = "0.8.0", path = "./crates/nu_plugin_binaryview", optional=true}
+nu_plugin_fetch = {version = "0.8.0", path = "./crates/nu_plugin_fetch", optional=true}
+nu_plugin_inc = {version = "0.8.0", path = "./crates/nu_plugin_inc", optional=true}
+nu_plugin_match = {version = "0.8.0", path = "./crates/nu_plugin_match", optional=true}
+nu_plugin_post = {version = "0.8.0", path = "./crates/nu_plugin_post", optional=true}
+nu_plugin_ps = {version = "0.8.0", path = "./crates/nu_plugin_ps", optional=true}
+nu_plugin_str = {version = "0.8.0", path = "./crates/nu_plugin_str", optional=true}
+nu_plugin_sum = {version = "0.8.0", path = "./crates/nu_plugin_sum", optional=true}
+nu_plugin_sys = {version = "0.8.0", path = "./crates/nu_plugin_sys", optional=true}
+nu_plugin_textview = {version = "0.8.0", path = "./crates/nu_plugin_textview", optional=true}
+nu_plugin_tree = {version = "0.8.0", path = "./crates/nu_plugin_tree", optional=true}
+nu-macros = { version = "0.8.0", path = "./crates/nu-macros" }
 
-rustyline = "5.0.4"
-chrono = { version = "0.4.9", features = ["serde"] }
+
+query_interface = "0.3.5"
+typetag = "0.1.4"
+rustyline = "5.0.6"
+chrono = { version = "0.4.10", features = ["serde"] }
 derive-new = "0.5.8"
 prettytable-rs = "0.8.0"
-itertools = "0.8.1"
+itertools = "0.8.2"
 ansi_term = "0.12.1"
 nom = "5.0.1"
 dunce = "1.0.0"
@@ -35,82 +77,86 @@ base64 = "0.11"
 futures-preview = { version = "=0.3.0-alpha.19", features = ["compat", "io-compat"] }
 async-stream = "0.1.2"
 futures_codec = "0.2.5"
-num-traits = "0.2.8"
+num-traits = "0.2.10"
 term = "0.5.2"
 bytes = "0.4.12"
 log = "0.4.8"
 pretty_env_logger = "0.3.1"
-serde = { version = "1.0.102", features = ["derive"] }
+serde = { version = "1.0.103", features = ["derive"] }
 bson = { version = "0.14.0", features = ["decimal128"] }
-serde_json = "1.0.41"
+serde_json = "1.0.44"
 serde-hjson = "0.9.1"
 serde_yaml = "0.8"
-serde_bytes = "0.11.2"
+serde_bytes = "0.11.3"
 getset = "0.0.9"
 language-reporting = "0.4.0"
 app_dirs = "1.2.1"
 csv = "1.1"
 toml = "0.5.5"
 clap = "2.33.0"
-git2 = { version = "0.10.1", default_features = false }
+git2 = { version = "0.10.2", default_features = false }
 dirs = "2.0.2"
 glob = "0.3.0"
 ctrlc = "3.1.3"
-surf = "1.0.3"
-url = "2.1.0"
-roxmltree = "0.7.2"
+roxmltree = "0.7.3"
 nom_locate = "1.0.0"
 nom-tracable = "0.4.1"
 unicode-xid = "0.2.0"
 serde_ini = "0.2.0"
 subprocess = "0.1.18"
-mime = "0.3.14"
 pretty-hex = "0.1.1"
 hex = "0.4"
 tempfile = "3.1.0"
-semver = "0.9.0"
-which = "3.1"
+ichwh = "0.2"
 textwrap = {version = "0.11.0", features = ["term_size"]}
 shellexpand = "1.0.0"
-futures-timer = "2.0.0"
 pin-utils = "0.1.0-alpha.4"
 num-bigint = { version = "0.2.3", features = ["serde"] }
 bigdecimal = { version = "0.1.0", features = ["serde"] }
-natural = "0.3.0"
 serde_urlencoded = "0.6.1"
-sublime_fuzzy = "0.6"
 trash = "1.0.0"
 regex = "1"
 cfg-if = "0.1"
 strip-ansi-escapes = "0.1.0"
 calamine = "0.16"
 umask = "0.1"
-futures-util = "0.3.0"
-pretty = "0.5.2"
+futures-util = "0.3.1"
 termcolor = "1.0.5"
-console = "0.9.1"
+natural = "0.3.0"
+parking_lot = "0.10.0"
 
-neso = { version = "0.5.0", optional = true }
-crossterm = { version = "0.10.2", optional = true }
-syntect = {version = "3.2.0", optional = true }
-onig_sys = {version = "=69.1.0", optional = true }
-heim = {version = "0.0.8", optional = true }
-battery = {version = "0.7.4", optional = true }
-rawkey = {version = "0.1.2", optional = true }
 clipboard = {version = "0.5", optional = true }
 ptree = {version = "0.2" }
-image = { version = "0.22.2", default_features = false, features = ["png_codec", "jpeg"], optional = true }
-starship = { version = "0.26.4", optional = true}
+starship = { version = "0.28", optional = true}
+heim = {version = "0.0.9", optional = true}
+battery = {version = "0.7.5", optional = true}
+syntect = {version = "3.2.0", optional = true }
+onig_sys = {version = "=69.1.0", optional = true }
+crossterm = {version = "0.10.2", optional = true}
+futures-timer = {version = "1.0.2", optional = true}
+url = {version = "2.1.0", optional = true}
 
 [features]
-default = ["textview", "sys", "ps"]
-raw-key = ["rawkey", "neso"]
-textview = ["syntect", "onig_sys", "crossterm"]
-binaryview = ["image", "crossterm"]
+default = ["sys", "ps", "textview", "inc", "str"]
+stable = ["sys", "ps", "textview", "inc", "str", "starship-prompt", "binaryview", "match", "tree", "average", "sum", "post", "fetch", "clipboard"]
+
+# Default
 sys = ["heim", "battery"]
-ps = ["heim"]
+ps = ["heim", "futures-timer"]
+textview = ["crossterm", "syntect", "onig_sys", "url"]
+inc = ["nu_plugin_inc"]
+str = ["nu_plugin_str"]
+
+# Stable
+average = ["nu_plugin_average"]
+binaryview = ["nu_plugin_binaryview"]
+fetch = ["nu_plugin_fetch"]
+match = ["nu_plugin_match"]
+post = ["nu_plugin_post"]
 starship-prompt = ["starship"]
-# trace = ["nom-tracable/trace"]
+sum = ["nu_plugin_sum"]
+trace = ["nu-parser/trace"]
+tree = ["nu_plugin_tree"]
 
 [dependencies.rusqlite]
 version = "0.20.0"
@@ -118,89 +164,47 @@ features = ["bundled", "blob"]
 
 [dev-dependencies]
 pretty_assertions = "0.6.1"
+nu-test-support = { version = "0.8.0", path = "./crates/nu-test-support" }
 
 [build-dependencies]
 toml = "0.5.5"
-serde = { version = "1.0.102", features = ["derive"] }
+serde = { version = "1.0.103", features = ["derive"] }
+nu-build = { version = "0.8.0", path = "./crates/nu-build" }
 
 [lib]
 name = "nu"
+doctest = false
 path = "src/lib.rs"
 
+# Core plugins that ship with `cargo install nu` by default
+# Currently, Cargo limits us to installing only one binary
+# unless we use [[bin]], so we use this as a workaround
 [[bin]]
-name = "nu_plugin_inc"
-path = "src/plugins/inc.rs"
-
-[[bin]]
-name = "nu_plugin_sum"
-path = "src/plugins/sum.rs"
-
-[[bin]]
-name = "nu_plugin_average"
-path = "src/plugins/average.rs"
-
-[[bin]]
-name = "nu_plugin_embed"
-path = "src/plugins/embed.rs"
-
-[[bin]]
-name = "nu_plugin_insert"
-path = "src/plugins/insert.rs"
-
-[[bin]]
-name = "nu_plugin_edit"
-path = "src/plugins/edit.rs"
-
-[[bin]]
-name = "nu_plugin_format"
-path = "src/plugins/format.rs"
-
-[[bin]]
-name = "nu_plugin_parse"
-path = "src/plugins/parse.rs"
-
-[[bin]]
-name = "nu_plugin_str"
-path = "src/plugins/str.rs"
-
-[[bin]]
-name = "nu_plugin_skip"
-path = "src/plugins/skip.rs"
-
-[[bin]]
-name = "nu_plugin_match"
-path = "src/plugins/match.rs"
-
-[[bin]]
-name = "nu_plugin_sys"
-path = "src/plugins/sys.rs"
-required-features = ["sys"]
-
-[[bin]]
-name = "nu_plugin_ps"
-path = "src/plugins/ps.rs"
-required-features = ["ps"]
-
-[[bin]]
-name = "nu_plugin_tree"
-path = "src/plugins/tree.rs"
-required-features = ["tree"]
-
-[[bin]]
-name = "nu_plugin_binaryview"
-path = "src/plugins/binaryview.rs"
-required-features = ["binaryview"]
-
-[[bin]]
-name = "nu_plugin_textview"
-path = "src/plugins/textview.rs"
+name = "nu_plugin_core_textview"
+path = "src/plugins/nu_plugin_core_textview.rs"
 required-features = ["textview"]
 
 [[bin]]
-name = "nu_plugin_docker"
-path = "src/plugins/docker.rs"
-required-features = ["docker"]
+name = "nu_plugin_core_inc"
+path = "src/plugins/nu_plugin_core_inc.rs"
+required-features = ["inc"]
 
+[[bin]]
+name = "nu_plugin_core_ps"
+path = "src/plugins/nu_plugin_core_ps.rs"
+required-features = ["ps"]
+
+[[bin]]
+name = "nu_plugin_core_str"
+path = "src/plugins/nu_plugin_core_str.rs"
+required-features = ["str"]
+
+[[bin]]
+name = "nu_plugin_core_sys"
+path = "src/plugins/nu_plugin_core_sys.rs"
+required-features = ["sys"]
+
+# Main nu binary
 [[bin]]
 name = "nu"
 path = "src/main.rs"

README.md

@@ -18,9 +18,9 @@ Nu comes with a set of built-in commands (listed below). If a command is unknown
 
 # Learning more
 
-There are a few good resources to learn about Nu. There is a [book](https://book.nushell.sh) about Nu that is currently in progress. The book focuses on using Nu and its core concepts.
+There are a few good resources to learn about Nu. There is a [book](https://www.nushell.sh/book/) about Nu that is currently in progress. The book focuses on using Nu and its core concepts.
 
-If you're a developer who would like to contribute to Nu, we're also working on a [book for developers](https://github.com/nushell/contributor-book/tree/master/en) to help you get started. There are also [good first issues](https://github.com/nushell/nushell/issues?q=is%3Aopen+is%3Aissue+label%3A%22good+first+issue%22) to help you dive in.
+If you're a developer who would like to contribute to Nu, we're also working on a [book for developers](https://www.nushell.sh/contributor-book/) to help you get started. There are also [good first issues](https://github.com/nushell/nushell/issues?q=is%3Aopen+is%3Aissue+label%3A%22good+first+issue%22) to help you dive in.
 
 We also have an active [Discord](https://discord.gg/NtAbbGn) and [Twitter](https://twitter.com/nu_shell) if you'd like to come and chat with us.
 
@@ -32,7 +32,7 @@ Try it in Gitpod.
 
 ## Local
 
-Up-to-date installation instructions can be found in the [installation chapter of the book](https://book.nushell.sh/en/installation).  **Windows users**: please note that Nu works on Windows 10 and does not currently have Windows 7/8.1 support.
+Up-to-date installation instructions can be found in the [installation chapter of the book](https://www.nushell.sh/book/en/installation.html).  **Windows users**: please note that Nu works on Windows 10 and does not currently have Windows 7/8.1 support.
 
 To build Nu, you will need to use the **latest stable (1.39 or later)** version of the compiler.
 
@@ -52,10 +52,10 @@ To install Nu via cargo (make sure you have installed [rustup](https://rustup.rs
 cargo install nu
 ```
 
-You can also install Nu with all the bells and whistles (be sure to have installed the [dependencies](https://book.nushell.sh/en/installation#dependencies) for your platform):
+You can also build Nu yourself with all the bells and whistles (be sure to have installed the [dependencies](https://www.nushell.sh/book/en/installation.html#dependencies) for your platform), once you have checked out this repo with git:
 
 ```
-cargo install nu --all-features
+cargo build --all --features=stable
 ```
 
 ## Docker
@@ -202,7 +202,7 @@ To set one of these variables, you can use `config --set`. For example:
 
 ```
 > config --set [edit_mode "vi"]
-> config --set [path $nu:path]
+> config --set [path $nu.path]
 ```
 
 ## Shells

TODO.md

@@ -46,3 +46,7 @@ Unify dictionary building, probably around a macro
 sys plugin in own crate
 
 textview in own crate
+
+Combine atomic and atomic_parse in parser
+
+at_end_possible_ws needs to be comment and separator sensitive

build.rs

@@ -1,39 +1,3 @@
-use serde::Deserialize;
-use std::collections::HashMap;
-use std::collections::HashSet;
-use std::env;
-use std::path::Path;
-
-#[derive(Deserialize)]
-struct Feature {
-    #[allow(unused)]
-    description: String,
-    enabled: bool,
-}
-
 fn main() -> Result<(), Box<dyn std::error::Error>> {
-    let input = env::var("CARGO_MANIFEST_DIR").unwrap();
-    let all_on = env::var("NUSHELL_ENABLE_ALL_FLAGS").is_ok();
-    let flags: HashSet<String> = env::var("NUSHELL_ENABLE_FLAGS")
-        .map(|s| s.split(",").map(|s| s.to_string()).collect())
-        .unwrap_or_else(|_| HashSet::new());
-
-    if all_on && !flags.is_empty() {
-        println!(
-            "cargo:warning={}",
-            "Both NUSHELL_ENABLE_ALL_FLAGS and NUSHELL_ENABLE_FLAGS were set. You don't need both."
-        );
-    }
-
-    let path = Path::new(&input).join("features.toml");
-
-    let toml: HashMap<String, Feature> = toml::from_str(&std::fs::read_to_string(path)?)?;
-
-    for (key, value) in toml.iter() {
-        if value.enabled == true || all_on || flags.contains(key) {
-            println!("cargo:rustc-cfg={}", key);
-        }
-    }
-
-    Ok(())
+    nu_build::build()
 }

crates/nu-build/Cargo.toml

@@ -0,0 +1,16 @@
+[package]
+name = "nu-build"
+version = "0.8.0"
+authors = ["Yehuda Katz <wycats@gmail.com>", "Jonathan Turner <jonathan.d.turner@gmail.com>", "Andrés N. Robalino <andres@androbtech.com>"]
+edition = "2018"
+description = "Core build system for nushell"
+license = "MIT"
+
+[lib]
+doctest = false
+
+[dependencies]
+serde = { version = "1.0.103", features = ["derive"] }
+lazy_static = "1.4.0"
+serde_json = "1.0.44"
+toml = "0.5.5"

crates/nu-build/src/lib.rs

@@ -0,0 +1,80 @@
+use lazy_static::lazy_static;
+use serde::Deserialize;
+use std::collections::BTreeMap;
+use std::collections::HashMap;
+use std::collections::HashSet;
+use std::env;
+use std::path::{Path, PathBuf};
+use std::sync::Mutex;
+
+lazy_static! {
+    static ref WORKSPACES: Mutex<BTreeMap<String, &'static Path>> = Mutex::new(BTreeMap::new());
+}
+
+// got from https://github.com/mitsuhiko/insta/blob/b113499249584cb650150d2d01ed96ee66db6b30/src/runtime.rs#L67-L88
+
+fn get_cargo_workspace(manifest_dir: &str) -> Result<Option<&Path>, Box<dyn std::error::Error>> {
+    let mut workspaces = WORKSPACES.lock()?;
+    if let Some(rv) = workspaces.get(manifest_dir) {
+        Ok(Some(rv))
+    } else {
+        #[derive(Deserialize)]
+        struct Manifest {
+            workspace_root: String,
+        }
+        let output = std::process::Command::new(env!("CARGO"))
+            .arg("metadata")
+            .arg("--format-version=1")
+            .current_dir(manifest_dir)
+            .output()?;
+        let manifest: Manifest = serde_json::from_slice(&output.stdout)?;
+        let path = Box::leak(Box::new(PathBuf::from(manifest.workspace_root)));
+        workspaces.insert(manifest_dir.to_string(), path.as_path());
+        Ok(workspaces.get(manifest_dir).cloned())
+    }
+}
+
+#[derive(Deserialize)]
+struct Feature {
+    #[allow(unused)]
+    description: String,
+    enabled: bool,
+}
+
+pub fn build() -> Result<(), Box<dyn std::error::Error>> {
+    let input = env::var("CARGO_MANIFEST_DIR")?;
+
+    let all_on = env::var("NUSHELL_ENABLE_ALL_FLAGS").is_ok();
+    let flags: HashSet<String> = env::var("NUSHELL_ENABLE_FLAGS")
+        .map(|s| s.split(',').map(|s| s.to_string()).collect())
+        .unwrap_or_else(|_| HashSet::new());
+
+    if all_on && !flags.is_empty() {
+        println!(
+            "cargo:warning=Both NUSHELL_ENABLE_ALL_FLAGS and NUSHELL_ENABLE_FLAGS were set. You don't need both."
+        );
+    }
+
+    let workspace = match get_cargo_workspace(&input)? {
+        // If the crate is being downloaded from crates.io, it won't have a workspace root, and that's ok
+        None => return Ok(()),
+        Some(workspace) => workspace,
+    };
+
+    let path = Path::new(&workspace).join("features.toml");
+
+    // If the crate is being downloaded from crates.io, it won't have a features.toml, and that's ok
+    if !path.exists() {
+        return Ok(());
+    }
+
+    let toml: HashMap<String, Feature> = toml::from_str(&std::fs::read_to_string(path)?)?;
+
+    for (key, value) in toml.iter() {
+        if value.enabled || all_on || flags.contains(key) {
+            println!("cargo:rustc-cfg={}", key);
+        }
+    }
+
+    Ok(())
+}

crates/nu-errors/Cargo.toml

@@ -0,0 +1,32 @@
+[package]
+name = "nu-errors"
+version = "0.8.0"
+authors = ["Yehuda Katz <wycats@gmail.com>", "Jonathan Turner <jonathan.d.turner@gmail.com>", "Andrés N. Robalino <andres@androbtech.com>"]
+edition = "2018"
+description = "Core error subsystem for Nushell"
+license = "MIT"
+
+[lib]
+doctest = false
+
+[dependencies]
+nu-source = { path = "../nu-source", version = "0.8.0" }
+
+ansi_term = "0.12.1"
+bigdecimal = { version = "0.1.0", features = ["serde"] }
+derive-new = "0.5.8"
+language-reporting = "0.4.0"
+num-bigint = { version = "0.2.3", features = ["serde"] }
+num-traits = "0.2.10"
+serde = { version = "1.0.103", features = ["derive"] }
+nom = "5.0.1"
+nom_locate = "1.0.0"
+
+# implement conversions
+subprocess = "0.1.18"
+serde_yaml = "0.8"
+toml = "0.5.5"
+serde_json = "1.0.44"
+
+[build-dependencies]
+nu-build = { version = "0.8.0", path = "../nu-build" }

crates/nu-errors/build.rs

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

crates/nu-errors/src/lib.rs

@@ -1,71 +1,67 @@
-use crate::prelude::*;
-
 use ansi_term::Color;
+use bigdecimal::BigDecimal;
 use derive_new::new;
 use language_reporting::{Diagnostic, Label, Severity};
-use nu_source::{Spanned, TracableContext};
+use nu_source::{b, DebugDocBuilder, PrettyDebug, Span, Spanned, SpannedItem, TracableContext};
+use num_bigint::BigInt;
+use num_traits::ToPrimitive;
 use serde::{Deserialize, Serialize};
 use std::fmt;
 use std::ops::Range;
 
-// TODO: Spanned<T> -> HasSpanAndItem<T> ?
-
-#[derive(Debug, Eq, PartialEq, Clone, Ord, PartialOrd, Hash, Serialize, Deserialize)]
-pub enum Description {
-    Source(Spanned<String>),
-    Synthetic(String),
-}
-
-impl Description {
-    fn from_spanned(item: Spanned<impl Into<String>>) -> Description {
-        Description::Source(item.map(|s| s.into()))
-    }
-
-    fn into_label(self) -> Result<Label<Span>, String> {
-        match self {
-            Description::Source(s) => Ok(Label::new_primary(s.span).with_message(s.item)),
-            Description::Synthetic(s) => Err(s),
-        }
-    }
-}
-
-impl PrettyDebug for Description {
-    fn pretty(&self) -> DebugDocBuilder {
-        match self {
-            Description::Source(s) => b::description(&s.item),
-            Description::Synthetic(s) => b::description(s),
-        }
-    }
-}
-
+/// A structured reason for a ParseError. Note that parsing in nu is more like macro expansion in
+/// other languages, so the kinds of errors that can occur during parsing are more contextual than
+/// you might expect.
 #[derive(Debug, Clone)]
 pub enum ParseErrorReason {
-    Eof {
-        expected: &'static str,
-        span: Span,
-    },
+    /// The parser encountered an EOF rather than what it was expecting
+    Eof { expected: &'static str, span: Span },
+    /// The parser expected to see the end of a token stream (possibly the token
+    /// stream from inside a delimited token node), but found something else.
+    ExtraTokens { actual: Spanned<String> },
+    /// The parser encountered something other than what it was expecting
     Mismatch {
         expected: &'static str,
         actual: Spanned<String>,
     },
+
+    /// An unexpected internal error has occurred
+    InternalError { message: Spanned<String> },
+
+    /// The parser tried to parse an argument for a command, but it failed for
+    /// some reason
     ArgumentError {
         command: Spanned<String>,
         error: ArgumentError,
     },
 }
 
+/// A newtype for `ParseErrorReason`
 #[derive(Debug, Clone)]
 pub struct ParseError {
     reason: ParseErrorReason,
 }
 
 impl ParseError {
+    /// Construct a [ParseErrorReason::Eof](ParseErrorReason::Eof)
     pub fn unexpected_eof(expected: &'static str, span: Span) -> ParseError {
         ParseError {
             reason: ParseErrorReason::Eof { expected, span },
         }
     }
 
+    /// Construct a [ParseErrorReason::ExtraTokens](ParseErrorReason::ExtraTokens)
+    pub fn extra_tokens(actual: Spanned<impl Into<String>>) -> ParseError {
+        let Spanned { span, item } = actual;
+
+        ParseError {
+            reason: ParseErrorReason::ExtraTokens {
+                actual: item.into().spanned(span),
+            },
+        }
+    }
+
+    /// Construct a [ParseErrorReason::Mismatch](ParseErrorReason::Mismatch)
     pub fn mismatch(expected: &'static str, actual: Spanned<impl Into<String>>) -> ParseError {
         let Spanned { span, item } = actual;
 
@@ -77,6 +73,16 @@ impl ParseError {
         }
     }
 
+    /// Construct a [ParseErrorReason::InternalError](ParseErrorReason::InternalError)
+    pub fn internal_error(message: Spanned<impl Into<String>>) -> ParseError {
+        ParseError {
+            reason: ParseErrorReason::InternalError {
+                message: message.item.into().spanned(message.span),
+            },
+        }
+    }
+
+    /// Construct a [ParseErrorReason::ArgumentError](ParseErrorReason::ArgumentError)
     pub fn argument_error(command: Spanned<impl Into<String>>, kind: ArgumentError) -> ParseError {
         ParseError {
             reason: ParseErrorReason::ArgumentError {
@@ -87,13 +93,20 @@ impl ParseError {
     }
 }
 
+/// Convert a [ParseError](ParseError) into a [ShellError](ShellError)
 impl From<ParseError> for ShellError {
     fn from(error: ParseError) -> ShellError {
         match error.reason {
             ParseErrorReason::Eof { expected, span } => ShellError::unexpected_eof(expected, span),
+            ParseErrorReason::ExtraTokens { actual } => ShellError::type_error("nothing", actual),
             ParseErrorReason::Mismatch { actual, expected } => {
-                ShellError::type_error(expected, actual.clone())
+                ShellError::type_error(expected, actual)
             }
+            ParseErrorReason::InternalError { message } => ShellError::labeled_error(
+                format!("Internal error: {}", message.item),
+                &message.item,
+                &message.span,
+            ),
             ParseErrorReason::ArgumentError { command, error } => {
                 ShellError::argument_error(command, error)
             }
@@ -101,11 +114,20 @@ impl From<ParseError> for ShellError {
     }
 }
 
+/// ArgumentError describes various ways that the parser could fail because of unexpected arguments.
+/// Nu commands are like a combination of functions and macros, and these errors correspond to
+/// problems that could be identified during expansion based on the syntactic signature of a
+/// command.
 #[derive(Debug, Eq, PartialEq, Clone, Ord, Hash, PartialOrd, Serialize, Deserialize)]
 pub enum ArgumentError {
+    /// The command specified a mandatory flag, but it was missing.
     MissingMandatoryFlag(String),
+    /// The command specified a mandatory positional argument, but it was missing.
     MissingMandatoryPositional(String),
+    /// A flag was found, and it should have been followed by a value, but no value was found
     MissingValueForName(String),
+    /// A sequence of characters was found that was not syntactically valid (but would have
+    /// been valid if the command was an external command)
     InvalidExternalWord,
 }
 
@@ -132,12 +154,16 @@ impl PrettyDebug for ArgumentError {
     }
 }
 
+/// A `ShellError` is a proximate error and a possible cause, which could have its own cause,
+/// creating a cause chain.
 #[derive(Debug, Eq, PartialEq, Ord, PartialOrd, Clone, Serialize, Deserialize, Hash)]
 pub struct ShellError {
     error: ProximateShellError,
-    cause: Option<Box<ProximateShellError>>,
+    cause: Option<Box<ShellError>>,
 }
 
+/// `PrettyDebug` is for internal debugging. For user-facing debugging, [into_diagnostic](ShellError::into_diagnostic)
+/// is used, which prints an error, highlighting spans.
 impl PrettyDebug for ShellError {
     fn pretty(&self) -> DebugDocBuilder {
         match &self.error {
@@ -159,7 +185,7 @@ impl PrettyDebug for ShellError {
                             + b::space()
                             + b::description("actual:")
                             + b::space()
-                            + b::option(actual.item.as_ref().map(|actual| b::description(actual))),
+                            + b::option(actual.item.as_ref().map(b::description)),
                         ")",
                     )
             }
@@ -170,12 +196,12 @@ impl PrettyDebug for ShellError {
                         "(",
                         b::description("expr:")
                             + b::space()
-                            + expr.pretty()
+                            + b::description(&expr.item)
                             + b::description(",")
                             + b::space()
                             + b::description("subpath:")
                             + b::space()
-                            + subpath.pretty(),
+                            + b::description(&subpath.item),
                         ")",
                     )
             }
@@ -184,7 +210,7 @@ impl PrettyDebug for ShellError {
                     + b::space()
                     + b::delimit(
                         "(",
-                        b::description("subpath:") + b::space() + subpath.pretty(),
+                        b::description("subpath:") + b::space() + b::description(&subpath.item),
                         ")",
                     )
             }
@@ -294,8 +320,8 @@ impl ShellError {
         expr: Spanned<impl Into<String>>,
     ) -> ShellError {
         ProximateShellError::MissingProperty {
-            subpath: Description::from_spanned(subpath),
-            expr: Description::from_spanned(expr),
+            subpath: subpath.map(|s| s.into()),
+            expr: expr.map(|e| e.into()),
         }
         .start()
     }
@@ -305,7 +331,7 @@ impl ShellError {
         integer: impl Into<Span>,
     ) -> ShellError {
         ProximateShellError::InvalidIntegerIndex {
-            subpath: Description::from_spanned(subpath),
+            subpath: subpath.map(|s| s.into()),
             integer: integer.into(),
         }
         .start()
@@ -318,7 +344,7 @@ impl ShellError {
         .start()
     }
 
-    pub(crate) fn unexpected_eof(expected: impl Into<String>, span: impl Into<Span>) -> ShellError {
+    pub fn unexpected_eof(expected: impl Into<String>, span: impl Into<Span>) -> ShellError {
         ProximateShellError::UnexpectedEof {
             expected: expected.into(),
             span: span.into(),
@@ -326,7 +352,7 @@ impl ShellError {
         .start()
     }
 
-    pub(crate) fn range_error(
+    pub fn range_error(
         expected: impl Into<ExpectedRange>,
         actual: &Spanned<impl fmt::Debug>,
         operation: impl Into<String>,
@@ -339,14 +365,14 @@ impl ShellError {
         .start()
     }
 
-    pub(crate) fn syntax_error(problem: Spanned<impl Into<String>>) -> ShellError {
+    pub fn syntax_error(problem: Spanned<impl Into<String>>) -> ShellError {
         ProximateShellError::SyntaxError {
             problem: problem.map(|p| p.into()),
         }
         .start()
     }
 
-    pub(crate) fn coerce_error(
+    pub fn coerce_error(
         left: Spanned<impl Into<String>>,
         right: Spanned<impl Into<String>>,
     ) -> ShellError {
@@ -357,10 +383,7 @@ impl ShellError {
         .start()
     }
 
-    pub(crate) fn argument_error(
-        command: Spanned<impl Into<String>>,
-        kind: ArgumentError,
-    ) -> ShellError {
+    pub fn argument_error(command: Spanned<impl Into<String>>, kind: ArgumentError) -> ShellError {
         ProximateShellError::ArgumentError {
             command: command.map(|c| c.into()),
             error: kind,
@@ -368,7 +391,7 @@ impl ShellError {
         .start()
     }
 
-    pub(crate) fn parse_error(
+    pub fn parse_error(
         error: nom::Err<(
             nom_locate::LocatedSpanEx<&str, TracableContext>,
             nom::error::ErrorKind,
@@ -381,13 +404,13 @@ impl ShellError {
                 // TODO: Get span of EOF
                 let diagnostic = Diagnostic::new(
                     Severity::Error,
-                    format!("Parse Error: Unexpected end of line"),
+                    "Parse Error: Unexpected end of line".to_string(),
                 );
 
                 ShellError::diagnostic(diagnostic)
             }
             nom::Err::Failure(span) | nom::Err::Error(span) => {
-                let diagnostic = Diagnostic::new(Severity::Error, format!("Parse Error"))
+                let diagnostic = Diagnostic::new(Severity::Error, "Parse Error".to_string())
                     .with_label(Label::new_primary(Span::from(span.0)));
 
                 ShellError::diagnostic(diagnostic)
@@ -395,11 +418,11 @@ impl ShellError {
         }
     }
 
-    pub(crate) fn diagnostic(diagnostic: Diagnostic<Span>) -> ShellError {
+    pub fn diagnostic(diagnostic: Diagnostic<Span>) -> ShellError {
         ProximateShellError::Diagnostic(ShellDiagnostic { diagnostic }).start()
     }
 
-    pub(crate) fn to_diagnostic(self) -> Diagnostic<Span> {
+    pub fn into_diagnostic(self) -> Diagnostic<Span> {
         match self.error {
             ProximateShellError::MissingValue { span, reason } => {
                 let mut d = Diagnostic::new(
@@ -419,7 +442,7 @@ impl ShellError {
             } => match error {
                 ArgumentError::InvalidExternalWord => Diagnostic::new(
                     Severity::Error,
-                    format!("Invalid bare word for Nu command (did you intend to invoke an external command?)"))
+                    "Invalid bare word for Nu command (did you intend to invoke an external command?)".to_string())
                 .with_label(Label::new_primary(command.span)),
                 ArgumentError::MissingMandatoryFlag(name) => Diagnostic::new(
                     Severity::Error,
@@ -476,7 +499,7 @@ impl ShellError {
 
             ProximateShellError::UnexpectedEof {
                 expected, span
-            } => Diagnostic::new(Severity::Error, format!("Unexpected end of input"))
+            } => Diagnostic::new(Severity::Error, "Unexpected end of input".to_string())
                 .with_label(Label::new_primary(span).with_message(format!("Expected {}", expected))),
 
             ProximateShellError::RangeError {
@@ -491,7 +514,7 @@ impl ShellError {
                 Label::new_primary(span).with_message(format!(
                     "Expected to convert {} to {} while {}, but it was out of range",
                     item,
-                    kind.desc(),
+                    kind.display(),
                     operation
                 )),
             ),
@@ -506,31 +529,33 @@ impl ShellError {
                 .with_label(Label::new_primary(span).with_message(item)),
 
             ProximateShellError::MissingProperty { subpath, expr, .. } => {
-                let subpath = subpath.into_label();
-                let expr = expr.into_label();
 
                 let mut diag = Diagnostic::new(Severity::Error, "Missing property");
 
-                match subpath {
-                    Ok(label) => diag = diag.with_label(label),
-                    Err(ty) => diag.message = format!("Missing property (for {})", ty),
-                }
+                if subpath.span == Span::unknown() {
+                    diag.message = format!("Missing property (for {})", subpath.item);
+                } else {
+                    let subpath = Label::new_primary(subpath.span).with_message(subpath.item);
+                    diag = diag.with_label(subpath);
+
+                    if expr.span != Span::unknown() {
+                        let expr = Label::new_primary(expr.span).with_message(expr.item);
+                        diag = diag.with_label(expr)
+                    }
 
-                if let Ok(label) = expr {
-                    diag = diag.with_label(label);
                 }
 
                 diag
             }
 
             ProximateShellError::InvalidIntegerIndex { subpath,integer } => {
-                let subpath = subpath.into_label();
-
                 let mut diag = Diagnostic::new(Severity::Error, "Invalid integer property");
 
-                match subpath {
-                    Ok(label) => diag = diag.with_label(label),
-                    Err(ty) => diag.message = format!("Invalid integer property (for {})", ty)
+                if subpath.span == Span::unknown() {
+                    diag.message = format!("Invalid integer property (for {})", subpath.item)
+                } else {
+                    let label = Label::new_primary(subpath.span).with_message(subpath.item);
+                    diag = diag.with_label(label)
                 }
 
                 diag = diag.with_label(Label::new_secondary(integer).with_message("integer"));
@@ -579,23 +604,19 @@ impl ShellError {
         )
     }
 
-    // pub fn string(title: impl Into<String>) -> ShellError {
-    //     ProximateShellError::String(StringError::new(title.into(), String::new())).start()
-    // }
-    //
-    // pub(crate) fn unreachable(title: impl Into<String>) -> ShellError {
-    //     ShellError::untagged_runtime_error(&format!("BUG: Unreachable: {}", title.into()))
-    // }
-
-    pub(crate) fn unimplemented(title: impl Into<String>) -> ShellError {
+    pub fn unimplemented(title: impl Into<String>) -> ShellError {
         ShellError::untagged_runtime_error(&format!("Unimplemented: {}", title.into()))
     }
 
-    pub(crate) fn unexpected(title: impl Into<String>) -> ShellError {
+    pub fn unexpected(title: impl Into<String>) -> ShellError {
         ShellError::untagged_runtime_error(&format!("Unexpected: {}", title.into()))
     }
 }
 
+/// `ExpectedRange` describes a range of values that was expected by a command. In addition
+/// to typical ranges, this enum allows an error to specify that the range of allowed values
+/// corresponds to a particular numeric type (which is a dominant use-case for the
+/// [RangeError](ProximateShellError::RangeError) error type).
 #[derive(Debug, Eq, PartialEq, Ord, PartialOrd, Hash, Clone, Serialize, Deserialize)]
 pub enum ExpectedRange {
     I8,
@@ -617,6 +638,7 @@ pub enum ExpectedRange {
     Range { start: usize, end: usize },
 }
 
+/// Convert a Rust range into an [ExpectedRange](ExpectedRange).
 impl From<Range<usize>> for ExpectedRange {
     fn from(range: Range<usize>) -> Self {
         ExpectedRange::Range {
@@ -628,13 +650,7 @@ impl From<Range<usize>> for ExpectedRange {
 
 impl PrettyDebug for ExpectedRange {
     fn pretty(&self) -> DebugDocBuilder {
-        b::description(self.desc())
-    }
-}
-
-impl ExpectedRange {
-    fn desc(&self) -> String {
-        match self {
+        b::description(match self {
             ExpectedRange::I8 => "an 8-bit signed integer",
             ExpectedRange::I16 => "a 16-bit signed integer",
             ExpectedRange::I32 => "a 32-bit signed integer",
@@ -651,9 +667,10 @@ impl ExpectedRange {
             ExpectedRange::Size => "a list offset",
             ExpectedRange::BigDecimal => "a decimal",
             ExpectedRange::BigInt => "an integer",
-            ExpectedRange::Range { start, end } => return format!("{} to {}", start, end),
-        }
-        .to_string()
+            ExpectedRange::Range { start, end } => {
+                return b::description(format!("{} to {}", start, end))
+            }
+        })
     }
 }
 
@@ -671,11 +688,11 @@ pub enum ProximateShellError {
         actual: Spanned<Option<String>>,
     },
     MissingProperty {
-        subpath: Description,
-        expr: Description,
+        subpath: Spanned<String>,
+        expr: Spanned<String>,
     },
     InvalidIntegerIndex {
-        subpath: Description,
+        subpath: Spanned<String>,
         integer: Span,
     },
     MissingValue {

crates/nu-macros/Cargo.toml

@@ -0,0 +1,13 @@
+[package]
+name = "nu-macros"
+version = "0.8.0"
+authors = ["Yehuda Katz <wycats@gmail.com>", "Jonathan Turner <jonathan.d.turner@gmail.com>", "Andrés N. Robalino <andres@androbtech.com>"]
+edition = "2018"
+description = "Core macros for building Nushell"
+license = "MIT"
+
+[lib]
+doctest = false
+
+[dependencies]
+nu-protocol = { path = "../nu-protocol", version = "0.8.0" }

crates/nu-macros/src/lib.rs

@@ -0,0 +1,25 @@
+#[macro_export]
+macro_rules! signature {
+    (def $name:tt {
+        $usage:tt
+        $(
+            $positional_name:tt $positional_ty:tt - $positional_desc:tt
+        )*
+    }) => {{
+        let signature = Signature::new(stringify!($name)).desc($usage);
+        $(
+            $crate::positional! { signature, $positional_name $positional_ty - $positional_desc }
+        )*
+        signature
+    }};
+}
+
+#[macro_export]
+macro_rules! positional {
+    ($ident:tt, $name:tt (optional $shape:tt) - $desc:tt) => {
+        let $ident = $ident.optional(stringify!($name), SyntaxShape::$shape, $desc);
+    };
+    ($ident:tt, $name:tt ($shape:tt)- $desc:tt) => {
+        let $ident = $ident.required(stringify!($name), SyntaxShape::$shape, $desc);
+    };
+}

crates/nu-parser/Cargo.toml

@@ -0,0 +1,48 @@
+[package]
+name = "nu-parser"
+version = "0.8.0"
+authors = ["Yehuda Katz <wycats@gmail.com>", "Jonathan Turner <jonathan.d.turner@gmail.com>", "Andrés N. Robalino <andres@androbtech.com>"]
+edition = "2018"
+description = "Core parser used in Nushell"
+license = "MIT"
+
+[lib]
+doctest = false
+
+[dependencies]
+nu-errors = { path = "../nu-errors", version = "0.8.0" }
+nu-source = { path = "../nu-source", version = "0.8.0" }
+nu-protocol = { path = "../nu-protocol", version = "0.8.0" }
+
+pretty_env_logger = "0.3.1"
+pretty = "0.5.2"
+termcolor = "1.0.5"
+log = "0.4.8"
+indexmap = { version = "1.3.0", features = ["serde-1"] }
+serde = { version = "1.0.102", features = ["derive"] }
+nom = "5.0.1"
+nom_locate = "1.0.0"
+nom-tracable = "0.4.1"
+num-traits = "0.2.8"
+num-bigint = { version = "0.2.3", features = ["serde"] }
+bigdecimal = { version = "0.1.0", features = ["serde"] }
+derive-new = "0.5.8"
+getset = "0.0.9"
+cfg-if = "0.1"
+itertools = "0.8.1"
+shellexpand = "1.0.0"
+ansi_term = "0.12.1"
+ptree = {version = "0.2" }
+language-reporting = "0.4.0"
+unicode-xid = "0.2.0"
+enumflags2 = "0.6.2"
+
+[dev-dependencies]
+pretty_assertions = "0.6.1"
+
+[build-dependencies]
+nu-build = { version = "0.8.0", path = "../nu-build" }
+
+[features]
+stable = []
+trace = ["nom-tracable/trace"]

crates/nu-parser/build.rs

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

crates/nu-parser/src/commands.rs

@@ -0,0 +1,35 @@
+pub mod classified;
+
+use crate::commands::classified::external::{ExternalArg, ExternalArgs, ExternalCommand};
+use crate::commands::classified::ClassifiedCommand;
+use crate::hir::expand_external_tokens::ExternalTokensShape;
+use crate::hir::syntax_shape::{expand_syntax, ExpandContext};
+use crate::hir::tokens_iterator::TokensIterator;
+use nu_errors::ParseError;
+use nu_source::{Spanned, Tagged};
+
+// Classify this command as an external command, which doesn't give special meaning
+// to nu syntactic constructs, and passes all arguments to the external command as
+// strings.
+pub(crate) fn external_command(
+    tokens: &mut TokensIterator,
+    context: &ExpandContext,
+    name: Tagged<&str>,
+) -> Result<ClassifiedCommand, ParseError> {
+    let Spanned { item, span } = expand_syntax(&ExternalTokensShape, tokens, context)?.tokens;
+
+    Ok(ClassifiedCommand::External(ExternalCommand {
+        name: name.to_string(),
+        name_tag: name.tag(),
+        args: ExternalArgs {
+            list: item
+                .iter()
+                .map(|x| ExternalArg {
+                    tag: x.span.into(),
+                    arg: x.item.clone(),
+                })
+                .collect(),
+            span,
+        },
+    }))
+}

crates/nu-parser/src/commands/classified.rs

@@ -0,0 +1,92 @@
+pub mod external;
+pub mod internal;
+
+use crate::commands::classified::external::ExternalCommand;
+use crate::commands::classified::internal::InternalCommand;
+use crate::hir;
+use crate::parse::token_tree::TokenNode;
+use derive_new::new;
+use nu_source::{b, DebugDocBuilder, HasSpan, PrettyDebugWithSource, Span};
+
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub enum ClassifiedCommand {
+    #[allow(unused)]
+    Expr(TokenNode),
+    #[allow(unused)]
+    Dynamic(hir::Call),
+    Internal(InternalCommand),
+    External(ExternalCommand),
+}
+
+impl PrettyDebugWithSource for ClassifiedCommand {
+    fn pretty_debug(&self, source: &str) -> DebugDocBuilder {
+        match self {
+            ClassifiedCommand::Expr(token) => b::typed("command", token.pretty_debug(source)),
+            ClassifiedCommand::Dynamic(call) => b::typed("command", call.pretty_debug(source)),
+            ClassifiedCommand::Internal(internal) => internal.pretty_debug(source),
+            ClassifiedCommand::External(external) => external.pretty_debug(source),
+        }
+    }
+}
+
+impl HasSpan for ClassifiedCommand {
+    fn span(&self) -> Span {
+        match self {
+            ClassifiedCommand::Expr(node) => node.span(),
+            ClassifiedCommand::Internal(command) => command.span(),
+            ClassifiedCommand::Dynamic(call) => call.span,
+            ClassifiedCommand::External(command) => command.span(),
+        }
+    }
+}
+
+#[derive(new, Debug, Eq, PartialEq)]
+pub(crate) struct DynamicCommand {
+    pub(crate) args: hir::Call,
+}
+
+#[derive(Debug, Clone)]
+pub struct Commands {
+    pub list: Vec<ClassifiedCommand>,
+    pub span: Span,
+}
+
+impl std::ops::Deref for Commands {
+    type Target = [ClassifiedCommand];
+
+    fn deref(&self) -> &Self::Target {
+        &self.list
+    }
+}
+
+#[derive(Debug, Clone)]
+pub struct ClassifiedPipeline {
+    pub commands: Commands,
+}
+
+impl ClassifiedPipeline {
+    pub fn commands(list: Vec<ClassifiedCommand>, span: impl Into<Span>) -> ClassifiedPipeline {
+        ClassifiedPipeline {
+            commands: Commands {
+                list,
+                span: span.into(),
+            },
+        }
+    }
+}
+
+impl HasSpan for ClassifiedPipeline {
+    fn span(&self) -> Span {
+        self.commands.span
+    }
+}
+
+impl PrettyDebugWithSource for ClassifiedPipeline {
+    fn pretty_debug(&self, source: &str) -> DebugDocBuilder {
+        b::intersperse(
+            self.commands.iter().map(|c| c.pretty_debug(source)),
+            b::operator(" | "),
+        )
+        .or(b::delimit("<", b::description("empty pipeline"), ">"))
+    }
+}

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

@@ -0,0 +1,65 @@
+use nu_source::{b, DebugDocBuilder, HasSpan, PrettyDebug, Span, Tag};
+
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub struct ExternalArg {
+    pub arg: String,
+    pub tag: Tag,
+}
+
+impl std::ops::Deref for ExternalArg {
+    type Target = str;
+
+    fn deref(&self) -> &str {
+        &self.arg
+    }
+}
+
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub struct ExternalArgs {
+    pub list: Vec<ExternalArg>,
+    pub span: Span,
+}
+
+impl ExternalArgs {
+    pub fn iter(&self) -> impl Iterator<Item = &ExternalArg> {
+        self.list.iter()
+    }
+}
+
+impl std::ops::Deref for ExternalArgs {
+    type Target = [ExternalArg];
+
+    fn deref(&self) -> &[ExternalArg] {
+        &self.list
+    }
+}
+
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub struct ExternalCommand {
+    pub name: String,
+
+    pub name_tag: Tag,
+    pub args: ExternalArgs,
+}
+
+impl PrettyDebug for ExternalCommand {
+    fn pretty(&self) -> DebugDocBuilder {
+        b::typed(
+            "external command",
+            b::description(&self.name)
+                + b::preceded(
+                    b::space(),
+                    b::intersperse(
+                        self.args.iter().map(|a| b::primitive(a.arg.to_string())),
+                        b::space(),
+                    ),
+                ),
+        )
+    }
+}
+
+impl HasSpan for ExternalCommand {
+    fn span(&self) -> Span {
+        self.name_tag.span.until(self.args.span)
+    }
+}

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

@@ -0,0 +1,28 @@
+use crate::hir;
+
+use derive_new::new;
+use nu_source::{b, DebugDocBuilder, HasSpan, PrettyDebugWithSource, Span, Tag};
+
+#[derive(new, Debug, Clone, Eq, PartialEq)]
+pub struct InternalCommand {
+    pub name: String,
+    pub name_tag: Tag,
+    pub args: hir::Call,
+}
+
+impl PrettyDebugWithSource for InternalCommand {
+    fn pretty_debug(&self, source: &str) -> DebugDocBuilder {
+        b::typed(
+            "internal command",
+            b::description(&self.name) + b::space() + self.args.pretty_debug(source),
+        )
+    }
+}
+
+impl HasSpan for InternalCommand {
+    fn span(&self) -> Span {
+        let start = self.name_tag.span;
+
+        start.until(self.args.span)
+    }
+}

crates/nu-parser/src/hir.rs

@@ -4,30 +4,61 @@ pub(crate) mod expand_external_tokens;
 pub(crate) mod external_command;
 pub(crate) mod named;
 pub(crate) mod path;
-pub(crate) mod syntax_shape;
+pub(crate) mod range;
+pub(crate) mod signature;
+pub mod syntax_shape;
 pub(crate) mod tokens_iterator;
 
-use crate::parser::hir::path::PathMember;
-use crate::parser::hir::syntax_shape::Member;
-use crate::parser::{registry, Operator, Unit};
-use crate::prelude::*;
+use crate::hir::syntax_shape::Member;
+use crate::parse::operator::CompareOperator;
+use crate::parse::parser::Number;
+use crate::parse::unit::Unit;
 use derive_new::new;
 use getset::Getters;
-use nu_source::Spanned;
+use nu_protocol::{PathMember, ShellTypeName};
+use nu_source::{
+    b, DebugDocBuilder, HasSpan, PrettyDebug, PrettyDebugWithSource, Span, Spanned, SpannedItem,
+};
 use serde::{Deserialize, Serialize};
 use std::path::PathBuf;
 
-use crate::evaluate::Scope;
-use crate::parser::parse::tokens::RawNumber;
+use crate::parse::tokens::RawNumber;
 
 pub(crate) use self::binary::Binary;
-pub(crate) use self::external_command::ExternalCommand;
-pub(crate) use self::named::NamedArguments;
 pub(crate) use self::path::Path;
+pub(crate) use self::range::Range;
 pub(crate) use self::syntax_shape::ExpandContext;
 pub(crate) use self::tokens_iterator::TokensIterator;
 
-pub use self::syntax_shape::SyntaxShape;
+pub use self::external_command::ExternalCommand;
+pub use self::named::{NamedArguments, NamedValue};
+
+#[derive(Debug, Clone)]
+pub struct Signature {
+    unspanned: nu_protocol::Signature,
+    span: Span,
+}
+
+impl Signature {
+    pub fn new(unspanned: nu_protocol::Signature, span: impl Into<Span>) -> Signature {
+        Signature {
+            unspanned,
+            span: span.into(),
+        }
+    }
+}
+
+impl HasSpan for Signature {
+    fn span(&self) -> Span {
+        self.span
+    }
+}
+
+impl PrettyDebugWithSource for Signature {
+    fn pretty_debug(&self, source: &str) -> DebugDocBuilder {
+        self.unspanned.pretty_debug(source)
+    }
+}
 
 #[derive(Debug, Clone, Eq, PartialEq, Getters, Serialize, Deserialize, new)]
 pub struct Call {
@@ -60,17 +91,6 @@ impl PrettyDebugWithSource for Call {
     }
 }
 
-impl Call {
-    pub fn evaluate(
-        &self,
-        registry: &registry::CommandRegistry,
-        scope: &Scope,
-        source: &Text,
-    ) -> Result<registry::EvaluatedArgs, ShellError> {
-        registry::evaluate_args(self, registry, scope, source)
-    }
-}
-
 #[derive(Debug, Clone, Eq, PartialEq, Ord, PartialOrd, Hash, Serialize, Deserialize)]
 pub enum RawExpression {
     Literal(Literal),
@@ -78,6 +98,7 @@ pub enum RawExpression {
     Synthetic(Synthetic),
     Variable(Variable),
     Binary(Box<Binary>),
+    Range(Box<Range>),
     Block(Vec<Expression>),
     List(Vec<Expression>),
     Path(Box<Path>),
@@ -100,6 +121,7 @@ impl ShellTypeName for RawExpression {
             RawExpression::Variable(..) => "variable",
             RawExpression::List(..) => "list",
             RawExpression::Binary(..) => "binary",
+            RawExpression::Range(..) => "range",
             RawExpression::Block(..) => "block",
             RawExpression::Path(..) => "variable path",
             RawExpression::Boolean(..) => "boolean",
@@ -169,6 +191,7 @@ impl PrettyDebugWithSource for Expression {
             },
             RawExpression::Variable(_) => b::keyword(self.span.slice(source)),
             RawExpression::Binary(binary) => binary.pretty_debug(source),
+            RawExpression::Range(range) => range.pretty_debug(source),
             RawExpression::Block(_) => b::opaque("block"),
             RawExpression::List(list) => b::delimit(
                 "[",
@@ -196,41 +219,37 @@ impl PrettyDebugWithSource for Expression {
 }
 
 impl Expression {
-    pub(crate) fn number(i: impl Into<Number>, span: impl Into<Span>) -> Expression {
+    pub fn number(i: impl Into<Number>, span: impl Into<Span>) -> Expression {
         let span = span.into();
 
         RawExpression::Literal(RawLiteral::Number(i.into()).into_literal(span)).into_expr(span)
     }
 
-    pub(crate) fn size(
-        i: impl Into<Number>,
-        unit: impl Into<Unit>,
-        span: impl Into<Span>,
-    ) -> Expression {
+    pub fn size(i: impl Into<Number>, unit: impl Into<Unit>, span: impl Into<Span>) -> Expression {
         let span = span.into();
 
         RawExpression::Literal(RawLiteral::Size(i.into(), unit.into()).into_literal(span))
             .into_expr(span)
     }
 
-    pub(crate) fn synthetic_string(s: impl Into<String>) -> Expression {
+    pub fn synthetic_string(s: impl Into<String>) -> Expression {
         RawExpression::Synthetic(Synthetic::String(s.into())).into_unspanned_expr()
     }
 
-    pub(crate) fn string(inner: impl Into<Span>, outer: impl Into<Span>) -> Expression {
+    pub fn string(inner: impl Into<Span>, outer: impl Into<Span>) -> Expression {
         let outer = outer.into();
 
         RawExpression::Literal(RawLiteral::String(inner.into()).into_literal(outer))
             .into_expr(outer)
     }
 
-    pub(crate) fn column_path(members: Vec<Member>, span: impl Into<Span>) -> Expression {
+    pub fn column_path(members: Vec<Member>, span: impl Into<Span>) -> Expression {
         let span = span.into();
 
         RawExpression::Literal(RawLiteral::ColumnPath(members).into_literal(span)).into_expr(span)
     }
 
-    pub(crate) fn path(
+    pub fn path(
         head: Expression,
         tail: Vec<impl Into<PathMember>>,
         span: impl Into<Span>,
@@ -239,7 +258,7 @@ impl Expression {
         RawExpression::Path(Box::new(Path::new(head, tail))).into_expr(span.into())
     }
 
-    pub(crate) fn dot_member(head: Expression, next: impl Into<PathMember>) -> Expression {
+    pub fn dot_member(head: Expression, next: impl Into<PathMember>) -> Expression {
         let Expression { expr: item, span } = head;
         let next = next.into();
 
@@ -257,9 +276,9 @@ impl Expression {
         }
     }
 
-    pub(crate) fn infix(
+    pub fn infix(
         left: Expression,
-        op: Spanned<impl Into<Operator>>,
+        op: Spanned<impl Into<CompareOperator>>,
         right: Expression,
     ) -> Expression {
         let new_span = left.span.until(right.span);
@@ -268,36 +287,42 @@ impl Expression {
             .into_expr(new_span)
     }
 
-    pub(crate) fn file_path(path: impl Into<PathBuf>, outer: impl Into<Span>) -> Expression {
+    pub fn range(left: Expression, op: Span, right: Expression) -> Expression {
+        let new_span = left.span.until(right.span);
+
+        RawExpression::Range(Box::new(Range::new(left, op, right))).into_expr(new_span)
+    }
+
+    pub fn file_path(path: impl Into<PathBuf>, outer: impl Into<Span>) -> Expression {
         RawExpression::FilePath(path.into()).into_expr(outer)
     }
 
-    pub(crate) fn list(list: Vec<Expression>, span: impl Into<Span>) -> Expression {
+    pub fn list(list: Vec<Expression>, span: impl Into<Span>) -> Expression {
         RawExpression::List(list).into_expr(span)
     }
 
-    pub(crate) fn bare(span: impl Into<Span>) -> Expression {
+    pub fn bare(span: impl Into<Span>) -> Expression {
         let span = span.into();
 
         RawExpression::Literal(RawLiteral::Bare.into_literal(span)).into_expr(span)
     }
 
-    pub(crate) fn pattern(inner: impl Into<String>, outer: impl Into<Span>) -> Expression {
+    pub fn pattern(inner: impl Into<String>, outer: impl Into<Span>) -> Expression {
         let outer = outer.into();
 
         RawExpression::Literal(RawLiteral::GlobPattern(inner.into()).into_literal(outer))
             .into_expr(outer)
     }
 
-    pub(crate) fn variable(inner: impl Into<Span>, outer: impl Into<Span>) -> Expression {
+    pub fn variable(inner: impl Into<Span>, outer: impl Into<Span>) -> Expression {
         RawExpression::Variable(Variable::Other(inner.into())).into_expr(outer)
     }
 
-    pub(crate) fn external_command(inner: impl Into<Span>, outer: impl Into<Span>) -> Expression {
+    pub fn external_command(inner: impl Into<Span>, outer: impl Into<Span>) -> Expression {
         RawExpression::ExternalCommand(ExternalCommand::new(inner.into())).into_expr(outer)
     }
 
-    pub(crate) fn it_variable(inner: impl Into<Span>, outer: impl Into<Span>) -> Expression {
+    pub fn it_variable(inner: impl Into<Span>, outer: impl Into<Span>) -> Expression {
         RawExpression::Variable(Variable::It(inner.into())).into_expr(outer)
     }
 }

crates/nu-parser/src/hir/baseline_parse.rs

@@ -0,0 +1,2 @@
+#[cfg(test)]
+pub mod tests;

crates/nu-parser/src/hir/baseline_parse/tests.rs

@@ -1,13 +1,13 @@
-use crate::commands::classified::InternalCommand;
-use crate::commands::ClassifiedCommand;
-use crate::env::host::BasicHost;
-use crate::parser::hir::TokensIterator;
-use crate::parser::hir::{
-    self, named::NamedValue, path::PathMember, syntax_shape::*, NamedArguments,
-};
-use crate::parser::parse::token_tree_builder::{CurriedToken, TokenTreeBuilder as b};
-use crate::parser::TokenNode;
+use crate::commands::classified::{internal::InternalCommand, ClassifiedCommand};
+use crate::hir::TokensIterator;
+use crate::hir::{self, named::NamedValue, syntax_shape::*, NamedArguments};
+use crate::parse::files::Files;
+use crate::parse::token_tree_builder::{CurriedToken, TokenTreeBuilder as b};
+use crate::TokenNode;
+use derive_new::new;
 use indexmap::IndexMap;
+use nu_errors::ShellError;
+use nu_protocol::{PathMember, Signature, SyntaxShape};
 use nu_source::{HasSpan, Span, Tag, Text};
 use pretty_assertions::assert_eq;
 use std::fmt::Debug;
@@ -23,7 +23,7 @@ fn test_parse_string() {
 fn test_parse_path() {
     parse_tokens(
         VariablePathShape,
-        vec![b::var("it"), b::op("."), b::bare("cpu")],
+        vec![b::var("it"), b::dot(), b::bare("cpu")],
         |tokens| {
             let (outer_var, inner_var) = tokens[0].expect_var();
             let bare = tokens[2].expect_bare();
@@ -39,9 +39,9 @@ fn test_parse_path() {
         VariablePathShape,
         vec![
             b::var("cpu"),
-            b::op("."),
+            b::dot(),
             b::bare("amount"),
-            b::op("."),
+            b::dot(),
             b::string("max ghz"),
         ],
         |tokens| {
@@ -90,6 +90,43 @@ fn test_parse_command() {
     );
 }
 
+#[derive(new)]
+struct TestRegistry {
+    #[new(default)]
+    signatures: indexmap::IndexMap<String, Signature>,
+}
+
+impl TestRegistry {
+    fn insert(&mut self, key: &str, value: Signature) {
+        self.signatures.insert(key.to_string(), value);
+    }
+}
+
+impl SignatureRegistry for TestRegistry {
+    fn has(&self, name: &str) -> Result<bool, ShellError> {
+        Ok(self.signatures.contains_key(name))
+    }
+    fn get(&self, name: &str) -> Result<Option<Signature>, ShellError> {
+        Ok(self.signatures.get(name).cloned())
+    }
+}
+
+fn with_empty_context(source: &Text, callback: impl FnOnce(ExpandContext)) {
+    let mut registry = TestRegistry::new();
+    registry.insert(
+        "ls",
+        Signature::build("ls")
+            .optional(
+                "path",
+                SyntaxShape::Pattern,
+                "a path to get the directory contents from",
+            )
+            .switch("full", "list all available columns for each entry"),
+    );
+
+    callback(ExpandContext::new(Box::new(registry), source, None))
+}
+
 fn parse_tokens<T: Eq + HasSpan + Clone + Debug + 'static>(
     shape: impl ExpandSyntax<Output = T>,
     tokens: Vec<CurriedToken>,
@@ -99,7 +136,7 @@ fn parse_tokens<T: Eq + HasSpan + Clone + Debug + 'static>(
     let (tokens, source) = b::build(tokens);
     let text = Text::from(source);
 
-    ExpandContext::with_empty(&text, |context| {
+    with_empty_context(&text, |context| {
         let tokens = tokens.expect_list();
         let mut iterator = TokensIterator::all(tokens.item, text.clone(), tokens.span);
 
@@ -108,7 +145,7 @@ fn parse_tokens<T: Eq + HasSpan + Clone + Debug + 'static>(
         let expr = match expr {
             Ok(expr) => expr,
             Err(err) => {
-                crate::cli::print_err(err.into(), &BasicHost, context.source().clone());
+                print_err(err.into(), &context.source().clone());
                 panic!("Parse failed");
             }
         };
@@ -120,3 +157,18 @@ fn parse_tokens<T: Eq + HasSpan + Clone + Debug + 'static>(
 fn inner_string_span(span: Span) -> Span {
     Span::new(span.start() + 1, span.end() - 1)
 }
+
+pub fn print_err(err: ShellError, source: &Text) {
+    let diag = err.into_diagnostic();
+
+    let writer = termcolor::StandardStream::stderr(termcolor::ColorChoice::Auto);
+    let mut source = source.to_string();
+    source.push_str(" ");
+    let files = Files::new(source);
+    let _ = language_reporting::emit(
+        &mut writer.lock(),
+        &files,
+        &diag,
+        &language_reporting::DefaultConfig,
+    );
+}

crates/nu-parser/src/hir/binary.rs

@@ -1,18 +1,17 @@
-use crate::parser::{hir::Expression, Operator};
-use crate::prelude::*;
+use crate::{hir::Expression, CompareOperator};
 
 use derive_new::new;
 use getset::Getters;
-use nu_source::Spanned;
+use nu_source::{b, DebugDocBuilder, PrettyDebugWithSource, Spanned};
 use serde::{Deserialize, Serialize};
 
 #[derive(
     Debug, Clone, Eq, PartialEq, Ord, PartialOrd, Hash, Getters, Serialize, Deserialize, new,
 )]
-#[get = "pub(crate)"]
+#[get = "pub"]
 pub struct Binary {
     left: Expression,
-    op: Spanned<Operator>,
+    op: Spanned<CompareOperator>,
     right: Expression,
 }
 

crates/nu-parser/src/hir/expand_external_tokens.rs

@@ -1,7 +1,4 @@
-use crate::errors::ParseError;
-#[cfg(not(coloring_in_tokens))]
-use crate::parser::hir::syntax_shape::FlatShape;
-use crate::parser::{
+use crate::{
     hir::syntax_shape::{
         color_syntax, expand_atom, expand_expr, expand_syntax, AtomicToken, ColorSyntax,
         ExpandContext, ExpandExpression, ExpandSyntax, ExpansionRule, MaybeSpaceShape,
@@ -10,6 +7,8 @@ use crate::parser::{
     hir::Expression,
     TokensIterator,
 };
+use nu_errors::ParseError;
+use nu_protocol::SpannedTypeName;
 use nu_source::{b, DebugDocBuilder, HasSpan, PrettyDebug, Span, Spanned, SpannedItem};
 
 #[derive(Debug, Clone)]
@@ -68,33 +67,6 @@ impl ExpandSyntax for ExternalTokensShape {
     }
 }
 
-#[cfg(not(coloring_in_tokens))]
-impl ColorSyntax for ExternalTokensShape {
-    type Info = ();
-    type Input = ();
-
-    fn color_syntax<'a, 'b>(
-        &self,
-        _input: &(),
-        token_nodes: &'b mut TokensIterator<'a>,
-        context: &ExpandContext,
-        shapes: &mut Vec<Spanned<FlatShape>>,
-    ) -> Self::Info {
-        loop {
-            // Allow a space
-            color_syntax(&MaybeSpaceShape, token_nodes, context, shapes);
-
-            // Process an external expression. External expressions are mostly words, with a
-            // few exceptions (like $variables and path expansion rules)
-            match color_syntax(&ExternalExpression, token_nodes, context, shapes).1 {
-                ExternalExpressionResult::Eof => break,
-                ExternalExpressionResult::Processed => continue,
-            }
-        }
-    }
-}
-
-#[cfg(coloring_in_tokens)]
 impl ColorSyntax for ExternalTokensShape {
     type Info = ();
     type Input = ();
@@ -115,7 +87,7 @@ impl ColorSyntax for ExternalTokensShape {
 
             // Process an external expression. External expressions are mostly words, with a
             // few exceptions (like $variables and path expansion rules)
-            match color_syntax(&ExternalExpression, token_nodes, context).1 {
+            match color_syntax(&ExternalExpressionShape, token_nodes, context).1 {
                 ExternalExpressionResult::Eof => break,
                 ExternalExpressionResult::Processed => continue,
             }
@@ -144,7 +116,7 @@ impl ExpandSyntax for ExternalExpressionShape {
             token_nodes,
             "external command",
             context,
-            ExpansionRule::new().allow_external_command(),
+            ExpansionRule::new().allow_external_word(),
         )?
         .span;
 
@@ -164,40 +136,6 @@ impl ExpandSyntax for ExternalExpressionShape {
     }
 }
 
-#[derive(Debug, Copy, Clone)]
-struct ExternalExpression;
-
-impl ExpandSyntax for ExternalExpression {
-    type Output = Option<Span>;
-
-    fn name(&self) -> &'static str {
-        "external expression"
-    }
-
-    fn expand_syntax<'a, 'b>(
-        &self,
-        token_nodes: &'b mut TokensIterator<'a>,
-        context: &ExpandContext,
-    ) -> Result<Self::Output, ParseError> {
-        expand_syntax(&MaybeSpaceShape, token_nodes, context)?;
-
-        let first = expand_syntax(&ExternalHeadShape, token_nodes, context)?.span;
-        let mut last = first;
-
-        loop {
-            let continuation = expand_syntax(&ExternalContinuationShape, token_nodes, context);
-
-            if let Ok(continuation) = continuation {
-                last = continuation.span;
-            } else {
-                break;
-            }
-        }
-
-        Ok(Some(first.until(last)))
-    }
-}
-
 #[derive(Debug, Copy, Clone)]
 struct ExternalHeadShape;
 
@@ -229,11 +167,18 @@ impl ExpandExpression for ExternalHeadShape {
             UnspannedAtomicToken::Whitespace { .. } => {
                 unreachable!("ExpansionRule doesn't allow Whitespace")
             }
+            UnspannedAtomicToken::Separator { .. } => {
+                unreachable!("ExpansionRule doesn't allow Separator")
+            }
+            UnspannedAtomicToken::Comment { .. } => {
+                unreachable!("ExpansionRule doesn't allow Comment")
+            }
             UnspannedAtomicToken::ShorthandFlag { .. }
-            | UnspannedAtomicToken::SquareDelimited { .. } => {
+            | UnspannedAtomicToken::SquareDelimited { .. }
+            | UnspannedAtomicToken::RoundDelimited { .. } => {
                 return Err(ParseError::mismatch(
                     "external command name",
-                    "pipeline".spanned(atom.span),
+                    atom.spanned_type_name(),
                 ))
             }
             UnspannedAtomicToken::ExternalCommand { command } => {
@@ -249,7 +194,10 @@ impl ExpandExpression for ExternalHeadShape {
             | UnspannedAtomicToken::GlobPattern { .. }
             | UnspannedAtomicToken::Word { .. }
             | UnspannedAtomicToken::Dot { .. }
-            | UnspannedAtomicToken::Operator { .. } => Expression::external_command(span, span),
+            | UnspannedAtomicToken::DotDot { .. }
+            | UnspannedAtomicToken::CompareOperator { .. } => {
+                Expression::external_command(span, span)
+            }
         })
     }
 }
@@ -291,6 +239,12 @@ impl ExpandExpression for ExternalContinuationShape {
             UnspannedAtomicToken::Whitespace { .. } => {
                 unreachable!("ExpansionRule doesn't allow Whitespace")
             }
+            UnspannedAtomicToken::Separator { .. } => {
+                unreachable!("ExpansionRule doesn't allow Separator")
+            }
+            UnspannedAtomicToken::Comment { .. } => {
+                unreachable!("ExpansionRule doesn't allow Comment")
+            }
             UnspannedAtomicToken::String { body } => Expression::string(*body, span),
             UnspannedAtomicToken::ItVariable { name } => Expression::it_variable(*name, span),
             UnspannedAtomicToken::Variable { name } => Expression::variable(*name, span),
@@ -299,24 +253,25 @@ impl ExpandExpression for ExternalContinuationShape {
             | UnspannedAtomicToken::Word { .. }
             | UnspannedAtomicToken::ShorthandFlag { .. }
             | UnspannedAtomicToken::Dot { .. }
-            | UnspannedAtomicToken::Operator { .. } => Expression::bare(span),
-            UnspannedAtomicToken::SquareDelimited { .. } => {
+            | UnspannedAtomicToken::DotDot { .. }
+            | UnspannedAtomicToken::CompareOperator { .. } => Expression::bare(span),
+            UnspannedAtomicToken::SquareDelimited { .. }
+            | UnspannedAtomicToken::RoundDelimited { .. } => {
                 return Err(ParseError::mismatch(
                     "external argument",
-                    "pipeline".spanned(atom.span),
+                    atom.spanned_type_name(),
                 ))
             }
         })
     }
 }
 
-#[cfg(coloring_in_tokens)]
-impl ColorSyntax for ExternalExpression {
+impl ColorSyntax for ExternalExpressionShape {
     type Info = ExternalExpressionResult;
     type Input = ();
 
     fn name(&self) -> &'static str {
-        "ExternalExpression"
+        "ExternalExpressionShape"
     }
 
     fn color_syntax<'a, 'b>(
@@ -340,43 +295,12 @@ impl ColorSyntax for ExternalExpression {
         };
 
         token_nodes.mutate_shapes(|shapes| atom.color_tokens(shapes));
-        return ExternalExpressionResult::Processed;
+        ExternalExpressionResult::Processed
     }
 }
 
 #[must_use]
-enum ExternalExpressionResult {
+pub enum ExternalExpressionResult {
     Eof,
     Processed,
 }
-
-#[cfg(not(coloring_in_tokens))]
-impl ColorSyntax for ExternalExpression {
-    type Info = ExternalExpressionResult;
-    type Input = ();
-
-    fn color_syntax<'a, 'b>(
-        &self,
-        _input: &(),
-        token_nodes: &'b mut TokensIterator<'a>,
-        context: &ExpandContext,
-        shapes: &mut Vec<Spanned<FlatShape>>,
-    ) -> ExternalExpressionResult {
-        let atom = match expand_atom(
-            token_nodes,
-            "external word",
-            context,
-            ExpansionRule::permissive(),
-        ) {
-            Err(_) => unreachable!("TODO: separate infallible expand_atom"),
-            Ok(AtomicToken {
-                unspanned: UnspannedAtomicToken::Eof { .. },
-                ..
-            }) => return ExternalExpressionResult::Eof,
-            Ok(atom) => atom,
-        };
-
-        atom.color_tokens(shapes);
-        return ExternalExpressionResult::Processed;
-    }
-}

crates/nu-parser/src/hir/external_command.rs

@@ -1,12 +1,12 @@
-use crate::prelude::*;
 use derive_new::new;
 use getset::Getters;
+use nu_source::Span;
 use serde::{Deserialize, Serialize};
 
 #[derive(
     Debug, Clone, Eq, PartialEq, Ord, PartialOrd, Hash, Getters, Serialize, Deserialize, new,
 )]
-#[get = "pub(crate)"]
+#[get = "pub"]
 pub struct ExternalCommand {
     pub(crate) name: Span,
 }

crates/nu-parser/src/hir/named.rs

@@ -1,8 +1,8 @@
-use crate::parser::hir::Expression;
-use crate::parser::Flag;
-use crate::prelude::*;
+use crate::hir::Expression;
+use crate::Flag;
 use indexmap::IndexMap;
 use log::trace;
+use nu_source::{b, DebugDocBuilder, PrettyDebugWithSource, Tag};
 use serde::{Deserialize, Serialize};
 
 #[derive(Debug, Clone, Eq, PartialEq, Serialize, Deserialize)]
@@ -24,16 +24,18 @@ impl PrettyDebugWithSource for NamedValue {
     }
 }
 
-#[derive(Debug, Clone, Eq, PartialEq, Serialize, Deserialize)]
+#[derive(Debug, Default, Clone, Eq, PartialEq, Serialize, Deserialize)]
 pub struct NamedArguments {
-    pub(crate) named: IndexMap<String, NamedValue>,
+    pub named: IndexMap<String, NamedValue>,
 }
 
 impl NamedArguments {
     pub fn new() -> NamedArguments {
-        NamedArguments {
-            named: IndexMap::new(),
-        }
+        Default::default()
+    }
+
+    pub fn iter(&self) -> impl Iterator<Item = (&String, &NamedValue)> {
+        self.named.iter()
     }
 }
 
@@ -43,7 +45,7 @@ impl NamedArguments {
         trace!("Inserting switch -- {} = {:?}", name, switch);
 
         match switch {
-            None => self.named.insert(name.into(), NamedValue::AbsentSwitch),
+            None => self.named.insert(name, NamedValue::AbsentSwitch),
             Some(flag) => self.named.insert(
                 name,
                 NamedValue::PresentSwitch(Tag {

crates/nu-parser/src/hir/path.rs

@@ -0,0 +1,41 @@
+use crate::hir::Expression;
+use derive_new::new;
+use getset::{Getters, MutGetters};
+use nu_protocol::PathMember;
+use nu_source::{b, DebugDocBuilder, PrettyDebug, PrettyDebugWithSource};
+use serde::{Deserialize, Serialize};
+
+#[derive(
+    Debug,
+    Clone,
+    Eq,
+    PartialEq,
+    Ord,
+    PartialOrd,
+    Hash,
+    Getters,
+    MutGetters,
+    Serialize,
+    Deserialize,
+    new,
+)]
+#[get = "pub"]
+pub struct Path {
+    head: Expression,
+    #[get_mut = "pub(crate)"]
+    tail: Vec<PathMember>,
+}
+
+impl PrettyDebugWithSource for Path {
+    fn pretty_debug(&self, source: &str) -> DebugDocBuilder {
+        self.head.pretty_debug(source)
+            + b::operator(".")
+            + b::intersperse(self.tail.iter().map(|m| m.pretty()), b::operator("."))
+    }
+}
+
+impl Path {
+    pub(crate) fn parts(self) -> (Expression, Vec<PathMember>) {
+        (self.head, self.tail)
+    }
+}

crates/nu-parser/src/hir/range.rs

@@ -0,0 +1,33 @@
+use crate::hir::Expression;
+
+use derive_new::new;
+use getset::Getters;
+use nu_source::{b, DebugDocBuilder, PrettyDebugWithSource, Span};
+use serde::{Deserialize, Serialize};
+
+#[derive(
+    Debug, Clone, Eq, PartialEq, Ord, PartialOrd, Hash, Getters, Serialize, Deserialize, new,
+)]
+pub struct Range {
+    #[get = "pub"]
+    left: Expression,
+    #[get = "pub"]
+    dotdot: Span,
+    #[get = "pub"]
+    right: Expression,
+}
+
+impl PrettyDebugWithSource for Range {
+    fn pretty_debug(&self, source: &str) -> DebugDocBuilder {
+        b::delimit(
+            "<",
+            self.left.pretty_debug(source)
+                + b::space()
+                + b::keyword(self.dotdot.slice(source))
+                + b::space()
+                + self.right.pretty_debug(source),
+            ">",
+        )
+        .group()
+    }
+}

crates/nu-parser/src/hir/signature.rs

@@ -0,0 +1,475 @@
+use crate::hir;
+use crate::hir::syntax_shape::{
+    expand_atom, expand_syntax, BareShape, ExpandContext, ExpandSyntax, ExpansionRule,
+    UnspannedAtomicToken, WhitespaceShape,
+};
+use crate::hir::tokens_iterator::TokensIterator;
+use crate::parse::comment::Comment;
+use derive_new::new;
+use nu_errors::ParseError;
+use nu_protocol::{RowType, SpannedTypeName, Type};
+use nu_source::{
+    b, DebugDocBuilder, HasFallibleSpan, HasSpan, PrettyDebugWithSource, Span, Spanned, SpannedItem,
+};
+use std::fmt::Debug;
+
+// A Signature is a command without implementation.
+//
+// In Nu, a command is a function combined with macro expansion rules.
+//
+// def cd
+//   # Change to a new path.
+//   optional directory(Path) # the directory to change to
+// end
+
+#[derive(new)]
+struct Expander<'a, 'b, 'c, 'd> {
+    iterator: &'b mut TokensIterator<'a>,
+    context: &'d ExpandContext<'c>,
+}
+
+impl<'a, 'b, 'c, 'd> Expander<'a, 'b, 'c, 'd> {
+    fn expand<O>(&mut self, syntax: impl ExpandSyntax<Output = O>) -> Result<O, ParseError>
+    where
+        O: HasFallibleSpan + Clone + std::fmt::Debug + 'static,
+    {
+        expand_syntax(&syntax, self.iterator, self.context)
+    }
+
+    fn optional<O>(&mut self, syntax: impl ExpandSyntax<Output = O>) -> Option<O>
+    where
+        O: HasFallibleSpan + Clone + std::fmt::Debug + 'static,
+    {
+        match expand_syntax(&syntax, self.iterator, self.context) {
+            Err(_) => None,
+            Ok(value) => Some(value),
+        }
+    }
+
+    fn pos(&mut self) -> Span {
+        self.iterator.span_at_cursor()
+    }
+
+    fn slice_string(&mut self, span: impl Into<Span>) -> String {
+        span.into().slice(self.context.source()).to_string()
+    }
+}
+
+#[derive(Debug, Copy, Clone)]
+struct SignatureShape;
+
+impl ExpandSyntax for SignatureShape {
+    type Output = hir::Signature;
+
+    fn name(&self) -> &'static str {
+        "signature"
+    }
+
+    fn expand_syntax<'a, 'b>(
+        &self,
+        token_nodes: &'b mut TokensIterator<'a>,
+        context: &ExpandContext,
+    ) -> Result<Self::Output, ParseError> {
+        token_nodes.atomic_parse(|token_nodes| {
+            let mut expander = Expander::new(token_nodes, context);
+            let start = expander.pos();
+            expander.expand(keyword("def"))?;
+            expander.expand(WhitespaceShape)?;
+            let name = expander.expand(BareShape)?;
+            expander.expand(SeparatorShape)?;
+            let usage = expander.expand(CommentShape)?;
+            expander.expand(SeparatorShape)?;
+            let end = expander.pos();
+
+            Ok(hir::Signature::new(
+                nu_protocol::Signature::new(&name.word).desc(expander.slice_string(usage.text)),
+                start.until(end),
+            ))
+        })
+    }
+}
+
+fn keyword(kw: &'static str) -> KeywordShape {
+    KeywordShape { keyword: kw }
+}
+
+#[derive(Debug, Copy, Clone)]
+struct KeywordShape {
+    keyword: &'static str,
+}
+
+impl ExpandSyntax for KeywordShape {
+    type Output = Span;
+
+    fn name(&self) -> &'static str {
+        "keyword"
+    }
+    fn expand_syntax<'a, 'b>(
+        &self,
+        token_nodes: &'b mut TokensIterator<'a>,
+        context: &ExpandContext,
+    ) -> Result<Self::Output, ParseError> {
+        let atom = expand_atom(token_nodes, "keyword", context, ExpansionRule::new())?;
+
+        if let UnspannedAtomicToken::Word { text } = &atom.unspanned {
+            let word = text.slice(context.source());
+
+            if word == self.keyword {
+                return Ok(atom.span);
+            }
+        }
+
+        Err(ParseError::mismatch(self.keyword, atom.spanned_type_name()))
+    }
+}
+
+#[derive(Debug, Copy, Clone)]
+struct SeparatorShape;
+
+impl ExpandSyntax for SeparatorShape {
+    type Output = Span;
+
+    fn name(&self) -> &'static str {
+        "separator"
+    }
+
+    fn expand_syntax<'a, 'b>(
+        &self,
+        token_nodes: &'b mut TokensIterator<'a>,
+        context: &ExpandContext,
+    ) -> Result<Self::Output, ParseError> {
+        let atom = expand_atom(token_nodes, "separator", context, ExpansionRule::new())?;
+
+        match &atom.unspanned {
+            UnspannedAtomicToken::Separator { text } => Ok(*text),
+            _ => Err(ParseError::mismatch("separator", atom.spanned_type_name())),
+        }
+    }
+}
+
+#[derive(Debug, Copy, Clone)]
+struct CommentShape;
+
+impl ExpandSyntax for CommentShape {
+    type Output = Comment;
+
+    fn name(&self) -> &'static str {
+        "comment"
+    }
+
+    fn expand_syntax<'a, 'b>(
+        &self,
+        token_nodes: &'b mut TokensIterator<'a>,
+        context: &ExpandContext,
+    ) -> Result<Self::Output, ParseError> {
+        let atom = expand_atom(token_nodes, "comment", context, ExpansionRule::new())?;
+
+        match &atom.unspanned {
+            UnspannedAtomicToken::Comment { body } => Ok(Comment::line(body, atom.span)),
+            _ => Err(ParseError::mismatch("separator", atom.spanned_type_name())),
+        }
+    }
+}
+
+#[derive(Debug, Copy, Clone, new)]
+struct TupleShape<A, B> {
+    first: A,
+    second: B,
+}
+
+#[derive(Debug, Clone, new)]
+struct TupleSyntax<A, B> {
+    first: A,
+    second: B,
+}
+
+impl<A, B> PrettyDebugWithSource for TupleSyntax<A, B>
+where
+    A: PrettyDebugWithSource,
+    B: PrettyDebugWithSource,
+{
+    fn pretty_debug(&self, source: &str) -> DebugDocBuilder {
+        b::typed(
+            "pair",
+            self.first.pretty_debug(source) + b::space() + self.second.pretty_debug(source),
+        )
+    }
+}
+
+impl<A, B> HasFallibleSpan for TupleSyntax<A, B>
+where
+    A: HasFallibleSpan + Debug + Clone,
+    B: HasFallibleSpan + Debug + Clone,
+{
+    fn maybe_span(&self) -> Option<Span> {
+        match (self.first.maybe_span(), self.second.maybe_span()) {
+            (Some(first), Some(second)) => Some(first.until(second)),
+            (Some(first), None) => Some(first),
+            (None, Some(second)) => Some(second),
+            (None, None) => None,
+        }
+    }
+}
+
+impl<A, B, AOut, BOut> ExpandSyntax for TupleShape<A, B>
+where
+    A: ExpandSyntax<Output = AOut> + Debug + Copy,
+    B: ExpandSyntax<Output = BOut> + Debug + Copy,
+    AOut: HasFallibleSpan + Debug + Clone + 'static,
+    BOut: HasFallibleSpan + Debug + Clone + 'static,
+{
+    type Output = TupleSyntax<AOut, BOut>;
+
+    fn name(&self) -> &'static str {
+        "pair"
+    }
+
+    fn expand_syntax<'a, 'b>(
+        &self,
+        token_nodes: &'b mut TokensIterator<'a>,
+        context: &ExpandContext,
+    ) -> Result<Self::Output, ParseError> {
+        token_nodes.atomic_parse(|token_nodes| {
+            let first = expand_syntax(&self.first, token_nodes, context)?;
+            let second = expand_syntax(&self.second, token_nodes, context)?;
+
+            Ok(TupleSyntax { first, second })
+        })
+    }
+}
+
+#[derive(Debug, Clone)]
+pub struct PositionalParam {
+    optional: Option<Span>,
+    name: Identifier,
+    ty: Spanned<Type>,
+    desc: Spanned<String>,
+    span: Span,
+}
+
+impl HasSpan for PositionalParam {
+    fn span(&self) -> Span {
+        self.span
+    }
+}
+
+impl PrettyDebugWithSource for PositionalParam {
+    fn pretty_debug(&self, source: &str) -> DebugDocBuilder {
+        (match self.optional {
+            Some(_) => b::description("optional") + b::space(),
+            None => b::blank(),
+        }) + self.ty.pretty_debug(source)
+    }
+}
+
+#[derive(Debug, Copy, Clone)]
+pub struct PositionalParamShape;
+
+impl ExpandSyntax for PositionalParamShape {
+    type Output = PositionalParam;
+
+    fn name(&self) -> &'static str {
+        "positional param"
+    }
+
+    fn expand_syntax<'a, 'b>(
+        &self,
+        token_nodes: &'b mut TokensIterator<'a>,
+        context: &ExpandContext,
+    ) -> Result<Self::Output, ParseError> {
+        token_nodes.atomic_parse(|token_nodes| {
+            let mut expander = Expander::new(token_nodes, context);
+
+            let optional = expander
+                .optional(TupleShape::new(keyword("optional"), WhitespaceShape))
+                .map(|s| s.first);
+
+            let name = expander.expand(IdentifierShape)?;
+
+            expander.optional(WhitespaceShape);
+
+            let _ty = expander.expand(TypeShape)?;
+
+            Ok(PositionalParam {
+                optional,
+                name,
+                ty: Type::Nothing.spanned(Span::unknown()),
+                desc: format!("").spanned(Span::unknown()),
+                span: Span::unknown(),
+            })
+        })
+    }
+}
+
+#[derive(Debug, Clone)]
+struct Identifier {
+    body: String,
+    span: Span,
+}
+
+impl HasSpan for Identifier {
+    fn span(&self) -> Span {
+        self.span
+    }
+}
+
+impl PrettyDebugWithSource for Identifier {
+    fn pretty_debug(&self, source: &str) -> DebugDocBuilder {
+        b::typed("id", b::description(self.span.slice(source)))
+    }
+}
+
+#[derive(Debug, Copy, Clone)]
+struct IdentifierShape;
+
+impl ExpandSyntax for IdentifierShape {
+    type Output = Identifier;
+    fn name(&self) -> &'static str {
+        "identifier"
+    }
+
+    fn expand_syntax<'a, 'b>(
+        &self,
+        token_nodes: &'b mut TokensIterator<'a>,
+        context: &ExpandContext,
+    ) -> Result<Self::Output, ParseError> {
+        let atom = expand_atom(token_nodes, "identifier", context, ExpansionRule::new())?;
+
+        if let UnspannedAtomicToken::Word { text } = atom.unspanned {
+            let body = text.slice(context.source());
+            if is_id(body) {
+                return Ok(Identifier {
+                    body: body.to_string(),
+                    span: text,
+                });
+            }
+        }
+
+        Err(ParseError::mismatch("identifier", atom.spanned_type_name()))
+    }
+}
+
+fn is_id(input: &str) -> bool {
+    let source = nu_source::nom_input(input);
+    match crate::parse::parser::ident(source) {
+        Err(_) => false,
+        Ok((input, _)) => input.fragment.is_empty(),
+    }
+}
+
+#[derive(Debug, Clone, new)]
+struct TypeSyntax {
+    ty: Type,
+    span: Span,
+}
+
+impl HasSpan for TypeSyntax {
+    fn span(&self) -> Span {
+        self.span
+    }
+}
+
+impl PrettyDebugWithSource for TypeSyntax {
+    fn pretty_debug(&self, source: &str) -> DebugDocBuilder {
+        self.ty.pretty_debug(source)
+    }
+}
+
+#[derive(Debug, Copy, Clone)]
+struct TypeShape;
+
+impl ExpandSyntax for TypeShape {
+    type Output = TypeSyntax;
+
+    fn name(&self) -> &'static str {
+        "type"
+    }
+    fn expand_syntax<'a, 'b>(
+        &self,
+        token_nodes: &'b mut TokensIterator<'a>,
+        context: &ExpandContext,
+    ) -> Result<Self::Output, ParseError> {
+        let atom = expand_atom(token_nodes, "type", context, ExpansionRule::new())?;
+
+        match atom.unspanned {
+            UnspannedAtomicToken::Word { text } => {
+                let word = text.slice(context.source());
+
+                Ok(TypeSyntax::new(
+                    match word {
+                        "nothing" => Type::Nothing,
+                        "integer" => Type::Int,
+                        "decimal" => Type::Decimal,
+                        "bytesize" => Type::Bytesize,
+                        "string" => Type::String,
+                        "column-path" => Type::ColumnPath,
+                        "pattern" => Type::Pattern,
+                        "boolean" => Type::Boolean,
+                        "date" => Type::Date,
+                        "duration" => Type::Duration,
+                        "filename" => Type::Path,
+                        "binary" => Type::Binary,
+                        "row" => Type::Row(RowType::new()),
+                        "table" => Type::Table(vec![]),
+                        "block" => Type::Block,
+                        _ => return Err(ParseError::mismatch("type", atom.spanned_type_name())),
+                    },
+                    atom.span,
+                ))
+            }
+            _ => Err(ParseError::mismatch("type", atom.spanned_type_name())),
+        }
+    }
+}
+
+#[derive(Debug, Copy, Clone)]
+struct TypeAnnotation;
+
+impl ExpandSyntax for TypeAnnotation {
+    type Output = TypeSyntax;
+
+    fn name(&self) -> &'static str {
+        "type annotation"
+    }
+
+    fn expand_syntax<'a, 'b>(
+        &self,
+        token_nodes: &'b mut TokensIterator<'a>,
+        context: &ExpandContext,
+    ) -> Result<Self::Output, ParseError> {
+        let atom = expand_atom(
+            token_nodes,
+            "type annotation",
+            context,
+            ExpansionRule::new(),
+        )?;
+
+        match atom.unspanned {
+            UnspannedAtomicToken::RoundDelimited { nodes, .. } => {
+                token_nodes.atomic_parse(|token_nodes| {
+                    token_nodes.child(
+                        (&nodes[..]).spanned(atom.span),
+                        context.source().clone(),
+                        |token_nodes| {
+                            let ty = expand_syntax(&TypeShape, token_nodes, context)?;
+
+                            let next = token_nodes.peek_non_ws();
+
+                            match next.node {
+                                None => Ok(ty),
+                                Some(node) => {
+                                    Err(ParseError::extra_tokens(node.spanned_type_name()))
+                                }
+                            }
+                        },
+                    )
+                })
+            }
+
+            _ => Err(ParseError::mismatch(
+                "type annotation",
+                atom.spanned_type_name(),
+            )),
+        }
+    }
+}

crates/nu-parser/src/hir/syntax_shape.rs

@@ -1,23 +1,27 @@
 mod block;
 mod expression;
-pub(crate) mod flat_shape;
+pub mod flat_shape;
 
-use crate::cli::external_command;
-use crate::commands::{
-    classified::{ClassifiedPipeline, InternalCommand},
-    ClassifiedCommand, Command,
-};
-use crate::parser::hir::expand_external_tokens::ExternalTokensShape;
-use crate::parser::hir::syntax_shape::block::AnyBlockShape;
-use crate::parser::hir::tokens_iterator::Peeked;
-use crate::parser::parse::tokens::Token;
-use crate::parser::parse_command::{parse_command_tail, CommandTailShape};
-use crate::parser::{hir, hir::TokensIterator, Operator, TokenNode, UnspannedToken};
-use crate::prelude::*;
+use crate::commands::classified::internal::InternalCommand;
+use crate::commands::classified::{ClassifiedCommand, ClassifiedPipeline};
+use crate::commands::external_command;
+use crate::hir;
+use crate::hir::expand_external_tokens::ExternalTokensShape;
+use crate::hir::syntax_shape::block::AnyBlockShape;
+use crate::hir::syntax_shape::expression::range::RangeShape;
+use crate::hir::tokens_iterator::{Peeked, TokensIterator};
+use crate::parse::operator::EvaluationOperator;
+use crate::parse::token_tree::TokenNode;
+use crate::parse::tokens::{Token, UnspannedToken};
+use crate::parse_command::{parse_command_tail, CommandTailShape};
 use derive_new::new;
 use getset::Getters;
-use nu_source::Spanned;
-use serde::{Deserialize, Serialize};
+use nu_errors::{ParseError, ShellError};
+use nu_protocol::{ShellTypeName, Signature};
+use nu_source::{
+    b, DebugDocBuilder, HasFallibleSpan, HasSpan, PrettyDebug, PrettyDebugWithSource, Span,
+    Spanned, SpannedItem, Tag, TaggedItem, Text,
+};
 use std::path::{Path, PathBuf};
 
 pub(crate) use self::expression::atom::{
@@ -40,89 +44,8 @@ pub(crate) use self::expression::variable_path::{
 pub(crate) use self::expression::{continue_expression, AnyExpressionShape};
 pub(crate) use self::flat_shape::FlatShape;
 
-#[cfg(not(coloring_in_tokens))]
-use crate::parser::hir::tokens_iterator::debug::debug_tokens;
-#[cfg(not(coloring_in_tokens))]
-use crate::parser::parse::pipeline::Pipeline;
-#[cfg(not(coloring_in_tokens))]
-use log::{log_enabled, trace};
+use nu_protocol::SyntaxShape;
 
-#[derive(Debug, Copy, Clone, Serialize, Deserialize)]
-pub enum SyntaxShape {
-    Any,
-    String,
-    Member,
-    ColumnPath,
-    Number,
-    Int,
-    Path,
-    Pattern,
-    Block,
-}
-
-impl PrettyDebug for SyntaxShape {
-    fn pretty(&self) -> DebugDocBuilder {
-        b::kind(match self {
-            SyntaxShape::Any => "any shape",
-            SyntaxShape::String => "string shape",
-            SyntaxShape::Member => "member shape",
-            SyntaxShape::ColumnPath => "column path shape",
-            SyntaxShape::Number => "number shape",
-            SyntaxShape::Int => "integer shape",
-            SyntaxShape::Path => "file path shape",
-            SyntaxShape::Pattern => "pattern shape",
-            SyntaxShape::Block => "block shape",
-        })
-    }
-}
-
-#[cfg(not(coloring_in_tokens))]
-impl FallibleColorSyntax for SyntaxShape {
-    type Info = ();
-    type Input = ();
-
-    fn color_syntax<'a, 'b>(
-        &self,
-        _input: &(),
-        token_nodes: &'b mut TokensIterator<'a>,
-        context: &ExpandContext,
-        shapes: &mut Vec<Spanned<FlatShape>>,
-    ) -> Result<(), ShellError> {
-        match self {
-            SyntaxShape::Any => {
-                color_fallible_syntax(&AnyExpressionShape, token_nodes, context, shapes)
-            }
-            SyntaxShape::Int => color_fallible_syntax(&IntShape, token_nodes, context, shapes),
-            SyntaxShape::String => color_fallible_syntax_with(
-                &StringShape,
-                &FlatShape::String,
-                token_nodes,
-                context,
-                shapes,
-            ),
-            SyntaxShape::Member => {
-                color_fallible_syntax(&MemberShape, token_nodes, context, shapes)
-            }
-            SyntaxShape::ColumnPath => {
-                color_fallible_syntax(&ColumnPathShape, token_nodes, context, shapes)
-            }
-            SyntaxShape::Number => {
-                color_fallible_syntax(&NumberShape, token_nodes, context, shapes)
-            }
-            SyntaxShape::Path => {
-                color_fallible_syntax(&FilePathShape, token_nodes, context, shapes)
-            }
-            SyntaxShape::Pattern => {
-                color_fallible_syntax(&PatternShape, token_nodes, context, shapes)
-            }
-            SyntaxShape::Block => {
-                color_fallible_syntax(&AnyBlockShape, token_nodes, context, shapes)
-            }
-        }
-    }
-}
-
-#[cfg(coloring_in_tokens)]
 impl FallibleColorSyntax for SyntaxShape {
     type Info = ();
     type Input = ();
@@ -140,6 +63,7 @@ impl FallibleColorSyntax for SyntaxShape {
         match self {
             SyntaxShape::Any => color_fallible_syntax(&AnyExpressionShape, token_nodes, context),
             SyntaxShape::Int => color_fallible_syntax(&IntShape, token_nodes, context),
+            SyntaxShape::Range => color_fallible_syntax(&RangeShape, token_nodes, context),
             SyntaxShape::String => {
                 color_fallible_syntax_with(&StringShape, &FlatShape::String, token_nodes, context)
             }
@@ -160,6 +84,7 @@ impl ExpandExpression for SyntaxShape {
         match self {
             SyntaxShape::Any => "shape[any]",
             SyntaxShape::Int => "shape[integer]",
+            SyntaxShape::Range => "shape[range]",
             SyntaxShape::String => "shape[string]",
             SyntaxShape::Member => "shape[column name]",
             SyntaxShape::ColumnPath => "shape[column path]",
@@ -178,6 +103,7 @@ impl ExpandExpression for SyntaxShape {
         match self {
             SyntaxShape::Any => expand_expr(&AnyExpressionShape, token_nodes, context),
             SyntaxShape::Int => expand_expr(&IntShape, token_nodes, context),
+            SyntaxShape::Range => expand_expr(&RangeShape, token_nodes, context),
             SyntaxShape::String => expand_expr(&StringShape, token_nodes, context),
             SyntaxShape::Member => {
                 let syntax = expand_syntax(&MemberShape, token_nodes, context)?;
@@ -200,13 +126,17 @@ impl ExpandExpression for SyntaxShape {
     }
 }
 
+pub trait SignatureRegistry {
+    fn has(&self, name: &str) -> Result<bool, ShellError>;
+    fn get(&self, name: &str) -> Result<Option<Signature>, ShellError>;
+}
+
 #[derive(Getters, new)]
 pub struct ExpandContext<'context> {
     #[get = "pub(crate)"]
-    registry: &'context CommandRegistry,
-    #[get = "pub(crate)"]
-    source: &'context Text,
-    homedir: Option<PathBuf>,
+    pub registry: Box<dyn SignatureRegistry>,
+    pub source: &'context Text,
+    pub homedir: Option<PathBuf>,
 }
 
 impl<'context> ExpandContext<'context> {
@@ -214,19 +144,8 @@ impl<'context> ExpandContext<'context> {
         self.homedir.as_ref().map(|h| h.as_path())
     }
 
-    #[cfg(test)]
-    pub fn with_empty(source: &Text, callback: impl FnOnce(ExpandContext)) {
-        let mut registry = CommandRegistry::new();
-        registry.insert(
-            "ls",
-            crate::commands::whole_stream_command(crate::commands::LS),
-        );
-
-        callback(ExpandContext {
-            registry: &registry,
-            source,
-            homedir: None,
-        })
+    pub(crate) fn source(&self) -> &'context Text {
+        self.source
     }
 }
 
@@ -248,7 +167,6 @@ pub trait ExpandExpression: std::fmt::Debug + Copy {
     ) -> Result<hir::Expression, ParseError>;
 }
 
-#[cfg(coloring_in_tokens)]
 pub trait FallibleColorSyntax: std::fmt::Debug + Copy {
     type Info;
     type Input;
@@ -263,35 +181,6 @@ pub trait FallibleColorSyntax: std::fmt::Debug + Copy {
     ) -> Result<Self::Info, ShellError>;
 }
 
-#[cfg(not(coloring_in_tokens))]
-pub trait FallibleColorSyntax: std::fmt::Debug + Copy {
-    type Info;
-    type Input;
-
-    fn color_syntax<'a, 'b>(
-        &self,
-        input: &Self::Input,
-        token_nodes: &'b mut TokensIterator<'a>,
-        context: &ExpandContext,
-        shapes: &mut Vec<Spanned<FlatShape>>,
-    ) -> Result<Self::Info, ShellError>;
-}
-
-#[cfg(not(coloring_in_tokens))]
-pub trait ColorSyntax: std::fmt::Debug + Copy {
-    type Info;
-    type Input;
-
-    fn color_syntax<'a, 'b>(
-        &self,
-        input: &Self::Input,
-        token_nodes: &'b mut TokensIterator<'a>,
-        context: &ExpandContext,
-        shapes: &mut Vec<Spanned<FlatShape>>,
-    ) -> Self::Info;
-}
-
-#[cfg(coloring_in_tokens)]
 pub trait ColorSyntax: std::fmt::Debug + Copy {
     type Info;
     type Input;
@@ -306,7 +195,7 @@ pub trait ColorSyntax: std::fmt::Debug + Copy {
     ) -> Self::Info;
 }
 
-pub(crate) trait ExpandSyntax: std::fmt::Debug + Copy {
+pub trait ExpandSyntax: std::fmt::Debug + Copy {
     type Output: HasFallibleSpan + Clone + std::fmt::Debug + 'static;
 
     fn name(&self) -> &'static str;
@@ -318,7 +207,7 @@ pub(crate) trait ExpandSyntax: std::fmt::Debug + Copy {
     ) -> Result<Self::Output, ParseError>;
 }
 
-pub(crate) fn expand_syntax<'a, 'b, T: ExpandSyntax>(
+pub fn expand_syntax<'a, 'b, T: ExpandSyntax>(
     shape: &T,
     token_nodes: &'b mut TokensIterator<'a>,
     context: &ExpandContext,
@@ -338,7 +227,6 @@ pub(crate) fn expand_expr<'a, 'b, T: ExpandExpression>(
     })
 }
 
-#[cfg(coloring_in_tokens)]
 pub fn color_syntax<'a, 'b, T: ColorSyntax<Info = U, Input = ()>, U>(
     shape: &T,
     token_nodes: &'b mut TokensIterator<'a>,
@@ -352,70 +240,6 @@ pub fn color_syntax<'a, 'b, T: ColorSyntax<Info = U, Input = ()>, U>(
     )
 }
 
-#[cfg(not(coloring_in_tokens))]
-pub fn color_syntax<'a, 'b, T: ColorSyntax<Info = U, Input = ()>, U>(
-    shape: &T,
-    token_nodes: &'b mut TokensIterator<'a>,
-    context: &ExpandContext,
-    shapes: &mut Vec<Spanned<FlatShape>>,
-) -> ((), U) {
-    trace!(target: "nu::color_syntax", "before {} :: {:?}", std::any::type_name::<T>(), debug_tokens(token_nodes.state(), context.source));
-
-    let len = shapes.len();
-    let result = shape.color_syntax(&(), token_nodes, context, shapes);
-
-    trace!(target: "nu::color_syntax", "ok :: {:?}", debug_tokens(token_nodes.state(), context.source));
-
-    if log_enabled!(target: "nu::color_syntax", log::Level::Trace) {
-        trace!(target: "nu::color_syntax", "after {}", std::any::type_name::<T>());
-
-        if len < shapes.len() {
-            for i in len..(shapes.len()) {
-                trace!(target: "nu::color_syntax", "new shape :: {:?}", shapes[i]);
-            }
-        } else {
-            trace!(target: "nu::color_syntax", "no new shapes");
-        }
-    }
-
-    ((), result)
-}
-
-#[cfg(not(coloring_in_tokens))]
-pub fn color_fallible_syntax<'a, 'b, T: FallibleColorSyntax<Info = U, Input = ()>, U>(
-    shape: &T,
-    token_nodes: &'b mut TokensIterator<'a>,
-    context: &ExpandContext,
-    shapes: &mut Vec<Spanned<FlatShape>>,
-) -> Result<U, ShellError> {
-    trace!(target: "nu::color_syntax", "before {} :: {:?}", std::any::type_name::<T>(), debug_tokens(token_nodes.state(), context.source));
-
-    if token_nodes.at_end() {
-        trace!(target: "nu::color_syntax", "at eof");
-        return Err(ShellError::unexpected_eof("coloring", Tag::unknown()));
-    }
-
-    let len = shapes.len();
-    let result = shape.color_syntax(&(), token_nodes, context, shapes);
-
-    trace!(target: "nu::color_syntax", "ok :: {:?}", debug_tokens(token_nodes.state(), context.source));
-
-    if log_enabled!(target: "nu::color_syntax", log::Level::Trace) {
-        trace!(target: "nu::color_syntax", "after {}", std::any::type_name::<T>());
-
-        if len < shapes.len() {
-            for i in len..(shapes.len()) {
-                trace!(target: "nu::color_syntax", "new shape :: {:?}", shapes[i]);
-            }
-        } else {
-            trace!(target: "nu::color_syntax", "no new shapes");
-        }
-    }
-
-    result
-}
-
-#[cfg(coloring_in_tokens)]
 pub fn color_fallible_syntax<'a, 'b, T: FallibleColorSyntax<Info = U, Input = ()>, U>(
     shape: &T,
     token_nodes: &'b mut TokensIterator<'a>,
@@ -426,37 +250,6 @@ pub fn color_fallible_syntax<'a, 'b, T: FallibleColorSyntax<Info = U, Input = ()
     })
 }
 
-#[cfg(not(coloring_in_tokens))]
-pub fn color_syntax_with<'a, 'b, T: ColorSyntax<Info = U, Input = I>, U, I>(
-    shape: &T,
-    input: &I,
-    token_nodes: &'b mut TokensIterator<'a>,
-    context: &ExpandContext,
-    shapes: &mut Vec<Spanned<FlatShape>>,
-) -> ((), U) {
-    trace!(target: "nu::color_syntax", "before {} :: {:?}", std::any::type_name::<T>(), debug_tokens(token_nodes.state(), context.source));
-
-    let len = shapes.len();
-    let result = shape.color_syntax(input, token_nodes, context, shapes);
-
-    trace!(target: "nu::color_syntax", "ok :: {:?}", debug_tokens(token_nodes.state(), context.source));
-
-    if log_enabled!(target: "nu::color_syntax", log::Level::Trace) {
-        trace!(target: "nu::color_syntax", "after {}", std::any::type_name::<T>());
-
-        if len < shapes.len() {
-            for i in len..(shapes.len()) {
-                trace!(target: "nu::color_syntax", "new shape :: {:?}", shapes[i]);
-            }
-        } else {
-            trace!(target: "nu::color_syntax", "no new shapes");
-        }
-    }
-
-    ((), result)
-}
-
-#[cfg(coloring_in_tokens)]
 pub fn color_syntax_with<'a, 'b, T: ColorSyntax<Info = U, Input = I>, U, I>(
     shape: &T,
     input: &I,
@@ -471,20 +264,6 @@ pub fn color_syntax_with<'a, 'b, T: ColorSyntax<Info = U, Input = I>, U, I>(
     )
 }
 
-#[cfg(not(coloring_in_tokens))]
-pub fn color_fallible_syntax_with<'a, 'b, T: FallibleColorSyntax<Info = U, Input = I>, U, I>(
-    shape: &T,
-    input: &I,
-    token_nodes: &'b mut TokensIterator<'a>,
-    context: &ExpandContext,
-    shapes: &mut Vec<Spanned<FlatShape>>,
-) -> Result<U, ShellError> {
-    token_nodes.color_fallible_frame(std::any::type_name::<T>(), |token_nodes| {
-        shape.color_syntax(input, token_nodes, context, shapes)
-    })
-}
-
-#[cfg(coloring_in_tokens)]
 pub fn color_fallible_syntax_with<'a, 'b, T: FallibleColorSyntax<Info = U, Input = I>, U, I>(
     shape: &T,
     input: &I,
@@ -604,7 +383,7 @@ impl ExpandSyntax for BarePathShape {
                 ..
             })
             | TokenNode::Token(Token {
-                unspanned: UnspannedToken::Operator(Operator::Dot),
+                unspanned: UnspannedToken::EvaluationOperator(EvaluationOperator::Dot),
                 ..
             }) => true,
 
@@ -616,37 +395,6 @@ impl ExpandSyntax for BarePathShape {
 #[derive(Debug, Copy, Clone)]
 pub struct BareShape;
 
-#[cfg(not(coloring_in_tokens))]
-impl FallibleColorSyntax for BareShape {
-    type Info = ();
-    type Input = FlatShape;
-
-    fn color_syntax<'a, 'b>(
-        &self,
-        input: &FlatShape,
-        token_nodes: &'b mut TokensIterator<'a>,
-        _context: &ExpandContext,
-        shapes: &mut Vec<Spanned<FlatShape>>,
-    ) -> Result<(), ShellError> {
-        token_nodes
-            .peek_any_token("word", |token| match token {
-                // If it's a bare token, color it
-                TokenNode::Token(Token {
-                    unspanned: UnspannedToken::Bare,
-                    span,
-                }) => {
-                    shapes.push((*input).spanned(*span));
-                    Ok(())
-                }
-
-                // otherwise, fail
-                other => Err(ParseError::mismatch("word", other.spanned_type_name())),
-            })
-            .map_err(|err| err.into())
-    }
-}
-
-#[cfg(coloring_in_tokens)]
 impl FallibleColorSyntax for BareShape {
     type Info = ();
     type Input = FlatShape;
@@ -747,7 +495,7 @@ impl TestSyntax for BareShape {
 
 #[derive(Debug, Clone)]
 pub enum CommandSignature {
-    Internal(Spanned<Arc<Command>>),
+    Internal(Spanned<Signature>),
     LiteralExternal { outer: Span, inner: Span },
     External(Span),
     Expression(hir::Expression),
@@ -757,7 +505,7 @@ impl PrettyDebugWithSource for CommandSignature {
     fn pretty_debug(&self, source: &str) -> DebugDocBuilder {
         match self {
             CommandSignature::Internal(internal) => {
-                b::typed("command", b::description(internal.name()))
+                b::typed("command", b::description(&internal.name))
             }
             CommandSignature::LiteralExternal { outer, .. } => {
                 b::typed("command", b::description(outer.slice(source)))
@@ -805,43 +553,6 @@ impl CommandSignature {
 #[derive(Debug, Copy, Clone)]
 pub struct PipelineShape;
 
-#[cfg(not(coloring_in_tokens))]
-// The failure mode is if the head of the token stream is not a pipeline
-impl FallibleColorSyntax for PipelineShape {
-    type Info = ();
-    type Input = ();
-
-    fn color_syntax<'a, 'b>(
-        &self,
-        _input: &(),
-        token_nodes: &'b mut TokensIterator<'a>,
-        context: &ExpandContext,
-        shapes: &mut Vec<Spanned<FlatShape>>,
-    ) -> Result<(), ShellError> {
-        // Make sure we're looking at a pipeline
-        let Pipeline { parts, .. } =
-            token_nodes.peek_any_token("pipeline", |node| node.as_pipeline())?;
-
-        // Enumerate the pipeline parts
-        for part in parts {
-            // If the pipeline part has a prefix `|`, emit a pipe to color
-            if let Some(pipe) = part.pipe {
-                shapes.push(FlatShape::Pipe.spanned(pipe));
-            }
-
-            // Create a new iterator containing the tokens in the pipeline part to color
-            let mut token_nodes =
-                TokensIterator::new(&part.tokens(), part.span(), context.source.clone(), false);
-
-            color_syntax(&MaybeSpaceShape, &mut token_nodes, context, shapes);
-            color_syntax(&CommandShape, &mut token_nodes, context, shapes);
-        }
-
-        Ok(())
-    }
-}
-
-#[cfg(coloring_in_tokens)]
 // The failure mode is if the head of the token stream is not a pipeline
 impl FallibleColorSyntax for PipelineShape {
     type Info = ();
@@ -881,46 +592,6 @@ impl FallibleColorSyntax for PipelineShape {
     }
 }
 
-#[cfg(coloring_in_tokens)]
-impl ExpandSyntax for PipelineShape {
-    type Output = ClassifiedPipeline;
-
-    fn name(&self) -> &'static str {
-        "pipeline"
-    }
-
-    fn expand_syntax<'content, 'me>(
-        &self,
-        iterator: &'me mut TokensIterator<'content>,
-        context: &ExpandContext,
-    ) -> Result<Self::Output, ParseError> {
-        let start = iterator.span_at_cursor();
-
-        let peeked = iterator.peek_any().not_eof("pipeline")?;
-        let pipeline = peeked.commit().as_pipeline()?;
-
-        let parts = &pipeline.parts[..];
-
-        let mut out = vec![];
-
-        for part in parts {
-            let tokens: Spanned<&[TokenNode]> = part.tokens().spanned(part.span());
-
-            let classified =
-                iterator.child(tokens, context.source.clone(), move |token_nodes| {
-                    expand_syntax(&ClassifiedCommandShape, token_nodes, context)
-                })?;
-
-            out.push(classified);
-        }
-
-        let end = iterator.span_at_cursor();
-
-        Ok(ClassifiedPipeline::commands(out, start.until(end)))
-    }
-}
-
-#[cfg(not(coloring_in_tokens))]
 impl ExpandSyntax for PipelineShape {
     type Output = ClassifiedPipeline;
 
@@ -967,61 +638,6 @@ pub enum CommandHeadKind {
 #[derive(Debug, Copy, Clone)]
 pub struct CommandHeadShape;
 
-#[cfg(not(coloring_in_tokens))]
-impl FallibleColorSyntax for CommandHeadShape {
-    type Info = CommandHeadKind;
-    type Input = ();
-
-    fn color_syntax<'a, 'b>(
-        &self,
-        _input: &(),
-        token_nodes: &'b mut TokensIterator<'a>,
-        context: &ExpandContext,
-        shapes: &mut Vec<Spanned<FlatShape>>,
-    ) -> Result<CommandHeadKind, ShellError> {
-        // If we don't ultimately find a token, roll back
-        token_nodes.atomic(|token_nodes| {
-            // First, take a look at the next token
-            let atom = expand_atom(
-                token_nodes,
-                "command head",
-                context,
-                ExpansionRule::permissive(),
-            )?;
-
-            match &atom.unspanned {
-                // If the head is an explicit external command (^cmd), color it as an external command
-                UnspannedAtomicToken::ExternalCommand { .. } => {
-                    shapes.push(FlatShape::ExternalCommand.spanned(atom.span));
-                    Ok(CommandHeadKind::External)
-                }
-
-                // If the head is a word, it depends on whether it matches a registered internal command
-                UnspannedAtomicToken::Word { text } => {
-                    let name = text.slice(context.source);
-
-                    if context.registry.has(name) {
-                        // If the registry has the command, color it as an internal command
-                        shapes.push(FlatShape::InternalCommand.spanned(text));
-                        let command = context.registry.expect_command(name);
-                        Ok(CommandHeadKind::Internal(command.signature()))
-                    } else {
-                        // Otherwise, color it as an external command
-                        shapes.push(FlatShape::ExternalCommand.spanned(text));
-                        Ok(CommandHeadKind::External)
-                    }
-                }
-
-                // Otherwise, we're not actually looking at a command
-                _ => Err(ShellError::syntax_error(
-                    "No command at the head".spanned(atom.span),
-                )),
-            }
-        })
-    }
-}
-
-#[cfg(coloring_in_tokens)]
 impl FallibleColorSyntax for CommandHeadShape {
     type Info = CommandHeadKind;
     type Input = ();
@@ -1057,11 +673,27 @@ impl FallibleColorSyntax for CommandHeadShape {
                 UnspannedAtomicToken::Word { text } => {
                     let name = text.slice(context.source);
 
-                    if context.registry.has(name) {
+                    if context.registry.has(name)? {
                         // If the registry has the command, color it as an internal command
                         token_nodes.color_shape(FlatShape::InternalCommand.spanned(text));
-                        let command = context.registry.expect_command(name);
-                        Ok(CommandHeadKind::Internal(command.signature()))
+                        let signature = context
+                            .registry
+                            .get(name)
+                            .map_err(|_| {
+                                ShellError::labeled_error(
+                                    "Internal error: could not load signature from registry",
+                                    "could not load from registry",
+                                    text,
+                                )
+                            })?
+                            .ok_or_else(|| {
+                                ShellError::labeled_error(
+                                    "Internal error: could not load signature from registry",
+                                    "could not load from registry",
+                                    text,
+                                )
+                            })?;
+                        Ok(CommandHeadKind::Internal(signature))
                     } else {
                         // Otherwise, color it as an external command
                         token_nodes.color_shape(FlatShape::ExternalCommand.spanned(text));
@@ -1099,9 +731,15 @@ impl ExpandSyntax for CommandHeadShape {
                     },
                     UnspannedToken::Bare => {
                         let name = token_span.slice(context.source);
-                        if context.registry.has(name) {
-                            let command = context.registry.expect_command(name);
-                            CommandSignature::Internal(command.spanned(token_span))
+                        if context.registry.has(name)? {
+                            let signature = context
+                                .registry
+                                .get(name)
+                                .map_err(|_| ParseError::internal_error(name.spanned(token_span)))?
+                                .ok_or_else(|| {
+                                    ParseError::internal_error(name.spanned(token_span))
+                                })?;
+                            CommandSignature::Internal(signature.spanned(token_span))
                         } else {
                             CommandSignature::External(token_span)
                         }
@@ -1116,9 +754,9 @@ impl ExpandSyntax for CommandHeadShape {
             });
 
         match node {
-            Ok(expr) => return Ok(expr),
+            Ok(expr) => Ok(expr),
             Err(_) => match expand_expr(&AnyExpressionShape, token_nodes, context) {
-                Ok(expr) => return Ok(CommandSignature::Expression(expr)),
+                Ok(expr) => Ok(CommandSignature::Expression(expr)),
                 Err(_) => Err(token_nodes.peek_non_ws().type_error("command head3")),
             },
         }
@@ -1162,9 +800,8 @@ impl ExpandSyntax for ClassifiedCommandShape {
                 external_command(iterator, context, name_str.tagged(outer))
             }
 
-            CommandSignature::Internal(command) => {
-                let tail =
-                    parse_command_tail(&command.signature(), &context, iterator, command.span)?;
+            CommandSignature::Internal(signature) => {
+                let tail = parse_command_tail(&signature.item, &context, iterator, signature.span)?;
 
                 let (positional, named) = match tail {
                     None => (None, None),
@@ -1181,9 +818,9 @@ impl ExpandSyntax for ClassifiedCommandShape {
                 };
 
                 Ok(ClassifiedCommand::Internal(InternalCommand::new(
-                    command.item.name().to_string(),
+                    signature.item.name.clone(),
                     Tag {
-                        span: command.span,
+                        span: signature.span,
                         anchor: None,
                     },
                     call,
@@ -1196,46 +833,6 @@ impl ExpandSyntax for ClassifiedCommandShape {
 #[derive(Debug, Copy, Clone)]
 pub struct InternalCommandHeadShape;
 
-#[cfg(not(coloring_in_tokens))]
-impl FallibleColorSyntax for InternalCommandHeadShape {
-    type Info = ();
-    type Input = ();
-
-    fn color_syntax<'a, 'b>(
-        &self,
-        _input: &(),
-        token_nodes: &'b mut TokensIterator<'a>,
-        _context: &ExpandContext,
-        shapes: &mut Vec<Spanned<FlatShape>>,
-    ) -> Result<(), ShellError> {
-        let peeked_head = token_nodes.peek_non_ws().not_eof("command head4");
-
-        let peeked_head = match peeked_head {
-            Err(_) => return Ok(()),
-            Ok(peeked_head) => peeked_head,
-        };
-
-        let _expr = match peeked_head.node {
-            TokenNode::Token(Token {
-                unspanned: UnspannedToken::Bare,
-                span,
-            }) => shapes.push(FlatShape::Word.spanned(*span)),
-
-            TokenNode::Token(Token {
-                unspanned: UnspannedToken::String(_inner_tag),
-                span,
-            }) => shapes.push(FlatShape::String.spanned(*span)),
-
-            _node => shapes.push(FlatShape::Error.spanned(peeked_head.node.span())),
-        };
-
-        peeked_head.commit();
-
-        Ok(())
-    }
-}
-
-#[cfg(coloring_in_tokens)]
 impl FallibleColorSyntax for InternalCommandHeadShape {
     type Info = ();
     type Input = ();
@@ -1259,7 +856,7 @@ impl FallibleColorSyntax for InternalCommandHeadShape {
 
         let node = peeked_head.commit();
 
-        let _expr = match node {
+        match node {
             TokenNode::Token(Token {
                 unspanned: UnspannedToken::Bare,
                 span,
@@ -1329,8 +926,8 @@ impl<'token> SingleError<'token> {
     }
 }
 
-fn parse_single_node<'a, 'b, T>(
-    token_nodes: &'b mut TokensIterator<'a>,
+fn parse_single_node<T>(
+    token_nodes: &mut TokensIterator<'_>,
     expected: &'static str,
     callback: impl FnOnce(UnspannedToken, Span, SingleError) -> Result<T, ParseError>,
 ) -> Result<T, ParseError> {
@@ -1351,8 +948,8 @@ fn parse_single_node<'a, 'b, T>(
     })
 }
 
-fn parse_single_node_skipping_ws<'a, 'b, T>(
-    token_nodes: &'b mut TokensIterator<'a>,
+fn parse_single_node_skipping_ws<T>(
+    token_nodes: &mut TokensIterator<'_>,
     expected: &'static str,
     callback: impl FnOnce(UnspannedToken, Span, SingleError) -> Result<T, ShellError>,
 ) -> Result<T, ShellError> {
@@ -1384,38 +981,6 @@ fn parse_single_node_skipping_ws<'a, 'b, T>(
 #[derive(Debug, Copy, Clone)]
 pub struct WhitespaceShape;
 
-#[cfg(not(coloring_in_tokens))]
-impl FallibleColorSyntax for WhitespaceShape {
-    type Info = ();
-    type Input = ();
-
-    fn color_syntax<'a, 'b>(
-        &self,
-        _input: &(),
-        token_nodes: &'b mut TokensIterator<'a>,
-        _context: &ExpandContext,
-        shapes: &mut Vec<Spanned<FlatShape>>,
-    ) -> Result<(), ShellError> {
-        let peeked = token_nodes.peek_any().not_eof("whitespace");
-
-        let peeked = match peeked {
-            Err(_) => return Ok(()),
-            Ok(peeked) => peeked,
-        };
-
-        let _tag = match peeked.node {
-            TokenNode::Whitespace(span) => shapes.push(FlatShape::Whitespace.spanned(*span)),
-
-            _other => return Ok(()),
-        };
-
-        peeked.commit();
-
-        Ok(())
-    }
-}
-
-#[cfg(coloring_in_tokens)]
 impl FallibleColorSyntax for WhitespaceShape {
     type Info = ();
     type Input = ();
@@ -1439,7 +1004,7 @@ impl FallibleColorSyntax for WhitespaceShape {
 
         let node = peeked.commit();
 
-        let _ = match node {
+        match node {
             TokenNode::Whitespace(span) => {
                 token_nodes.color_shape(FlatShape::Whitespace.spanned(*span))
             }
@@ -1556,33 +1121,6 @@ impl ExpandSyntax for MaybeSpaceShape {
     }
 }
 
-#[cfg(not(coloring_in_tokens))]
-impl ColorSyntax for MaybeSpaceShape {
-    type Info = ();
-    type Input = ();
-
-    fn color_syntax<'a, 'b>(
-        &self,
-        _input: &(),
-        token_nodes: &'b mut TokensIterator<'a>,
-        _context: &ExpandContext,
-        shapes: &mut Vec<Spanned<FlatShape>>,
-    ) -> Self::Info {
-        let peeked = token_nodes.peek_any().not_eof("whitespace");
-
-        let peeked = match peeked {
-            Err(_) => return,
-            Ok(peeked) => peeked,
-        };
-
-        if let TokenNode::Whitespace(span) = peeked.node {
-            peeked.commit();
-            shapes.push(FlatShape::Whitespace.spanned(*span));
-        }
-    }
-}
-
-#[cfg(coloring_in_tokens)]
 impl ColorSyntax for MaybeSpaceShape {
     type Info = ();
     type Input = ();
@@ -1614,36 +1152,6 @@ impl ColorSyntax for MaybeSpaceShape {
 #[derive(Debug, Copy, Clone)]
 pub struct SpaceShape;
 
-#[cfg(not(coloring_in_tokens))]
-impl FallibleColorSyntax for SpaceShape {
-    type Info = ();
-    type Input = ();
-
-    fn color_syntax<'a, 'b>(
-        &self,
-        _input: &(),
-        token_nodes: &'b mut TokensIterator<'a>,
-        _context: &ExpandContext,
-        shapes: &mut Vec<Spanned<FlatShape>>,
-    ) -> Result<(), ShellError> {
-        let peeked = token_nodes.peek_any().not_eof("whitespace")?;
-
-        match peeked.node {
-            TokenNode::Whitespace(span) => {
-                peeked.commit();
-                shapes.push(FlatShape::Whitespace.spanned(*span));
-                Ok(())
-            }
-
-            other => Err(ShellError::type_error(
-                "whitespace",
-                other.spanned_type_name(),
-            )),
-        }
-    }
-}
-
-#[cfg(coloring_in_tokens)]
 impl FallibleColorSyntax for SpaceShape {
     type Info = ();
     type Input = ();
@@ -1717,38 +1225,6 @@ fn expand_variable(span: Span, token_span: Span, source: &Text) -> hir::Expressi
 #[derive(Debug, Copy, Clone)]
 pub struct CommandShape;
 
-#[cfg(not(coloring_in_tokens))]
-impl ColorSyntax for CommandShape {
-    type Info = ();
-    type Input = ();
-
-    fn color_syntax<'a, 'b>(
-        &self,
-        _input: &(),
-        token_nodes: &'b mut TokensIterator<'a>,
-        context: &ExpandContext,
-        shapes: &mut Vec<Spanned<FlatShape>>,
-    ) {
-        let kind = color_fallible_syntax(&CommandHeadShape, token_nodes, context, shapes);
-
-        match kind {
-            Err(_) => {
-                // We didn't find a command, so we'll have to fall back to parsing this pipeline part
-                // as a blob of undifferentiated expressions
-                color_syntax(&ExpressionListShape, token_nodes, context, shapes);
-            }
-
-            Ok(CommandHeadKind::External) => {
-                color_syntax(&ExternalTokensShape, token_nodes, context, shapes);
-            }
-            Ok(CommandHeadKind::Internal(signature)) => {
-                color_syntax_with(&CommandTailShape, &signature, token_nodes, context, shapes);
-            }
-        };
-    }
-}
-
-#[cfg(coloring_in_tokens)]
 impl ColorSyntax for CommandShape {
     type Info = ();
     type Input = ();

crates/nu-parser/src/hir/syntax_shape/block.rs

@@ -0,0 +1,251 @@
+use crate::{
+    hir,
+    hir::syntax_shape::{
+        color_fallible_syntax, color_syntax_with, continue_expression, expand_expr, expand_syntax,
+        DelimitedShape, ExpandContext, ExpandExpression, ExpressionContinuationShape,
+        ExpressionListShape, FallibleColorSyntax, MemberShape, PathTailShape, PathTailSyntax,
+        VariablePathShape,
+    },
+    hir::tokens_iterator::TokensIterator,
+    parse::token_tree::Delimiter,
+};
+use nu_errors::{ParseError, ShellError};
+use nu_source::Span;
+
+#[derive(Debug, Copy, Clone)]
+pub struct AnyBlockShape;
+
+impl FallibleColorSyntax for AnyBlockShape {
+    type Info = ();
+    type Input = ();
+
+    fn name(&self) -> &'static str {
+        "AnyBlockShape"
+    }
+
+    fn color_syntax<'a, 'b>(
+        &self,
+        _input: &(),
+        token_nodes: &'b mut TokensIterator<'a>,
+        context: &ExpandContext,
+    ) -> Result<(), ShellError> {
+        let block = token_nodes.peek_non_ws().not_eof("block");
+
+        let block = match block {
+            Err(_) => return Ok(()),
+            Ok(block) => block,
+        };
+
+        // is it just a block?
+        let block = block.node.as_block();
+
+        if let Some((children, spans)) = block {
+            token_nodes.child(children, context.source.clone(), |token_nodes| {
+                color_syntax_with(
+                    &DelimitedShape,
+                    &(Delimiter::Brace, spans.0, spans.1),
+                    token_nodes,
+                    context,
+                );
+            });
+
+            return Ok(());
+        }
+
+        // Otherwise, look for a shorthand block. If none found, fail
+        color_fallible_syntax(&ShorthandBlock, token_nodes, context)
+    }
+}
+
+impl ExpandExpression for AnyBlockShape {
+    fn name(&self) -> &'static str {
+        "any block"
+    }
+
+    fn expand_expr<'a, 'b>(
+        &self,
+        token_nodes: &mut TokensIterator<'_>,
+        context: &ExpandContext,
+    ) -> Result<hir::Expression, ParseError> {
+        let block = token_nodes.peek_non_ws().not_eof("block")?;
+
+        // is it just a block?
+        let block = block.node.as_block();
+
+        if let Some((block, _tags)) = block {
+            let mut iterator =
+                TokensIterator::new(&block.item, block.span, context.source.clone(), false);
+
+            let exprs = expand_syntax(&ExpressionListShape, &mut iterator, context)?.exprs;
+
+            return Ok(hir::RawExpression::Block(exprs.item).into_expr(block.span));
+        }
+
+        expand_syntax(&ShorthandBlock, token_nodes, context)
+    }
+}
+
+#[derive(Debug, Copy, Clone)]
+pub struct ShorthandBlock;
+
+impl FallibleColorSyntax for ShorthandBlock {
+    type Info = ();
+    type Input = ();
+
+    fn name(&self) -> &'static str {
+        "ShorthandBlock"
+    }
+
+    fn color_syntax<'a, 'b>(
+        &self,
+        _input: &(),
+        token_nodes: &'b mut TokensIterator<'a>,
+        context: &ExpandContext,
+    ) -> Result<(), ShellError> {
+        // Try to find a shorthand head. If none found, fail
+        color_fallible_syntax(&ShorthandPath, token_nodes, context)?;
+
+        loop {
+            // Check to see whether there's any continuation after the head expression
+            let result = color_fallible_syntax(&ExpressionContinuationShape, token_nodes, context);
+
+            match result {
+                // if no continuation was found, we're done
+                Err(_) => break,
+                // if a continuation was found, look for another one
+                Ok(_) => continue,
+            }
+        }
+
+        Ok(())
+    }
+}
+
+impl ExpandExpression for ShorthandBlock {
+    fn name(&self) -> &'static str {
+        "shorthand block"
+    }
+
+    fn expand_expr<'a, 'b>(
+        &self,
+        token_nodes: &'b mut TokensIterator<'a>,
+        context: &ExpandContext,
+    ) -> Result<hir::Expression, ParseError> {
+        let path = expand_expr(&ShorthandPath, token_nodes, context)?;
+        let start = path.span;
+        let expr = continue_expression(path, token_nodes, context);
+        let end = expr.span;
+        let block = hir::RawExpression::Block(vec![expr]).into_expr(start.until(end));
+
+        Ok(block)
+    }
+}
+
+/// A shorthand for `$it.foo."bar"`, used inside of a shorthand block
+#[derive(Debug, Copy, Clone)]
+pub struct ShorthandPath;
+
+impl FallibleColorSyntax for ShorthandPath {
+    type Info = ();
+    type Input = ();
+
+    fn name(&self) -> &'static str {
+        "ShorthandPath"
+    }
+
+    fn color_syntax<'a, 'b>(
+        &self,
+        _input: &(),
+        token_nodes: &'b mut TokensIterator<'a>,
+        context: &ExpandContext,
+    ) -> Result<(), ShellError> {
+        token_nodes.atomic(|token_nodes| {
+            let variable = color_fallible_syntax(&VariablePathShape, token_nodes, context);
+
+            if variable.is_ok() {
+                // if it's a variable path, that's the head part
+                return Ok(());
+            }
+
+            // otherwise, we'll try to find a member path
+
+            // look for a member (`<member>` -> `$it.<member>`)
+            color_fallible_syntax(&MemberShape, token_nodes, context)?;
+
+            // Now that we've synthesized the head, of the path, proceed to expand the tail of the path
+            // like any other path.
+            // It's ok if there's no path tail; a single member is sufficient
+            let _ = color_fallible_syntax(&PathTailShape, token_nodes, context);
+
+            Ok(())
+        })
+    }
+}
+
+impl ExpandExpression for ShorthandPath {
+    fn name(&self) -> &'static str {
+        "shorthand path"
+    }
+
+    fn expand_expr<'a, 'b>(
+        &self,
+        token_nodes: &'b mut TokensIterator<'a>,
+        context: &ExpandContext,
+    ) -> Result<hir::Expression, ParseError> {
+        // if it's a variable path, that's the head part
+        let path = expand_expr(&VariablePathShape, token_nodes, context);
+
+        if let Ok(path) = path {
+            return Ok(path);
+        }
+
+        // Synthesize the head of the shorthand path (`<member>` -> `$it.<member>`)
+        let mut head = expand_expr(&ShorthandHeadShape, token_nodes, context)?;
+
+        // Now that we've synthesized the head, of the path, proceed to expand the tail of the path
+        // like any other path.
+        let tail = expand_syntax(&PathTailShape, token_nodes, context);
+
+        match tail {
+            Err(_) => Ok(head),
+            Ok(PathTailSyntax { tail, .. }) => {
+                // For each member that `PathTailShape` expanded, join it onto the existing expression
+                // to form a new path
+                for member in tail {
+                    head = hir::Expression::dot_member(head, member);
+                }
+
+                Ok(head)
+            }
+        }
+    }
+}
+
+/// A shorthand for `$it.foo."bar"`, used inside of a shorthand block
+#[derive(Debug, Copy, Clone)]
+pub struct ShorthandHeadShape;
+
+impl ExpandExpression for ShorthandHeadShape {
+    fn name(&self) -> &'static str {
+        "shorthand head"
+    }
+
+    fn expand_expr<'a, 'b>(
+        &self,
+        token_nodes: &'b mut TokensIterator<'a>,
+        context: &ExpandContext,
+    ) -> Result<hir::Expression, ParseError> {
+        let head = expand_syntax(&MemberShape, token_nodes, context)?;
+        let head = head.to_path_member(context.source);
+
+        // Synthesize an `$it` expression
+        let it = synthetic_it();
+        let span = head.span;
+
+        Ok(hir::Expression::path(it, vec![head], span))
+    }
+}
+
+fn synthetic_it() -> hir::Expression {
+    hir::Expression::it_variable(Span::unknown(), Span::unknown())
+}

crates/nu-parser/src/hir/syntax_shape/expression.rs

@@ -4,22 +4,23 @@ pub(crate) mod file_path;
 pub(crate) mod list;
 pub(crate) mod number;
 pub(crate) mod pattern;
+pub(crate) mod range;
 pub(crate) mod string;
 pub(crate) mod unit;
 pub(crate) mod variable_path;
 
-use crate::parser::hir::syntax_shape::{
+use crate::hir::syntax_shape::{
     color_delimited_square, color_fallible_syntax, color_fallible_syntax_with, expand_atom,
     expand_delimited_square, expand_expr, expand_syntax, BareShape, ColorableDotShape, DotShape,
     ExpandContext, ExpandExpression, ExpandSyntax, ExpansionRule, ExpressionContinuation,
-    ExpressionContinuationShape, FallibleColorSyntax, FlatShape, ParseError, UnspannedAtomicToken,
+    ExpressionContinuationShape, FallibleColorSyntax, FlatShape, UnspannedAtomicToken,
 };
-use crate::parser::{
+use crate::{
     hir,
     hir::{Expression, TokensIterator},
 };
-use crate::prelude::*;
-use nu_source::Spanned;
+use nu_errors::{ParseError, ShellError};
+use nu_source::{HasSpan, Span, Spanned, SpannedItem, Tag};
 use std::path::PathBuf;
 
 #[derive(Debug, Copy, Clone)]
@@ -42,34 +43,6 @@ impl ExpandExpression for AnyExpressionShape {
     }
 }
 
-#[cfg(not(coloring_in_tokens))]
-impl FallibleColorSyntax for AnyExpressionShape {
-    type Info = ();
-    type Input = ();
-
-    fn color_syntax<'a, 'b>(
-        &self,
-        _input: &(),
-        token_nodes: &'b mut TokensIterator<'a>,
-        context: &ExpandContext,
-        shapes: &mut Vec<Spanned<FlatShape>>,
-    ) -> Result<(), ShellError> {
-        // Look for an expression at the cursor
-        color_fallible_syntax(&AnyExpressionStartShape, token_nodes, context, shapes)?;
-
-        match continue_coloring_expression(token_nodes, context, shapes) {
-            Err(_) => {
-                // it's fine for there to be no continuation
-            }
-
-            Ok(()) => {}
-        }
-
-        Ok(())
-    }
-}
-
-#[cfg(coloring_in_tokens)]
 impl FallibleColorSyntax for AnyExpressionShape {
     type Info = ();
     type Input = ();
@@ -127,32 +100,6 @@ pub(crate) fn continue_expression(
     }
 }
 
-#[cfg(not(coloring_in_tokens))]
-pub(crate) fn continue_coloring_expression(
-    token_nodes: &mut TokensIterator<'_>,
-    context: &ExpandContext,
-    shapes: &mut Vec<Spanned<FlatShape>>,
-) -> Result<(), ShellError> {
-    // if there's not even one expression continuation, fail
-    color_fallible_syntax(&ExpressionContinuationShape, token_nodes, context, shapes)?;
-
-    loop {
-        // Check to see whether there's any continuation after the head expression
-        let result =
-            color_fallible_syntax(&ExpressionContinuationShape, token_nodes, context, shapes);
-
-        match result {
-            Err(_) => {
-                // We already saw one continuation, so just return
-                return Ok(());
-            }
-
-            Ok(_) => {}
-        }
-    }
-}
-
-#[cfg(coloring_in_tokens)]
 pub(crate) fn continue_coloring_expression(
     token_nodes: &mut TokensIterator<'_>,
     context: &ExpandContext,
@@ -164,13 +111,9 @@ pub(crate) fn continue_coloring_expression(
         // Check to see whether there's any continuation after the head expression
         let result = color_fallible_syntax(&ExpressionContinuationShape, token_nodes, context);
 
-        match result {
-            Err(_) => {
-                // We already saw one continuation, so just return
-                return Ok(());
-            }
-
-            Ok(_) => {}
+        if result.is_err() {
+            // We already saw one continuation, so just return
+            return Ok(());
         }
     }
 }
@@ -191,19 +134,17 @@ impl ExpandExpression for AnyExpressionStartShape {
         let atom = expand_atom(token_nodes, "expression", context, ExpansionRule::new())?;
 
         match atom.unspanned {
-            UnspannedAtomicToken::Size { number, unit } => {
-                return Ok(hir::Expression::size(
-                    number.to_number(context.source),
-                    unit.item,
-                    Tag {
-                        span: atom.span,
-                        anchor: None,
-                    },
-                ))
-            }
+            UnspannedAtomicToken::Size { number, unit } => Ok(hir::Expression::size(
+                number.to_number(context.source),
+                unit.item,
+                Tag {
+                    span: atom.span,
+                    anchor: None,
+                },
+            )),
 
             UnspannedAtomicToken::SquareDelimited { nodes, .. } => {
-                expand_delimited_square(&nodes, atom.span.into(), context)
+                expand_delimited_square(&nodes, atom.span, context)
             }
 
             UnspannedAtomicToken::Word { .. } => {
@@ -211,75 +152,13 @@ impl ExpandExpression for AnyExpressionStartShape {
                 Ok(hir::Expression::bare(atom.span.until_option(end)))
             }
 
-            other => {
-                return other
-                    .into_atomic_token(atom.span)
-                    .into_hir(context, "expression")
-            }
+            other => other
+                .into_atomic_token(atom.span)
+                .to_hir(context, "expression"),
         }
     }
 }
 
-#[cfg(not(coloring_in_tokens))]
-impl FallibleColorSyntax for AnyExpressionStartShape {
-    type Info = ();
-    type Input = ();
-
-    fn color_syntax<'a, 'b>(
-        &self,
-        _input: &(),
-        token_nodes: &'b mut TokensIterator<'a>,
-        context: &ExpandContext,
-        shapes: &mut Vec<Spanned<FlatShape>>,
-    ) -> Result<(), ShellError> {
-        let atom = token_nodes.spanned(|token_nodes| {
-            expand_atom(
-                token_nodes,
-                "expression",
-                context,
-                ExpansionRule::permissive(),
-            )
-        });
-
-        let atom = match atom {
-            Spanned {
-                item: Err(_err),
-                span,
-            } => {
-                shapes.push(FlatShape::Error.spanned(span));
-                return Ok(());
-            }
-
-            Spanned {
-                item: Ok(value), ..
-            } => value,
-        };
-
-        match &atom.unspanned {
-            UnspannedAtomicToken::Size { number, unit } => shapes.push(
-                FlatShape::Size {
-                    number: number.span(),
-                    unit: unit.span.into(),
-                }
-                .spanned(atom.span),
-            ),
-
-            UnspannedAtomicToken::SquareDelimited { nodes, spans } => {
-                color_delimited_square(*spans, &nodes, atom.span.into(), context, shapes)
-            }
-
-            UnspannedAtomicToken::Word { .. } => {
-                shapes.push(FlatShape::Word.spanned(atom.span));
-            }
-
-            _ => atom.color_tokens(shapes),
-        }
-
-        Ok(())
-    }
-}
-
-#[cfg(coloring_in_tokens)]
 impl FallibleColorSyntax for AnyExpressionStartShape {
     type Info = ();
     type Input = ();
@@ -321,7 +200,7 @@ impl FallibleColorSyntax for AnyExpressionStartShape {
             UnspannedAtomicToken::Size { number, unit } => token_nodes.color_shape(
                 FlatShape::Size {
                     number: number.span(),
-                    unit: unit.span.into(),
+                    unit: unit.span,
                 }
                 .spanned(atom.span),
             ),
@@ -331,7 +210,7 @@ impl FallibleColorSyntax for AnyExpressionStartShape {
                     (&nodes[..]).spanned(atom.span),
                     context.source.clone(),
                     |tokens| {
-                        color_delimited_square(spans, tokens, atom.span.into(), context);
+                        color_delimited_square(spans, tokens, atom.span, context);
                     },
                 );
             }
@@ -350,64 +229,6 @@ impl FallibleColorSyntax for AnyExpressionStartShape {
 #[derive(Debug, Copy, Clone)]
 pub struct BareTailShape;
 
-#[cfg(not(coloring_in_tokens))]
-impl FallibleColorSyntax for BareTailShape {
-    type Info = ();
-    type Input = ();
-
-    fn color_syntax<'a, 'b>(
-        &self,
-        _input: &(),
-        token_nodes: &'b mut TokensIterator<'a>,
-        context: &ExpandContext,
-        shapes: &mut Vec<Spanned<FlatShape>>,
-    ) -> Result<(), ShellError> {
-        let len = shapes.len();
-
-        loop {
-            let word = color_fallible_syntax_with(
-                &BareShape,
-                &FlatShape::Word,
-                token_nodes,
-                context,
-                shapes,
-            );
-
-            match word {
-                // if a word was found, continue
-                Ok(_) => continue,
-                // if a word wasn't found, try to find a dot
-                Err(_) => {}
-            }
-
-            // try to find a dot
-            let dot = color_fallible_syntax_with(
-                &ColorableDotShape,
-                &FlatShape::Word,
-                token_nodes,
-                context,
-                shapes,
-            );
-
-            match dot {
-                // if a dot was found, try to find another word
-                Ok(_) => continue,
-                // otherwise, we're done
-                Err(_) => break,
-            }
-        }
-
-        if shapes.len() > len {
-            Ok(())
-        } else {
-            Err(ShellError::syntax_error(
-                "No tokens matched BareTailShape".spanned_unknown(),
-            ))
-        }
-    }
-}
-
-#[cfg(coloring_in_tokens)]
 impl FallibleColorSyntax for BareTailShape {
     type Info = ();
     type Input = ();
@@ -428,13 +249,13 @@ impl FallibleColorSyntax for BareTailShape {
             let word =
                 color_fallible_syntax_with(&BareShape, &FlatShape::Word, token_nodes, context);
 
-            match word {
+            if word.is_ok() {
                 // if a word was found, continue
-                Ok(_) => continue,
-                // if a word wasn't found, try to find a dot
-                Err(_) => {}
+                continue;
             }
 
+            // if a word wasn't found, try to find a dot
+
             // try to find a dot
             let dot = color_fallible_syntax_with(
                 &ColorableDotShape,

crates/nu-parser/src/hir/syntax_shape/expression/atom.rs

@@ -1,15 +1,20 @@
-use crate::parser::hir::syntax_shape::{
+use crate::hir::syntax_shape::FlatShape;
+use crate::hir::syntax_shape::{
     expand_syntax, expression::expand_file_path, parse_single_node, BarePathShape,
     BarePatternShape, ExpandContext, UnitShape, UnitSyntax,
 };
-use crate::parser::{
+use crate::parse::operator::EvaluationOperator;
+use crate::parse::token_tree::{DelimitedNode, Delimiter, TokenNode};
+use crate::parse::tokens::UnspannedToken;
+use crate::parse::unit::Unit;
+use crate::{
     hir,
     hir::{Expression, RawNumber, TokensIterator},
     parse::flag::{Flag, FlagKind},
-    DelimitedNode, Delimiter, FlatShape, TokenNode, Unit, UnspannedToken,
 };
-use crate::prelude::*;
-use nu_source::Spanned;
+use nu_errors::{ParseError, ShellError};
+use nu_protocol::{ShellTypeName, SpannedTypeName};
+use nu_source::{b, DebugDocBuilder, HasSpan, PrettyDebugWithSource, Span, Spanned, SpannedItem};
 use std::ops::Deref;
 
 #[derive(Debug, Clone)]
@@ -48,23 +53,36 @@ pub enum UnspannedAtomicToken<'tokens> {
     Word {
         text: Span,
     },
-    #[allow(unused)]
-    Dot {
-        text: Span,
-    },
     SquareDelimited {
         spans: (Span, Span),
         nodes: &'tokens Vec<TokenNode>,
     },
+    #[allow(unused)]
+    RoundDelimited {
+        spans: (Span, Span),
+        nodes: &'tokens Vec<TokenNode>,
+    },
     ShorthandFlag {
         name: Span,
     },
-    Operator {
+    CompareOperator {
+        text: Span,
+    },
+    Dot {
+        text: Span,
+    },
+    DotDot {
         text: Span,
     },
     Whitespace {
         text: Span,
     },
+    Separator {
+        text: Span,
+    },
+    Comment {
+        body: Span,
+    },
 }
 
 impl<'tokens> UnspannedAtomicToken<'tokens> {
@@ -76,15 +94,24 @@ impl<'tokens> UnspannedAtomicToken<'tokens> {
     }
 }
 
+impl<'tokens> ShellTypeName for AtomicToken<'tokens> {
+    fn type_name(&self) -> &'static str {
+        self.unspanned.type_name()
+    }
+}
+
 impl<'tokens> ShellTypeName for UnspannedAtomicToken<'tokens> {
     fn type_name(&self) -> &'static str {
         match &self {
             UnspannedAtomicToken::Eof { .. } => "eof",
             UnspannedAtomicToken::Error { .. } => "error",
-            UnspannedAtomicToken::Operator { .. } => "operator",
+            UnspannedAtomicToken::CompareOperator { .. } => "compare operator",
             UnspannedAtomicToken::ShorthandFlag { .. } => "shorthand flag",
             UnspannedAtomicToken::Whitespace { .. } => "whitespace",
+            UnspannedAtomicToken::Separator { .. } => "separator",
+            UnspannedAtomicToken::Comment { .. } => "comment",
             UnspannedAtomicToken::Dot { .. } => "dot",
+            UnspannedAtomicToken::DotDot { .. } => "dotdot",
             UnspannedAtomicToken::Number { .. } => "number",
             UnspannedAtomicToken::Size { .. } => "size",
             UnspannedAtomicToken::String { .. } => "string",
@@ -95,6 +122,7 @@ impl<'tokens> ShellTypeName for UnspannedAtomicToken<'tokens> {
             UnspannedAtomicToken::GlobPattern { .. } => "file pattern",
             UnspannedAtomicToken::Word { .. } => "word",
             UnspannedAtomicToken::SquareDelimited { .. } => "array literal",
+            UnspannedAtomicToken::RoundDelimited { .. } => "paren delimited",
         }
     }
 }
@@ -105,6 +133,12 @@ pub struct AtomicToken<'tokens> {
     pub span: Span,
 }
 
+impl<'tokens> HasSpan for AtomicToken<'tokens> {
+    fn span(&self) -> Span {
+        self.span
+    }
+}
+
 impl<'tokens> Deref for AtomicToken<'tokens> {
     type Target = UnspannedAtomicToken<'tokens>;
 
@@ -114,7 +148,7 @@ impl<'tokens> Deref for AtomicToken<'tokens> {
 }
 
 impl<'tokens> AtomicToken<'tokens> {
-    pub fn into_hir(
+    pub fn to_hir(
         &self,
         context: &ExpandContext,
         expected: &'static str,
@@ -127,31 +161,18 @@ impl<'tokens> AtomicToken<'tokens> {
                 ))
             }
             UnspannedAtomicToken::Error { .. } => {
-                return Err(ParseError::mismatch(
-                    expected,
-                    "eof atomic token".spanned(self.span),
-                ))
+                return Err(ParseError::mismatch(expected, "error".spanned(self.span)))
             }
-            UnspannedAtomicToken::Operator { .. } => {
-                return Err(ParseError::mismatch(
-                    expected,
-                    "operator".spanned(self.span),
-                ))
-            }
-            UnspannedAtomicToken::ShorthandFlag { .. } => {
-                return Err(ParseError::mismatch(
-                    expected,
-                    "shorthand flag".spanned(self.span),
-                ))
-            }
-            UnspannedAtomicToken::Whitespace { .. } => {
-                return Err(ParseError::mismatch(
-                    expected,
-                    "whitespace".spanned(self.span),
-                ))
-            }
-            UnspannedAtomicToken::Dot { .. } => {
-                return Err(ParseError::mismatch(expected, "dot".spanned(self.span)))
+            UnspannedAtomicToken::RoundDelimited { .. }
+            | UnspannedAtomicToken::CompareOperator { .. }
+            | UnspannedAtomicToken::ShorthandFlag { .. }
+            | UnspannedAtomicToken::Whitespace { .. }
+            | UnspannedAtomicToken::Separator { .. }
+            | UnspannedAtomicToken::Comment { .. }
+            | UnspannedAtomicToken::Dot { .. }
+            | UnspannedAtomicToken::DotDot { .. }
+            | UnspannedAtomicToken::SquareDelimited { .. } => {
+                return Err(ParseError::mismatch(expected, self.spanned_type_name()));
             }
             UnspannedAtomicToken::Number { number } => {
                 Expression::number(number.to_number(context.source), self.span)
@@ -171,89 +192,55 @@ impl<'tokens> AtomicToken<'tokens> {
                 self.span,
             ),
             UnspannedAtomicToken::Word { text } => Expression::string(*text, *text),
-            UnspannedAtomicToken::SquareDelimited { .. } => unimplemented!("into_hir"),
         })
     }
 
-    #[cfg(not(coloring_in_tokens))]
-    pub fn spanned_type_name(&self) -> Spanned<&'static str> {
-        match &self.unspanned {
-            UnspannedAtomicToken::Eof { .. } => "eof",
-            UnspannedAtomicToken::Error { .. } => "error",
-            UnspannedAtomicToken::Operator { .. } => "operator",
-            UnspannedAtomicToken::ShorthandFlag { .. } => "shorthand flag",
-            UnspannedAtomicToken::Whitespace { .. } => "whitespace",
-            UnspannedAtomicToken::Dot { .. } => "dot",
-            UnspannedAtomicToken::Number { .. } => "number",
-            UnspannedAtomicToken::Size { .. } => "size",
-            UnspannedAtomicToken::String { .. } => "string",
-            UnspannedAtomicToken::ItVariable { .. } => "$it",
-            UnspannedAtomicToken::Variable { .. } => "variable",
-            UnspannedAtomicToken::ExternalCommand { .. } => "external command",
-            UnspannedAtomicToken::ExternalWord { .. } => "external word",
-            UnspannedAtomicToken::GlobPattern { .. } => "file pattern",
-            UnspannedAtomicToken::Word { .. } => "word",
-            UnspannedAtomicToken::SquareDelimited { .. } => "array literal",
-        }
-        .spanned(self.span)
-    }
-
     pub(crate) fn color_tokens(&self, shapes: &mut Vec<Spanned<FlatShape>>) {
         match &self.unspanned {
             UnspannedAtomicToken::Eof { .. } => {}
-            UnspannedAtomicToken::Error { .. } => {
-                return shapes.push(FlatShape::Error.spanned(self.span))
-            }
-            UnspannedAtomicToken::Operator { .. } => {
-                return shapes.push(FlatShape::Operator.spanned(self.span));
+            UnspannedAtomicToken::Error { .. } => shapes.push(FlatShape::Error.spanned(self.span)),
+            UnspannedAtomicToken::CompareOperator { .. } => {
+                shapes.push(FlatShape::CompareOperator.spanned(self.span))
             }
             UnspannedAtomicToken::ShorthandFlag { .. } => {
-                return shapes.push(FlatShape::ShorthandFlag.spanned(self.span));
+                shapes.push(FlatShape::ShorthandFlag.spanned(self.span))
             }
             UnspannedAtomicToken::Whitespace { .. } => {
-                return shapes.push(FlatShape::Whitespace.spanned(self.span));
+                shapes.push(FlatShape::Whitespace.spanned(self.span))
             }
             UnspannedAtomicToken::Number {
                 number: RawNumber::Decimal(_),
-            } => {
-                return shapes.push(FlatShape::Decimal.spanned(self.span));
-            }
+            } => shapes.push(FlatShape::Decimal.spanned(self.span)),
             UnspannedAtomicToken::Number {
                 number: RawNumber::Int(_),
-            } => {
-                return shapes.push(FlatShape::Int.spanned(self.span));
-            }
-            UnspannedAtomicToken::Size { number, unit } => {
-                return shapes.push(
-                    FlatShape::Size {
-                        number: number.span(),
-                        unit: unit.span,
-                    }
-                    .spanned(self.span),
-                );
-            }
+            } => shapes.push(FlatShape::Int.spanned(self.span)),
+            UnspannedAtomicToken::Size { number, unit } => shapes.push(
+                FlatShape::Size {
+                    number: number.span(),
+                    unit: unit.span,
+                }
+                .spanned(self.span),
+            ),
             UnspannedAtomicToken::String { .. } => {
-                return shapes.push(FlatShape::String.spanned(self.span))
+                shapes.push(FlatShape::String.spanned(self.span))
             }
             UnspannedAtomicToken::ItVariable { .. } => {
-                return shapes.push(FlatShape::ItVariable.spanned(self.span))
+                shapes.push(FlatShape::ItVariable.spanned(self.span))
             }
             UnspannedAtomicToken::Variable { .. } => {
-                return shapes.push(FlatShape::Variable.spanned(self.span))
+                shapes.push(FlatShape::Variable.spanned(self.span))
             }
             UnspannedAtomicToken::ExternalCommand { .. } => {
-                return shapes.push(FlatShape::ExternalCommand.spanned(self.span));
+                shapes.push(FlatShape::ExternalCommand.spanned(self.span))
             }
             UnspannedAtomicToken::ExternalWord { .. } => {
-                return shapes.push(FlatShape::ExternalWord.spanned(self.span))
+                shapes.push(FlatShape::ExternalWord.spanned(self.span))
             }
             UnspannedAtomicToken::GlobPattern { .. } => {
-                return shapes.push(FlatShape::GlobPattern.spanned(self.span))
+                shapes.push(FlatShape::GlobPattern.spanned(self.span))
             }
-            UnspannedAtomicToken::Word { .. } => {
-                return shapes.push(FlatShape::Word.spanned(self.span))
-            }
-            _ => return shapes.push(FlatShape::Error.spanned(self.span)),
+            UnspannedAtomicToken::Word { .. } => shapes.push(FlatShape::Word.spanned(self.span)),
+            _ => shapes.push(FlatShape::Error.spanned(self.span)),
         }
     }
 }
@@ -301,17 +288,30 @@ impl PrettyDebugWithSource for AtomicToken<'_> {
                 b::intersperse_with_source(nodes.iter(), b::space(), source),
                 "]",
             ),
+            UnspannedAtomicToken::RoundDelimited { nodes, .. } => b::delimit(
+                "(",
+                b::intersperse_with_source(nodes.iter(), b::space(), source),
+                ")",
+            ),
             UnspannedAtomicToken::ShorthandFlag { name } => {
                 atom_kind("shorthand flag", b::key(name.slice(source)))
             }
             UnspannedAtomicToken::Dot { .. } => atom(b::kind("dot")),
-            UnspannedAtomicToken::Operator { text } => {
+            UnspannedAtomicToken::DotDot { .. } => atom(b::kind("dotdot")),
+            UnspannedAtomicToken::CompareOperator { text } => {
                 atom_kind("operator", b::keyword(text.slice(source)))
             }
             UnspannedAtomicToken::Whitespace { text } => atom_kind(
                 "whitespace",
                 b::description(format!("{:?}", text.slice(source))),
             ),
+            UnspannedAtomicToken::Separator { text } => atom_kind(
+                "separator",
+                b::description(format!("{:?}", text.slice(source))),
+            ),
+            UnspannedAtomicToken::Comment { body } => {
+                atom_kind("comment", b::description(body.slice(source)))
+            }
         })
     }
 }
@@ -327,12 +327,15 @@ pub enum WhitespaceHandling {
 pub struct ExpansionRule {
     pub(crate) allow_external_command: bool,
     pub(crate) allow_external_word: bool,
-    pub(crate) allow_operator: bool,
+    pub(crate) allow_cmp_operator: bool,
+    pub(crate) allow_eval_operator: bool,
     pub(crate) allow_eof: bool,
+    pub(crate) allow_separator: bool,
     pub(crate) treat_size_as_word: bool,
     pub(crate) separate_members: bool,
     pub(crate) commit_errors: bool,
     pub(crate) whitespace: WhitespaceHandling,
+    pub(crate) allow_comments: bool,
 }
 
 impl ExpansionRule {
@@ -340,12 +343,15 @@ impl ExpansionRule {
         ExpansionRule {
             allow_external_command: false,
             allow_external_word: false,
-            allow_operator: false,
+            allow_eval_operator: false,
+            allow_cmp_operator: false,
             allow_eof: false,
             treat_size_as_word: false,
             separate_members: false,
             commit_errors: false,
+            allow_separator: false,
             whitespace: WhitespaceHandling::RejectWhitespace,
+            allow_comments: false,
         }
     }
 
@@ -356,11 +362,14 @@ impl ExpansionRule {
         ExpansionRule {
             allow_external_command: true,
             allow_external_word: true,
-            allow_operator: true,
+            allow_cmp_operator: true,
+            allow_eval_operator: true,
             allow_eof: true,
             separate_members: false,
             treat_size_as_word: false,
             commit_errors: true,
+            allow_separator: true,
+            allow_comments: true,
             whitespace: WhitespaceHandling::AllowWhitespace,
         }
     }
@@ -372,14 +381,26 @@ impl ExpansionRule {
     }
 
     #[allow(unused)]
-    pub fn allow_operator(mut self) -> ExpansionRule {
-        self.allow_operator = true;
+    pub fn allow_cmp_operator(mut self) -> ExpansionRule {
+        self.allow_cmp_operator = true;
+        self
+    }
+
+    #[allow(unused)]
+    pub fn no_cmp_operator(mut self) -> ExpansionRule {
+        self.allow_cmp_operator = false;
+        self
+    }
+
+    #[allow(unused)]
+    pub fn allow_eval_operator(mut self) -> ExpansionRule {
+        self.allow_eval_operator = true;
         self
     }
 
     #[allow(unused)]
     pub fn no_operator(mut self) -> ExpansionRule {
-        self.allow_operator = false;
+        self.allow_eval_operator = false;
         self
     }
 
@@ -436,6 +457,30 @@ impl ExpansionRule {
         self.whitespace = WhitespaceHandling::RejectWhitespace;
         self
     }
+
+    #[allow(unused)]
+    pub fn allow_separator(mut self) -> ExpansionRule {
+        self.allow_separator = true;
+        self
+    }
+
+    #[allow(unused)]
+    pub fn reject_separator(mut self) -> ExpansionRule {
+        self.allow_separator = false;
+        self
+    }
+
+    #[allow(unused)]
+    pub fn allow_comments(mut self) -> ExpansionRule {
+        self.allow_comments = true;
+        self
+    }
+
+    #[allow(unused)]
+    pub fn reject_comments(mut self) -> ExpansionRule {
+        self.allow_comments = false;
+        self
+    }
 }
 
 pub fn expand_atom<'me, 'content>(
@@ -469,14 +514,13 @@ fn expand_atom_inner<'me, 'content>(
     rule: ExpansionRule,
 ) -> Result<AtomicToken<'content>, ParseError> {
     if token_nodes.at_end() {
-        match rule.allow_eof {
-            true => {
-                return Ok(UnspannedAtomicToken::Eof {
-                    span: Span::unknown(),
-                }
-                .into_atomic_token(Span::unknown()))
+        if rule.allow_eof {
+            return Ok(UnspannedAtomicToken::Eof {
+                span: Span::unknown(),
             }
-            false => return Err(ParseError::unexpected_eof("anything", Span::unknown())),
+            .into_atomic_token(Span::unknown()));
+        } else {
+            return Err(ParseError::unexpected_eof("anything", Span::unknown()));
         }
     }
 
@@ -485,9 +529,8 @@ fn expand_atom_inner<'me, 'content>(
 
     // If treat_size_as_word, don't try to parse the head of the token stream
     // as a size.
-    match rule.treat_size_as_word {
-        true => {}
-        false => match expand_syntax(&UnitShape, token_nodes, context) {
+    if !rule.treat_size_as_word {
+        match expand_syntax(&UnitShape, token_nodes, context) {
             // If the head of the stream isn't a valid unit, we'll try to parse
             // it again next as a word
             Err(_) => {}
@@ -497,31 +540,28 @@ fn expand_atom_inner<'me, 'content>(
                 unit: (number, unit),
                 span,
             }) => return Ok(UnspannedAtomicToken::Size { number, unit }.into_atomic_token(span)),
-        },
+        }
     }
 
-    match rule.separate_members {
-        false => {}
-        true => {
-            let mut next = token_nodes.peek_any();
+    if rule.separate_members {
+        let mut next = token_nodes.peek_any();
 
-            match next.node {
-                Some(token) if token.is_word() => {
-                    next.commit();
-                    return Ok(UnspannedAtomicToken::Word { text: token.span() }
-                        .into_atomic_token(token.span()));
-                }
-
-                Some(token) if token.is_int() => {
-                    next.commit();
-                    return Ok(UnspannedAtomicToken::Number {
-                        number: RawNumber::Int(token.span()),
-                    }
+        match next.node {
+            Some(token) if token.is_word() => {
+                next.commit();
+                return Ok(UnspannedAtomicToken::Word { text: token.span() }
                     .into_atomic_token(token.span()));
-                }
-
-                _ => {}
             }
+
+            Some(token) if token.is_int() => {
+                next.commit();
+                return Ok(UnspannedAtomicToken::Number {
+                    number: RawNumber::Int(token.span()),
+                }
+                .into_atomic_token(token.span()));
+            }
+
+            _ => {}
         }
     }
 
@@ -574,6 +614,17 @@ fn expand_atom_inner<'me, 'content>(
             .into_atomic_token(error.span));
         }
 
+        TokenNode::Separator(span) if rule.allow_separator => {
+            peeked.commit();
+            return Ok(UnspannedAtomicToken::Separator { text: *span }.into_atomic_token(span));
+        }
+
+        TokenNode::Comment(comment) if rule.allow_comments => {
+            peeked.commit();
+            return Ok(UnspannedAtomicToken::Comment { body: comment.text }
+                .into_atomic_token(comment.span()));
+        }
+
         // [ ... ]
         TokenNode::Delimited(Spanned {
             item:
@@ -645,8 +696,16 @@ fn expand_atom_inner<'me, 'content>(
             // First, the error cases. Each error case corresponds to a expansion rule
             // flag that can be used to allow the case
 
-            // rule.allow_operator
-            UnspannedToken::Operator(_) if !rule.allow_operator => return Err(err.error()),
+            // rule.allow_cmp_operator
+            UnspannedToken::CompareOperator(_) if !rule.allow_cmp_operator => {
+                return Err(err.error())
+            }
+
+            // rule.allow_eval_operator
+            UnspannedToken::EvaluationOperator(_) if !rule.allow_eval_operator => {
+                return Err(err.error())
+            }
+
             // rule.allow_external_command
             UnspannedToken::ExternalCommand(_) if !rule.allow_external_command => {
                 return Err(ParseError::mismatch(
@@ -665,8 +724,15 @@ fn expand_atom_inner<'me, 'content>(
             UnspannedToken::Number(number) => {
                 UnspannedAtomicToken::Number { number }.into_atomic_token(token_span)
             }
-            UnspannedToken::Operator(_) => {
-                UnspannedAtomicToken::Operator { text: token_span }.into_atomic_token(token_span)
+            UnspannedToken::CompareOperator(_) => {
+                UnspannedAtomicToken::CompareOperator { text: token_span }
+                    .into_atomic_token(token_span)
+            }
+            UnspannedToken::EvaluationOperator(EvaluationOperator::Dot) => {
+                UnspannedAtomicToken::Dot { text: token_span }.into_atomic_token(token_span)
+            }
+            UnspannedToken::EvaluationOperator(EvaluationOperator::DotDot) => {
+                UnspannedAtomicToken::DotDot { text: token_span }.into_atomic_token(token_span)
             }
             UnspannedToken::String(body) => {
                 UnspannedAtomicToken::String { body }.into_atomic_token(token_span)

crates/nu-parser/src/hir/syntax_shape/expression/delimited.rs

@@ -1,13 +1,12 @@
-use crate::parser::hir::syntax_shape::{
+use crate::hir::syntax_shape::{
     color_syntax, expand_syntax, ColorSyntax, ExpandContext, ExpressionListShape, TokenNode,
 };
-use crate::parser::{hir, hir::TokensIterator, Delimiter, FlatShape};
-use crate::prelude::*;
-#[cfg(not(coloring_in_tokens))]
-use nu_source::Spanned;
+use crate::{hir, hir::TokensIterator, Delimiter, FlatShape};
+use nu_errors::ParseError;
+use nu_source::{Span, SpannedItem, Tag};
 
 pub fn expand_delimited_square(
-    children: &Vec<TokenNode>,
+    children: &[TokenNode],
     span: Span,
     context: &ExpandContext,
 ) -> Result<hir::Expression, ParseError> {
@@ -21,21 +20,6 @@ pub fn expand_delimited_square(
     ))
 }
 
-#[cfg(not(coloring_in_tokens))]
-pub fn color_delimited_square(
-    (open, close): (Span, Span),
-    children: &Vec<TokenNode>,
-    span: Span,
-    context: &ExpandContext,
-    shapes: &mut Vec<Spanned<FlatShape>>,
-) {
-    shapes.push(FlatShape::OpenDelimiter(Delimiter::Square).spanned(open));
-    let mut tokens = TokensIterator::new(&children, span, context.source.clone(), false);
-    let _list = color_syntax(&ExpressionListShape, &mut tokens, context, shapes);
-    shapes.push(FlatShape::CloseDelimiter(Delimiter::Square).spanned(close));
-}
-
-#[cfg(coloring_in_tokens)]
 pub fn color_delimited_square(
     (open, close): (Span, Span),
     token_nodes: &mut TokensIterator,
@@ -50,24 +34,6 @@ pub fn color_delimited_square(
 #[derive(Debug, Copy, Clone)]
 pub struct DelimitedShape;
 
-#[cfg(not(coloring_in_tokens))]
-impl ColorSyntax for DelimitedShape {
-    type Info = ();
-    type Input = (Delimiter, Span, Span);
-    fn color_syntax<'a, 'b>(
-        &self,
-        (delimiter, open, close): &(Delimiter, Span, Span),
-        token_nodes: &'b mut TokensIterator<'a>,
-        context: &ExpandContext,
-        shapes: &mut Vec<Spanned<FlatShape>>,
-    ) -> Self::Info {
-        shapes.push(FlatShape::OpenDelimiter(*delimiter).spanned(*open));
-        color_syntax(&ExpressionListShape, token_nodes, context, shapes);
-        shapes.push(FlatShape::CloseDelimiter(*delimiter).spanned(*close));
-    }
-}
-
-#[cfg(coloring_in_tokens)]
 impl ColorSyntax for DelimitedShape {
     type Info = ();
     type Input = (Delimiter, Span, Span);

crates/nu-parser/src/hir/syntax_shape/expression/file_path.rs

@@ -1,56 +1,16 @@
-use crate::parser::hir::syntax_shape::expression::atom::{
+use crate::hir::syntax_shape::expression::atom::{
     expand_atom, ExpansionRule, UnspannedAtomicToken,
 };
-use crate::parser::hir::syntax_shape::{
+use crate::hir::syntax_shape::{
     expression::expand_file_path, ExpandContext, ExpandExpression, FallibleColorSyntax, FlatShape,
-    ParseError,
 };
-use crate::parser::{hir, hir::TokensIterator};
-use crate::prelude::*;
+use crate::{hir, hir::TokensIterator};
+use nu_errors::{ParseError, ShellError};
+use nu_source::SpannedItem;
 
 #[derive(Debug, Copy, Clone)]
 pub struct FilePathShape;
 
-#[cfg(not(coloring_in_tokens))]
-impl FallibleColorSyntax for FilePathShape {
-    type Info = ();
-    type Input = ();
-
-    fn color_syntax<'a, 'b>(
-        &self,
-        _input: &(),
-        token_nodes: &'b mut TokensIterator<'a>,
-        context: &ExpandContext,
-        shapes: &mut Vec<nu_source::Spanned<FlatShape>>,
-    ) -> Result<(), ShellError> {
-        let atom = expand_atom(
-            token_nodes,
-            "file path",
-            context,
-            ExpansionRule::permissive(),
-        );
-
-        let atom = match atom {
-            Err(_) => return Ok(()),
-            Ok(atom) => atom,
-        };
-
-        match &atom.unspanned {
-            UnspannedAtomicToken::Word { .. }
-            | UnspannedAtomicToken::String { .. }
-            | UnspannedAtomicToken::Number { .. }
-            | UnspannedAtomicToken::Size { .. } => {
-                shapes.push(FlatShape::Path.spanned(atom.span));
-            }
-
-            _ => atom.color_tokens(shapes),
-        }
-
-        Ok(())
-    }
-}
-
-#[cfg(coloring_in_tokens)]
 impl FallibleColorSyntax for FilePathShape {
     type Info = ();
     type Input = ();
@@ -102,20 +62,27 @@ impl ExpandExpression for FilePathShape {
         token_nodes: &mut TokensIterator<'_>,
         context: &ExpandContext,
     ) -> Result<hir::Expression, ParseError> {
-        let atom = expand_atom(token_nodes, "file path", context, ExpansionRule::new())?;
+        let atom = expand_atom(
+            token_nodes,
+            "file path",
+            context,
+            ExpansionRule::new().allow_external_word(),
+        )?;
 
         match atom.unspanned {
-            UnspannedAtomicToken::Word { text: body } | UnspannedAtomicToken::String { body } => {
+            UnspannedAtomicToken::Word { text: body }
+            | UnspannedAtomicToken::ExternalWord { text: body }
+            | UnspannedAtomicToken::String { body } => {
                 let path = expand_file_path(body.slice(context.source), context);
-                return Ok(hir::Expression::file_path(path, atom.span));
+                Ok(hir::Expression::file_path(path, atom.span))
             }
 
             UnspannedAtomicToken::Number { .. } | UnspannedAtomicToken::Size { .. } => {
                 let path = atom.span.slice(context.source);
-                return Ok(hir::Expression::file_path(path, atom.span));
+                Ok(hir::Expression::file_path(path, atom.span))
             }
 
-            _ => return atom.into_hir(context, "file path"),
+            _ => atom.to_hir(context, "file path"),
         }
     }
 }

crates/nu-parser/src/hir/syntax_shape/expression/list.rs

@@ -1,7 +1,4 @@
-use crate::errors::ParseError;
-#[cfg(not(coloring_in_tokens))]
-use crate::parser::hir::syntax_shape::FlatShape;
-use crate::parser::{
+use crate::{
     hir,
     hir::syntax_shape::{
         color_fallible_syntax, color_syntax, expand_atom, expand_expr, maybe_spaced, spaced,
@@ -10,6 +7,7 @@ use crate::parser::{
     },
     hir::TokensIterator,
 };
+use nu_errors::ParseError;
 use nu_source::{b, DebugDocBuilder, HasSpan, PrettyDebugWithSource, Span, Spanned, SpannedItem};
 
 #[derive(Debug, Clone)]
@@ -76,77 +74,6 @@ impl ExpandSyntax for ExpressionListShape {
     }
 }
 
-#[cfg(not(coloring_in_tokens))]
-impl ColorSyntax for ExpressionListShape {
-    type Info = ();
-    type Input = ();
-
-    /// The intent of this method is to fully color an expression list shape infallibly.
-    /// This means that if we can't expand a token into an expression, we fall back to
-    /// a simpler coloring strategy.
-    ///
-    /// This would apply to something like `where x >`, which includes an incomplete
-    /// binary operator. Since we will fail to process it as a binary operator, we'll
-    /// fall back to a simpler coloring and move on.
-    fn color_syntax<'a, 'b>(
-        &self,
-        _input: &(),
-        token_nodes: &'b mut TokensIterator<'a>,
-        context: &ExpandContext,
-        shapes: &mut Vec<Spanned<FlatShape>>,
-    ) {
-        // We encountered a parsing error and will continue with simpler coloring ("backoff
-        // coloring mode")
-        let mut backoff = false;
-
-        // Consume any leading whitespace
-        color_syntax(&MaybeSpaceShape, token_nodes, context, shapes);
-
-        loop {
-            // If we reached the very end of the token stream, we're done
-            if token_nodes.at_end() {
-                return;
-            }
-
-            if backoff {
-                let len = shapes.len();
-
-                // If we previously encountered a parsing error, use backoff coloring mode
-                color_syntax(&SimplestExpression, token_nodes, context, shapes);
-
-                if len == shapes.len() && !token_nodes.at_end() {
-                    // This should never happen, but if it does, a panic is better than an infinite loop
-                    panic!("Unexpected tokens left that couldn't be colored even with SimplestExpression")
-                }
-            } else {
-                // Try to color the head of the stream as an expression
-                match color_fallible_syntax(&AnyExpressionShape, token_nodes, context, shapes) {
-                    // If no expression was found, switch to backoff coloring mode
-                    Err(_) => {
-                        backoff = true;
-                        continue;
-                    }
-                    Ok(_) => {}
-                }
-
-                // If an expression was found, consume a space
-                match color_fallible_syntax(&SpaceShape, token_nodes, context, shapes) {
-                    Err(_) => {
-                        // If no space was found, we're either at the end or there's an error.
-                        // Either way, switch to backoff coloring mode. If we're at the end
-                        // it won't have any consequences.
-                        backoff = true;
-                    }
-                    Ok(_) => {
-                        // Otherwise, move on to the next expression
-                    }
-                }
-            }
-        }
-    }
-}
-
-#[cfg(coloring_in_tokens)]
 impl ColorSyntax for ExpressionListShape {
     type Info = ();
     type Input = ();
@@ -193,27 +120,21 @@ impl ColorSyntax for ExpressionListShape {
                 }
             } else {
                 // Try to color the head of the stream as an expression
-                match color_fallible_syntax(&AnyExpressionShape, token_nodes, context) {
+                if color_fallible_syntax(&AnyExpressionShape, token_nodes, context).is_err() {
                     // If no expression was found, switch to backoff coloring mode
-                    Err(_) => {
-                        backoff = true;
-                        continue;
-                    }
-                    Ok(_) => {}
+
+                    backoff = true;
+                    continue;
                 }
 
                 // If an expression was found, consume a space
-                match color_fallible_syntax(&SpaceShape, token_nodes, context) {
-                    Err(_) => {
-                        // If no space was found, we're either at the end or there's an error.
-                        // Either way, switch to backoff coloring mode. If we're at the end
-                        // it won't have any consequences.
-                        backoff = true;
-                    }
-                    Ok(_) => {
-                        // Otherwise, move on to the next expression
-                    }
+                if color_fallible_syntax(&SpaceShape, token_nodes, context).is_err() {
+                    // If no space was found, we're either at the end or there's an error.
+                    // Either way, switch to backoff coloring mode. If we're at the end
+                    // it won't have any consequences.
+                    backoff = true;
                 }
+                // Otherwise, move on to the next expression
             }
         }
     }
@@ -223,35 +144,6 @@ impl ColorSyntax for ExpressionListShape {
 #[derive(Debug, Copy, Clone)]
 pub struct BackoffColoringMode;
 
-#[cfg(not(coloring_in_tokens))]
-impl ColorSyntax for BackoffColoringMode {
-    type Info = ();
-    type Input = ();
-
-    fn color_syntax<'a, 'b>(
-        &self,
-        _input: &Self::Input,
-        token_nodes: &'b mut TokensIterator<'a>,
-        context: &ExpandContext,
-        shapes: &mut Vec<Spanned<FlatShape>>,
-    ) -> Self::Info {
-        loop {
-            if token_nodes.at_end() {
-                break;
-            }
-
-            let len = shapes.len();
-            color_syntax(&SimplestExpression, token_nodes, context, shapes);
-
-            if len == shapes.len() && !token_nodes.at_end() {
-                // This shouldn't happen, but if it does, a panic is better than an infinite loop
-                panic!("SimplestExpression failed to consume any tokens, but it's not at the end. This is unexpected\n== token nodes==\n{:#?}\n\n== shapes ==\n{:#?}", token_nodes, shapes);
-            }
-        }
-    }
-}
-
-#[cfg(coloring_in_tokens)]
 impl ColorSyntax for BackoffColoringMode {
     type Info = ();
     type Input = ();
@@ -288,33 +180,6 @@ impl ColorSyntax for BackoffColoringMode {
 #[derive(Debug, Copy, Clone)]
 pub struct SimplestExpression;
 
-#[cfg(not(coloring_in_tokens))]
-impl ColorSyntax for SimplestExpression {
-    type Info = ();
-    type Input = ();
-
-    fn color_syntax<'a, 'b>(
-        &self,
-        _input: &(),
-        token_nodes: &'b mut TokensIterator<'a>,
-        context: &ExpandContext,
-        shapes: &mut Vec<Spanned<FlatShape>>,
-    ) {
-        let atom = expand_atom(
-            token_nodes,
-            "any token",
-            context,
-            ExpansionRule::permissive(),
-        );
-
-        match atom {
-            Err(_) => {}
-            Ok(atom) => atom.color_tokens(shapes),
-        }
-    }
-}
-
-#[cfg(coloring_in_tokens)]
 impl ColorSyntax for SimplestExpression {
     type Info = ();
     type Input = ();

crates/nu-parser/src/hir/syntax_shape/expression/number.rs

@@ -1,15 +1,15 @@
-use crate::parser::hir::syntax_shape::{
+use crate::hir::syntax_shape::{
     expand_atom, parse_single_node, ExpandContext, ExpandExpression, ExpansionRule,
-    FallibleColorSyntax, FlatShape, ParseError, TestSyntax,
+    FallibleColorSyntax, FlatShape, TestSyntax,
 };
-use crate::parser::hir::tokens_iterator::Peeked;
-use crate::parser::{
+use crate::hir::tokens_iterator::Peeked;
+use crate::parse::tokens::UnspannedToken;
+use crate::{
     hir,
     hir::{RawNumber, TokensIterator},
-    UnspannedToken,
 };
-use crate::prelude::*;
-use nu_source::Spanned;
+use nu_errors::{ParseError, ShellError};
+use nu_source::{Spanned, SpannedItem};
 
 #[derive(Debug, Copy, Clone)]
 pub struct NumberShape;
@@ -26,9 +26,9 @@ impl ExpandExpression for NumberShape {
     ) -> Result<hir::Expression, ParseError> {
         parse_single_node(token_nodes, "Number", |token, token_span, err| {
             Ok(match token {
-                UnspannedToken::GlobPattern | UnspannedToken::Operator(..) => {
-                    return Err(err.error())
-                }
+                UnspannedToken::GlobPattern
+                | UnspannedToken::CompareOperator(..)
+                | UnspannedToken::EvaluationOperator(..) => return Err(err.error()),
                 UnspannedToken::Variable(tag) if tag.slice(context.source) == "it" => {
                     hir::Expression::it_variable(tag, token_span)
                 }
@@ -52,37 +52,6 @@ impl ExpandExpression for NumberShape {
     }
 }
 
-#[cfg(not(coloring_in_tokens))]
-impl FallibleColorSyntax for NumberShape {
-    type Info = ();
-    type Input = ();
-
-    fn color_syntax<'a, 'b>(
-        &self,
-        _input: &(),
-        token_nodes: &'b mut TokensIterator<'a>,
-        context: &ExpandContext,
-        shapes: &mut Vec<Spanned<FlatShape>>,
-    ) -> Result<(), ShellError> {
-        let atom = token_nodes.spanned(|token_nodes| {
-            expand_atom(token_nodes, "number", context, ExpansionRule::permissive())
-        });
-
-        let atom = match atom {
-            Spanned { item: Err(_), span } => {
-                shapes.push(FlatShape::Error.spanned(span));
-                return Ok(());
-            }
-            Spanned { item: Ok(atom), .. } => atom,
-        };
-
-        atom.color_tokens(shapes);
-
-        Ok(())
-    }
-}
-
-#[cfg(coloring_in_tokens)]
 impl FallibleColorSyntax for NumberShape {
     type Info = ();
     type Input = ();
@@ -131,7 +100,8 @@ impl ExpandExpression for IntShape {
         parse_single_node(token_nodes, "Integer", |token, token_span, err| {
             Ok(match token {
                 UnspannedToken::GlobPattern
-                | UnspannedToken::Operator(..)
+                | UnspannedToken::CompareOperator(..)
+                | UnspannedToken::EvaluationOperator(..)
                 | UnspannedToken::ExternalWord => return Err(err.error()),
                 UnspannedToken::Variable(span) if span.slice(context.source) == "it" => {
                     hir::Expression::it_variable(span, token_span)
@@ -151,37 +121,6 @@ impl ExpandExpression for IntShape {
     }
 }
 
-#[cfg(not(coloring_in_tokens))]
-impl FallibleColorSyntax for IntShape {
-    type Info = ();
-    type Input = ();
-
-    fn color_syntax<'a, 'b>(
-        &self,
-        _input: &(),
-        token_nodes: &'b mut TokensIterator<'a>,
-        context: &ExpandContext,
-        shapes: &mut Vec<Spanned<FlatShape>>,
-    ) -> Result<(), ShellError> {
-        let atom = token_nodes.spanned(|token_nodes| {
-            expand_atom(token_nodes, "integer", context, ExpansionRule::permissive())
-        });
-
-        let atom = match atom {
-            Spanned { item: Err(_), span } => {
-                shapes.push(FlatShape::Error.spanned(span));
-                return Ok(());
-            }
-            Spanned { item: Ok(atom), .. } => atom,
-        };
-
-        atom.color_tokens(shapes);
-
-        Ok(())
-    }
-}
-
-#[cfg(coloring_in_tokens)]
 impl FallibleColorSyntax for IntShape {
     type Info = ();
     type Input = ();

crates/nu-parser/src/hir/syntax_shape/expression/pattern.rs

@@ -1,44 +1,18 @@
-use crate::parser::hir::syntax_shape::{
+use crate::hir::syntax_shape::{
     expand_atom, expand_bare, expression::expand_file_path, ExpandContext, ExpandExpression,
-    ExpandSyntax, ExpansionRule, FallibleColorSyntax, FlatShape, ParseError, UnspannedAtomicToken,
+    ExpandSyntax, ExpansionRule, FallibleColorSyntax, FlatShape, UnspannedAtomicToken,
 };
-use crate::parser::parse::tokens::Token;
-use crate::parser::{hir, hir::TokensIterator, Operator, TokenNode, UnspannedToken};
-use crate::prelude::*;
-#[cfg(not(coloring_in_tokens))]
-use nu_source::Spanned;
+use crate::parse::operator::EvaluationOperator;
+use crate::parse::tokens::{Token, UnspannedToken};
+use crate::{hir, hir::TokensIterator, TokenNode};
+use nu_errors::{ParseError, ShellError};
+
+use nu_protocol::ShellTypeName;
+use nu_source::{Span, SpannedItem};
 
 #[derive(Debug, Copy, Clone)]
 pub struct PatternShape;
 
-#[cfg(not(coloring_in_tokens))]
-impl FallibleColorSyntax for PatternShape {
-    type Info = ();
-    type Input = ();
-
-    fn color_syntax<'a, 'b>(
-        &self,
-        _input: &(),
-        token_nodes: &'b mut TokensIterator<'a>,
-        context: &ExpandContext,
-        shapes: &mut Vec<Spanned<FlatShape>>,
-    ) -> Result<(), ShellError> {
-        token_nodes.atomic(|token_nodes| {
-            let atom = expand_atom(token_nodes, "pattern", context, ExpansionRule::permissive())?;
-
-            match &atom.unspanned {
-                UnspannedAtomicToken::GlobPattern { .. } | UnspannedAtomicToken::Word { .. } => {
-                    shapes.push(FlatShape::GlobPattern.spanned(atom.span));
-                    Ok(())
-                }
-
-                _ => Err(ShellError::type_error("pattern", atom.spanned_type_name())),
-            }
-        })
-    }
-}
-
-#[cfg(coloring_in_tokens)]
 impl FallibleColorSyntax for PatternShape {
     type Info = ();
     type Input = ();
@@ -81,16 +55,22 @@ impl ExpandExpression for PatternShape {
         token_nodes: &mut TokensIterator<'_>,
         context: &ExpandContext,
     ) -> Result<hir::Expression, ParseError> {
-        let atom = expand_atom(token_nodes, "pattern", context, ExpansionRule::new())?;
+        let atom = expand_atom(
+            token_nodes,
+            "pattern",
+            context,
+            ExpansionRule::new().allow_external_word(),
+        )?;
 
         match atom.unspanned {
             UnspannedAtomicToken::Word { text: body }
             | UnspannedAtomicToken::String { body }
+            | UnspannedAtomicToken::ExternalWord { text: body }
             | UnspannedAtomicToken::GlobPattern { pattern: body } => {
                 let path = expand_file_path(body.slice(context.source), context);
-                return Ok(hir::Expression::pattern(path.to_string_lossy(), atom.span));
+                Ok(hir::Expression::pattern(path.to_string_lossy(), atom.span))
             }
-            _ => return atom.into_hir(context, "pattern"),
+            _ => atom.to_hir(context, "pattern"),
         }
     }
 }
@@ -116,7 +96,7 @@ impl ExpandSyntax for BarePatternShape {
                 ..
             })
             | TokenNode::Token(Token {
-                unspanned: UnspannedToken::Operator(Operator::Dot),
+                unspanned: UnspannedToken::EvaluationOperator(EvaluationOperator::Dot),
                 ..
             })
             | TokenNode::Token(Token {

crates/nu-parser/src/hir/syntax_shape/expression/range.rs

@@ -0,0 +1,103 @@
+use crate::hir::syntax_shape::expression::UnspannedAtomicToken;
+use crate::hir::syntax_shape::{
+    color_fallible_syntax, expand_atom, expand_expr, AnyExpressionShape, ExpandContext,
+    ExpandExpression, ExpansionRule, FallibleColorSyntax, FlatShape,
+};
+use crate::parse::operator::EvaluationOperator;
+use crate::parse::token_tree::TokenNode;
+use crate::parse::tokens::{Token, UnspannedToken};
+use crate::{hir, hir::TokensIterator};
+use nu_errors::{ParseError, ShellError};
+use nu_protocol::SpannedTypeName;
+use nu_source::SpannedItem;
+
+#[derive(Debug, Copy, Clone)]
+pub struct RangeShape;
+
+impl ExpandExpression for RangeShape {
+    fn name(&self) -> &'static str {
+        "range"
+    }
+
+    fn expand_expr<'a, 'b>(
+        &self,
+        token_nodes: &'b mut TokensIterator<'a>,
+        context: &ExpandContext,
+    ) -> Result<hir::Expression, ParseError> {
+        token_nodes.atomic_parse(|token_nodes| {
+            let left = expand_expr(&AnyExpressionShape, token_nodes, context)?;
+
+            let atom = expand_atom(
+                token_nodes,
+                "..",
+                context,
+                ExpansionRule::new().allow_eval_operator(),
+            )?;
+
+            let span = match atom.unspanned {
+                UnspannedAtomicToken::DotDot { text } => text,
+                _ => return Err(ParseError::mismatch("..", atom.spanned_type_name())),
+            };
+
+            let right = expand_expr(&AnyExpressionShape, token_nodes, context)?;
+
+            Ok(hir::Expression::range(left, span, right))
+        })
+    }
+}
+
+impl FallibleColorSyntax for RangeShape {
+    type Info = ();
+    type Input = ();
+
+    fn name(&self) -> &'static str {
+        "RangeShape"
+    }
+
+    fn color_syntax<'a, 'b>(
+        &self,
+        _input: &(),
+        token_nodes: &'b mut TokensIterator<'a>,
+        context: &ExpandContext,
+    ) -> Result<(), ShellError> {
+        token_nodes.atomic_parse(|token_nodes| {
+            color_fallible_syntax(&AnyExpressionShape, token_nodes, context)?;
+            color_fallible_syntax(&DotDotShape, token_nodes, context)?;
+            color_fallible_syntax(&AnyExpressionShape, token_nodes, context)
+        })?;
+
+        Ok(())
+    }
+}
+
+#[derive(Debug, Copy, Clone)]
+struct DotDotShape;
+
+impl FallibleColorSyntax for DotDotShape {
+    type Info = ();
+    type Input = ();
+
+    fn name(&self) -> &'static str {
+        ".."
+    }
+
+    fn color_syntax<'a, 'b>(
+        &self,
+        _input: &Self::Input,
+        token_nodes: &'b mut TokensIterator<'a>,
+        _context: &ExpandContext,
+    ) -> Result<Self::Info, ShellError> {
+        let peeked = token_nodes.peek_any().not_eof("..")?;
+        match &peeked.node {
+            TokenNode::Token(Token {
+                unspanned: UnspannedToken::EvaluationOperator(EvaluationOperator::DotDot),
+                span,
+            }) => {
+                peeked.commit();
+                token_nodes.color_shape(FlatShape::DotDot.spanned(span));
+                Ok(())
+            }
+            token => Err(ShellError::type_error("..", token.spanned_type_name())),
+        }
+    }
+}

crates/nu-parser/src/hir/syntax_shape/expression/string.rs

@@ -1,48 +1,16 @@
-use crate::parser::hir::syntax_shape::{
+use crate::hir::syntax_shape::{
     expand_atom, expand_variable, parse_single_node, AtomicToken, ExpandContext, ExpandExpression,
-    ExpansionRule, FallibleColorSyntax, FlatShape, ParseError, TestSyntax, UnspannedAtomicToken,
+    ExpansionRule, FallibleColorSyntax, FlatShape, TestSyntax, UnspannedAtomicToken,
 };
-use crate::parser::hir::tokens_iterator::Peeked;
-use crate::parser::{hir, hir::TokensIterator, UnspannedToken};
-use crate::prelude::*;
-#[cfg(not(coloring_in_tokens))]
-use nu_source::Spanned;
+use crate::hir::tokens_iterator::Peeked;
+use crate::parse::tokens::UnspannedToken;
+use crate::{hir, hir::TokensIterator};
+use nu_errors::{ParseError, ShellError};
+use nu_source::SpannedItem;
 
 #[derive(Debug, Copy, Clone)]
 pub struct StringShape;
 
-#[cfg(not(coloring_in_tokens))]
-impl FallibleColorSyntax for StringShape {
-    type Info = ();
-    type Input = FlatShape;
-
-    fn color_syntax<'a, 'b>(
-        &self,
-        input: &FlatShape,
-        token_nodes: &'b mut TokensIterator<'a>,
-        context: &ExpandContext,
-        shapes: &mut Vec<Spanned<FlatShape>>,
-    ) -> Result<(), ShellError> {
-        let atom = expand_atom(token_nodes, "string", context, ExpansionRule::permissive());
-
-        let atom = match atom {
-            Err(_) => return Ok(()),
-            Ok(atom) => atom,
-        };
-
-        match atom {
-            AtomicToken {
-                unspanned: UnspannedAtomicToken::String { .. },
-                span,
-            } => shapes.push((*input).spanned(span)),
-            other => other.color_tokens(shapes),
-        }
-
-        Ok(())
-    }
-}
-
-#[cfg(coloring_in_tokens)]
 impl FallibleColorSyntax for StringShape {
     type Info = ();
     type Input = FlatShape;
@@ -89,7 +57,8 @@ impl ExpandExpression for StringShape {
         parse_single_node(token_nodes, "String", |token, token_span, err| {
             Ok(match token {
                 UnspannedToken::GlobPattern
-                | UnspannedToken::Operator(..)
+                | UnspannedToken::CompareOperator(..)
+                | UnspannedToken::EvaluationOperator(..)
                 | UnspannedToken::ExternalWord => return Err(err.error()),
                 UnspannedToken::Variable(span) => {
                     expand_variable(span, token_span, &context.source)

crates/nu-parser/src/hir/syntax_shape/expression/unit.rs

@@ -1,15 +1,16 @@
-use crate::parser::hir::syntax_shape::{ExpandContext, ExpandSyntax, ParseError};
-use crate::parser::parse::tokens::RawNumber;
-use crate::parser::parse::tokens::Token;
-use crate::parser::parse::unit::Unit;
-use crate::parser::{hir::TokensIterator, TokenNode, UnspannedToken};
-use crate::prelude::*;
+use crate::hir::syntax_shape::{ExpandContext, ExpandSyntax};
+use crate::parse::tokens::RawNumber;
+use crate::parse::tokens::Token;
+use crate::parse::tokens::UnspannedToken;
+use crate::parse::unit::Unit;
+use crate::{hir::TokensIterator, TokenNode};
 use nom::branch::alt;
 use nom::bytes::complete::tag;
 use nom::character::complete::digit1;
 use nom::combinator::{all_consuming, opt, value};
 use nom::IResult;
-use nu_source::{Span, Spanned};
+use nu_errors::ParseError;
+use nu_source::{b, DebugDocBuilder, HasSpan, PrettyDebugWithSource, Span, Spanned, SpannedItem};
 
 #[derive(Debug, Clone)]
 pub struct UnitSyntax {

crates/nu-parser/src/hir/syntax_shape/expression/variable_path.rs

@@ -1,16 +1,19 @@
-use crate::parser::hir::path::PathMember;
-use crate::parser::hir::syntax_shape::{
+use crate::hir::syntax_shape::{
     color_fallible_syntax, color_fallible_syntax_with, expand_atom, expand_expr, expand_syntax,
     parse_single_node, AnyExpressionShape, BareShape, ExpandContext, ExpandExpression,
     ExpandSyntax, ExpansionRule, FallibleColorSyntax, FlatShape, ParseError, Peeked, SkipSyntax,
     StringShape, TestSyntax, UnspannedAtomicToken, WhitespaceShape,
 };
-use crate::parser::{
-    hir, hir::Expression, hir::TokensIterator, Operator, RawNumber, UnspannedToken,
+use crate::parse::tokens::{RawNumber, UnspannedToken};
+use crate::{hir, hir::Expression, hir::TokensIterator, CompareOperator, EvaluationOperator};
+use nu_errors::ShellError;
+use nu_protocol::{PathMember, ShellTypeName};
+use nu_source::{
+    b, DebugDocBuilder, HasSpan, PrettyDebug, PrettyDebugWithSource, Span, Spanned, SpannedItem,
+    Tag, Tagged, TaggedItem, Text,
 };
-use crate::prelude::*;
-use nu_source::{Spanned, Tagged};
-use serde::Serialize;
+use num_bigint::BigInt;
+use serde::{Deserialize, Serialize};
 use std::str::FromStr;
 
 #[derive(Debug, Copy, Clone)]
@@ -38,9 +41,8 @@ impl ExpandExpression for VariablePathShape {
         let mut tail: Vec<PathMember> = vec![];
 
         loop {
-            match DotShape.skip(token_nodes, context) {
-                Err(_) => break,
-                Ok(_) => {}
+            if DotShape.skip(token_nodes, context).is_err() {
+                break;
             }
 
             let member = expand_syntax(&MemberShape, token_nodes, context)?;
@@ -54,48 +56,6 @@ impl ExpandExpression for VariablePathShape {
     }
 }
 
-#[cfg(not(coloring_in_tokens))]
-impl FallibleColorSyntax for VariablePathShape {
-    type Info = ();
-    type Input = ();
-
-    fn color_syntax<'a, 'b>(
-        &self,
-        _input: &(),
-        token_nodes: &'b mut TokensIterator<'a>,
-        context: &ExpandContext,
-        shapes: &mut Vec<Spanned<FlatShape>>,
-    ) -> Result<(), ShellError> {
-        token_nodes.atomic(|token_nodes| {
-            // If the head of the token stream is not a variable, fail
-            color_fallible_syntax(&VariableShape, token_nodes, context, shapes)?;
-
-            loop {
-                // look for a dot at the head of a stream
-                let dot = color_fallible_syntax_with(
-                    &ColorableDotShape,
-                    &FlatShape::Dot,
-                    token_nodes,
-                    context,
-                    shapes,
-                );
-
-                // if there's no dot, we're done
-                match dot {
-                    Err(_) => break,
-                    Ok(_) => {}
-                }
-
-                // otherwise, look for a member, and if you don't find one, fail
-                color_fallible_syntax(&MemberShape, token_nodes, context, shapes)?;
-            }
-
-            Ok(())
-        })
-    }
-}
-
-#[cfg(coloring_in_tokens)]
 impl FallibleColorSyntax for VariablePathShape {
     type Info = ();
     type Input = ();
@@ -116,17 +76,16 @@ impl FallibleColorSyntax for VariablePathShape {
 
             loop {
                 // look for a dot at the head of a stream
-                let dot = color_fallible_syntax_with(
+                if color_fallible_syntax_with(
                     &ColorableDotShape,
                     &FlatShape::Dot,
                     token_nodes,
                     context,
-                );
-
-                // if there's no dot, we're done
-                match dot {
-                    Err(_) => break,
-                    Ok(_) => {}
+                )
+                .is_err()
+                {
+                    // if there's no dot, we're done
+                    break;
                 }
 
                 // otherwise, look for a member, and if you don't find one, fail
@@ -141,40 +100,6 @@ impl FallibleColorSyntax for VariablePathShape {
 #[derive(Debug, Copy, Clone)]
 pub struct PathTailShape;
 
-#[cfg(not(coloring_in_tokens))]
-/// The failure mode of `PathTailShape` is a dot followed by a non-member
-impl FallibleColorSyntax for PathTailShape {
-    type Info = ();
-    type Input = ();
-
-    fn color_syntax<'a, 'b>(
-        &self,
-        _input: &(),
-        token_nodes: &'b mut TokensIterator<'a>,
-        context: &ExpandContext,
-        shapes: &mut Vec<Spanned<FlatShape>>,
-    ) -> Result<(), ShellError> {
-        token_nodes.atomic(|token_nodes| loop {
-            let result = color_fallible_syntax_with(
-                &ColorableDotShape,
-                &FlatShape::Dot,
-                token_nodes,
-                context,
-                shapes,
-            );
-
-            match result {
-                Err(_) => return Ok(()),
-                Ok(_) => {}
-            }
-
-            // If we've seen a dot but not a member, fail
-            color_fallible_syntax(&MemberShape, token_nodes, context, shapes)?;
-        })
-    }
-}
-
-#[cfg(coloring_in_tokens)]
 /// The failure mode of `PathTailShape` is a dot followed by a non-member
 impl FallibleColorSyntax for PathTailShape {
     type Info = ();
@@ -198,9 +123,8 @@ impl FallibleColorSyntax for PathTailShape {
                 context,
             );
 
-            match result {
-                Err(_) => return Ok(()),
-                Ok(_) => {}
+            if result.is_err() {
+                return Ok(());
             }
 
             // If we've seen a dot but not a member, fail
@@ -243,9 +167,8 @@ impl ExpandSyntax for PathTailShape {
         let mut tail: Vec<PathMember> = vec![];
 
         loop {
-            match DotShape.skip(token_nodes, context) {
-                Err(_) => break,
-                Ok(_) => {}
+            if DotShape.skip(token_nodes, context).is_err() {
+                break;
             }
 
             let member = expand_syntax(&MemberShape, token_nodes, context)?;
@@ -268,7 +191,7 @@ impl ExpandSyntax for PathTailShape {
 #[derive(Debug, Clone)]
 pub enum ExpressionContinuation {
     DotSuffix(Span, PathMember),
-    InfixSuffix(Spanned<Operator>, Expression),
+    InfixSuffix(Spanned<CompareOperator>, Expression),
 }
 
 impl PrettyDebugWithSource for ExpressionContinuation {
@@ -339,60 +262,6 @@ pub enum ContinuationInfo {
     Infix,
 }
 
-#[cfg(not(coloring_in_tokens))]
-impl FallibleColorSyntax for ExpressionContinuationShape {
-    type Info = ContinuationInfo;
-    type Input = ();
-
-    fn color_syntax<'a, 'b>(
-        &self,
-        _input: &(),
-        token_nodes: &'b mut TokensIterator<'a>,
-        context: &ExpandContext,
-        shapes: &mut Vec<Spanned<FlatShape>>,
-    ) -> Result<ContinuationInfo, ShellError> {
-        token_nodes.atomic(|token_nodes| {
-            // Try to expand a `.`
-            let dot = color_fallible_syntax_with(
-                &ColorableDotShape,
-                &FlatShape::Dot,
-                token_nodes,
-                context,
-                shapes,
-            );
-
-            match dot {
-                Ok(_) => {
-                    // we found a dot, so let's keep looking for a member; if no member was found, fail
-                    color_fallible_syntax(&MemberShape, token_nodes, context, shapes)?;
-
-                    Ok(ContinuationInfo::Dot)
-                }
-                Err(_) => {
-                    let mut new_shapes = vec![];
-                    let result = token_nodes.atomic(|token_nodes| {
-                        // we didn't find a dot, so let's see if we're looking at an infix. If not found, fail
-                        color_fallible_syntax(&InfixShape, token_nodes, context, &mut new_shapes)?;
-
-                        // now that we've seen an infix shape, look for any expression. If not found, fail
-                        color_fallible_syntax(
-                            &AnyExpressionShape,
-                            token_nodes,
-                            context,
-                            &mut new_shapes,
-                        )?;
-
-                        Ok(ContinuationInfo::Infix)
-                    })?;
-                    shapes.extend(new_shapes);
-                    Ok(result)
-                }
-            }
-        })
-    }
-}
-
-#[cfg(coloring_in_tokens)]
 impl FallibleColorSyntax for ExpressionContinuationShape {
     type Info = ContinuationInfo;
     type Input = ();
@@ -469,45 +338,6 @@ impl ExpandExpression for VariableShape {
     }
 }
 
-#[cfg(not(coloring_in_tokens))]
-impl FallibleColorSyntax for VariableShape {
-    type Info = ();
-    type Input = ();
-
-    fn color_syntax<'a, 'b>(
-        &self,
-        _input: &(),
-        token_nodes: &'b mut TokensIterator<'a>,
-        context: &ExpandContext,
-        shapes: &mut Vec<Spanned<FlatShape>>,
-    ) -> Result<(), ShellError> {
-        let atom = expand_atom(
-            token_nodes,
-            "variable",
-            context,
-            ExpansionRule::permissive(),
-        );
-
-        let atom = match atom {
-            Err(err) => return Err(err.into()),
-            Ok(atom) => atom,
-        };
-
-        match &atom.unspanned {
-            UnspannedAtomicToken::Variable { .. } => {
-                shapes.push(FlatShape::Variable.spanned(atom.span));
-                Ok(())
-            }
-            UnspannedAtomicToken::ItVariable { .. } => {
-                shapes.push(FlatShape::ItVariable.spanned(atom.span));
-                Ok(())
-            }
-            _ => Err(ShellError::type_error("variable", atom.spanned_type_name())),
-        }
-    }
-}
-
-#[cfg(coloring_in_tokens)]
 impl FallibleColorSyntax for VariableShape {
     type Info = ();
     type Input = ();
@@ -705,57 +535,6 @@ pub fn expand_column_path<'a, 'b>(
 #[derive(Debug, Copy, Clone)]
 pub struct ColumnPathShape;
 
-#[cfg(not(coloring_in_tokens))]
-impl FallibleColorSyntax for ColumnPathShape {
-    type Info = ();
-    type Input = ();
-
-    fn color_syntax<'a, 'b>(
-        &self,
-        _input: &(),
-        token_nodes: &'b mut TokensIterator<'a>,
-        context: &ExpandContext,
-        shapes: &mut Vec<Spanned<FlatShape>>,
-    ) -> Result<(), ShellError> {
-        // If there's not even one member shape, fail
-        color_fallible_syntax(&MemberShape, token_nodes, context, shapes)?;
-
-        loop {
-            let checkpoint = token_nodes.checkpoint();
-
-            match color_fallible_syntax_with(
-                &ColorableDotShape,
-                &FlatShape::Dot,
-                checkpoint.iterator,
-                context,
-                shapes,
-            ) {
-                Err(_) => {
-                    // we already saw at least one member shape, so return successfully
-                    return Ok(());
-                }
-
-                Ok(_) => {
-                    match color_fallible_syntax(&MemberShape, checkpoint.iterator, context, shapes)
-                    {
-                        Err(_) => {
-                            // we saw a dot but not a member (but we saw at least one member),
-                            // so don't commit the dot but return successfully
-                            return Ok(());
-                        }
-
-                        Ok(_) => {
-                            // we saw a dot and a member, so commit it and continue on
-                            checkpoint.commit();
-                        }
-                    }
-                }
-            }
-        }
-    }
-}
-
-#[cfg(coloring_in_tokens)]
 impl FallibleColorSyntax for ColumnPathShape {
     type Info = ();
     type Input = ();
@@ -849,45 +628,6 @@ impl ExpandSyntax for ColumnPathShape {
 #[derive(Debug, Copy, Clone)]
 pub struct MemberShape;
 
-#[cfg(not(coloring_in_tokens))]
-impl FallibleColorSyntax for MemberShape {
-    type Info = ();
-    type Input = ();
-
-    fn color_syntax<'a, 'b>(
-        &self,
-        _input: &(),
-        token_nodes: &'b mut TokensIterator<'a>,
-        context: &ExpandContext,
-        shapes: &mut Vec<Spanned<FlatShape>>,
-    ) -> Result<(), ShellError> {
-        let bare = color_fallible_syntax_with(
-            &BareShape,
-            &FlatShape::BareMember,
-            token_nodes,
-            context,
-            shapes,
-        );
-
-        match bare {
-            Ok(_) => return Ok(()),
-            Err(_) => {
-                // If we don't have a bare word, we'll look for a string
-            }
-        }
-
-        // Look for a string token. If we don't find one, fail
-        color_fallible_syntax_with(
-            &StringShape,
-            &FlatShape::StringMember,
-            token_nodes,
-            context,
-            shapes,
-        )
-    }
-}
-
-#[cfg(coloring_in_tokens)]
 impl FallibleColorSyntax for MemberShape {
     type Info = ();
     type Input = ();
@@ -905,13 +645,12 @@ impl FallibleColorSyntax for MemberShape {
         let bare =
             color_fallible_syntax_with(&BareShape, &FlatShape::BareMember, token_nodes, context);
 
-        match bare {
-            Ok(_) => return Ok(()),
-            Err(_) => {
-                // If we don't have a bare word, we'll look for a string
-            }
+        if bare.is_ok() {
+            return Ok(());
         }
 
+        // If we don't have a bare word, we'll look for a string
+
         // Look for a string token. If we don't find one, fail
         color_fallible_syntax_with(&StringShape, &FlatShape::StringMember, token_nodes, context)
     }
@@ -944,7 +683,11 @@ impl ExpandSyntax for IntMemberShape {
                 UnspannedAtomicToken::Number {
                     number: RawNumber::Int(int),
                 } => Ok(Member::Int(
-                    BigInt::from_str(int.slice(context.source)).unwrap(),
+                    BigInt::from_str(int.slice(context.source)).map_err(|_| {
+                        ParseError::internal_error(
+                            "can't convert from string to big int".spanned(int),
+                        )
+                    })?,
                     int,
                 )),
 
@@ -952,7 +695,7 @@ impl ExpandSyntax for IntMemberShape {
                     let int = BigInt::from_str(text.slice(context.source));
 
                     match int {
-                        Ok(int) => return Ok(Member::Int(int, text)),
+                        Ok(int) => Ok(Member::Int(int, text)),
                         Err(_) => Err(ParseError::mismatch("integer member", "word".spanned(text))),
                     }
                 }
@@ -993,7 +736,9 @@ impl ExpandSyntax for MemberShape {
 
         if let Some(peeked) = number {
             let node = peeked.not_eof("column")?.commit();
-            let (n, span) = node.as_number().unwrap();
+            let (n, span) = node.as_number().ok_or_else(|| {
+                ParseError::internal_error("can't convert node to number".spanned(node.span()))
+            })?;
 
             return Ok(Member::Number(n, span))
         }*/
@@ -1002,7 +747,9 @@ impl ExpandSyntax for MemberShape {
 
         if let Some(peeked) = string {
             let node = peeked.not_eof("column")?.commit();
-            let (outer, inner) = node.as_string().unwrap();
+            let (outer, inner) = node.as_string().ok_or_else(|| {
+                ParseError::internal_error("can't convert node to string".spanned(node.span()))
+            })?;
 
             return Ok(Member::String(outer, inner));
         }
@@ -1017,33 +764,6 @@ pub struct DotShape;
 #[derive(Debug, Copy, Clone)]
 pub struct ColorableDotShape;
 
-#[cfg(not(coloring_in_tokens))]
-impl FallibleColorSyntax for ColorableDotShape {
-    type Info = ();
-    type Input = FlatShape;
-
-    fn color_syntax<'a, 'b>(
-        &self,
-        input: &FlatShape,
-        token_nodes: &'b mut TokensIterator<'a>,
-        _context: &ExpandContext,
-        shapes: &mut Vec<Spanned<FlatShape>>,
-    ) -> Result<(), ShellError> {
-        let peeked = token_nodes.peek_any().not_eof("dot")?;
-
-        match peeked.node {
-            node if node.is_dot() => {
-                peeked.commit();
-                shapes.push((*input).spanned(node.span()));
-                Ok(())
-            }
-
-            other => Err(ShellError::type_error("dot", other.spanned_type_name())),
-        }
-    }
-}
-
-#[cfg(coloring_in_tokens)]
 impl FallibleColorSyntax for ColorableDotShape {
     type Info = ();
     type Input = FlatShape;
@@ -1101,7 +821,7 @@ impl ExpandSyntax for DotShape {
     ) -> Result<Self::Output, ParseError> {
         parse_single_node(token_nodes, "dot", |token, token_span, _| {
             Ok(match token {
-                UnspannedToken::Operator(Operator::Dot) => token_span,
+                UnspannedToken::EvaluationOperator(EvaluationOperator::Dot) => token_span,
                 _ => {
                     return Err(ParseError::mismatch(
                         "dot",
@@ -1116,52 +836,6 @@ impl ExpandSyntax for DotShape {
 #[derive(Debug, Copy, Clone)]
 pub struct InfixShape;
 
-#[cfg(not(coloring_in_tokens))]
-impl FallibleColorSyntax for InfixShape {
-    type Info = ();
-    type Input = ();
-
-    fn color_syntax<'a, 'b>(
-        &self,
-        _input: &(),
-        token_nodes: &'b mut TokensIterator<'a>,
-        context: &ExpandContext,
-        outer_shapes: &mut Vec<Spanned<FlatShape>>,
-    ) -> Result<(), ShellError> {
-        let checkpoint = token_nodes.checkpoint();
-        let mut shapes = vec![];
-
-        // An infix operator must be prefixed by whitespace. If no whitespace was found, fail
-        color_fallible_syntax(&WhitespaceShape, checkpoint.iterator, context, &mut shapes)?;
-
-        // Parse the next TokenNode after the whitespace
-        parse_single_node(
-            checkpoint.iterator,
-            "infix operator",
-            |token, token_span, err| {
-                match token {
-                    // If it's an operator (and not `.`), it's a match
-                    UnspannedToken::Operator(operator) if operator != Operator::Dot => {
-                        shapes.push(FlatShape::Operator.spanned(token_span));
-                        Ok(())
-                    }
-
-                    // Otherwise, it's not a match
-                    _ => Err(err.error()),
-                }
-            },
-        )?;
-
-        // An infix operator must be followed by whitespace. If no whitespace was found, fail
-        color_fallible_syntax(&WhitespaceShape, checkpoint.iterator, context, &mut shapes)?;
-
-        outer_shapes.extend(shapes);
-        checkpoint.commit();
-        Ok(())
-    }
-}
-
-#[cfg(coloring_in_tokens)]
 impl FallibleColorSyntax for InfixShape {
     type Info = ();
     type Input = ();
@@ -1188,9 +862,7 @@ impl FallibleColorSyntax for InfixShape {
             |token, token_span, _| {
                 match token {
                     // If it's an operator (and not `.`), it's a match
-                    UnspannedToken::Operator(operator) if operator != Operator::Dot => {
-                        Ok(token_span)
-                    }
+                    UnspannedToken::CompareOperator(_operator) => Ok(token_span),
 
                     // Otherwise, it's not a match
                     _ => Err(ParseError::mismatch(
@@ -1203,7 +875,7 @@ impl FallibleColorSyntax for InfixShape {
 
         checkpoint
             .iterator
-            .color_shape(FlatShape::Operator.spanned(operator_span));
+            .color_shape(FlatShape::CompareOperator.spanned(operator_span));
 
         // An infix operator must be followed by whitespace. If no whitespace was found, fail
         color_fallible_syntax(&WhitespaceShape, checkpoint.iterator, context)?;
@@ -1263,7 +935,7 @@ impl ExpandSyntax for InfixShape {
 
 #[derive(Debug, Clone)]
 pub struct InfixInnerSyntax {
-    pub operator: Spanned<Operator>,
+    pub operator: Spanned<CompareOperator>,
 }
 
 impl HasSpan for InfixInnerSyntax {
@@ -1295,12 +967,10 @@ impl ExpandSyntax for InfixInnerShape {
     ) -> Result<Self::Output, ParseError> {
         parse_single_node(token_nodes, "infix operator", |token, token_span, err| {
             Ok(match token {
-                // If it's an operator (and not `.`), it's a match
-                UnspannedToken::Operator(operator) if operator != Operator::Dot => {
-                    InfixInnerSyntax {
-                        operator: operator.spanned(token_span),
-                    }
-                }
+                // If it's a comparison operator, it's a match
+                UnspannedToken::CompareOperator(operator) => InfixInnerSyntax {
+                    operator: operator.spanned(token_span),
+                },
 
                 // Otherwise, it's not a match
                 _ => return Err(err.error()),

crates/nu-parser/src/hir/syntax_shape/flat_shape.rs

@@ -1,4 +1,7 @@
-use crate::parser::{Delimiter, Flag, FlagKind, Operator, RawNumber, TokenNode, UnspannedToken};
+use crate::parse::flag::{Flag, FlagKind};
+use crate::parse::operator::EvaluationOperator;
+use crate::parse::token_tree::{Delimiter, TokenNode};
+use crate::parse::tokens::{RawNumber, UnspannedToken};
 use nu_source::{HasSpan, Span, Spanned, SpannedItem, Text};
 
 #[derive(Debug, Copy, Clone)]
@@ -7,8 +10,9 @@ pub enum FlatShape {
     CloseDelimiter(Delimiter),
     ItVariable,
     Variable,
-    Operator,
+    CompareOperator,
     Dot,
+    DotDot,
     InternalCommand,
     ExternalCommand,
     ExternalWord,
@@ -24,12 +28,14 @@ pub enum FlatShape {
     Int,
     Decimal,
     Whitespace,
+    Separator,
     Error,
+    Comment,
     Size { number: Span, unit: Span },
 }
 
 impl FlatShape {
-    pub fn from(token: &TokenNode, source: &Text, shapes: &mut Vec<Spanned<FlatShape>>) -> () {
+    pub fn from(token: &TokenNode, source: &Text, shapes: &mut Vec<Spanned<FlatShape>>) {
         match token {
             TokenNode::Token(token) => match token.unspanned {
                 UnspannedToken::Number(RawNumber::Int(_)) => {
@@ -38,10 +44,15 @@ impl FlatShape {
                 UnspannedToken::Number(RawNumber::Decimal(_)) => {
                     shapes.push(FlatShape::Decimal.spanned(token.span))
                 }
-                UnspannedToken::Operator(Operator::Dot) => {
+                UnspannedToken::EvaluationOperator(EvaluationOperator::Dot) => {
                     shapes.push(FlatShape::Dot.spanned(token.span))
                 }
-                UnspannedToken::Operator(_) => shapes.push(FlatShape::Operator.spanned(token.span)),
+                UnspannedToken::EvaluationOperator(EvaluationOperator::DotDot) => {
+                    shapes.push(FlatShape::DotDot.spanned(token.span))
+                }
+                UnspannedToken::CompareOperator(_) => {
+                    shapes.push(FlatShape::CompareOperator.spanned(token.span))
+                }
                 UnspannedToken::String(_) => shapes.push(FlatShape::String.spanned(token.span)),
                 UnspannedToken::Variable(v) if v.slice(source) == "it" => {
                     shapes.push(FlatShape::ItVariable.spanned(token.span))
@@ -73,7 +84,7 @@ impl FlatShape {
             }
             TokenNode::Pipeline(pipeline) => {
                 for part in &pipeline.parts {
-                    if let Some(_) = part.pipe {
+                    if part.pipe.is_some() {
                         shapes.push(FlatShape::Pipe.spanned(part.span()));
                     }
                 }
@@ -89,6 +100,8 @@ impl FlatShape {
                 ..
             }) => shapes.push(FlatShape::ShorthandFlag.spanned(*span)),
             TokenNode::Whitespace(_) => shapes.push(FlatShape::Whitespace.spanned(token.span())),
+            TokenNode::Separator(_) => shapes.push(FlatShape::Separator.spanned(token.span())),
+            TokenNode::Comment(_) => shapes.push(FlatShape::Comment.spanned(token.span())),
             TokenNode::Error(v) => shapes.push(FlatShape::Error.spanned(v.span)),
         }
     }

crates/nu-parser/src/hir/tokens_iterator.rs

@@ -1,38 +1,24 @@
 pub(crate) mod debug;
 
 use self::debug::{ColorTracer, ExpandTracer};
-use crate::errors::ShellError;
-#[cfg(coloring_in_tokens)]
-use crate::parser::hir::syntax_shape::FlatShape;
-use crate::parser::hir::Expression;
-use crate::parser::TokenNode;
-use crate::prelude::*;
-#[allow(unused)]
-use getset::{Getters, MutGetters};
-use nu_source::Spanned;
 
-cfg_if::cfg_if! {
-    if #[cfg(coloring_in_tokens)] {
-        #[derive(Getters, Debug)]
-        pub struct TokensIteratorState<'content> {
-            tokens: &'content [TokenNode],
-            span: Span,
-            skip_ws: bool,
-            index: usize,
-            seen: indexmap::IndexSet<usize>,
-            #[get = "pub"]
-            shapes: Vec<Spanned<FlatShape>>,
-        }
-    } else {
-        #[derive(Getters, Debug)]
-        pub struct TokensIteratorState<'content> {
-            tokens: &'content [TokenNode],
-            span: Span,
-            skip_ws: bool,
-            index: usize,
-            seen: indexmap::IndexSet<usize>,
-        }
-    }
+use crate::hir::syntax_shape::FlatShape;
+use crate::hir::Expression;
+use crate::TokenNode;
+use getset::{Getters, MutGetters};
+use nu_errors::{ParseError, ShellError};
+use nu_protocol::SpannedTypeName;
+use nu_source::{HasFallibleSpan, HasSpan, Span, Spanned, SpannedItem, Tag, Text};
+
+#[derive(Getters, Debug)]
+pub struct TokensIteratorState<'content> {
+    tokens: &'content [TokenNode],
+    span: Span,
+    skip_ws: bool,
+    index: usize,
+    seen: indexmap::IndexSet<usize>,
+    #[get = "pub"]
+    shapes: Vec<Spanned<FlatShape>>,
 }
 
 #[derive(Getters, MutGetters, Debug)]
@@ -53,7 +39,7 @@ pub struct Checkpoint<'content, 'me> {
     pub(crate) iterator: &'me mut TokensIterator<'content>,
     index: usize,
     seen: indexmap::IndexSet<usize>,
-    #[cfg(coloring_in_tokens)]
+
     shape_start: usize,
     committed: bool,
 }
@@ -71,7 +57,7 @@ impl<'content, 'me> std::ops::Drop for Checkpoint<'content, 'me> {
 
             state.index = self.index;
             state.seen = self.seen.clone();
-            #[cfg(coloring_in_tokens)]
+
             state.shapes.truncate(self.shape_start);
         }
     }
@@ -81,8 +67,8 @@ impl<'content, 'me> std::ops::Drop for Checkpoint<'content, 'me> {
 pub struct Peeked<'content, 'me> {
     pub(crate) node: Option<&'content TokenNode>,
     iterator: &'me mut TokensIterator<'content>,
-    from: usize,
-    to: usize,
+    pub from: usize,
+    pub to: usize,
 }
 
 impl<'content, 'me> Peeked<'content, 'me> {
@@ -115,7 +101,7 @@ impl<'content, 'me> Peeked<'content, 'me> {
     }
 
     pub fn type_error(&self, expected: &'static str) -> ParseError {
-        peek_error(&self.node, self.iterator.eof_span(), expected)
+        peek_error(self.node, self.iterator.eof_span(), expected)
     }
 }
 
@@ -143,14 +129,14 @@ impl<'content, 'me> PeekedNode<'content, 'me> {
     pub fn rollback(self) {}
 
     pub fn type_error(&self, expected: &'static str) -> ParseError {
-        peek_error(&Some(self.node), self.iterator.eof_span(), expected)
+        peek_error(Some(self.node), self.iterator.eof_span(), expected)
     }
 }
 
-pub fn peek_error(node: &Option<&TokenNode>, eof_span: Span, expected: &'static str) -> ParseError {
+pub fn peek_error(node: Option<&TokenNode>, eof_span: Span, expected: &'static str) -> ParseError {
     match node {
         None => ParseError::unexpected_eof(expected, eof_span),
-        Some(node) => ParseError::mismatch(expected, node.type_name().spanned(node.span())),
+        Some(node) => ParseError::mismatch(expected, node.spanned_type_name()),
     }
 }
 
@@ -161,34 +147,17 @@ impl<'content> TokensIterator<'content> {
         source: Text,
         skip_ws: bool,
     ) -> TokensIterator<'content> {
-        cfg_if::cfg_if! {
-            if #[cfg(coloring_in_tokens)] {
-                TokensIterator {
-                    state: TokensIteratorState {
-                        tokens: items,
-                        span,
-                        skip_ws,
-                        index: 0,
-                        seen: indexmap::IndexSet::new(),
-                        shapes: vec![],
-                    },
-                    color_tracer: ColorTracer::new(source.clone()),
-                    expand_tracer: ExpandTracer::new(source.clone()),
-                }
-            } else {
-                TokensIterator {
-                    state: TokensIteratorState {
-                        tokens: items,
-                        span,
-                        skip_ws,
-                        index: 0,
-                        seen: indexmap::IndexSet::new(),
-                    },
-                    color_tracer: ColorTracer::new(source.clone()),
-                    expand_tracer: ExpandTracer::new(source.clone()),
-                }
-            }
-
+        TokensIterator {
+            state: TokensIteratorState {
+                tokens: items,
+                span,
+                skip_ws,
+                index: 0,
+                seen: indexmap::IndexSet::new(),
+                shapes: vec![],
+            },
+            color_tracer: ColorTracer::new(source.clone()),
+            expand_tracer: ExpandTracer::new(source),
         }
     }
 
@@ -204,6 +173,10 @@ impl<'content> TokensIterator<'content> {
         self.state.tokens.len()
     }
 
+    pub fn is_empty(&self) -> bool {
+        self.len() == 0
+    }
+
     pub fn spanned<T>(
         &mut self,
         block: impl FnOnce(&mut TokensIterator<'content>) -> T,
@@ -217,13 +190,11 @@ impl<'content> TokensIterator<'content> {
         result.spanned(start.until(end))
     }
 
-    #[cfg(coloring_in_tokens)]
     pub fn color_shape(&mut self, shape: Spanned<FlatShape>) {
         self.with_color_tracer(|_, tracer| tracer.add_shape(shape));
         self.state.shapes.push(shape);
     }
 
-    #[cfg(coloring_in_tokens)]
     pub fn mutate_shapes(&mut self, block: impl FnOnce(&mut Vec<Spanned<FlatShape>>)) {
         let new_shapes: Vec<Spanned<FlatShape>> = {
             let shapes = &mut self.state.shapes;
@@ -239,13 +210,11 @@ impl<'content> TokensIterator<'content> {
         });
     }
 
-    #[cfg(coloring_in_tokens)]
     pub fn silently_mutate_shapes(&mut self, block: impl FnOnce(&mut Vec<Spanned<FlatShape>>)) {
         let shapes = &mut self.state.shapes;
         block(shapes);
     }
 
-    #[cfg(coloring_in_tokens)]
     pub fn sort_shapes(&mut self) {
         // This is pretty dubious, but it works. We should look into a better algorithm that doesn't end up requiring
         // this solution.
@@ -255,7 +224,6 @@ impl<'content> TokensIterator<'content> {
             .sort_by(|a, b| a.span.start().cmp(&b.span.start()));
     }
 
-    #[cfg(coloring_in_tokens)]
     pub fn child<'me, T>(
         &'me mut self,
         tokens: Spanned<&'me [TokenNode]>,
@@ -268,58 +236,7 @@ impl<'content> TokensIterator<'content> {
         let mut color_tracer = ColorTracer::new(source.clone());
         std::mem::swap(&mut color_tracer, &mut self.color_tracer);
 
-        let mut expand_tracer = ExpandTracer::new(source.clone());
-        std::mem::swap(&mut expand_tracer, &mut self.expand_tracer);
-
-        cfg_if::cfg_if! {
-            if #[cfg(coloring_in_tokens)] {
-                let mut iterator = TokensIterator {
-                    state: TokensIteratorState {
-                        tokens: tokens.item,
-                        span: tokens.span,
-                        skip_ws: false,
-                        index: 0,
-                        seen: indexmap::IndexSet::new(),
-                        shapes,
-                    },
-                    color_tracer,
-                    expand_tracer,
-                };
-            } else {
-                let mut iterator = TokensIterator {
-                    state: TokensIteratorState {
-                        tokens: tokens.item,
-                        span: tokens.span,
-                        skip_ws: false,
-                        index: 0,
-                        seen: indexmap::IndexSet::new(),
-                    },
-                    color_tracer,
-                    expand_tracer,
-                };
-            }
-        }
-
-        let result = block(&mut iterator);
-
-        std::mem::swap(&mut iterator.state.shapes, &mut self.state.shapes);
-        std::mem::swap(&mut iterator.color_tracer, &mut self.color_tracer);
-        std::mem::swap(&mut iterator.expand_tracer, &mut self.expand_tracer);
-
-        result
-    }
-
-    #[cfg(not(coloring_in_tokens))]
-    pub fn child<'me, T>(
-        &'me mut self,
-        tokens: Spanned<&'me [TokenNode]>,
-        source: Text,
-        block: impl FnOnce(&mut TokensIterator<'me>) -> T,
-    ) -> T {
-        let mut color_tracer = ColorTracer::new(source.clone());
-        std::mem::swap(&mut color_tracer, &mut self.color_tracer);
-
-        let mut expand_tracer = ExpandTracer::new(source.clone());
+        let mut expand_tracer = ExpandTracer::new(source);
         std::mem::swap(&mut expand_tracer, &mut self.expand_tracer);
 
         let mut iterator = TokensIterator {
@@ -329,6 +246,7 @@ impl<'content> TokensIterator<'content> {
                 skip_ws: false,
                 index: 0,
                 seen: indexmap::IndexSet::new(),
+                shapes,
             },
             color_tracer,
             expand_tracer,
@@ -336,6 +254,7 @@ impl<'content> TokensIterator<'content> {
 
         let result = block(&mut iterator);
 
+        std::mem::swap(&mut iterator.state.shapes, &mut self.state.shapes);
         std::mem::swap(&mut iterator.color_tracer, &mut self.color_tracer);
         std::mem::swap(&mut iterator.expand_tracer, &mut self.expand_tracer);
 
@@ -362,7 +281,6 @@ impl<'content> TokensIterator<'content> {
         block(state, tracer)
     }
 
-    #[cfg(coloring_in_tokens)]
     pub fn color_frame<T>(
         &mut self,
         desc: &'static str,
@@ -455,7 +373,7 @@ impl<'content> TokensIterator<'content> {
         let state = &mut self.state;
 
         let index = state.index;
-        #[cfg(coloring_in_tokens)]
+
         let shape_start = state.shapes.len();
         let seen = state.seen.clone();
 
@@ -464,7 +382,7 @@ impl<'content> TokensIterator<'content> {
             index,
             seen,
             committed: false,
-            #[cfg(coloring_in_tokens)]
+
             shape_start,
         }
     }
@@ -478,7 +396,7 @@ impl<'content> TokensIterator<'content> {
         let state = &mut self.state;
 
         let index = state.index;
-        #[cfg(coloring_in_tokens)]
+
         let shape_start = state.shapes.len();
         let seen = state.seen.clone();
 
@@ -487,26 +405,26 @@ impl<'content> TokensIterator<'content> {
             index,
             seen,
             committed: false,
-            #[cfg(coloring_in_tokens)]
+
             shape_start,
         };
 
         let value = block(checkpoint.iterator)?;
 
         checkpoint.commit();
-        return Ok(value);
+        Ok(value)
     }
 
     /// Use a checkpoint when you need to peek more than one token ahead, but can't be sure
     /// that you'll succeed.
-    pub fn atomic_parse<'me, T>(
+    pub fn atomic_parse<'me, T, E>(
         &'me mut self,
-        block: impl FnOnce(&mut TokensIterator<'content>) -> Result<T, ParseError>,
-    ) -> Result<T, ParseError> {
+        block: impl FnOnce(&mut TokensIterator<'content>) -> Result<T, E>,
+    ) -> Result<T, E> {
         let state = &mut self.state;
 
         let index = state.index;
-        #[cfg(coloring_in_tokens)]
+
         let shape_start = state.shapes.len();
         let seen = state.seen.clone();
 
@@ -515,17 +433,16 @@ impl<'content> TokensIterator<'content> {
             index,
             seen,
             committed: false,
-            #[cfg(coloring_in_tokens)]
+
             shape_start,
         };
 
         let value = block(checkpoint.iterator)?;
 
         checkpoint.commit();
-        return Ok(value);
+        Ok(value)
     }
 
-    #[cfg(coloring_in_tokens)]
     /// Use a checkpoint when you need to peek more than one token ahead, but can't be sure
     /// that you'll succeed.
     pub fn atomic_returning_shapes<'me, T>(
@@ -560,7 +477,7 @@ impl<'content> TokensIterator<'content> {
 
         checkpoint.commit();
         std::mem::swap(&mut self.state.shapes, &mut shapes);
-        return (Ok(value), shapes);
+        (Ok(value), shapes)
     }
 
     fn eof_span(&self) -> Span {
@@ -641,7 +558,7 @@ impl<'content> TokensIterator<'content> {
     //             index: state.index,
     //             seen: state.seen.clone(),
     //             skip_ws: state.skip_ws,
-    //             #[cfg(coloring_in_tokens)]
+    //
     //             shapes: state.shapes.clone(),
     //         },
     //         color_tracer: self.color_tracer.clone(),
@@ -669,12 +586,12 @@ impl<'content> TokensIterator<'content> {
         let peeked = peeked.not_eof(expected);
 
         match peeked {
-            Err(err) => return Err(err),
+            Err(err) => Err(err),
             Ok(peeked) => match block(peeked.node) {
-                Err(err) => return Err(err),
+                Err(err) => Err(err),
                 Ok(val) => {
                     peeked.commit();
-                    return Ok(val);
+                    Ok(val)
                 }
             },
         }
@@ -744,10 +661,7 @@ fn peek<'content, 'me>(
     }
 }
 
-fn peek_pos<'content, 'me>(
-    iterator: &'me TokensIterator<'content>,
-    skip_ws: bool,
-) -> Option<usize> {
+fn peek_pos(iterator: &TokensIterator<'_>, skip_ws: bool) -> Option<usize> {
     let state = iterator.state();
 
     let mut to = state.index;

crates/nu-parser/src/hir/tokens_iterator/debug.rs

@@ -6,7 +6,7 @@ pub(crate) mod expand_trace;
 pub(crate) use self::color_trace::*;
 pub(crate) use self::expand_trace::*;
 
-use crate::parser::hir::tokens_iterator::TokensIteratorState;
+use crate::hir::tokens_iterator::TokensIteratorState;
 use nu_source::{PrettyDebug, PrettyDebugWithSource, Text};
 
 #[derive(Debug)]
@@ -24,13 +24,11 @@ pub(crate) fn debug_tokens(state: &TokensIteratorState, source: &str) -> Vec<Deb
             out.push(DebugIteratorToken::Cursor);
         }
 
+        let msg = token.debug(source).to_string();
         if state.seen.contains(&i) {
-            out.push(DebugIteratorToken::Seen(format!("{}", token.debug(source))));
+            out.push(DebugIteratorToken::Seen(msg));
         } else {
-            out.push(DebugIteratorToken::Unseen(format!(
-                "{}",
-                token.debug(source)
-            )));
+            out.push(DebugIteratorToken::Unseen(msg));
         }
     }
 

crates/nu-parser/src/hir/tokens_iterator/debug/color_trace.rs

@@ -1,9 +1,8 @@
-use crate::errors::ShellError;
-use crate::parser::hir::syntax_shape::FlatShape;
-use crate::prelude::*;
+use crate::hir::syntax_shape::FlatShape;
 use ansi_term::Color;
 use log::trace;
-use nu_source::Spanned;
+use nu_errors::ShellError;
+use nu_source::{Spanned, Text};
 use ptree::*;
 use std::borrow::Cow;
 use std::io;
@@ -50,7 +49,7 @@ pub struct ColorFrame {
 impl ColorFrame {
     fn colored_leaf_description(&self, f: &mut impl io::Write) -> io::Result<()> {
         if self.has_only_error_descendents() {
-            if self.children.len() == 0 {
+            if self.children.is_empty() {
                 write!(
                     f,
                     "{}",
@@ -110,14 +109,10 @@ impl ColorFrame {
 
     fn any_child_shape(&self, predicate: impl Fn(Spanned<FlatShape>) -> bool) -> bool {
         for item in &self.children {
-            match item {
-                FrameChild::Shape(shape) => {
-                    if predicate(*shape) {
-                        return true;
-                    }
+            if let FrameChild::Shape(shape) = item {
+                if predicate(*shape) {
+                    return true;
                 }
-
-                _ => {}
             }
         }
 
@@ -126,14 +121,10 @@ impl ColorFrame {
 
     fn any_child_frame(&self, predicate: impl Fn(&ColorFrame) -> bool) -> bool {
         for item in &self.children {
-            match item {
-                FrameChild::Frame(frame) => {
-                    if predicate(frame) {
-                        return true;
-                    }
+            if let FrameChild::Frame(frame) = item {
+                if predicate(frame) {
+                    return true;
                 }
-
-                _ => {}
             }
         }
 
@@ -149,7 +140,7 @@ impl ColorFrame {
     }
 
     fn has_only_error_descendents(&self) -> bool {
-        if self.children.len() == 0 {
+        if self.children.is_empty() {
             // if this frame has no children at all, it has only error descendents if this frame
             // is an error
             self.error.is_some()
@@ -260,7 +251,7 @@ impl ColorTracer {
 
         let result = self.frame_stack.pop().expect("Can't pop root tracer frame");
 
-        if self.frame_stack.len() == 0 {
+        if self.frame_stack.is_empty() {
             panic!("Can't pop root tracer frame {:#?}", self);
         }
 

crates/nu-parser/src/hir/tokens_iterator/debug/expand_trace.rs

@@ -1,8 +1,9 @@
-use crate::parser::hir::Expression;
-use crate::prelude::*;
+use crate::hir::Expression;
 use ansi_term::Color;
 use log::trace;
-use nu_source::DebugDoc;
+use nu_errors::ParseError;
+use nu_protocol::ShellTypeName;
+use nu_source::{DebugDoc, PrettyDebug, PrettyDebugWithSource, Text};
 use ptree::*;
 use std::borrow::Cow;
 use std::io;
@@ -18,7 +19,7 @@ impl FrameChild {
     fn get_error_leaf(&self) -> Option<&'static str> {
         match self {
             FrameChild::Frame(frame) if frame.error.is_some() => {
-                if frame.children.len() == 0 {
+                if frame.children.is_empty() {
                     Some(frame.description)
                 } else {
                     None
@@ -32,12 +33,12 @@ impl FrameChild {
         match self {
             FrameChild::Expr(expr) => TreeChild::OkExpr(expr.clone(), text.clone()),
             FrameChild::Result(result) => {
-                let result = format!("{}", result.display());
+                let result = result.display();
                 TreeChild::OkNonExpr(result)
             }
             FrameChild::Frame(frame) => {
                 if frame.error.is_some() {
-                    if frame.children.len() == 0 {
+                    if frame.children.is_empty() {
                         TreeChild::ErrorLeaf(vec![frame.description])
                     } else {
                         TreeChild::ErrorFrame(frame.to_tree_frame(text), text.clone())
@@ -66,7 +67,7 @@ impl ExprFrame {
             if let Some(error_leaf) = child.get_error_leaf() {
                 errors.push(error_leaf);
                 continue;
-            } else if errors.len() > 0 {
+            } else if !errors.is_empty() {
                 children.push(TreeChild::ErrorLeaf(errors));
                 errors = vec![];
             }
@@ -74,7 +75,7 @@ impl ExprFrame {
             children.push(child.to_tree_child(text));
         }
 
-        if errors.len() > 0 {
+        if !errors.is_empty() {
             children.push(TreeChild::ErrorLeaf(errors));
         }
 
@@ -114,22 +115,20 @@ impl TreeFrame {
 
             write!(f, " -> ")?;
             self.children[0].leaf_description(f)
-        } else {
-            if self.error.is_some() {
-                if self.children.len() == 0 {
-                    write!(
-                        f,
-                        "{}",
-                        Color::White.bold().on(Color::Red).paint(self.description)
-                    )
-                } else {
-                    write!(f, "{}", Color::Red.normal().paint(self.description))
-                }
-            } else if self.has_descendent_green() {
-                write!(f, "{}", Color::Green.normal().paint(self.description))
+        } else if self.error.is_some() {
+            if self.children.is_empty() {
+                write!(
+                    f,
+                    "{}",
+                    Color::White.bold().on(Color::Red).paint(self.description)
+                )
             } else {
-                write!(f, "{}", Color::Yellow.bold().paint(self.description))
+                write!(f, "{}", Color::Red.normal().paint(self.description))
             }
+        } else if self.has_descendent_green() {
+            write!(f, "{}", Color::Green.normal().paint(self.description))
+        } else {
+            write!(f, "{}", Color::Yellow.bold().paint(self.description))
         }
     }
 
@@ -142,14 +141,10 @@ impl TreeFrame {
 
     fn any_child_frame(&self, predicate: impl Fn(&TreeFrame) -> bool) -> bool {
         for item in &self.children {
-            match item {
-                TreeChild::OkFrame(frame, ..) => {
-                    if predicate(frame) {
-                        return true;
-                    }
+            if let TreeChild::OkFrame(frame, ..) = item {
+                if predicate(frame) {
+                    return true;
                 }
-
-                _ => {}
             }
         }
 
@@ -208,7 +203,7 @@ impl TreeChild {
                 Color::White
                     .bold()
                     .on(Color::Green)
-                    .paint(format!("{}", result))
+                    .paint(result.to_string())
             ),
 
             TreeChild::ErrorLeaf(desc) => {
@@ -259,12 +254,7 @@ pub struct ExpandTracer {
 
 impl ExpandTracer {
     pub fn print(&self, source: Text) -> PrintTracer {
-        let root = self
-            .frame_stack
-            .iter()
-            .nth(0)
-            .unwrap()
-            .to_tree_frame(&source);
+        let root = self.frame_stack[0].to_tree_frame(&source);
 
         PrintTracer { root, source }
     }
@@ -291,7 +281,7 @@ impl ExpandTracer {
     fn pop_frame(&mut self) -> ExprFrame {
         let result = self.frame_stack.pop().expect("Can't pop root tracer frame");
 
-        if self.frame_stack.len() == 0 {
+        if self.frame_stack.is_empty() {
             panic!("Can't pop root tracer frame");
         }
 

crates/nu-parser/src/hir/tokens_iterator/tests.rs

@@ -0,0 +1,16 @@
+use crate::hir::TokensIterator;
+use crate::parse::token_tree_builder::TokenTreeBuilder as b;
+use crate::Span;
+
+#[test]
+fn supplies_tokens() -> Result<(), Box<dyn std::error::Error>> {
+    let tokens = b::token_list(vec![b::var("it"), b::op("."), b::bare("cpu")]);
+    let (tokens, _) = b::build(tokens);
+
+    let tokens = tokens.expect_list();
+    let mut iterator = TokensIterator::all(tokens, Span::unknown());
+
+    iterator.next()?.expect_var();
+    iterator.next()?.expect_dot();
+    iterator.next()?.expect_bare();
+}

crates/nu-parser/src/lib.rs

@@ -0,0 +1,43 @@
+#![allow(clippy::large_enum_variant, clippy::type_complexity)]
+
+pub mod commands;
+pub mod hir;
+pub mod parse;
+pub mod parse_command;
+
+pub use crate::commands::classified::{
+    external::ExternalCommand, internal::InternalCommand, ClassifiedCommand, ClassifiedPipeline,
+};
+pub use crate::hir::syntax_shape::flat_shape::FlatShape;
+pub use crate::hir::syntax_shape::{
+    expand_syntax, ExpandContext, ExpandSyntax, PipelineShape, SignatureRegistry,
+};
+pub use crate::hir::tokens_iterator::TokensIterator;
+pub use crate::parse::files::Files;
+pub use crate::parse::flag::Flag;
+pub use crate::parse::operator::{CompareOperator, EvaluationOperator};
+pub use crate::parse::parser::Number;
+pub use crate::parse::parser::{module, pipeline};
+pub use crate::parse::token_tree::{Delimiter, TokenNode};
+pub use crate::parse::token_tree_builder::TokenTreeBuilder;
+
+use nu_errors::ShellError;
+use nu_source::nom_input;
+
+pub fn parse(input: &str) -> Result<TokenNode, ShellError> {
+    let _ = pretty_env_logger::try_init();
+
+    match pipeline(nom_input(input)) {
+        Ok((_rest, val)) => Ok(val),
+        Err(err) => Err(ShellError::parse_error(err)),
+    }
+}
+
+pub fn parse_script(input: &str) -> Result<TokenNode, ShellError> {
+    let _ = pretty_env_logger::try_init();
+
+    match module(nom_input(input)) {
+        Ok((_rest, val)) => Ok(val),
+        Err(err) => Err(ShellError::parse_error(err)),
+    }
+}

crates/nu-parser/src/parse.rs

@@ -1,4 +1,5 @@
 pub(crate) mod call_node;
+pub(crate) mod comment;
 pub(crate) mod files;
 pub(crate) mod flag;
 pub(crate) mod operator;

crates/nu-parser/src/parse/call_node.rs

@@ -1,6 +1,6 @@
-use crate::parser::TokenNode;
-use crate::prelude::*;
+use crate::TokenNode;
 use getset::Getters;
+use nu_source::{b, DebugDocBuilder, PrettyDebugWithSource};
 
 #[derive(Debug, Clone, Eq, PartialEq, Ord, PartialOrd, Getters)]
 pub struct CallNode {
@@ -30,7 +30,7 @@ impl PrettyDebugWithSource for CallNode {
 
 impl CallNode {
     pub fn new(head: Box<TokenNode>, children: Vec<TokenNode>) -> CallNode {
-        if children.len() == 0 {
+        if children.is_empty() {
             CallNode {
                 head,
                 children: None,

crates/nu-parser/src/parse/comment.rs

@@ -0,0 +1,42 @@
+use derive_new::new;
+use getset::Getters;
+use nu_source::{b, DebugDocBuilder, HasSpan, PrettyDebugWithSource, Span};
+use serde::{Deserialize, Serialize};
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Deserialize, Serialize)]
+pub enum CommentKind {
+    Line,
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Getters, new)]
+pub struct Comment {
+    pub(crate) kind: CommentKind,
+    pub(crate) text: Span,
+    pub(crate) span: Span,
+}
+
+impl Comment {
+    pub fn line(text: impl Into<Span>, outer: impl Into<Span>) -> Comment {
+        Comment {
+            kind: CommentKind::Line,
+            text: text.into(),
+            span: outer.into(),
+        }
+    }
+}
+
+impl PrettyDebugWithSource for Comment {
+    fn pretty_debug(&self, source: &str) -> DebugDocBuilder {
+        let prefix = match self.kind {
+            CommentKind::Line => b::description("#"),
+        };
+
+        prefix + b::description(self.text.slice(source))
+    }
+}
+
+impl HasSpan for Comment {
+    fn span(&self) -> Span {
+        self.span
+    }
+}

crates/nu-parser/src/parse/files.rs

@@ -0,0 +1,151 @@
+use derive_new::new;
+use language_reporting::{FileName, Location};
+use log::trace;
+use nu_source::Span;
+
+#[derive(new, Debug, Clone)]
+pub struct Files {
+    snippet: String,
+}
+
+impl language_reporting::ReportingFiles for Files {
+    type Span = Span;
+    type FileId = usize;
+
+    fn byte_span(
+        &self,
+        _file: Self::FileId,
+        from_index: usize,
+        to_index: usize,
+    ) -> Option<Self::Span> {
+        Some(Span::new(from_index, to_index))
+    }
+
+    fn file_id(&self, _tag: Self::Span) -> Self::FileId {
+        0
+    }
+
+    fn file_name(&self, _file: Self::FileId) -> FileName {
+        FileName::Verbatim("shell".to_string())
+    }
+
+    fn byte_index(&self, _file: Self::FileId, _line: usize, _column: usize) -> Option<usize> {
+        unimplemented!("byte_index")
+    }
+
+    fn location(&self, _file: Self::FileId, byte_index: usize) -> Option<Location> {
+        trace!("finding location for {}", byte_index);
+
+        let source = &self.snippet;
+        let mut seen_lines = 0;
+        let mut seen_bytes = 0;
+
+        for (pos, slice) in source.match_indices('\n') {
+            trace!(
+                "searching byte_index={} seen_bytes={} pos={} slice={:?} slice.len={} source={:?}",
+                byte_index,
+                seen_bytes,
+                pos,
+                slice,
+                source.len(),
+                source
+            );
+
+            if pos >= byte_index {
+                trace!(
+                    "returning {}:{} seen_lines={} byte_index={} pos={} seen_bytes={}",
+                    seen_lines,
+                    byte_index,
+                    pos,
+                    seen_lines,
+                    byte_index,
+                    seen_bytes
+                );
+
+                return Some(language_reporting::Location::new(
+                    seen_lines,
+                    byte_index - pos,
+                ));
+            } else {
+                seen_lines += 1;
+                seen_bytes = pos;
+            }
+        }
+
+        if seen_lines == 0 {
+            trace!("seen_lines=0 end={}", source.len() - 1);
+
+            // if we got here, there were no newlines in the source
+            Some(language_reporting::Location::new(0, source.len() - 1))
+        } else {
+            trace!(
+                "last line seen_lines={} end={}",
+                seen_lines,
+                source.len() - 1 - byte_index
+            );
+
+            // if we got here and we didn't return, it should mean that we're talking about
+            // the last line
+            Some(language_reporting::Location::new(
+                seen_lines,
+                source.len() - 1 - byte_index,
+            ))
+        }
+    }
+
+    fn line_span(&self, _file: Self::FileId, lineno: usize) -> Option<Self::Span> {
+        trace!("finding line_span for {}", lineno);
+
+        let source = &self.snippet;
+        let mut seen_lines = 0;
+        let mut seen_bytes = 0;
+
+        for (pos, _) in source.match_indices('\n') {
+            trace!(
+                "lineno={} seen_lines={} seen_bytes={} pos={}",
+                lineno,
+                seen_lines,
+                seen_bytes,
+                pos
+            );
+
+            if seen_lines == lineno {
+                trace!("returning start={} end={}", seen_bytes, pos);
+                // If the number of seen lines is the lineno, seen_bytes is the start of the
+                // line and pos is the end of the line
+                return Some(Span::new(seen_bytes, pos));
+            } else {
+                // If it's not, increment seen_lines, and move seen_bytes to the beginning of
+                // the next line
+                seen_lines += 1;
+                seen_bytes = pos + 1;
+            }
+        }
+
+        if seen_lines == 0 {
+            trace!("returning start={} end={}", 0, self.snippet.len() - 1);
+
+            // if we got here, there were no newlines in the source
+            Some(Span::new(0, self.snippet.len() - 1))
+        } else {
+            trace!(
+                "returning start={} end={}",
+                seen_bytes,
+                self.snippet.len() - 1
+            );
+
+            // if we got here and we didn't return, it should mean that we're talking about
+            // the last line
+            Some(Span::new(seen_bytes, self.snippet.len() - 1))
+        }
+    }
+
+    fn source(&self, span: Self::Span) -> Option<String> {
+        trace!("source(tag={:?}) snippet={:?}", span, self.snippet);
+
+        if span.start() > span.end() || span.end() > self.snippet.len() {
+            return None;
+        }
+        Some(span.slice(&self.snippet).to_string())
+    }
+}

crates/nu-parser/src/parse/flag.rs

@@ -1,8 +1,7 @@
-use crate::parser::hir::syntax_shape::flat_shape::FlatShape;
-use crate::prelude::*;
+use crate::hir::syntax_shape::flat_shape::FlatShape;
 use derive_new::new;
 use getset::Getters;
-use nu_source::{Span, Spanned, SpannedItem};
+use nu_source::{b, DebugDocBuilder, PrettyDebugWithSource, Span, Spanned, SpannedItem};
 use serde::{Deserialize, Serialize};
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Deserialize, Serialize)]

crates/nu-parser/src/parse/operator.rs

@@ -0,0 +1,114 @@
+use nu_source::{b, DebugDocBuilder, PrettyDebug};
+use serde::{Deserialize, Serialize};
+
+use std::str::FromStr;
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Deserialize, Serialize)]
+pub enum CompareOperator {
+    Equal,
+    NotEqual,
+    LessThan,
+    GreaterThan,
+    LessThanOrEqual,
+    GreaterThanOrEqual,
+    Contains,
+    NotContains,
+}
+
+impl PrettyDebug for CompareOperator {
+    fn pretty(&self) -> DebugDocBuilder {
+        b::operator(self.as_str())
+    }
+}
+
+impl CompareOperator {
+    pub fn print(self) -> String {
+        self.as_str().to_string()
+    }
+
+    pub fn as_str(self) -> &'static str {
+        match self {
+            CompareOperator::Equal => "==",
+            CompareOperator::NotEqual => "!=",
+            CompareOperator::LessThan => "<",
+            CompareOperator::GreaterThan => ">",
+            CompareOperator::LessThanOrEqual => "<=",
+            CompareOperator::GreaterThanOrEqual => ">=",
+            CompareOperator::Contains => "=~",
+            CompareOperator::NotContains => "!~",
+        }
+    }
+}
+
+impl From<&str> for CompareOperator {
+    fn from(input: &str) -> CompareOperator {
+        if let Ok(output) = CompareOperator::from_str(input) {
+            output
+        } else {
+            unreachable!("Internal error: CompareOperator from failed")
+        }
+    }
+}
+
+impl FromStr for CompareOperator {
+    type Err = ();
+    fn from_str(input: &str) -> Result<Self, <Self as std::str::FromStr>::Err> {
+        match input {
+            "==" => Ok(CompareOperator::Equal),
+            "!=" => Ok(CompareOperator::NotEqual),
+            "<" => Ok(CompareOperator::LessThan),
+            ">" => Ok(CompareOperator::GreaterThan),
+            "<=" => Ok(CompareOperator::LessThanOrEqual),
+            ">=" => Ok(CompareOperator::GreaterThanOrEqual),
+            "=~" => Ok(CompareOperator::Contains),
+            "!~" => Ok(CompareOperator::NotContains),
+            _ => Err(()),
+        }
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Deserialize, Serialize)]
+pub enum EvaluationOperator {
+    Dot,
+    DotDot,
+}
+
+impl PrettyDebug for EvaluationOperator {
+    fn pretty(&self) -> DebugDocBuilder {
+        b::operator(self.as_str())
+    }
+}
+
+impl EvaluationOperator {
+    pub fn print(self) -> String {
+        self.as_str().to_string()
+    }
+
+    pub fn as_str(self) -> &'static str {
+        match self {
+            EvaluationOperator::Dot => ".",
+            EvaluationOperator::DotDot => "..",
+        }
+    }
+}
+
+impl From<&str> for EvaluationOperator {
+    fn from(input: &str) -> EvaluationOperator {
+        if let Ok(output) = EvaluationOperator::from_str(input) {
+            output
+        } else {
+            unreachable!("Internal error: EvaluationOperator 'from' failed")
+        }
+    }
+}
+
+impl FromStr for EvaluationOperator {
+    type Err = ();
+    fn from_str(input: &str) -> Result<Self, <Self as std::str::FromStr>::Err> {
+        match input {
+            "." => Ok(EvaluationOperator::Dot),
+            ".." => Ok(EvaluationOperator::DotDot),
+            _ => Err(()),
+        }
+    }
+}

crates/nu-parser/src/parse/pipeline.rs

@@ -1,8 +1,7 @@
-use crate::parser::TokenNode;
-use crate::prelude::*;
+use crate::TokenNode;
 use derive_new::new;
 use getset::Getters;
-use nu_source::{DebugDocBuilder, PrettyDebugWithSource, Span, Spanned};
+use nu_source::{b, DebugDocBuilder, HasSpan, PrettyDebugWithSource, Span, Spanned};
 
 #[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord, Getters, new)]
 pub struct Pipeline {

crates/nu-parser/src/parse/token_tree.rs

@@ -1,10 +1,12 @@
-use crate::errors::{ParseError, ShellError};
-use crate::parser::parse::{call_node::*, flag::*, operator::*, pipeline::*, tokens::*};
-use crate::prelude::*;
+use crate::parse::{call_node::*, comment::*, flag::*, operator::*, pipeline::*, tokens::*};
 use derive_new::new;
 use getset::Getters;
-use nu_source::Spanned;
-use nu_source::{Tagged, Text};
+use nu_errors::{ParseError, ShellError};
+use nu_protocol::ShellTypeName;
+use nu_source::{
+    b, DebugDocBuilder, HasSpan, PrettyDebugWithSource, Span, Spanned, SpannedItem, Tagged,
+    TaggedItem, Text,
+};
 use std::fmt;
 
 #[derive(Debug, Clone, Eq, PartialEq, Ord, PartialOrd)]
@@ -16,7 +18,9 @@ pub enum TokenNode {
     Delimited(Spanned<DelimitedNode>),
     Pipeline(Pipeline),
     Flag(Flag),
+    Comment(Comment),
     Whitespace(Span),
+    Separator(Span),
 
     Error(Spanned<ShellError>),
 }
@@ -37,14 +41,32 @@ impl PrettyDebugWithSource for TokenNode {
                 "whitespace",
                 b::description(format!("{:?}", space.slice(source))),
             ),
+            TokenNode::Separator(span) => b::typed(
+                "separator",
+                b::description(format!("{:?}", span.slice(source))),
+            ),
+            TokenNode::Comment(comment) => {
+                b::typed("comment", b::description(comment.text.slice(source)))
+            }
             TokenNode::Error(_) => b::error("error"),
         }
     }
 }
 
-impl HasSpan for TokenNode {
-    fn span(&self) -> Span {
-        self.get_span()
+impl ShellTypeName for TokenNode {
+    fn type_name(&self) -> &'static str {
+        match self {
+            TokenNode::Token(t) => t.type_name(),
+            TokenNode::Nodes(_) => "nodes",
+            TokenNode::Call(_) => "command",
+            TokenNode::Delimited(d) => d.type_name(),
+            TokenNode::Pipeline(_) => "pipeline",
+            TokenNode::Flag(_) => "flag",
+            TokenNode::Whitespace(_) => "whitespace",
+            TokenNode::Separator(_) => "separator",
+            TokenNode::Comment(_) => "comment",
+            TokenNode::Error(_) => "error",
+        }
     }
 }
 
@@ -105,12 +127,12 @@ impl fmt::Debug for DebugTokenNode<'_> {
 
 impl From<&TokenNode> for Span {
     fn from(token: &TokenNode) -> Span {
-        token.get_span()
+        token.span()
     }
 }
 
-impl TokenNode {
-    pub fn get_span(&self) -> Span {
+impl HasSpan for TokenNode {
+    fn span(&self) -> Span {
         match self {
             TokenNode::Token(t) => t.span,
             TokenNode::Nodes(t) => t.span,
@@ -119,27 +141,14 @@ impl TokenNode {
             TokenNode::Pipeline(s) => s.span,
             TokenNode::Flag(s) => s.span,
             TokenNode::Whitespace(s) => *s,
+            TokenNode::Separator(s) => *s,
+            TokenNode::Comment(c) => c.span(),
             TokenNode::Error(s) => s.span,
         }
     }
+}
 
-    pub fn type_name(&self) -> &'static str {
-        match self {
-            TokenNode::Token(t) => t.type_name(),
-            TokenNode::Nodes(_) => "nodes",
-            TokenNode::Call(_) => "command",
-            TokenNode::Delimited(d) => d.type_name(),
-            TokenNode::Pipeline(_) => "pipeline",
-            TokenNode::Flag(_) => "flag",
-            TokenNode::Whitespace(_) => "whitespace",
-            TokenNode::Error(_) => "error",
-        }
-    }
-
-    pub fn spanned_type_name(&self) -> Spanned<&'static str> {
-        self.type_name().spanned(self.span())
-    }
-
+impl TokenNode {
     pub fn tagged_type_name(&self) -> Tagged<&'static str> {
         self.type_name().tagged(self.span())
     }
@@ -242,7 +251,7 @@ impl TokenNode {
     pub fn is_dot(&self) -> bool {
         match self {
             TokenNode::Token(Token {
-                unspanned: UnspannedToken::Operator(Operator::Dot),
+                unspanned: UnspannedToken::EvaluationOperator(EvaluationOperator::Dot),
                 ..
             }) => true,
             _ => false,
@@ -340,7 +349,7 @@ pub enum Delimiter {
 }
 
 impl Delimiter {
-    pub(crate) fn open(&self) -> &'static str {
+    pub(crate) fn open(self) -> &'static str {
         match self {
             Delimiter::Paren => "(",
             Delimiter::Brace => "{",
@@ -348,7 +357,7 @@ impl Delimiter {
         }
     }
 
-    pub(crate) fn close(&self) -> &'static str {
+    pub(crate) fn close(self) -> &'static str {
         match self {
             Delimiter::Paren => ")",
             Delimiter::Brace => "}",
@@ -419,7 +428,7 @@ impl TokenNode {
     pub fn expect_dot(&self) -> Span {
         match self {
             TokenNode::Token(Token {
-                unspanned: UnspannedToken::Operator(Operator::Dot),
+                unspanned: UnspannedToken::EvaluationOperator(EvaluationOperator::Dot),
                 span,
             }) => *span,
             other => panic!("Expected dot, found {:?}", other),

crates/nu-parser/src/parse/token_tree_builder.rs

@@ -1,24 +1,23 @@
-use crate::prelude::*;
-
-use crate::parser::parse::flag::{Flag, FlagKind};
-use crate::parser::parse::operator::Operator;
-use crate::parser::parse::pipeline::{Pipeline, PipelineElement};
-use crate::parser::parse::token_tree::{DelimitedNode, Delimiter, TokenNode};
-use crate::parser::parse::tokens::{RawNumber, UnspannedToken};
-use crate::parser::CallNode;
-use nu_source::Spanned;
+use crate::parse::call_node::CallNode;
+use crate::parse::comment::Comment;
+use crate::parse::flag::{Flag, FlagKind};
+use crate::parse::operator::{CompareOperator, EvaluationOperator};
+use crate::parse::pipeline::{Pipeline, PipelineElement};
+use crate::parse::token_tree::{DelimitedNode, Delimiter, TokenNode};
+use crate::parse::tokens::{RawNumber, UnspannedToken};
+use bigdecimal::BigDecimal;
+use nu_source::{Span, Spanned, SpannedItem};
+use num_bigint::BigInt;
 
+#[derive(Default)]
 pub struct TokenTreeBuilder {
     pos: usize,
     output: String,
 }
 
 impl TokenTreeBuilder {
-    pub fn new() -> TokenTreeBuilder {
-        TokenTreeBuilder {
-            pos: 0,
-            output: String::new(),
-        }
+    pub fn new() -> Self {
+        Default::default()
     }
 }
 
@@ -96,7 +95,7 @@ impl TokenTreeBuilder {
         TokenNode::Nodes(input.spanned(span.into()))
     }
 
-    pub fn op(input: impl Into<Operator>) -> CurriedToken {
+    pub fn op(input: impl Into<CompareOperator>) -> CurriedToken {
         let input = input.into();
 
         Box::new(move |b| {
@@ -104,12 +103,39 @@ impl TokenTreeBuilder {
 
             b.pos = end;
 
-            TokenTreeBuilder::spanned_op(input, Span::new(start, end))
+            TokenTreeBuilder::spanned_cmp_op(input, Span::new(start, end))
         })
     }
 
-    pub fn spanned_op(input: impl Into<Operator>, span: impl Into<Span>) -> TokenNode {
-        TokenNode::Token(UnspannedToken::Operator(input.into()).into_token(span))
+    pub fn spanned_cmp_op(input: impl Into<CompareOperator>, span: impl Into<Span>) -> TokenNode {
+        TokenNode::Token(UnspannedToken::CompareOperator(input.into()).into_token(span))
+    }
+
+    pub fn dot() -> CurriedToken {
+        Box::new(move |b| {
+            let (start, end) = b.consume(".");
+
+            b.pos = end;
+
+            TokenTreeBuilder::spanned_eval_op(".", Span::new(start, end))
+        })
+    }
+
+    pub fn dotdot() -> CurriedToken {
+        Box::new(move |b| {
+            let (start, end) = b.consume("..");
+
+            b.pos = end;
+
+            TokenTreeBuilder::spanned_eval_op("..", Span::new(start, end))
+        })
+    }
+
+    pub fn spanned_eval_op(
+        input: impl Into<EvaluationOperator>,
+        span: impl Into<Span>,
+    ) -> TokenNode {
+        TokenNode::Token(UnspannedToken::EvaluationOperator(input.into()).into_token(span))
     }
 
     pub fn string(input: impl Into<String>) -> CurriedToken {
@@ -291,16 +317,19 @@ impl TokenTreeBuilder {
     }
 
     pub fn spanned_call(input: Vec<TokenNode>, span: impl Into<Span>) -> Spanned<CallNode> {
-        if input.len() == 0 {
+        if input.is_empty() {
             panic!("BUG: spanned call (TODO)")
         }
 
         let mut input = input.into_iter();
 
-        let head = input.next().unwrap();
-        let tail = input.collect();
+        if let Some(head) = input.next() {
+            let tail = input.collect();
 
-        CallNode::new(Box::new(head), tail).spanned(span.into())
+            CallNode::new(Box::new(head), tail).spanned(span.into())
+        } else {
+            unreachable!("Internal error: spanned_call failed")
+        }
     }
 
     fn consume_delimiter(
@@ -398,6 +427,36 @@ impl TokenTreeBuilder {
         TokenNode::Whitespace(span.into())
     }
 
+    pub fn sep(input: impl Into<String>) -> CurriedToken {
+        let input = input.into();
+
+        Box::new(move |b| {
+            let (start, end) = b.consume(&input);
+            TokenTreeBuilder::spanned_sep(Span::new(start, end))
+        })
+    }
+
+    pub fn spanned_sep(span: impl Into<Span>) -> TokenNode {
+        TokenNode::Separator(span.into())
+    }
+
+    pub fn comment(input: impl Into<String>) -> CurriedToken {
+        let input = input.into();
+
+        Box::new(move |b| {
+            let outer_start = b.pos;
+            b.consume("#");
+            let (start, end) = b.consume(&input);
+            let outer_end = b.pos;
+
+            TokenTreeBuilder::spanned_comment((start, end), (outer_start, outer_end))
+        })
+    }
+
+    pub fn spanned_comment(input: impl Into<Span>, span: impl Into<Span>) -> TokenNode {
+        TokenNode::Comment(Comment::line(input, span))
+    }
+
     fn consume(&mut self, input: &str) -> (usize, usize) {
         let start = self.pos;
         self.pos += input.len();

crates/nu-parser/src/parse/tokens.rs

@@ -1,13 +1,20 @@
-use crate::parser::Operator;
-use crate::prelude::*;
-use nu_source::{Spanned, Text};
+use crate::parse::parser::Number;
+use crate::{CompareOperator, EvaluationOperator};
+use bigdecimal::BigDecimal;
+use nu_protocol::ShellTypeName;
+use nu_source::{
+    b, DebugDocBuilder, HasSpan, PrettyDebug, PrettyDebugWithSource, Span, Spanned, SpannedItem,
+    Text,
+};
+use num_bigint::BigInt;
 use std::fmt;
 use std::str::FromStr;
 
 #[derive(Debug, Clone, Copy, Eq, PartialEq, Ord, PartialOrd, Hash)]
 pub enum UnspannedToken {
     Number(RawNumber),
-    Operator(Operator),
+    CompareOperator(CompareOperator),
+    EvaluationOperator(EvaluationOperator),
     String(Span),
     Variable(Span),
     ExternalCommand(Span),
@@ -29,7 +36,9 @@ impl ShellTypeName for UnspannedToken {
     fn type_name(&self) -> &'static str {
         match self {
             UnspannedToken::Number(_) => "number",
-            UnspannedToken::Operator(..) => "operator",
+            UnspannedToken::CompareOperator(..) => "comparison operator",
+            UnspannedToken::EvaluationOperator(EvaluationOperator::Dot) => "dot",
+            UnspannedToken::EvaluationOperator(EvaluationOperator::DotDot) => "dotdot",
             UnspannedToken::String(_) => "string",
             UnspannedToken::Variable(_) => "variable",
             UnspannedToken::ExternalCommand(_) => "syntax error",
@@ -79,9 +88,19 @@ impl RawNumber {
 
     pub(crate) fn to_number(self, source: &Text) -> Number {
         match self {
-            RawNumber::Int(tag) => Number::Int(BigInt::from_str(tag.slice(source)).unwrap()),
+            RawNumber::Int(tag) => {
+                if let Ok(int) = BigInt::from_str(tag.slice(source)) {
+                    Number::Int(int)
+                } else {
+                    unreachable!("Internal error: to_number failed")
+                }
+            }
             RawNumber::Decimal(tag) => {
-                Number::Decimal(BigDecimal::from_str(tag.slice(source)).unwrap())
+                if let Ok(decimal) = BigDecimal::from_str(tag.slice(source)) {
+                    Number::Decimal(decimal)
+                } else {
+                    unreachable!("Internal error: to_number failed")
+                }
             }
         }
     }
@@ -105,7 +124,8 @@ impl PrettyDebugWithSource for Token {
     fn pretty_debug(&self, source: &str) -> DebugDocBuilder {
         match self.unspanned {
             UnspannedToken::Number(number) => number.pretty_debug(source),
-            UnspannedToken::Operator(operator) => operator.pretty(),
+            UnspannedToken::CompareOperator(operator) => operator.pretty(),
+            UnspannedToken::EvaluationOperator(operator) => operator.pretty(),
             UnspannedToken::String(_) => b::primitive(self.span.slice(source)),
             UnspannedToken::Variable(_) => b::var(self.span.slice(source)),
             UnspannedToken::ExternalCommand(_) => b::primitive(self.span.slice(source)),
@@ -149,9 +169,9 @@ impl Token {
         }
     }
 
-    pub fn extract_operator(&self) -> Option<Spanned<Operator>> {
+    pub fn extract_operator(&self) -> Option<Spanned<CompareOperator>> {
         match self.unspanned {
-            UnspannedToken::Operator(operator) => Some(operator.spanned(self.span)),
+            UnspannedToken::CompareOperator(operator) => Some(operator.spanned(self.span)),
             _ => None,
         }
     }

crates/nu-parser/src/parse/unit.rs

@@ -0,0 +1,127 @@
+use crate::parse::parser::Number;
+use nu_protocol::{Primitive, UntaggedValue};
+use nu_source::{b, DebugDocBuilder, PrettyDebug};
+use num_traits::ToPrimitive;
+use serde::{Deserialize, Serialize};
+
+use std::str::FromStr;
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Deserialize, Serialize)]
+pub enum Unit {
+    // Filesize units
+    Byte,
+    Kilobyte,
+    Megabyte,
+    Gigabyte,
+    Terabyte,
+    Petabyte,
+
+    // Duration units
+    Second,
+    Minute,
+    Hour,
+    Day,
+    Week,
+    Month,
+    Year,
+}
+
+impl PrettyDebug for Unit {
+    fn pretty(&self) -> DebugDocBuilder {
+        b::keyword(self.as_str())
+    }
+}
+
+fn convert_number_to_u64(number: &Number) -> u64 {
+    match number {
+        Number::Int(big_int) => {
+            if let Some(x) = big_int.to_u64() {
+                x
+            } else {
+                unreachable!("Internal error: convert_number_to_u64 given incompatible number")
+            }
+        }
+        Number::Decimal(big_decimal) => {
+            if let Some(x) = big_decimal.to_u64() {
+                x
+            } else {
+                unreachable!("Internal error: convert_number_to_u64 given incompatible number")
+            }
+        }
+    }
+}
+
+impl Unit {
+    pub fn as_str(self) -> &'static str {
+        match self {
+            Unit::Byte => "B",
+            Unit::Kilobyte => "KB",
+            Unit::Megabyte => "MB",
+            Unit::Gigabyte => "GB",
+            Unit::Terabyte => "TB",
+            Unit::Petabyte => "PB",
+            Unit::Second => "s",
+            Unit::Minute => "m",
+            Unit::Hour => "h",
+            Unit::Day => "d",
+            Unit::Week => "w",
+            Unit::Month => "M",
+            Unit::Year => "y",
+        }
+    }
+
+    pub fn compute(self, size: &Number) -> UntaggedValue {
+        let size = size.clone();
+
+        match self {
+            Unit::Byte => number(size),
+            Unit::Kilobyte => number(size * 1024),
+            Unit::Megabyte => number(size * 1024 * 1024),
+            Unit::Gigabyte => number(size * 1024 * 1024 * 1024),
+            Unit::Terabyte => number(size * 1024 * 1024 * 1024 * 1024),
+            Unit::Petabyte => number(size * 1024 * 1024 * 1024 * 1024 * 1024),
+            Unit::Second => duration(convert_number_to_u64(&size)),
+            Unit::Minute => duration(60 * convert_number_to_u64(&size)),
+            Unit::Hour => duration(60 * 60 * convert_number_to_u64(&size)),
+            Unit::Day => duration(24 * 60 * 60 * convert_number_to_u64(&size)),
+            Unit::Week => duration(7 * 24 * 60 * 60 * convert_number_to_u64(&size)),
+            Unit::Month => duration(30 * 24 * 60 * 60 * convert_number_to_u64(&size)),
+            Unit::Year => duration(365 * 24 * 60 * 60 * convert_number_to_u64(&size)),
+        }
+    }
+}
+
+fn number(number: impl Into<Number>) -> UntaggedValue {
+    let number = number.into();
+
+    match number {
+        Number::Int(int) => UntaggedValue::Primitive(Primitive::Int(int)),
+        Number::Decimal(decimal) => UntaggedValue::Primitive(Primitive::Decimal(decimal)),
+    }
+}
+
+pub fn duration(secs: u64) -> UntaggedValue {
+    UntaggedValue::Primitive(Primitive::Duration(secs))
+}
+
+impl FromStr for Unit {
+    type Err = ();
+    fn from_str(input: &str) -> Result<Self, <Self as std::str::FromStr>::Err> {
+        match input {
+            "B" | "b" => Ok(Unit::Byte),
+            "KB" | "kb" | "Kb" | "K" | "k" => Ok(Unit::Kilobyte),
+            "MB" | "mb" | "Mb" => Ok(Unit::Megabyte),
+            "GB" | "gb" | "Gb" => Ok(Unit::Gigabyte),
+            "TB" | "tb" | "Tb" => Ok(Unit::Terabyte),
+            "PB" | "pb" | "Pb" => Ok(Unit::Petabyte),
+            "s" => Ok(Unit::Second),
+            "m" => Ok(Unit::Minute),
+            "h" => Ok(Unit::Hour),
+            "d" => Ok(Unit::Day),
+            "w" => Ok(Unit::Week),
+            "M" => Ok(Unit::Month),
+            "y" => Ok(Unit::Year),
+            _ => Err(()),
+        }
+    }
+}

crates/nu-parser/src/parse_command.rs

@@ -1,17 +1,17 @@
-use crate::errors::{ArgumentError, ParseError};
-use crate::parser::hir::syntax_shape::{
+use crate::hir::syntax_shape::{
     color_fallible_syntax, color_syntax, expand_expr, flat_shape::FlatShape, spaced,
     BackoffColoringMode, ColorSyntax, MaybeSpaceShape,
 };
-use crate::parser::registry::{NamedType, PositionalType, Signature};
-use crate::parser::TokensIterator;
-use crate::parser::{
+use crate::TokensIterator;
+use crate::{
     hir::{self, ExpandContext, NamedArguments},
     Flag,
 };
 use log::trace;
-use nu_source::{PrettyDebugWithSource, Text};
-use nu_source::{Span, Spanned, SpannedItem};
+use nu_source::{PrettyDebugWithSource, Span, Spanned, SpannedItem, Text};
+
+use nu_errors::{ArgumentError, ParseError};
+use nu_protocol::{NamedType, PositionalType, Signature};
 
 pub fn parse_command_tail(
     config: &Signature,
@@ -134,7 +134,7 @@ pub fn parse_command_tail(
 
     trace!(target: "nu::parse", "Constructed positional={:?} named={:?}", positional, named);
 
-    let positional = if positional.len() == 0 {
+    let positional = if positional.is_empty() {
         None
     } else {
         Some(positional)
@@ -183,198 +183,6 @@ impl ColoringArgs {
 #[derive(Debug, Copy, Clone)]
 pub struct CommandTailShape;
 
-#[cfg(not(coloring_in_tokens))]
-impl ColorSyntax for CommandTailShape {
-    type Info = ();
-    type Input = Signature;
-
-    fn color_syntax<'a, 'b>(
-        &self,
-        signature: &Signature,
-        token_nodes: &'b mut TokensIterator<'a>,
-        context: &ExpandContext,
-        shapes: &mut Vec<Spanned<FlatShape>>,
-    ) -> Self::Info {
-        let mut args = ColoringArgs::new(token_nodes.len());
-        for (name, kind) in &signature.named {
-            trace!(target: "nu::color_syntax", "looking for {} : {:?}", name, kind);
-
-            match &kind.0 {
-                NamedType::Switch => {
-                    match token_nodes.extract(|t| t.as_flag(name, context.source())) {
-                        Some((pos, flag)) => args.insert(pos, vec![flag.color()]),
-                        None => {}
-                    }
-                }
-                NamedType::Mandatory(syntax_type) => {
-                    match extract_mandatory(
-                        signature,
-                        name,
-                        token_nodes,
-                        context.source(),
-                        Span::unknown(),
-                    ) {
-                        Err(_) => {
-                            // The mandatory flag didn't exist at all, so there's nothing to color
-                        }
-                        Ok((pos, flag)) => {
-                            let mut shapes = vec![flag.color()];
-                            token_nodes.move_to(pos);
-
-                            if token_nodes.at_end() {
-                                args.insert(pos, shapes);
-                                token_nodes.restart();
-                                continue;
-                            }
-
-                            // We can live with unmatched syntax after a mandatory flag
-                            let _ = token_nodes.atomic(|token_nodes| {
-                                color_syntax(&MaybeSpaceShape, token_nodes, context, &mut shapes);
-
-                                // If the part after a mandatory flag isn't present, that's ok, but we
-                                // should roll back any whitespace we chomped
-                                color_fallible_syntax(
-                                    syntax_type,
-                                    token_nodes,
-                                    context,
-                                    &mut shapes,
-                                )
-                            });
-
-                            args.insert(pos, shapes);
-                            token_nodes.restart();
-                        }
-                    }
-                }
-                NamedType::Optional(syntax_type) => {
-                    match extract_optional(name, token_nodes, context.source()) {
-                        Err(_) => {
-                            // The optional flag didn't exist at all, so there's nothing to color
-                        }
-                        Ok(Some((pos, flag))) => {
-                            let mut shapes = vec![flag.color()];
-                            token_nodes.move_to(pos);
-
-                            if token_nodes.at_end() {
-                                args.insert(pos, shapes);
-                                token_nodes.restart();
-                                continue;
-                            }
-
-                            // We can live with unmatched syntax after an optional flag
-                            let _ = token_nodes.atomic(|token_nodes| {
-                                color_syntax(&MaybeSpaceShape, token_nodes, context, &mut shapes);
-
-                                // If the part after a mandatory flag isn't present, that's ok, but we
-                                // should roll back any whitespace we chomped
-                                color_fallible_syntax(
-                                    syntax_type,
-                                    token_nodes,
-                                    context,
-                                    &mut shapes,
-                                )
-                            });
-
-                            args.insert(pos, shapes);
-                            token_nodes.restart();
-                        }
-
-                        Ok(None) => {
-                            token_nodes.restart();
-                        }
-                    }
-                }
-            };
-        }
-
-        for arg in &signature.positional {
-            trace!("Processing positional {:?}", arg);
-
-            match arg.0 {
-                PositionalType::Mandatory(..) => {
-                    if token_nodes.at_end() {
-                        break;
-                    }
-                }
-
-                PositionalType::Optional(..) => {
-                    if token_nodes.at_end() {
-                        break;
-                    }
-                }
-            }
-
-            let mut shapes = vec![];
-            let pos = token_nodes.pos(false);
-
-            match pos {
-                None => break,
-                Some(pos) => {
-                    // We can live with an unmatched positional argument. Hopefully it will be
-                    // matched by a future token
-                    let _ = token_nodes.atomic(|token_nodes| {
-                        color_syntax(&MaybeSpaceShape, token_nodes, context, &mut shapes);
-
-                        // If no match, we should roll back any whitespace we chomped
-                        color_fallible_syntax(
-                            &arg.0.syntax_type(),
-                            token_nodes,
-                            context,
-                            &mut shapes,
-                        )?;
-
-                        args.insert(pos, shapes);
-
-                        Ok(())
-                    });
-                }
-            }
-        }
-
-        if let Some((syntax_type, _)) = signature.rest_positional {
-            loop {
-                if token_nodes.at_end_possible_ws() {
-                    break;
-                }
-
-                let pos = token_nodes.pos(false);
-
-                match pos {
-                    None => break,
-                    Some(pos) => {
-                        let mut shapes = vec![];
-
-                        // If any arguments don't match, we'll fall back to backoff coloring mode
-                        let result = token_nodes.atomic(|token_nodes| {
-                            color_syntax(&MaybeSpaceShape, token_nodes, context, &mut shapes);
-
-                            // If no match, we should roll back any whitespace we chomped
-                            color_fallible_syntax(&syntax_type, token_nodes, context, &mut shapes)?;
-
-                            args.insert(pos, shapes);
-
-                            Ok(())
-                        });
-
-                        match result {
-                            Err(_) => break,
-                            Ok(_) => continue,
-                        }
-                    }
-                }
-            }
-        }
-
-        args.spread_shapes(shapes);
-
-        // Consume any remaining tokens with backoff coloring mode
-        color_syntax(&BackoffColoringMode, token_nodes, context, shapes);
-
-        shapes.sort_by(|a, b| a.span.start().cmp(&b.span.start()));
-    }
-}
-
-#[cfg(coloring_in_tokens)]
 impl ColorSyntax for CommandTailShape {
     type Info = ();
     type Input = Signature;
@@ -389,14 +197,14 @@ impl ColorSyntax for CommandTailShape {
         token_nodes: &'b mut TokensIterator<'a>,
         context: &ExpandContext,
     ) -> Self::Info {
-        use crate::parser::hir::syntax_shape::SyntaxShape;
+        use nu_protocol::SyntaxShape;
 
         let mut args = ColoringArgs::new(token_nodes.len());
         trace_remaining("nodes", &token_nodes, context.source());
 
         fn insert_flag(
             token_nodes: &mut TokensIterator,
-            syntax_type: &SyntaxShape,
+            syntax_type: SyntaxShape,
             args: &mut ColoringArgs,
             flag: Flag,
             pos: usize,
@@ -418,7 +226,7 @@ impl ColorSyntax for CommandTailShape {
 
                     // If the part after a mandatory flag isn't present, that's ok, but we
                     // should roll back any whitespace we chomped
-                    color_fallible_syntax(syntax_type, token_nodes, context)?;
+                    color_fallible_syntax(&syntax_type, token_nodes, context)?;
 
                     Ok(())
                 });
@@ -435,9 +243,10 @@ impl ColorSyntax for CommandTailShape {
 
             match &kind.0 {
                 NamedType::Switch => {
-                    match token_nodes.extract(|t| t.as_flag(name, context.source())) {
-                        Some((pos, flag)) => args.insert(pos, vec![flag.color()]),
-                        None => {}
+                    if let Some((pos, flag)) =
+                        token_nodes.extract(|t| t.as_flag(name, context.source()))
+                    {
+                        args.insert(pos, vec![flag.color()])
                     }
                 }
                 NamedType::Mandatory(syntax_type) => {
@@ -452,7 +261,7 @@ impl ColorSyntax for CommandTailShape {
                             // The mandatory flag didn't exist at all, so there's nothing to color
                         }
                         Ok((pos, flag)) => {
-                            insert_flag(token_nodes, syntax_type, &mut args, flag, pos, context)
+                            insert_flag(token_nodes, *syntax_type, &mut args, flag, pos, context)
                         }
                     }
                 }
@@ -462,7 +271,7 @@ impl ColorSyntax for CommandTailShape {
                             // The optional flag didn't exist at all, so there's nothing to color
                         }
                         Ok(Some((pos, flag))) => {
-                            insert_flag(token_nodes, syntax_type, &mut args, flag, pos, context)
+                            insert_flag(token_nodes, *syntax_type, &mut args, flag, pos, context)
                         }
 
                         Ok(None) => {

crates/nu-plugin/Cargo.toml

@@ -0,0 +1,24 @@
+[package]
+name = "nu-plugin"
+version = "0.8.0"
+authors = ["Yehuda Katz <wycats@gmail.com>", "Jonathan Turner <jonathan.d.turner@gmail.com>", "Andrés N. Robalino <andres@androbtech.com>"]
+edition = "2018"
+description = "Nushell Plugin"
+license = "MIT"
+
+[lib]
+doctest = false
+
+[dependencies]
+nu-protocol = { path = "../nu-protocol", version = "0.8.0" }
+nu-source = { path = "../nu-source", version = "0.8.0" }
+nu-errors = { path = "../nu-errors", version = "0.8.0" }
+nu-value-ext = { path = "../nu-value-ext", version = "0.8.0" }
+
+indexmap = { version = "1.3.0", features = ["serde-1"] }
+serde = { version = "1.0.103", features = ["derive"] }
+num-bigint = { version = "0.2.3", features = ["serde"] }
+serde_json = "1.0.44"
+
+[build-dependencies]
+nu-build = { version = "0.8.0", path = "../nu-build" }

crates/nu-plugin/build.rs

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

crates/nu-plugin/src/lib.rs

@@ -0,0 +1,4 @@
+mod plugin;
+pub mod test_helpers;
+
+pub use crate::plugin::{serve_plugin, Plugin};

crates/nu-plugin/src/plugin.rs

@@ -1,5 +1,5 @@
-use crate::Signature;
-use crate::{CallInfo, ReturnValue, ShellError, Value};
+use nu_errors::ShellError;
+use nu_protocol::{outln, CallInfo, ReturnValue, Signature, Value};
 use serde::{Deserialize, Serialize};
 use std::io;
 
@@ -24,9 +24,9 @@ pub trait Plugin {
 }
 
 pub fn serve_plugin(plugin: &mut dyn Plugin) {
-    let args = std::env::args();
+    let mut args = std::env::args();
     if args.len() > 1 {
-        let input = args.skip(1).next();
+        let input = args.nth(1);
 
         let input = match input {
             Some(arg) => std::fs::read_to_string(arg),

crates/nu-plugin/src/test_helpers.rs

@@ -0,0 +1,213 @@
+use crate::Plugin;
+use indexmap::IndexMap;
+use nu_errors::ShellError;
+use nu_protocol::{CallInfo, EvaluatedArgs, ReturnSuccess, ReturnValue, UntaggedValue, Value};
+use nu_source::Tag;
+
+pub struct PluginTest<'a, T: Plugin> {
+    plugin: &'a mut T,
+    call_info: CallInfo,
+    input: Value,
+}
+
+impl<'a, T: Plugin> PluginTest<'a, T> {
+    pub fn for_plugin(plugin: &'a mut T) -> Self {
+        PluginTest {
+            plugin,
+            call_info: CallStub::new().create(),
+            input: UntaggedValue::nothing().into_value(Tag::unknown()),
+        }
+    }
+
+    pub fn args(&mut self, call_info: CallInfo) -> &mut PluginTest<'a, T> {
+        self.call_info = call_info;
+        self
+    }
+
+    pub fn configure(&mut self, callback: impl FnOnce(Vec<String>)) -> &mut PluginTest<'a, T> {
+        let signature = self
+            .plugin
+            .config()
+            .expect("There was a problem configuring the plugin.");
+        callback(signature.named.keys().map(String::from).collect());
+        self
+    }
+
+    pub fn input(&mut self, value: Value) -> &mut PluginTest<'a, T> {
+        self.input = value;
+        self
+    }
+
+    pub fn test(&mut self) -> Result<Vec<ReturnValue>, ShellError> {
+        let return_values = self.plugin.filter(self.input.clone());
+
+        let mut return_values = match return_values {
+            Ok(filtered) => filtered,
+            Err(reason) => return Err(reason),
+        };
+
+        let end = self.plugin.end_filter();
+
+        match end {
+            Ok(filter_ended) => return_values.extend(filter_ended),
+            Err(reason) => return Err(reason),
+        }
+
+        self.plugin.quit();
+        Ok(return_values)
+    }
+
+    pub fn setup(
+        &mut self,
+        callback: impl FnOnce(&mut T, Result<Vec<ReturnValue>, ShellError>),
+    ) -> &mut PluginTest<'a, T> {
+        let call_stub = self.call_info.clone();
+
+        self.configure(|flags_configured| {
+            let flags_registered = &call_stub.args.named;
+
+            let flag_passed = match flags_registered {
+                Some(names) => Some(names.keys().map(String::from).collect::<Vec<String>>()),
+                None => None,
+            };
+
+            if let Some(flags) = flag_passed {
+                for flag in flags {
+                    assert!(
+                        flags_configured.iter().any(|f| *f == flag),
+                        format!(
+                            "The flag you passed ({}) is not configured in the plugin.",
+                            flag
+                        )
+                    );
+                }
+            }
+        });
+
+        let began = self.plugin.begin_filter(call_stub);
+
+        let return_values = match began {
+            Ok(values) => Ok(values),
+            Err(reason) => Err(reason),
+        };
+
+        callback(self.plugin, return_values);
+        self
+    }
+}
+
+pub fn plugin<T: Plugin>(plugin: &mut T) -> PluginTest<T> {
+    PluginTest::for_plugin(plugin)
+}
+
+#[derive(Default)]
+pub struct CallStub {
+    positionals: Vec<Value>,
+    flags: IndexMap<String, Value>,
+}
+
+impl CallStub {
+    pub fn new() -> Self {
+        Default::default()
+    }
+
+    pub fn with_named_parameter(&mut self, name: &str, value: Value) -> &mut Self {
+        self.flags.insert(name.to_string(), value);
+        self
+    }
+
+    pub fn with_long_flag(&mut self, name: &str) -> &mut Self {
+        self.flags.insert(
+            name.to_string(),
+            UntaggedValue::boolean(true).into_value(Tag::unknown()),
+        );
+        self
+    }
+
+    pub fn with_parameter(&mut self, name: &str) -> Result<&mut Self, ShellError> {
+        let fields: Vec<Value> = name
+            .split('.')
+            .map(|s| UntaggedValue::string(s.to_string()).into_value(Tag::unknown()))
+            .collect();
+
+        self.positionals.push(value::column_path(&fields)?);
+        Ok(self)
+    }
+
+    pub fn create(&self) -> CallInfo {
+        CallInfo {
+            args: EvaluatedArgs::new(Some(self.positionals.clone()), Some(self.flags.clone())),
+            name_tag: Tag::unknown(),
+        }
+    }
+}
+
+pub fn expect_return_value_at(
+    for_results: Result<Vec<Result<ReturnSuccess, ShellError>>, ShellError>,
+    at: usize,
+) -> Value {
+    let return_values = for_results
+        .expect("Failed! This seems to be an error getting back the results from the plugin.");
+
+    for (idx, item) in return_values.iter().enumerate() {
+        let item = match item {
+            Ok(return_value) => return_value,
+            Err(reason) => panic!(format!("{}", reason)),
+        };
+
+        if idx == at {
+            if let Some(value) = item.raw_value() {
+                return value;
+            } else {
+                panic!("Internal error: could not get raw value in expect_return_value_at")
+            }
+        }
+    }
+
+    panic!(format!(
+        "Couldn't get return value from stream at {}. (There are {} items)",
+        at,
+        return_values.len() - 1
+    ))
+}
+
+pub mod value {
+    use nu_errors::ShellError;
+    use nu_protocol::{Primitive, TaggedDictBuilder, UntaggedValue, Value};
+    use nu_source::Tag;
+    use nu_value_ext::ValueExt;
+    use num_bigint::BigInt;
+
+    pub fn get_data(for_value: Value, key: &str) -> Value {
+        for_value.get_data(&key.to_string()).borrow().clone()
+    }
+
+    pub fn int(i: impl Into<BigInt>) -> Value {
+        UntaggedValue::Primitive(Primitive::Int(i.into())).into_untagged_value()
+    }
+
+    pub fn string(input: impl Into<String>) -> Value {
+        UntaggedValue::string(input.into()).into_untagged_value()
+    }
+
+    pub fn structured_sample_record(key: &str, value: &str) -> Value {
+        let mut record = TaggedDictBuilder::new(Tag::unknown());
+        record.insert_untagged(key, UntaggedValue::string(value));
+        record.into_value()
+    }
+
+    pub fn unstructured_sample_record(value: &str) -> Value {
+        UntaggedValue::string(value).into_value(Tag::unknown())
+    }
+
+    pub fn table(list: &[Value]) -> Value {
+        UntaggedValue::table(list).into_untagged_value()
+    }
+
+    pub fn column_path(paths: &[Value]) -> Result<Value, ShellError> {
+        Ok(UntaggedValue::Primitive(Primitive::ColumnPath(
+            table(&paths.to_vec()).as_column_path()?.item,
+        ))
+        .into_untagged_value())
+    }
+}

crates/nu-protocol/Cargo.toml

@@ -0,0 +1,43 @@
+[package]
+name = "nu-protocol"
+version = "0.8.0"
+authors = ["Yehuda Katz <wycats@gmail.com>", "Jonathan Turner <jonathan.d.turner@gmail.com>", "Andrés N. Robalino <andres@androbtech.com>"]
+edition = "2018"
+description = "Core values and protocols for Nushell"
+license = "MIT"
+
+[lib]
+doctest = false
+
+[dependencies]
+nu-source = { path = "../nu-source", version = "0.8.0" }
+nu-errors = { path = "../nu-errors", version = "0.8.0" }
+
+serde = { version = "1.0.103", features = ["derive"] }
+indexmap = { version = "1.3.0", features = ["serde-1"] }
+num-bigint = { version = "0.2.3", features = ["serde"] }
+bigdecimal = { version = "0.1.0", features = ["serde"] }
+chrono = { version = "0.4.10", features = ["serde"] }
+num-traits = "0.2.8"
+serde_bytes = "0.11.3"
+getset = "0.0.9"
+derive-new = "0.5.8"
+ansi_term = "0.12.1"
+language-reporting = "0.4.0"
+nom = "5.0.1"
+nom_locate = "1.0.0"
+nom-tracable = "0.4.1"
+typetag = "0.1.4"
+query_interface = "0.3.5"
+byte-unit = "3.0.3"
+chrono-humanize = "0.0.11"
+natural = "0.3.0"
+
+# implement conversions
+subprocess = "0.1.18"
+serde_yaml = "0.8"
+toml = "0.5.5"
+serde_json = "1.0.44"
+
+[build-dependencies]
+nu-build = { version = "0.8.0", path = "../nu-build" }

crates/nu-protocol/build.rs

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

crates/nu-protocol/src/call_info.rs

@@ -0,0 +1,97 @@
+use crate::value::Value;
+use derive_new::new;
+use indexmap::IndexMap;
+use nu_errors::ShellError;
+use nu_source::Tag;
+use serde::{Deserialize, Serialize};
+
+#[derive(Deserialize, Serialize, Debug, Clone)]
+pub struct CallInfo {
+    pub args: EvaluatedArgs,
+    pub name_tag: Tag,
+}
+
+#[derive(Debug, Default, new, Serialize, Deserialize, Clone)]
+pub struct EvaluatedArgs {
+    pub positional: Option<Vec<Value>>,
+    pub named: Option<IndexMap<String, Value>>,
+}
+
+impl EvaluatedArgs {
+    pub fn slice_from(&self, from: usize) -> Vec<Value> {
+        let positional = &self.positional;
+
+        match positional {
+            None => vec![],
+            Some(list) => list[from..].to_vec(),
+        }
+    }
+
+    pub fn nth(&self, pos: usize) -> Option<&Value> {
+        match &self.positional {
+            None => None,
+            Some(array) => array.get(pos),
+        }
+    }
+
+    pub fn expect_nth(&self, pos: usize) -> Result<&Value, ShellError> {
+        match &self.positional {
+            None => Err(ShellError::unimplemented("Better error: expect_nth")),
+            Some(array) => match array.get(pos) {
+                None => Err(ShellError::unimplemented("Better error: expect_nth")),
+                Some(item) => Ok(item),
+            },
+        }
+    }
+
+    pub fn len(&self) -> usize {
+        match &self.positional {
+            None => 0,
+            Some(array) => array.len(),
+        }
+    }
+
+    pub fn is_empty(&self) -> bool {
+        self.len() == 0
+    }
+
+    pub fn has(&self, name: &str) -> bool {
+        match &self.named {
+            None => false,
+            Some(named) => named.contains_key(name),
+        }
+    }
+
+    pub fn get(&self, name: &str) -> Option<&Value> {
+        match &self.named {
+            None => None,
+            Some(named) => named.get(name),
+        }
+    }
+
+    pub fn positional_iter(&self) -> PositionalIter<'_> {
+        match &self.positional {
+            None => PositionalIter::Empty,
+            Some(v) => {
+                let iter = v.iter();
+                PositionalIter::Array(iter)
+            }
+        }
+    }
+}
+
+pub enum PositionalIter<'a> {
+    Empty,
+    Array(std::slice::Iter<'a, Value>),
+}
+
+impl<'a> Iterator for PositionalIter<'a> {
+    type Item = &'a Value;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        match self {
+            PositionalIter::Empty => None,
+            PositionalIter::Array(iter) => iter.next(),
+        }
+    }
+}

crates/nu-protocol/src/lib.rs

@@ -0,0 +1,26 @@
+#[macro_use]
+mod macros;
+
+mod call_info;
+mod maybe_owned;
+mod return_value;
+mod signature;
+mod syntax_shape;
+mod type_name;
+mod type_shape;
+mod value;
+
+pub use crate::call_info::{CallInfo, EvaluatedArgs};
+pub use crate::maybe_owned::MaybeOwned;
+pub use crate::return_value::{CommandAction, ReturnSuccess, ReturnValue};
+pub use crate::signature::{NamedType, PositionalType, Signature};
+pub use crate::syntax_shape::SyntaxShape;
+pub use crate::type_name::{PrettyType, ShellTypeName, SpannedTypeName};
+pub use crate::type_shape::{Row as RowType, Type};
+pub use crate::value::column_path::{did_you_mean, ColumnPath, PathMember, UnspannedPathMember};
+pub use crate::value::dict::{Dictionary, TaggedDictBuilder};
+pub use crate::value::evaluate::{Evaluate, EvaluateTrait, Scope};
+pub use crate::value::primitive::format_primitive;
+pub use crate::value::primitive::Primitive;
+pub use crate::value::range::{Range, RangeInclusion};
+pub use crate::value::{UntaggedValue, Value};

crates/nu-protocol/src/macros.rs

@@ -0,0 +1,12 @@
+// These macros exist to differentiate between intentional writing to stdout
+// and stray printlns left by accident
+
+#[macro_export]
+macro_rules! outln {
+    ($($tokens:tt)*) => { println!($($tokens)*) }
+}
+
+#[macro_export]
+macro_rules! errln {
+    ($($tokens:tt)*) => { eprintln!($($tokens)*) }
+}

crates/nu-protocol/src/maybe_owned.rs

@@ -0,0 +1,16 @@
+#![allow(clippy::should_implement_trait)]
+
+#[derive(Debug)]
+pub enum MaybeOwned<'a, T> {
+    Owned(T),
+    Borrowed(&'a T),
+}
+
+impl<T> MaybeOwned<'_, T> {
+    pub fn borrow(&self) -> &T {
+        match self {
+            MaybeOwned::Owned(v) => v,
+            MaybeOwned::Borrowed(v) => v,
+        }
+    }
+}

crates/nu-protocol/src/return_value.rs

@@ -0,0 +1,88 @@
+use crate::value::Value;
+use nu_errors::ShellError;
+use nu_source::{b, DebugDocBuilder, PrettyDebug};
+use serde::{Deserialize, Serialize};
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub enum CommandAction {
+    ChangePath(String),
+    Exit,
+    Error(ShellError),
+    EnterShell(String),
+    AutoConvert(Value, String),
+    EnterValueShell(Value),
+    EnterHelpShell(Value),
+    PreviousShell,
+    NextShell,
+    LeaveShell,
+}
+
+impl PrettyDebug for CommandAction {
+    fn pretty(&self) -> DebugDocBuilder {
+        match self {
+            CommandAction::ChangePath(path) => b::typed("change path", b::description(path)),
+            CommandAction::Exit => b::description("exit"),
+            CommandAction::Error(_) => b::error("error"),
+            CommandAction::AutoConvert(_, extension) => {
+                b::typed("auto convert", b::description(extension))
+            }
+            CommandAction::EnterShell(s) => b::typed("enter shell", b::description(s)),
+            CommandAction::EnterValueShell(v) => b::typed("enter value shell", v.pretty()),
+            CommandAction::EnterHelpShell(v) => b::typed("enter help shell", v.pretty()),
+            CommandAction::PreviousShell => b::description("previous shell"),
+            CommandAction::NextShell => b::description("next shell"),
+            CommandAction::LeaveShell => b::description("leave shell"),
+        }
+    }
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub enum ReturnSuccess {
+    Value(Value),
+    DebugValue(Value),
+    Action(CommandAction),
+}
+
+impl PrettyDebug for ReturnSuccess {
+    fn pretty(&self) -> DebugDocBuilder {
+        match self {
+            ReturnSuccess::Value(value) => b::typed("value", value.pretty()),
+            ReturnSuccess::DebugValue(value) => b::typed("debug value", value.pretty()),
+            ReturnSuccess::Action(action) => b::typed("action", action.pretty()),
+        }
+    }
+}
+
+pub type ReturnValue = Result<ReturnSuccess, ShellError>;
+
+impl Into<ReturnValue> for Value {
+    fn into(self) -> ReturnValue {
+        Ok(ReturnSuccess::Value(self))
+    }
+}
+
+impl ReturnSuccess {
+    pub fn raw_value(&self) -> Option<Value> {
+        match self {
+            ReturnSuccess::Value(raw) => Some(raw.clone()),
+            ReturnSuccess::DebugValue(raw) => Some(raw.clone()),
+            ReturnSuccess::Action(_) => None,
+        }
+    }
+
+    pub fn change_cwd(path: String) -> ReturnValue {
+        Ok(ReturnSuccess::Action(CommandAction::ChangePath(path)))
+    }
+
+    pub fn value(input: impl Into<Value>) -> ReturnValue {
+        Ok(ReturnSuccess::Value(input.into()))
+    }
+
+    pub fn debug_value(input: impl Into<Value>) -> ReturnValue {
+        Ok(ReturnSuccess::DebugValue(input.into()))
+    }
+
+    pub fn action(input: CommandAction) -> ReturnValue {
+        Ok(ReturnSuccess::Action(input))
+    }
+}

crates/nu-protocol/src/signature.rs

@@ -1,11 +1,7 @@
-// TODO: Temporary redirect
-pub(crate) use crate::context::CommandRegistry;
-use crate::evaluate::{evaluate_baseline_expr, Scope};
-use crate::parser::{hir, hir::SyntaxShape};
-use crate::prelude::*;
-use derive_new::new;
+use crate::syntax_shape::SyntaxShape;
+use crate::type_shape::Type;
 use indexmap::IndexMap;
-
+use nu_source::{b, DebugDocBuilder, PrettyDebug, PrettyDebugWithSource};
 use serde::{Deserialize, Serialize};
 
 #[derive(Debug, Serialize, Deserialize, Clone)]
@@ -25,12 +21,12 @@ impl PrettyDebug for PositionalType {
     fn pretty(&self) -> DebugDocBuilder {
         match self {
             PositionalType::Mandatory(string, shape) => {
-                b::description(string) + b::delimit("(", shape.pretty(), ")").as_kind().group()
+                b::description(string) + b::delimit("(", shape.pretty(), ")").into_kind().group()
             }
             PositionalType::Optional(string, shape) => {
                 b::description(string)
                     + b::operator("?")
-                    + b::delimit("(", shape.pretty(), ")").as_kind().group()
+                    + b::delimit("(", shape.pretty(), ")").into_kind().group()
             }
         }
     }
@@ -57,14 +53,14 @@ impl PositionalType {
         PositionalType::Optional(name.to_string(), SyntaxShape::Any)
     }
 
-    pub(crate) fn name(&self) -> &str {
+    pub fn name(&self) -> &str {
         match self {
             PositionalType::Mandatory(s, _) => s,
             PositionalType::Optional(s, _) => s,
         }
     }
 
-    pub(crate) fn syntax_type(&self) -> SyntaxShape {
+    pub fn syntax_type(&self) -> SyntaxShape {
         match *self {
             PositionalType::Mandatory(_, t) => t,
             PositionalType::Optional(_, t) => t,
@@ -81,6 +77,8 @@ pub struct Signature {
     pub positional: Vec<(PositionalType, Description)>,
     pub rest_positional: Option<(SyntaxShape, Description)>,
     pub named: IndexMap<String, (NamedType, Description)>,
+    pub yields: Option<Type>,
+    pub input: Option<Type>,
     pub is_filter: bool,
 }
 
@@ -103,14 +101,16 @@ impl PrettyDebugWithSource for Signature {
 }
 
 impl Signature {
-    pub fn new(name: String) -> Signature {
+    pub fn new(name: impl Into<String>) -> Signature {
         Signature {
-            name,
+            name: name.into(),
             usage: String::new(),
             positional: vec![],
             rest_positional: None,
             named: IndexMap::new(),
             is_filter: false,
+            yields: None,
+            input: None,
         }
     }
 
@@ -191,136 +191,14 @@ impl Signature {
         self.rest_positional = Some((ty, desc.into()));
         self
     }
-}
 
-#[derive(Debug, Default, new, Serialize, Deserialize, Clone)]
-pub struct EvaluatedArgs {
-    pub positional: Option<Vec<Value>>,
-    pub named: Option<IndexMap<String, Value>>,
-}
+    pub fn yields(mut self, ty: Type) -> Signature {
+        self.yields = Some(ty);
+        self
+    }
 
-impl EvaluatedArgs {
-    pub fn slice_from(&self, from: usize) -> Vec<Value> {
-        let positional = &self.positional;
-
-        match positional {
-            None => vec![],
-            Some(list) => list[from..].to_vec(),
-        }
+    pub fn input(mut self, ty: Type) -> Signature {
+        self.input = Some(ty);
+        self
     }
 }
-
-impl EvaluatedArgs {
-    pub fn nth(&self, pos: usize) -> Option<&Value> {
-        match &self.positional {
-            None => None,
-            Some(array) => array.iter().nth(pos),
-        }
-    }
-
-    pub fn expect_nth(&self, pos: usize) -> Result<&Value, ShellError> {
-        match &self.positional {
-            None => Err(ShellError::unimplemented("Better error: expect_nth")),
-            Some(array) => match array.iter().nth(pos) {
-                None => Err(ShellError::unimplemented("Better error: expect_nth")),
-                Some(item) => Ok(item),
-            },
-        }
-    }
-
-    pub fn len(&self) -> usize {
-        match &self.positional {
-            None => 0,
-            Some(array) => array.len(),
-        }
-    }
-
-    pub fn has(&self, name: &str) -> bool {
-        match &self.named {
-            None => false,
-            Some(named) => named.contains_key(name),
-        }
-    }
-
-    pub fn get(&self, name: &str) -> Option<&Value> {
-        match &self.named {
-            None => None,
-            Some(named) => named.get(name),
-        }
-    }
-
-    pub fn positional_iter(&self) -> PositionalIter<'_> {
-        match &self.positional {
-            None => PositionalIter::Empty,
-            Some(v) => {
-                let iter = v.iter();
-                PositionalIter::Array(iter)
-            }
-        }
-    }
-}
-
-pub enum PositionalIter<'a> {
-    Empty,
-    Array(std::slice::Iter<'a, Value>),
-}
-
-impl<'a> Iterator for PositionalIter<'a> {
-    type Item = &'a Value;
-
-    fn next(&mut self) -> Option<Self::Item> {
-        match self {
-            PositionalIter::Empty => None,
-            PositionalIter::Array(iter) => iter.next(),
-        }
-    }
-}
-
-pub(crate) fn evaluate_args(
-    call: &hir::Call,
-    registry: &CommandRegistry,
-    scope: &Scope,
-    source: &Text,
-) -> Result<EvaluatedArgs, ShellError> {
-    let positional: Result<Option<Vec<_>>, _> = call
-        .positional()
-        .as_ref()
-        .map(|p| {
-            p.iter()
-                .map(|e| evaluate_baseline_expr(e, registry, scope, source))
-                .collect()
-        })
-        .transpose();
-
-    let positional = positional?;
-
-    let named: Result<Option<IndexMap<String, Value>>, ShellError> = call
-        .named()
-        .as_ref()
-        .map(|n| {
-            let mut results = IndexMap::new();
-
-            for (name, value) in n.named.iter() {
-                match value {
-                    hir::named::NamedValue::PresentSwitch(tag) => {
-                        results.insert(name.clone(), UntaggedValue::boolean(true).into_value(tag));
-                    }
-                    hir::named::NamedValue::Value(expr) => {
-                        results.insert(
-                            name.clone(),
-                            evaluate_baseline_expr(expr, registry, scope, source)?,
-                        );
-                    }
-
-                    _ => {}
-                };
-            }
-
-            Ok(results)
-        })
-        .transpose();
-
-    let named = named?;
-
-    Ok(EvaluatedArgs::new(positional, named))
-}

crates/nu-protocol/src/syntax_shape.rs

@@ -0,0 +1,33 @@
+use nu_source::{b, DebugDocBuilder, PrettyDebug};
+use serde::{Deserialize, Serialize};
+
+#[derive(Debug, Copy, Clone, Serialize, Deserialize)]
+pub enum SyntaxShape {
+    Any,
+    String,
+    Member,
+    ColumnPath,
+    Number,
+    Range,
+    Int,
+    Path,
+    Pattern,
+    Block,
+}
+
+impl PrettyDebug for SyntaxShape {
+    fn pretty(&self) -> DebugDocBuilder {
+        b::kind(match self {
+            SyntaxShape::Any => "any shape",
+            SyntaxShape::String => "string shape",
+            SyntaxShape::Member => "member shape",
+            SyntaxShape::ColumnPath => "column path shape",
+            SyntaxShape::Number => "number shape",
+            SyntaxShape::Range => "range shape",
+            SyntaxShape::Int => "integer shape",
+            SyntaxShape::Path => "file path shape",
+            SyntaxShape::Pattern => "pattern shape",
+            SyntaxShape::Block => "block shape",
+        })
+    }
+}

crates/nu-protocol/src/type_name.rs

@@ -1,5 +1,4 @@
-use crate::prelude::*;
-use nu_source::{DebugDocBuilder, Spanned, SpannedItem, Tagged};
+use nu_source::{DebugDocBuilder, HasSpan, Spanned, SpannedItem, Tagged};
 
 pub trait ShellTypeName {
     fn type_name(&self) -> &'static str;

crates/nu-protocol/src/type_shape.rs

@@ -0,0 +1,382 @@
+use crate::value::dict::Dictionary;
+use crate::value::primitive::Primitive;
+use crate::value::range::RangeInclusion;
+use crate::value::{UntaggedValue, Value};
+use derive_new::new;
+use nu_source::{b, DebugDoc, DebugDocBuilder, PrettyDebug};
+use serde::{Deserialize, Deserializer, Serialize};
+use std::collections::BTreeMap;
+use std::fmt::Debug;
+use std::hash::Hash;
+
+/**
+  This file describes the structural types of the nushell system.
+
+  Its primary purpose today is to identify "equivalent" values for the purpose
+  of merging rows into a single table or identify rows in a table that have the
+  same shape for reflection.
+*/
+
+#[derive(Debug, Clone, Eq, PartialEq, Ord, PartialOrd, Hash, Serialize, Deserialize, new)]
+pub struct RangeType {
+    from: (Type, RangeInclusion),
+    to: (Type, RangeInclusion),
+}
+
+#[derive(Debug, Clone, Eq, PartialEq, Ord, PartialOrd, Hash, Serialize, Deserialize)]
+pub enum Type {
+    Nothing,
+    Int,
+    Range(Box<RangeType>),
+    Decimal,
+    Bytesize,
+    String,
+    Line,
+    ColumnPath,
+    Pattern,
+    Boolean,
+    Date,
+    Duration,
+    Path,
+    Binary,
+
+    Row(Row),
+    Table(Vec<Type>),
+
+    // TODO: Block arguments
+    Block,
+    // TODO: Error type
+    Error,
+
+    // Stream markers (used as bookend markers rather than actual values)
+    BeginningOfStream,
+    EndOfStream,
+}
+
+#[derive(Debug, Clone, Eq, PartialEq, Ord, PartialOrd, Hash, new)]
+pub struct Row {
+    #[new(default)]
+    map: BTreeMap<Column, Type>,
+}
+
+impl Serialize for Row {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: serde::Serializer,
+    {
+        serializer.collect_map(self.map.iter())
+    }
+}
+
+impl<'de> Deserialize<'de> for Row {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        struct RowVisitor;
+
+        impl<'de> serde::de::Visitor<'de> for RowVisitor {
+            type Value = Row;
+            fn expecting(&self, formatter: &mut std::fmt::Formatter) -> std::fmt::Result {
+                write!(formatter, "a row")
+            }
+
+            fn visit_map<A>(self, mut map: A) -> Result<Self::Value, A::Error>
+            where
+                A: serde::de::MapAccess<'de>,
+            {
+                let mut new_map = BTreeMap::new();
+
+                loop {
+                    let entry = map.next_entry()?;
+
+                    match entry {
+                        None => return Ok(Row { map: new_map }),
+                        Some((key, value)) => {
+                            new_map.insert(key, value);
+                        }
+                    }
+                }
+            }
+        }
+        deserializer.deserialize_map(RowVisitor)
+    }
+}
+
+impl Type {
+    pub fn from_primitive(primitive: &Primitive) -> Type {
+        match primitive {
+            Primitive::Nothing => Type::Nothing,
+            Primitive::Int(_) => Type::Int,
+            Primitive::Range(range) => {
+                let (left_value, left_inclusion) = &range.from;
+                let (right_value, right_inclusion) = &range.to;
+
+                let left_type = (Type::from_primitive(left_value), *left_inclusion);
+                let right_type = (Type::from_primitive(right_value), *right_inclusion);
+
+                let range = RangeType::new(left_type, right_type);
+                Type::Range(Box::new(range))
+            }
+            Primitive::Decimal(_) => Type::Decimal,
+            Primitive::Bytes(_) => Type::Bytesize,
+            Primitive::String(_) => Type::String,
+            Primitive::Line(_) => Type::Line,
+            Primitive::ColumnPath(_) => Type::ColumnPath,
+            Primitive::Pattern(_) => Type::Pattern,
+            Primitive::Boolean(_) => Type::Boolean,
+            Primitive::Date(_) => Type::Date,
+            Primitive::Duration(_) => Type::Duration,
+            Primitive::Path(_) => Type::Path,
+            Primitive::Binary(_) => Type::Binary,
+            Primitive::BeginningOfStream => Type::BeginningOfStream,
+            Primitive::EndOfStream => Type::EndOfStream,
+        }
+    }
+
+    pub fn from_dictionary(dictionary: &Dictionary) -> Type {
+        let mut map = BTreeMap::new();
+
+        for (key, value) in dictionary.entries.iter() {
+            let column = Column::String(key.clone());
+            map.insert(column, Type::from_value(value));
+        }
+
+        Type::Row(Row { map })
+    }
+
+    pub fn from_table<'a>(table: impl IntoIterator<Item = &'a Value>) -> Type {
+        let mut vec = vec![];
+
+        for item in table.into_iter() {
+            vec.push(Type::from_value(item))
+        }
+
+        Type::Table(vec)
+    }
+
+    pub fn from_value<'a>(value: impl Into<&'a UntaggedValue>) -> Type {
+        match value.into() {
+            UntaggedValue::Primitive(p) => Type::from_primitive(p),
+            UntaggedValue::Row(row) => Type::from_dictionary(row),
+            UntaggedValue::Table(table) => Type::from_table(table.iter()),
+            UntaggedValue::Error(_) => Type::Error,
+            UntaggedValue::Block(_) => Type::Block,
+        }
+    }
+}
+
+impl PrettyDebug for Type {
+    fn pretty(&self) -> DebugDocBuilder {
+        match self {
+            Type::Nothing => ty("nothing"),
+            Type::Int => ty("integer"),
+            Type::Range(range) => {
+                let (left, left_inclusion) = &range.from;
+                let (right, right_inclusion) = &range.to;
+
+                let left_bracket = b::delimiter(match left_inclusion {
+                    RangeInclusion::Exclusive => "(",
+                    RangeInclusion::Inclusive => "[",
+                });
+
+                let right_bracket = b::delimiter(match right_inclusion {
+                    RangeInclusion::Exclusive => ")",
+                    RangeInclusion::Inclusive => "]",
+                });
+
+                b::typed(
+                    "range",
+                    (left_bracket
+                        + left.pretty()
+                        + b::operator(",")
+                        + b::space()
+                        + right.pretty()
+                        + right_bracket)
+                        .group(),
+                )
+            }
+            Type::Decimal => ty("decimal"),
+            Type::Bytesize => ty("bytesize"),
+            Type::String => ty("string"),
+            Type::Line => ty("line"),
+            Type::ColumnPath => ty("column-path"),
+            Type::Pattern => ty("pattern"),
+            Type::Boolean => ty("boolean"),
+            Type::Date => ty("date"),
+            Type::Duration => ty("duration"),
+            Type::Path => ty("path"),
+            Type::Binary => ty("binary"),
+            Type::Error => b::error("error"),
+            Type::BeginningOfStream => b::keyword("beginning-of-stream"),
+            Type::EndOfStream => b::keyword("end-of-stream"),
+            Type::Row(row) => (b::kind("row")
+                + b::space()
+                + b::intersperse(
+                    row.map.iter().map(|(key, ty)| {
+                        (b::key(match key {
+                            Column::String(string) => string.clone(),
+                            Column::Value => "<value>".to_string(),
+                        }) + b::delimit("(", ty.pretty(), ")").into_kind())
+                        .nest()
+                    }),
+                    b::space(),
+                )
+                .nest())
+            .nest(),
+
+            Type::Table(table) => {
+                let mut group: Group<DebugDoc, Vec<(usize, usize)>> = Group::new();
+
+                for (i, item) in table.iter().enumerate() {
+                    group.add(item.to_doc(), i);
+                }
+
+                (b::kind("table") + b::space() + b::keyword("of")).group()
+                    + b::space()
+                    + (if group.len() == 1 {
+                        let (doc, _) = group.into_iter().collect::<Vec<_>>()[0].clone();
+                        DebugDocBuilder::from_doc(doc)
+                    } else {
+                        b::intersperse(
+                            group.into_iter().map(|(doc, rows)| {
+                                (b::intersperse(
+                                    rows.iter().map(|(from, to)| {
+                                        if from == to {
+                                            b::description(from)
+                                        } else {
+                                            (b::description(from)
+                                                + b::space()
+                                                + b::keyword("to")
+                                                + b::space()
+                                                + b::description(to))
+                                            .group()
+                                        }
+                                    }),
+                                    b::description(", "),
+                                ) + b::description(":")
+                                    + b::space()
+                                    + DebugDocBuilder::from_doc(doc))
+                                .nest()
+                            }),
+                            b::space(),
+                        )
+                    })
+            }
+            Type::Block => ty("block"),
+        }
+    }
+}
+
+#[derive(Debug, new)]
+struct DebugEntry<'a> {
+    key: &'a Column,
+    value: &'a Type,
+}
+
+impl<'a> PrettyDebug for DebugEntry<'a> {
+    fn pretty(&self) -> DebugDocBuilder {
+        (b::key(match self.key {
+            Column::String(string) => string.clone(),
+            Column::Value => "<value>".to_string(),
+        }) + b::delimit("(", self.value.pretty(), ")").into_kind())
+    }
+}
+
+fn ty(name: impl std::fmt::Display) -> DebugDocBuilder {
+    b::kind(format!("{}", name))
+}
+
+pub trait GroupedValue: Debug + Clone {
+    type Item;
+
+    fn new() -> Self;
+    fn merge(&mut self, value: Self::Item);
+}
+
+impl GroupedValue for Vec<(usize, usize)> {
+    type Item = usize;
+
+    fn new() -> Vec<(usize, usize)> {
+        vec![]
+    }
+
+    fn merge(&mut self, new_value: usize) {
+        match self.last_mut() {
+            Some(value) if value.1 == new_value - 1 => {
+                value.1 += 1;
+            }
+
+            _ => self.push((new_value, new_value)),
+        }
+    }
+}
+
+#[derive(Debug)]
+pub struct Group<K: Debug + Eq + Hash, V: GroupedValue> {
+    values: indexmap::IndexMap<K, V>,
+}
+
+impl<K, G> Group<K, G>
+where
+    K: Debug + Eq + Hash,
+    G: GroupedValue,
+{
+    pub fn new() -> Group<K, G> {
+        Group {
+            values: indexmap::IndexMap::default(),
+        }
+    }
+
+    pub fn len(&self) -> usize {
+        self.values.len()
+    }
+
+    pub fn into_iter(self) -> impl Iterator<Item = (K, G)> {
+        self.values.into_iter()
+    }
+
+    pub fn add(&mut self, key: impl Into<K>, value: impl Into<G::Item>) {
+        let key = key.into();
+        let value = value.into();
+
+        let group = self.values.get_mut(&key);
+
+        match group {
+            None => {
+                self.values.insert(key, {
+                    let mut group = G::new();
+                    group.merge(value);
+                    group
+                });
+            }
+            Some(group) => {
+                group.merge(value);
+            }
+        }
+    }
+}
+
+#[derive(Debug, Clone, Eq, PartialEq, Ord, PartialOrd, Serialize, Deserialize, Hash)]
+pub enum Column {
+    String(String),
+    Value,
+}
+
+impl Into<Column> for String {
+    fn into(self) -> Column {
+        Column::String(self)
+    }
+}
+
+impl Into<Column> for &String {
+    fn into(self) -> Column {
+        Column::String(self.clone())
+    }
+}
+
+impl Into<Column> for &str {
+    fn into(self) -> Column {
+        Column::String(self.to_string())
+    }
+}

crates/nu-protocol/src/value.rs

@@ -0,0 +1,300 @@
+pub mod column_path;
+mod convert;
+mod debug;
+pub mod dict;
+pub mod evaluate;
+pub mod primitive;
+pub mod range;
+mod serde_bigdecimal;
+mod serde_bigint;
+
+use crate::type_name::{ShellTypeName, SpannedTypeName};
+use crate::value::dict::Dictionary;
+use crate::value::evaluate::Evaluate;
+use crate::value::primitive::Primitive;
+use crate::value::range::{Range, RangeInclusion};
+use crate::{ColumnPath, PathMember};
+use bigdecimal::BigDecimal;
+use indexmap::IndexMap;
+use nu_errors::ShellError;
+use nu_source::{AnchorLocation, HasSpan, Span, Spanned, Tag};
+use num_bigint::BigInt;
+use serde::{Deserialize, Serialize};
+use std::path::PathBuf;
+use std::time::SystemTime;
+
+#[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash, Serialize, Deserialize)]
+pub enum UntaggedValue {
+    Primitive(Primitive),
+    Row(Dictionary),
+    Table(Vec<Value>),
+
+    // Errors are a type of value too
+    Error(ShellError),
+
+    Block(Evaluate),
+}
+
+impl UntaggedValue {
+    pub fn retag(self, tag: impl Into<Tag>) -> Value {
+        Value {
+            value: self,
+            tag: tag.into(),
+        }
+    }
+
+    pub fn data_descriptors(&self) -> Vec<String> {
+        match self {
+            UntaggedValue::Primitive(_) => vec![],
+            UntaggedValue::Row(columns) => columns.entries.keys().map(|x| x.to_string()).collect(),
+            UntaggedValue::Block(_) => vec![],
+            UntaggedValue::Table(_) => vec![],
+            UntaggedValue::Error(_) => vec![],
+        }
+    }
+
+    pub fn into_value(self, tag: impl Into<Tag>) -> Value {
+        Value {
+            value: self,
+            tag: tag.into(),
+        }
+    }
+
+    pub fn into_untagged_value(self) -> Value {
+        Value {
+            value: self,
+            tag: Tag::unknown(),
+        }
+    }
+
+    pub fn is_true(&self) -> bool {
+        match self {
+            UntaggedValue::Primitive(Primitive::Boolean(true)) => true,
+            _ => false,
+        }
+    }
+
+    pub fn is_some(&self) -> bool {
+        !self.is_none()
+    }
+
+    pub fn is_none(&self) -> bool {
+        match self {
+            UntaggedValue::Primitive(Primitive::Nothing) => true,
+            _ => false,
+        }
+    }
+
+    pub fn is_error(&self) -> bool {
+        match self {
+            UntaggedValue::Error(_err) => true,
+            _ => false,
+        }
+    }
+
+    pub fn expect_error(&self) -> ShellError {
+        match self {
+            UntaggedValue::Error(err) => err.clone(),
+            _ => panic!("Don't call expect_error without first calling is_error"),
+        }
+    }
+
+    pub fn expect_string(&self) -> &str {
+        match self {
+            UntaggedValue::Primitive(Primitive::String(string)) => &string[..],
+            _ => panic!("expect_string assumes that the value must be a string"),
+        }
+    }
+
+    #[allow(unused)]
+    pub fn row(entries: IndexMap<String, Value>) -> UntaggedValue {
+        UntaggedValue::Row(entries.into())
+    }
+
+    pub fn table(list: &[Value]) -> UntaggedValue {
+        UntaggedValue::Table(list.to_vec())
+    }
+
+    pub fn string(s: impl Into<String>) -> UntaggedValue {
+        UntaggedValue::Primitive(Primitive::String(s.into()))
+    }
+
+    pub fn line(s: impl Into<String>) -> UntaggedValue {
+        UntaggedValue::Primitive(Primitive::Line(s.into()))
+    }
+
+    pub fn column_path(s: Vec<impl Into<PathMember>>) -> UntaggedValue {
+        UntaggedValue::Primitive(Primitive::ColumnPath(ColumnPath::new(
+            s.into_iter().map(|p| p.into()).collect(),
+        )))
+    }
+
+    pub fn int(i: impl Into<BigInt>) -> UntaggedValue {
+        UntaggedValue::Primitive(Primitive::Int(i.into()))
+    }
+
+    pub fn pattern(s: impl Into<String>) -> UntaggedValue {
+        UntaggedValue::Primitive(Primitive::String(s.into()))
+    }
+
+    pub fn path(s: impl Into<PathBuf>) -> UntaggedValue {
+        UntaggedValue::Primitive(Primitive::Path(s.into()))
+    }
+
+    pub fn bytes(s: impl Into<u64>) -> UntaggedValue {
+        UntaggedValue::Primitive(Primitive::Bytes(s.into()))
+    }
+
+    pub fn decimal(s: impl Into<BigDecimal>) -> UntaggedValue {
+        UntaggedValue::Primitive(Primitive::Decimal(s.into()))
+    }
+
+    pub fn binary(binary: Vec<u8>) -> UntaggedValue {
+        UntaggedValue::Primitive(Primitive::Binary(binary))
+    }
+
+    pub fn range(
+        left: (Spanned<Primitive>, RangeInclusion),
+        right: (Spanned<Primitive>, RangeInclusion),
+    ) -> UntaggedValue {
+        UntaggedValue::Primitive(Primitive::Range(Box::new(Range::new(left, right))))
+    }
+
+    pub fn boolean(s: impl Into<bool>) -> UntaggedValue {
+        UntaggedValue::Primitive(Primitive::Boolean(s.into()))
+    }
+
+    pub fn duration(secs: u64) -> UntaggedValue {
+        UntaggedValue::Primitive(Primitive::Duration(secs))
+    }
+
+    pub fn system_date(s: SystemTime) -> UntaggedValue {
+        UntaggedValue::Primitive(Primitive::Date(s.into()))
+    }
+
+    pub fn nothing() -> UntaggedValue {
+        UntaggedValue::Primitive(Primitive::Nothing)
+    }
+}
+
+#[derive(Debug, Clone, PartialOrd, PartialEq, Ord, Eq, Hash, Serialize, Deserialize)]
+pub struct Value {
+    pub value: UntaggedValue,
+    pub tag: Tag,
+}
+
+impl std::ops::Deref for Value {
+    type Target = UntaggedValue;
+
+    fn deref(&self) -> &Self::Target {
+        &self.value
+    }
+}
+
+impl Value {
+    pub fn anchor(&self) -> Option<AnchorLocation> {
+        self.tag.anchor()
+    }
+
+    pub fn anchor_name(&self) -> Option<String> {
+        self.tag.anchor_name()
+    }
+
+    pub fn tag(&self) -> Tag {
+        self.tag.clone()
+    }
+
+    pub fn as_string(&self) -> Result<String, ShellError> {
+        match &self.value {
+            UntaggedValue::Primitive(Primitive::String(string)) => Ok(string.clone()),
+            UntaggedValue::Primitive(Primitive::Line(line)) => Ok(line.clone() + "\n"),
+            _ => Err(ShellError::type_error("string", self.spanned_type_name())),
+        }
+    }
+
+    pub fn as_forgiving_string(&self) -> Result<&str, ShellError> {
+        match &self.value {
+            UntaggedValue::Primitive(Primitive::String(string)) => Ok(&string[..]),
+            _ => Err(ShellError::type_error("string", self.spanned_type_name())),
+        }
+    }
+
+    pub fn as_path(&self) -> Result<PathBuf, ShellError> {
+        match &self.value {
+            UntaggedValue::Primitive(Primitive::Path(path)) => Ok(path.clone()),
+            UntaggedValue::Primitive(Primitive::String(path_str)) => Ok(PathBuf::from(&path_str)),
+            _ => Err(ShellError::type_error("Path", self.spanned_type_name())),
+        }
+    }
+
+    pub fn as_primitive(&self) -> Result<Primitive, ShellError> {
+        match &self.value {
+            UntaggedValue::Primitive(primitive) => Ok(primitive.clone()),
+            _ => Err(ShellError::type_error(
+                "Primitive",
+                self.spanned_type_name(),
+            )),
+        }
+    }
+
+    pub fn as_u64(&self) -> Result<u64, ShellError> {
+        match &self.value {
+            UntaggedValue::Primitive(primitive) => primitive.as_u64(self.tag.span),
+            _ => Err(ShellError::type_error("integer", self.spanned_type_name())),
+        }
+    }
+}
+
+impl Into<UntaggedValue> for &str {
+    fn into(self) -> UntaggedValue {
+        UntaggedValue::Primitive(Primitive::String(self.to_string()))
+    }
+}
+
+impl Into<UntaggedValue> for Value {
+    fn into(self) -> UntaggedValue {
+        self.value
+    }
+}
+
+impl<'a> Into<&'a UntaggedValue> for &'a Value {
+    fn into(self) -> &'a UntaggedValue {
+        &self.value
+    }
+}
+
+impl HasSpan for Value {
+    fn span(&self) -> Span {
+        self.tag.span
+    }
+}
+
+impl ShellTypeName for Value {
+    fn type_name(&self) -> &'static str {
+        ShellTypeName::type_name(&self.value)
+    }
+}
+
+impl ShellTypeName for UntaggedValue {
+    fn type_name(&self) -> &'static str {
+        match &self {
+            UntaggedValue::Primitive(p) => p.type_name(),
+            UntaggedValue::Row(_) => "row",
+            UntaggedValue::Table(_) => "table",
+            UntaggedValue::Error(_) => "error",
+            UntaggedValue::Block(_) => "block",
+        }
+    }
+}
+
+impl From<Primitive> for UntaggedValue {
+    fn from(input: Primitive) -> UntaggedValue {
+        UntaggedValue::Primitive(input)
+    }
+}
+
+impl From<String> for UntaggedValue {
+    fn from(input: String) -> UntaggedValue {
+        UntaggedValue::Primitive(Primitive::String(input))
+    }
+}

crates/nu-protocol/src/value/column_path.rs

@@ -1,8 +1,8 @@
-use crate::parser::hir::Expression;
-use crate::prelude::*;
+use crate::Value;
 use derive_new::new;
-use getset::{Getters, MutGetters};
-use nu_source::{b, span_for_spanned_list, PrettyDebug};
+use getset::Getters;
+use nu_source::{b, span_for_spanned_list, DebugDocBuilder, HasFallibleSpan, PrettyDebug, Span};
+use num_bigint::BigInt;
 use serde::{Deserialize, Serialize};
 
 #[derive(Clone, Debug, Eq, PartialEq, Ord, PartialOrd, Hash, Serialize, Deserialize)]
@@ -48,8 +48,8 @@ impl ColumnPath {
         self.members.iter()
     }
 
-    pub fn split_last(&self) -> (&PathMember, &[PathMember]) {
-        self.members.split_last().unwrap()
+    pub fn split_last(&self) -> Option<(&PathMember, &[PathMember])> {
+        self.members.split_last()
     }
 }
 
@@ -69,7 +69,7 @@ impl PrettyDebug for ColumnPath {
 
 impl HasFallibleSpan for ColumnPath {
     fn maybe_span(&self) -> Option<Span> {
-        if self.members.len() == 0 {
+        if self.members.is_empty() {
             None
         } else {
             Some(span_for_spanned_list(self.members.iter().map(|m| m.span)))
@@ -87,37 +87,28 @@ impl PathMember {
     }
 }
 
-#[derive(
-    Debug,
-    Clone,
-    Eq,
-    PartialEq,
-    Ord,
-    PartialOrd,
-    Hash,
-    Getters,
-    MutGetters,
-    Serialize,
-    Deserialize,
-    new,
-)]
-#[get = "pub(crate)"]
-pub struct Path {
-    head: Expression,
-    #[get_mut = "pub(crate)"]
-    tail: Vec<PathMember>,
-}
+pub fn did_you_mean(obj_source: &Value, field_tried: &PathMember) -> Option<Vec<(usize, String)>> {
+    let field_tried = match &field_tried.unspanned {
+        UnspannedPathMember::String(string) => string.clone(),
+        UnspannedPathMember::Int(int) => format!("{}", int),
+    };
 
-impl PrettyDebugWithSource for Path {
-    fn pretty_debug(&self, source: &str) -> DebugDocBuilder {
-        self.head.pretty_debug(source)
-            + b::operator(".")
-            + b::intersperse(self.tail.iter().map(|m| m.pretty()), b::operator("."))
-    }
-}
-
-impl Path {
-    pub(crate) fn parts(self) -> (Expression, Vec<PathMember>) {
-        (self.head, self.tail)
+    let possibilities = obj_source.data_descriptors();
+
+    let mut possible_matches: Vec<_> = possibilities
+        .into_iter()
+        .map(|x| {
+            let word = x;
+            let distance = natural::distance::levenshtein_distance(&word, &field_tried);
+
+            (distance, word)
+        })
+        .collect();
+
+    if !possible_matches.is_empty() {
+        possible_matches.sort();
+        Some(possible_matches)
+    } else {
+        None
     }
 }

crates/nu-protocol/src/value/convert.rs

@@ -0,0 +1,55 @@
+use crate::type_name::SpannedTypeName;
+use crate::value::dict::Dictionary;
+use crate::value::primitive::Primitive;
+use crate::value::{UntaggedValue, Value};
+use nu_errors::{CoerceInto, ShellError};
+use nu_source::TaggedItem;
+
+impl std::convert::TryFrom<&Value> for i64 {
+    type Error = ShellError;
+
+    fn try_from(value: &Value) -> Result<i64, ShellError> {
+        match &value.value {
+            UntaggedValue::Primitive(Primitive::Int(int)) => {
+                int.tagged(&value.tag).coerce_into("converting to i64")
+            }
+            _ => Err(ShellError::type_error("Integer", value.spanned_type_name())),
+        }
+    }
+}
+
+impl std::convert::TryFrom<&Value> for String {
+    type Error = ShellError;
+
+    fn try_from(value: &Value) -> Result<String, ShellError> {
+        match &value.value {
+            UntaggedValue::Primitive(Primitive::String(s)) => Ok(s.clone()),
+            _ => Err(ShellError::type_error("String", value.spanned_type_name())),
+        }
+    }
+}
+
+impl std::convert::TryFrom<&Value> for Vec<u8> {
+    type Error = ShellError;
+
+    fn try_from(value: &Value) -> Result<Vec<u8>, ShellError> {
+        match &value.value {
+            UntaggedValue::Primitive(Primitive::Binary(b)) => Ok(b.clone()),
+            _ => Err(ShellError::type_error("Binary", value.spanned_type_name())),
+        }
+    }
+}
+
+impl<'a> std::convert::TryFrom<&'a Value> for &'a Dictionary {
+    type Error = ShellError;
+
+    fn try_from(value: &'a Value) -> Result<&'a Dictionary, ShellError> {
+        match &value.value {
+            UntaggedValue::Row(d) => Ok(d),
+            _ => Err(ShellError::type_error(
+                "Dictionary",
+                value.spanned_type_name(),
+            )),
+        }
+    }
+}

crates/nu-protocol/src/value/debug.rs

@@ -1,15 +1,38 @@
-use crate::data::base::Primitive;
-use crate::traits::PrettyType;
+use crate::type_name::PrettyType;
+use crate::value::primitive::Primitive;
+use crate::value::{UntaggedValue, Value};
 use nu_source::{b, DebugDocBuilder, PrettyDebug};
 
+impl PrettyDebug for &Value {
+    fn pretty(&self) -> DebugDocBuilder {
+        PrettyDebug::pretty(*self)
+    }
+}
+
+impl PrettyDebug for Value {
+    fn pretty(&self) -> DebugDocBuilder {
+        match &self.value {
+            UntaggedValue::Primitive(p) => p.pretty(),
+            UntaggedValue::Row(row) => row.pretty_builder().nest(1).group().into(),
+            UntaggedValue::Table(table) => {
+                b::delimit("[", b::intersperse(table, b::space()), "]").nest()
+            }
+            UntaggedValue::Error(_) => b::error("error"),
+            UntaggedValue::Block(_) => b::opaque("block"),
+        }
+    }
+}
+
 impl PrettyType for Primitive {
     fn pretty_type(&self) -> DebugDocBuilder {
         match self {
             Primitive::Nothing => ty("nothing"),
             Primitive::Int(_) => ty("integer"),
+            Primitive::Range(_) => ty("range"),
             Primitive::Decimal(_) => ty("decimal"),
             Primitive::Bytes(_) => ty("bytesize"),
             Primitive::String(_) => ty("string"),
+            Primitive::Line(_) => ty("line"),
             Primitive::ColumnPath(_) => ty("column-path"),
             Primitive::Pattern(_) => ty("pattern"),
             Primitive::Boolean(_) => ty("boolean"),
@@ -29,8 +52,24 @@ impl PrettyDebug for Primitive {
             Primitive::Nothing => b::primitive("nothing"),
             Primitive::Int(int) => prim(format_args!("{}", int)),
             Primitive::Decimal(decimal) => prim(format_args!("{}", decimal)),
+            Primitive::Range(range) => {
+                let (left, left_inclusion) = &range.from;
+                let (right, right_inclusion) = &range.to;
+
+                b::typed(
+                    "range",
+                    (left_inclusion.debug_left_bracket()
+                        + left.pretty()
+                        + b::operator(",")
+                        + b::space()
+                        + right.pretty()
+                        + right_inclusion.debug_right_bracket())
+                    .group(),
+                )
+            }
             Primitive::Bytes(bytes) => primitive_doc(bytes, "bytesize"),
             Primitive::String(string) => prim(string),
+            Primitive::Line(string) => prim(string),
             Primitive::ColumnPath(path) => path.pretty(),
             Primitive::Pattern(pattern) => primitive_doc(pattern, "pattern"),
             Primitive::Boolean(boolean) => match boolean {
@@ -51,10 +90,10 @@ fn prim(name: impl std::fmt::Debug) -> DebugDocBuilder {
     b::primitive(format!("{:?}", name))
 }
 
-fn ty(name: impl std::fmt::Debug) -> DebugDocBuilder {
-    b::kind(format!("{:?}", name))
-}
-
 fn primitive_doc(name: impl std::fmt::Debug, ty: impl Into<String>) -> DebugDocBuilder {
     b::primitive(format!("{:?}", name)) + b::delimit("(", b::kind(ty.into()), ")")
 }
+
+fn ty(name: impl std::fmt::Debug) -> DebugDocBuilder {
+    b::kind(format!("{:?}", name))
+}

crates/nu-protocol/src/value/dict.rs

@@ -0,0 +1,207 @@
+use crate::maybe_owned::MaybeOwned;
+use crate::value::primitive::Primitive;
+use crate::value::{UntaggedValue, Value};
+use derive_new::new;
+use getset::Getters;
+use indexmap::IndexMap;
+use nu_source::{b, DebugDocBuilder, PrettyDebug, Spanned, Tag};
+use serde::{Deserialize, Serialize};
+use std::cmp::{Ord, Ordering, PartialOrd};
+use std::hash::{Hash, Hasher};
+
+#[derive(Debug, Default, Serialize, Deserialize, PartialEq, Eq, Clone, Getters, new)]
+pub struct Dictionary {
+    #[get = "pub"]
+    pub entries: IndexMap<String, Value>,
+}
+
+#[allow(clippy::derive_hash_xor_eq)]
+impl Hash for Dictionary {
+    fn hash<H: Hasher>(&self, state: &mut H) {
+        let mut entries = self.entries.clone();
+        entries.sort_keys();
+        entries.keys().collect::<Vec<&String>>().hash(state);
+        entries.values().collect::<Vec<&Value>>().hash(state);
+    }
+}
+
+impl PartialOrd for Dictionary {
+    fn partial_cmp(&self, other: &Dictionary) -> Option<Ordering> {
+        let this: Vec<&String> = self.entries.keys().collect();
+        let that: Vec<&String> = other.entries.keys().collect();
+
+        if this != that {
+            return this.partial_cmp(&that);
+        }
+
+        let this: Vec<&Value> = self.entries.values().collect();
+        let that: Vec<&Value> = self.entries.values().collect();
+
+        this.partial_cmp(&that)
+    }
+}
+
+impl Ord for Dictionary {
+    fn cmp(&self, other: &Dictionary) -> Ordering {
+        let this: Vec<&String> = self.entries.keys().collect();
+        let that: Vec<&String> = other.entries.keys().collect();
+
+        if this != that {
+            return this.cmp(&that);
+        }
+
+        let this: Vec<&Value> = self.entries.values().collect();
+        let that: Vec<&Value> = self.entries.values().collect();
+
+        this.cmp(&that)
+    }
+}
+
+impl PartialEq<Value> for Dictionary {
+    fn eq(&self, other: &Value) -> bool {
+        match &other.value {
+            UntaggedValue::Row(d) => self == d,
+            _ => false,
+        }
+    }
+}
+
+#[derive(Debug, new)]
+struct DebugEntry<'a> {
+    key: &'a str,
+    value: &'a Value,
+}
+
+impl<'a> PrettyDebug for DebugEntry<'a> {
+    fn pretty(&self) -> DebugDocBuilder {
+        (b::key(self.key.to_string()) + b::equals() + self.value.pretty().into_value()).group()
+    }
+}
+
+impl PrettyDebug for Dictionary {
+    fn pretty(&self) -> DebugDocBuilder {
+        b::delimit(
+            "(",
+            b::intersperse(
+                self.entries()
+                    .iter()
+                    .map(|(key, value)| DebugEntry::new(key, value)),
+                b::space(),
+            ),
+            ")",
+        )
+    }
+}
+
+impl From<IndexMap<String, Value>> for Dictionary {
+    fn from(input: IndexMap<String, Value>) -> Dictionary {
+        let mut out = IndexMap::default();
+
+        for (key, value) in input {
+            out.insert(key, value);
+        }
+
+        Dictionary::new(out)
+    }
+}
+
+impl Dictionary {
+    pub fn get_data(&self, desc: &str) -> MaybeOwned<'_, Value> {
+        match self.entries.get(desc) {
+            Some(v) => MaybeOwned::Borrowed(v),
+            None => MaybeOwned::Owned(
+                UntaggedValue::Primitive(Primitive::Nothing).into_untagged_value(),
+            ),
+        }
+    }
+
+    pub fn keys(&self) -> impl Iterator<Item = &String> {
+        self.entries.keys()
+    }
+
+    pub fn get_data_by_key(&self, name: Spanned<&str>) -> Option<Value> {
+        let result = self
+            .entries
+            .iter()
+            .find(|(desc_name, _)| *desc_name == name.item)?
+            .1;
+
+        Some(
+            result
+                .value
+                .clone()
+                .into_value(Tag::new(result.tag.anchor(), name.span)),
+        )
+    }
+
+    pub fn get_mut_data_by_key(&mut self, name: &str) -> Option<&mut Value> {
+        match self
+            .entries
+            .iter_mut()
+            .find(|(desc_name, _)| *desc_name == name)
+        {
+            Some((_, v)) => Some(v),
+            None => None,
+        }
+    }
+
+    pub fn insert_data_at_key(&mut self, name: &str, value: Value) {
+        self.entries.insert(name.to_string(), value);
+    }
+}
+
+#[derive(Debug)]
+pub struct TaggedDictBuilder {
+    tag: Tag,
+    dict: IndexMap<String, Value>,
+}
+
+impl TaggedDictBuilder {
+    pub fn new(tag: impl Into<Tag>) -> TaggedDictBuilder {
+        TaggedDictBuilder {
+            tag: tag.into(),
+            dict: IndexMap::default(),
+        }
+    }
+
+    pub fn build(tag: impl Into<Tag>, block: impl FnOnce(&mut TaggedDictBuilder)) -> Value {
+        let mut builder = TaggedDictBuilder::new(tag);
+        block(&mut builder);
+        builder.into_value()
+    }
+
+    pub fn with_capacity(tag: impl Into<Tag>, n: usize) -> TaggedDictBuilder {
+        TaggedDictBuilder {
+            tag: tag.into(),
+            dict: IndexMap::with_capacity(n),
+        }
+    }
+
+    pub fn insert_untagged(&mut self, key: impl Into<String>, value: impl Into<UntaggedValue>) {
+        self.dict
+            .insert(key.into(), value.into().into_value(&self.tag));
+    }
+
+    pub fn insert_value(&mut self, key: impl Into<String>, value: impl Into<Value>) {
+        self.dict.insert(key.into(), value.into());
+    }
+
+    pub fn into_value(self) -> Value {
+        let tag = self.tag.clone();
+        self.into_untagged_value().into_value(tag)
+    }
+
+    pub fn into_untagged_value(self) -> UntaggedValue {
+        UntaggedValue::Row(Dictionary { entries: self.dict })
+    }
+
+    pub fn is_empty(&self) -> bool {
+        self.dict.is_empty()
+    }
+}
+
+impl From<TaggedDictBuilder> for Value {
+    fn from(input: TaggedDictBuilder) -> Value {
+        input.into_value()
+    }
+}

crates/nu-protocol/src/value/evaluate.rs

@@ -0,0 +1,102 @@
+use crate::value::{Primitive, UntaggedValue, Value};
+use indexmap::IndexMap;
+use nu_errors::ShellError;
+use query_interface::{interfaces, vtable_for, Object, ObjectHash};
+use serde::{Deserialize, Serialize};
+use std::cmp::{Ord, Ordering, PartialOrd};
+use std::fmt::Debug;
+
+#[derive(Debug)]
+pub struct Scope {
+    pub it: Value,
+    pub vars: IndexMap<String, Value>,
+}
+
+impl Scope {
+    pub fn new(it: Value) -> Scope {
+        Scope {
+            it,
+            vars: IndexMap::new(),
+        }
+    }
+}
+
+impl Scope {
+    pub fn empty() -> Scope {
+        Scope {
+            it: UntaggedValue::Primitive(Primitive::Nothing).into_untagged_value(),
+            vars: IndexMap::new(),
+        }
+    }
+
+    pub fn it_value(value: Value) -> Scope {
+        Scope {
+            it: value,
+            vars: IndexMap::new(),
+        }
+    }
+}
+
+#[typetag::serde(tag = "type")]
+pub trait EvaluateTrait: Debug + Send + Sync + Object + ObjectHash + 'static {
+    fn invoke(&self, scope: &Scope) -> Result<Value, ShellError>;
+    fn clone_box(&self) -> Evaluate;
+}
+
+interfaces!(Evaluate: dyn ObjectHash);
+
+#[typetag::serde]
+impl EvaluateTrait for Evaluate {
+    fn invoke(&self, scope: &Scope) -> Result<Value, ShellError> {
+        self.expr.invoke(scope)
+    }
+
+    fn clone_box(&self) -> Evaluate {
+        self.expr.clone_box()
+    }
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+pub struct Evaluate {
+    expr: Box<dyn EvaluateTrait>,
+}
+
+impl Evaluate {
+    pub fn new(evaluate: impl EvaluateTrait) -> Evaluate {
+        Evaluate {
+            expr: Box::new(evaluate),
+        }
+    }
+}
+
+impl std::hash::Hash for Evaluate {
+    fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
+        self.expr.obj_hash(state)
+    }
+}
+
+impl Clone for Evaluate {
+    fn clone(&self) -> Evaluate {
+        self.expr.clone_box()
+    }
+}
+
+impl Ord for Evaluate {
+    fn cmp(&self, _: &Self) -> Ordering {
+        Ordering::Equal
+    }
+}
+
+impl PartialOrd for Evaluate {
+    fn partial_cmp(&self, _: &Evaluate) -> Option<Ordering> {
+        Some(Ordering::Equal)
+    }
+}
+
+impl PartialEq for Evaluate {
+    fn eq(&self, _: &Evaluate) -> bool {
+        true
+    }
+}
+
+impl Eq for Evaluate {}

crates/nu-protocol/src/value/primitive.rs

@@ -0,0 +1,173 @@
+use crate::type_name::ShellTypeName;
+use crate::value::column_path::ColumnPath;
+use crate::value::range::Range;
+use crate::value::{serde_bigdecimal, serde_bigint};
+use bigdecimal::BigDecimal;
+use chrono::{DateTime, Utc};
+use chrono_humanize::Humanize;
+use nu_errors::{ExpectedRange, ShellError};
+use nu_source::{PrettyDebug, Span, SpannedItem};
+use num_bigint::BigInt;
+use num_traits::cast::{FromPrimitive, ToPrimitive};
+use serde::{Deserialize, Serialize};
+use std::path::PathBuf;
+
+#[derive(Debug, Clone, Ord, PartialOrd, Eq, PartialEq, Hash, Deserialize, Serialize)]
+pub enum Primitive {
+    Nothing,
+    #[serde(with = "serde_bigint")]
+    Int(BigInt),
+    #[serde(with = "serde_bigdecimal")]
+    Decimal(BigDecimal),
+    Bytes(u64),
+    String(String),
+    Line(String),
+    ColumnPath(ColumnPath),
+    Pattern(String),
+    Boolean(bool),
+    Date(DateTime<Utc>),
+    Duration(u64), // Duration in seconds
+    Range(Box<Range>),
+    Path(PathBuf),
+    #[serde(with = "serde_bytes")]
+    Binary(Vec<u8>),
+
+    // Stream markers (used as bookend markers rather than actual values)
+    BeginningOfStream,
+    EndOfStream,
+}
+
+impl Primitive {
+    pub fn as_u64(&self, span: Span) -> Result<u64, ShellError> {
+        match self {
+            Primitive::Int(int) => match int.to_u64() {
+                None => Err(ShellError::range_error(
+                    ExpectedRange::U64,
+                    &format!("{}", int).spanned(span),
+                    "converting an integer into a 64-bit integer",
+                )),
+                Some(num) => Ok(num),
+            },
+            other => Err(ShellError::type_error(
+                "integer",
+                other.type_name().spanned(span),
+            )),
+        }
+    }
+}
+
+impl From<BigDecimal> for Primitive {
+    fn from(decimal: BigDecimal) -> Primitive {
+        Primitive::Decimal(decimal)
+    }
+}
+
+impl From<f64> for Primitive {
+    fn from(float: f64) -> Primitive {
+        if let Some(f) = BigDecimal::from_f64(float) {
+            Primitive::Decimal(f)
+        } else {
+            unreachable!("Internal error: protocol did not use f64-compatible decimal")
+        }
+    }
+}
+
+impl ShellTypeName for Primitive {
+    fn type_name(&self) -> &'static str {
+        match self {
+            Primitive::Nothing => "nothing",
+            Primitive::Int(_) => "integer",
+            Primitive::Range(_) => "range",
+            Primitive::Decimal(_) => "decimal",
+            Primitive::Bytes(_) => "bytes",
+            Primitive::String(_) => "string",
+            Primitive::Line(_) => "line",
+            Primitive::ColumnPath(_) => "column path",
+            Primitive::Pattern(_) => "pattern",
+            Primitive::Boolean(_) => "boolean",
+            Primitive::Date(_) => "date",
+            Primitive::Duration(_) => "duration",
+            Primitive::Path(_) => "file path",
+            Primitive::Binary(_) => "binary",
+            Primitive::BeginningOfStream => "marker<beginning of stream>",
+            Primitive::EndOfStream => "marker<end of stream>",
+        }
+    }
+}
+
+pub fn format_primitive(primitive: &Primitive, field_name: Option<&String>) -> String {
+    match primitive {
+        Primitive::Nothing => String::new(),
+        Primitive::BeginningOfStream => String::new(),
+        Primitive::EndOfStream => String::new(),
+        Primitive::Path(p) => format!("{}", p.display()),
+        Primitive::Bytes(b) => {
+            let byte = byte_unit::Byte::from_bytes(*b as u128);
+
+            if byte.get_bytes() == 0u128 {
+                return "—".to_string();
+            }
+
+            let byte = byte.get_appropriate_unit(false);
+
+            match byte.get_unit() {
+                byte_unit::ByteUnit::B => format!("{} B ", byte.get_value()),
+                _ => byte.format(1),
+            }
+        }
+        Primitive::Duration(sec) => format_duration(*sec),
+        Primitive::Int(i) => i.to_string(),
+        Primitive::Decimal(decimal) => format!("{:.4}", decimal),
+        Primitive::Range(range) => format!(
+            "{}..{}",
+            format_primitive(&range.from.0.item, None),
+            format_primitive(&range.to.0.item, None)
+        ),
+        Primitive::Pattern(s) => s.to_string(),
+        Primitive::String(s) => s.to_owned(),
+        Primitive::Line(s) => s.to_owned(),
+        Primitive::ColumnPath(p) => {
+            let mut members = p.iter();
+            let mut f = String::new();
+
+            f.push_str(
+                &members
+                    .next()
+                    .expect("BUG: column path with zero members")
+                    .display(),
+            );
+
+            for member in members {
+                f.push_str(".");
+                f.push_str(&member.display())
+            }
+
+            f
+        }
+        Primitive::Boolean(b) => match (b, field_name) {
+            (true, None) => "Yes",
+            (false, None) => "No",
+            (true, Some(s)) if !s.is_empty() => s,
+            (false, Some(s)) if !s.is_empty() => "",
+            (true, Some(_)) => "Yes",
+            (false, Some(_)) => "No",
+        }
+        .to_owned(),
+        Primitive::Binary(_) => "<binary>".to_owned(),
+        Primitive::Date(d) => d.humanize(),
+    }
+}
+
+pub fn format_duration(sec: u64) -> String {
+    let (minutes, seconds) = (sec / 60, sec % 60);
+    let (hours, minutes) = (minutes / 60, minutes % 60);
+    let (days, hours) = (hours / 24, hours % 24);
+
+    match (days, hours, minutes, seconds) {
+        (0, 0, 0, 1) => "1 sec".to_owned(),
+        (0, 0, 0, s) => format!("{} secs", s),
+        (0, 0, m, s) => format!("{}:{:02}", m, s),
+        (0, h, m, s) => format!("{}:{:02}:{:02}", h, m, s),
+        (d, h, m, s) => format!("{}:{:02}:{:02}:{:02}", d, h, m, s),
+    }
+}

crates/nu-protocol/src/value/range.rs

@@ -0,0 +1,32 @@
+use crate::value::Primitive;
+use derive_new::new;
+use nu_source::{b, DebugDocBuilder, Spanned};
+use serde::{Deserialize, Serialize};
+
+#[derive(Debug, Copy, Clone, PartialEq, PartialOrd, Eq, Ord, Hash, Serialize, Deserialize)]
+pub enum RangeInclusion {
+    Inclusive,
+    Exclusive,
+}
+
+impl RangeInclusion {
+    pub fn debug_left_bracket(self) -> DebugDocBuilder {
+        b::delimiter(match self {
+            RangeInclusion::Exclusive => "(",
+            RangeInclusion::Inclusive => "[",
+        })
+    }
+
+    pub fn debug_right_bracket(self) -> DebugDocBuilder {
+        b::delimiter(match self {
+            RangeInclusion::Exclusive => ")",
+            RangeInclusion::Inclusive => "]",
+        })
+    }
+}
+
+#[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash, Serialize, Deserialize, new)]
+pub struct Range {
+    pub from: (Spanned<Primitive>, RangeInclusion),
+    pub to: (Spanned<Primitive>, RangeInclusion),
+}

crates/nu-protocol/src/value/serde_bigdecimal.rs

@@ -0,0 +1,24 @@
+use bigdecimal::BigDecimal;
+use num_traits::cast::FromPrimitive;
+use num_traits::cast::ToPrimitive;
+
+pub fn serialize<S>(big_decimal: &BigDecimal, serializer: S) -> Result<S::Ok, S::Error>
+where
+    S: serde::Serializer,
+{
+    serde::Serialize::serialize(
+        &big_decimal
+            .to_f64()
+            .ok_or_else(|| serde::ser::Error::custom("expected a f64-sized bignum"))?,
+        serializer,
+    )
+}
+
+pub fn deserialize<'de, D>(deserializer: D) -> Result<BigDecimal, D::Error>
+where
+    D: serde::Deserializer<'de>,
+{
+    let x: f64 = serde::Deserialize::deserialize(deserializer)?;
+    Ok(BigDecimal::from_f64(x)
+        .ok_or_else(|| serde::de::Error::custom("expected a f64-sized bigdecimal"))?)
+}

crates/nu-protocol/src/value/serde_bigint.rs

@@ -0,0 +1,24 @@
+use num_bigint::BigInt;
+use num_traits::cast::FromPrimitive;
+use num_traits::cast::ToPrimitive;
+
+pub fn serialize<S>(big_int: &BigInt, serializer: S) -> Result<S::Ok, S::Error>
+where
+    S: serde::Serializer,
+{
+    serde::Serialize::serialize(
+        &big_int
+            .to_i64()
+            .ok_or_else(|| serde::ser::Error::custom("expected a i64-sized bignum"))?,
+        serializer,
+    )
+}
+
+pub fn deserialize<'de, D>(deserializer: D) -> Result<BigInt, D::Error>
+where
+    D: serde::Deserializer<'de>,
+{
+    let x: i64 = serde::Deserialize::deserialize(deserializer)?;
+    Ok(BigInt::from_i64(x)
+        .ok_or_else(|| serde::de::Error::custom("expected a i64-sized bignum"))?)
+}

crates/nu-source/Cargo.toml

@@ -1,16 +1,16 @@
 [package]
 name = "nu-source"
-version = "0.1.0"
-authors = ["Yehuda Katz <wycats@gmail.com>"]
+version = "0.8.0"
+authors = ["Yehuda Katz <wycats@gmail.com>", "Jonathan Turner <jonathan.d.turner@gmail.com>", "Andrés N. Robalino <andres@androbtech.com>"]
 edition = "2018"
 description = "A source string characterizer for Nushell"
 license = "MIT"
 
-# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+[lib]
+doctest = false
 
 [dependencies]
-
-serde = { version = "1.0.102", features = ["derive"] }
+serde = { version = "1.0.103", features = ["derive"] }
 derive-new = "0.5.8"
 getset = "0.0.9"
 nom_locate = "1.0.0"
@@ -18,3 +18,6 @@ nom-tracable = "0.4.1"
 language-reporting = "0.4.0"
 termcolor = "1.0.5"
 pretty = "0.5.2"
+
+[build-dependencies]
+nu-build = { version = "0.8.0", path = "../nu-build" }

crates/nu-source/build.rs

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

crates/nu-source/src/lib.rs

@@ -11,5 +11,6 @@ pub use self::meta::{
 pub use self::pretty::{
     b, DebugDoc, DebugDocBuilder, PrettyDebug, PrettyDebugWithSource, ShellAnnotation,
 };
+pub use self::term_colored::TermColored;
 pub use self::text::Text;
 pub use self::tracable::{nom_input, NomSpan, TracableContext};

crates/nu-source/src/meta.rs

@@ -38,7 +38,7 @@ impl Spanned<String> {
     pub fn items<'a, U>(
         items: impl Iterator<Item = &'a Spanned<String>>,
     ) -> impl Iterator<Item = &'a str> {
-        items.into_iter().map(|item| &item.item[..])
+        items.map(|item| &item.item[..])
     }
 }
 
@@ -156,7 +156,7 @@ impl<T> Tagged<T> {
 
         Tagged {
             item: self.item,
-            tag: tag,
+            tag,
         }
     }
 
@@ -220,10 +220,7 @@ impl<T>
             nom_locate::LocatedSpanEx<T, u64>,
         ),
     ) -> Span {
-        Span {
-            start: input.0.offset,
-            end: input.1.offset,
-        }
+        Span::new(input.0.offset, input.1.offset)
     }
 }
 
@@ -235,10 +232,7 @@ impl From<(usize, usize)> for Span {
 
 impl From<&std::ops::Range<usize>> for Span {
     fn from(input: &std::ops::Range<usize>) -> Span {
-        Span {
-            start: input.start,
-            end: input.end,
-        }
+        Span::new(input.start, input.end)
     }
 }
 
@@ -321,10 +315,7 @@ impl Tag {
     pub fn for_char(pos: usize, anchor: AnchorLocation) -> Tag {
         Tag {
             anchor: Some(anchor),
-            span: Span {
-                start: pos,
-                end: pos + 1,
-            },
+            span: Span::new(pos, pos + 1),
         }
     }
 
@@ -528,11 +519,19 @@ impl Span {
 
 impl language_reporting::ReportingSpan for Span {
     fn with_start(&self, start: usize) -> Self {
-        Span::new(start, self.end)
+        if self.end < start {
+            Span::new(start, start)
+        } else {
+            Span::new(start, self.end)
+        }
     }
 
     fn with_end(&self, end: usize) -> Self {
-        Span::new(self.start, end)
+        if end < self.start {
+            Span::new(end, end)
+        } else {
+            Span::new(self.start, end)
+        }
     }
 
     fn start(&self) -> usize {

crates/nu-source/src/pretty.rs

@@ -135,7 +135,7 @@ impl DebugDocBuilder {
         DebugDocBuilder::styled(string, ShellStyle::Value)
     }
 
-    pub fn as_value(self) -> DebugDocBuilder {
+    pub fn into_value(self) -> DebugDocBuilder {
         self.inner
             .annotate(ShellAnnotation::style(ShellStyle::Value))
             .into()
@@ -149,7 +149,7 @@ impl DebugDocBuilder {
         DebugDocBuilder::styled(string, ShellStyle::Kind)
     }
 
-    pub fn as_kind(self) -> DebugDocBuilder {
+    pub fn into_kind(self) -> DebugDocBuilder {
         self.inner
             .annotate(ShellAnnotation::style(ShellStyle::Kind))
             .into()
@@ -316,7 +316,7 @@ impl DebugDocBuilder {
             result = result + item;
         }
 
-        result.into()
+        result
     }
 
     fn styled(string: impl std::fmt::Display, style: ShellStyle) -> DebugDocBuilder {
@@ -414,8 +414,7 @@ pub trait PrettyDebug {
         let doc = self.pretty_doc();
         let mut buffer = termcolor::Buffer::no_color();
 
-        doc.render_raw(width, &mut TermColored::new(&mut buffer))
-            .unwrap();
+        let _ = doc.render_raw(width, &mut TermColored::new(&mut buffer));
 
         String::from_utf8_lossy(buffer.as_slice()).to_string()
     }
@@ -424,8 +423,7 @@ pub trait PrettyDebug {
         let doc = self.pretty_doc();
         let mut buffer = termcolor::Buffer::ansi();
 
-        doc.render_raw(width, &mut TermColored::new(&mut buffer))
-            .unwrap();
+        let _ = doc.render_raw(width, &mut TermColored::new(&mut buffer));
 
         String::from_utf8_lossy(buffer.as_slice()).to_string()
     }
@@ -488,6 +486,7 @@ fn hash_doc<H: std::hash::Hasher>(doc: &PrettyDebugDoc, state: &mut H) {
     }
 }
 
+#[allow(clippy::derive_hash_xor_eq)]
 impl std::hash::Hash for DebugDoc {
     fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
         hash_doc(&self.inner, state);

crates/nu-test-support/Cargo.toml

@@ -0,0 +1,17 @@
+[package]
+name = "nu-test-support"
+version = "0.8.0"
+authors = ["Yehuda Katz <wycats@gmail.com>", "Jonathan Turner <jonathan.d.turner@gmail.com>", "Andrés N. Robalino <andres@androbtech.com>"]
+edition = "2018"
+description = "A source string characterizer for Nushell"
+license = "MIT"
+
+[lib]
+doctest = false
+
+[dependencies]
+app_dirs = "1.2.1"
+dunce = "1.0.0"
+getset = "0.0.9"
+glob = "0.3.0"
+tempfile = "3.1.0"

crates/nu-test-support/src/fs.rs

@@ -0,0 +1,232 @@
+use std::io::Read;
+use std::ops::Div;
+use std::path::{Path, PathBuf};
+
+pub struct AbsoluteFile {
+    inner: PathBuf,
+}
+
+impl AbsoluteFile {
+    pub fn new(path: impl AsRef<Path>) -> AbsoluteFile {
+        let path = path.as_ref();
+
+        if !path.is_absolute() {
+            panic!(
+                "AbsoluteFile::new must take an absolute path :: {}",
+                path.display()
+            )
+        } else if path.is_dir() {
+            // At the moment, this is not an invariant, but rather a way to catch bugs
+            // in tests.
+            panic!(
+                "AbsoluteFile::new must not take a directory :: {}",
+                path.display()
+            )
+        } else {
+            AbsoluteFile {
+                inner: path.to_path_buf(),
+            }
+        }
+    }
+
+    pub fn dir(&self) -> AbsolutePath {
+        AbsolutePath::new(if let Some(parent) = self.inner.parent() {
+            parent
+        } else {
+            unreachable!("Internal error: could not get parent in dir")
+        })
+    }
+}
+
+impl From<AbsoluteFile> for PathBuf {
+    fn from(file: AbsoluteFile) -> Self {
+        file.inner
+    }
+}
+
+pub struct AbsolutePath {
+    inner: PathBuf,
+}
+
+impl AbsolutePath {
+    pub fn new(path: impl AsRef<Path>) -> AbsolutePath {
+        let path = path.as_ref();
+
+        if path.is_absolute() {
+            AbsolutePath {
+                inner: path.to_path_buf(),
+            }
+        } else {
+            panic!("AbsolutePath::new must take an absolute path")
+        }
+    }
+}
+
+impl Div<&str> for &AbsolutePath {
+    type Output = AbsolutePath;
+
+    fn div(self, rhs: &str) -> Self::Output {
+        let parts = rhs.split('/');
+        let mut result = self.inner.clone();
+
+        for part in parts {
+            result = result.join(part);
+        }
+
+        AbsolutePath::new(result)
+    }
+}
+
+impl AsRef<Path> for AbsolutePath {
+    fn as_ref(&self) -> &Path {
+        self.inner.as_path()
+    }
+}
+
+pub struct RelativePath {
+    inner: PathBuf,
+}
+
+impl RelativePath {
+    pub fn new(path: impl Into<PathBuf>) -> RelativePath {
+        let path = path.into();
+
+        if path.is_relative() {
+            RelativePath { inner: path }
+        } else {
+            panic!("RelativePath::new must take a relative path")
+        }
+    }
+}
+
+impl<T: AsRef<str>> Div<T> for &RelativePath {
+    type Output = RelativePath;
+
+    fn div(self, rhs: T) -> Self::Output {
+        let parts = rhs.as_ref().split('/');
+        let mut result = self.inner.clone();
+
+        for part in parts {
+            result = result.join(part);
+        }
+
+        RelativePath::new(result)
+    }
+}
+pub trait DisplayPath {
+    fn display_path(&self) -> String;
+}
+
+impl DisplayPath for AbsolutePath {
+    fn display_path(&self) -> String {
+        self.inner.display().to_string()
+    }
+}
+
+impl DisplayPath for PathBuf {
+    fn display_path(&self) -> String {
+        self.display().to_string()
+    }
+}
+
+impl DisplayPath for str {
+    fn display_path(&self) -> String {
+        self.to_string()
+    }
+}
+
+impl DisplayPath for &str {
+    fn display_path(&self) -> String {
+        (*self).to_string()
+    }
+}
+
+impl DisplayPath for String {
+    fn display_path(&self) -> String {
+        self.clone()
+    }
+}
+
+impl DisplayPath for &String {
+    fn display_path(&self) -> String {
+        (*self).to_string()
+    }
+}
+pub enum Stub<'a> {
+    FileWithContent(&'a str, &'a str),
+    FileWithContentToBeTrimmed(&'a str, &'a str),
+    EmptyFile(&'a str),
+}
+
+pub fn file_contents(full_path: impl AsRef<Path>) -> String {
+    let mut file = std::fs::File::open(full_path.as_ref()).expect("can not open file");
+    let mut contents = String::new();
+    file.read_to_string(&mut contents)
+        .expect("can not read file");
+    contents
+}
+
+pub fn file_contents_binary(full_path: impl AsRef<Path>) -> Vec<u8> {
+    let mut file = std::fs::File::open(full_path.as_ref()).expect("can not open file");
+    let mut contents = Vec::new();
+    file.read_to_end(&mut contents).expect("can not read file");
+    contents
+}
+
+pub fn line_ending() -> String {
+    #[cfg(windows)]
+    {
+        String::from("\r\n")
+    }
+
+    #[cfg(not(windows))]
+    {
+        String::from("\n")
+    }
+}
+
+pub fn delete_file_at(full_path: impl AsRef<Path>) {
+    let full_path = full_path.as_ref();
+
+    if full_path.exists() {
+        std::fs::remove_file(full_path).expect("can not delete file");
+    }
+}
+
+pub fn create_file_at(full_path: impl AsRef<Path>) -> Result<(), std::io::Error> {
+    let full_path = full_path.as_ref();
+
+    if let Some(parent) = full_path.parent() {
+        panic!(format!("{:?} exists", parent.display()));
+    }
+
+    std::fs::write(full_path, b"fake data")
+}
+
+pub fn copy_file_to(source: &str, destination: &str) {
+    std::fs::copy(source, destination).expect("can not copy file");
+}
+
+pub fn files_exist_at(files: Vec<impl AsRef<Path>>, path: impl AsRef<Path>) -> bool {
+    files.iter().all(|f| {
+        let mut loc = PathBuf::from(path.as_ref());
+        loc.push(f);
+        loc.exists()
+    })
+}
+
+pub fn delete_directory_at(full_path: &str) {
+    std::fs::remove_dir_all(PathBuf::from(full_path)).expect("can not remove directory");
+}
+
+pub fn executable_path() -> PathBuf {
+    let mut buf = PathBuf::new();
+    buf.push("target");
+    buf.push("debug");
+    buf.push("nu");
+    buf
+}
+
+pub fn in_directory(str: impl AsRef<Path>) -> String {
+    str.as_ref().display().to_string()
+}

crates/nu-test-support/src/lib.rs

@@ -0,0 +1,38 @@
+pub mod fs;
+pub mod macros;
+pub mod playground;
+
+pub fn pipeline(commands: &str) -> String {
+    commands
+        .lines()
+        .skip(1)
+        .map(|line| line.trim())
+        .collect::<Vec<&str>>()
+        .join(" ")
+        .trim_end()
+        .to_string()
+}
+
+#[cfg(tests)]
+mod tests {
+    use super::pipeline;
+
+    #[test]
+    fn constructs_a_pipeline() {
+        let actual = pipeline(
+            r#"
+                open los_tres_amigos.txt
+                | from-csv
+                | get rusty_luck
+                | str --to-int
+                | sum
+                | echo "$it"
+            "#,
+        );
+
+        assert_eq!(
+            actual,
+            r#"open los_tres_amigos.txt | from-csv | get rusty_luck | str --to-int | sum | echo "$it""#
+        );
+    }
+}

crates/nu-test-support/src/macros.rs

@@ -0,0 +1,105 @@
+#[macro_export]
+macro_rules! nu {
+    (cwd: $cwd:expr, $path:expr, $($part:expr),*) => {{
+        use $crate::fs::DisplayPath;
+
+        let path = format!($path, $(
+            $part.display_path()
+        ),*);
+
+        nu!($cwd, &path)
+    }};
+
+    (cwd: $cwd:expr, $path:expr) => {{
+        nu!($cwd, $path)
+    }};
+
+    ($cwd:expr, $path:expr) => {{
+        pub use std::error::Error;
+        pub use std::io::prelude::*;
+        pub use std::process::{Command, Stdio};
+
+        let commands = &*format!(
+            "
+                            cd {}
+                            {}
+                            exit",
+            $crate::fs::in_directory($cwd),
+            $crate::fs::DisplayPath::display_path(&$path)
+        );
+
+        let mut process = match Command::new($crate::fs::executable_path())
+            .stdin(Stdio::piped())
+            .stdout(Stdio::piped())
+            .spawn()
+        {
+            Ok(child) => child,
+            Err(why) => panic!("Can't run test {}", why.to_string()),
+        };
+
+        let stdin = process.stdin.as_mut().expect("couldn't open stdin");
+        stdin
+            .write_all(commands.as_bytes())
+            .expect("couldn't write to stdin");
+
+
+        let output = process
+            .wait_with_output()
+            .expect("couldn't read from stdout");
+
+        let out = String::from_utf8_lossy(&output.stdout);
+        let out = out.replace("\r\n", "");
+        let out = out.replace("\n", "");
+        out
+    }};
+}
+
+#[macro_export]
+macro_rules! nu_error {
+    (cwd: $cwd:expr, $path:expr, $($part:expr),*) => {{
+        use $crate::fs::DisplayPath;
+
+        let path = format!($path, $(
+            $part.display_path()
+        ),*);
+
+        nu_error!($cwd, &path)
+    }};
+
+    (cwd: $cwd:expr, $path:expr) => {{
+        nu_error!($cwd, $path)
+    }};
+
+    ($cwd:expr, $path:expr) => {{
+        pub use std::error::Error;
+        pub use std::io::prelude::*;
+        pub use std::process::{Command, Stdio};
+
+        let commands = &*format!(
+            "
+                            cd {}
+                            {}
+                            exit",
+            $crate::fs::in_directory($cwd),
+            $crate::fs::DisplayPath::display_path(&$path)
+        );
+
+        let mut process = Command::new($crate::fs::executable_path())
+            .stdin(Stdio::piped())
+            .stderr(Stdio::piped())
+            .spawn()
+            .expect("couldn't run test");
+
+        let stdin = process.stdin.as_mut().expect("couldn't open stdin");
+        stdin
+            .write_all(commands.as_bytes())
+            .expect("couldn't write to stdin");
+
+        let output = process
+            .wait_with_output()
+            .expect("couldn't read from stderr");
+
+        let out = String::from_utf8_lossy(&output.stderr);
+        out.into_owned()
+    }};
+}

crates/nu-test-support/src/playground.rs

@@ -0,0 +1,156 @@
+use crate::fs::line_ending;
+use crate::fs::Stub;
+
+use getset::Getters;
+use glob::glob;
+use std::path::{Path, PathBuf};
+use tempfile::{tempdir, TempDir};
+
+pub struct Playground {
+    root: TempDir,
+    tests: String,
+    cwd: PathBuf,
+}
+
+#[derive(Getters)]
+#[get = "pub"]
+pub struct Dirs {
+    pub root: PathBuf,
+    pub test: PathBuf,
+    pub fixtures: PathBuf,
+}
+
+impl Dirs {
+    pub fn formats(&self) -> PathBuf {
+        self.fixtures.join("formats")
+    }
+}
+
+impl Playground {
+    pub fn root(&self) -> &Path {
+        self.root.path()
+    }
+
+    pub fn back_to_playground(&mut self) -> &mut Self {
+        self.cwd = PathBuf::from(self.root()).join(self.tests.clone());
+        self
+    }
+
+    pub fn setup(topic: &str, block: impl FnOnce(Dirs, &mut Playground)) {
+        let root = tempdir().expect("Couldn't create a tempdir");
+        let nuplay_dir = root.path().join(topic);
+
+        if PathBuf::from(&nuplay_dir).exists() {
+            std::fs::remove_dir_all(PathBuf::from(&nuplay_dir)).expect("can not remove directory");
+        }
+
+        std::fs::create_dir(PathBuf::from(&nuplay_dir)).expect("can not create directory");
+
+        let mut playground = Playground {
+            root,
+            tests: topic.to_string(),
+            cwd: nuplay_dir,
+        };
+
+        let project_root = PathBuf::from(env!("CARGO_MANIFEST_DIR"));
+        let playground_root = playground.root.path();
+
+        let fixtures = project_root;
+        let fixtures = fixtures
+            .parent()
+            .expect("Couldn't find the fixtures directory")
+            .parent()
+            .expect("Couldn't find the fixtures directory")
+            .join("tests/fixtures");
+
+        let fixtures = dunce::canonicalize(fixtures.clone()).unwrap_or_else(|e| {
+            panic!(
+                "Couldn't canonicalize fixtures path {}: {:?}",
+                fixtures.display(),
+                e
+            )
+        });
+
+        let test = dunce::canonicalize(playground_root.join(topic)).unwrap_or_else(|e| {
+            panic!(
+                "Couldn't canonicalize test path {}: {:?}",
+                playground_root.join(topic).display(),
+                e
+            )
+        });
+
+        let root = dunce::canonicalize(playground_root).unwrap_or_else(|e| {
+            panic!(
+                "Couldn't canonicalize tests root path {}: {:?}",
+                playground_root.display(),
+                e
+            )
+        });
+
+        let dirs = Dirs {
+            root,
+            test,
+            fixtures,
+        };
+
+        block(dirs, &mut playground);
+    }
+
+    pub fn mkdir(&mut self, directory: &str) -> &mut Self {
+        self.cwd.push(directory);
+        std::fs::create_dir_all(&self.cwd).expect("can not create directory");
+        self.back_to_playground();
+        self
+    }
+
+    pub fn with_files(&mut self, files: Vec<Stub>) -> &mut Self {
+        let endl = line_ending();
+
+        files
+            .iter()
+            .map(|f| {
+                let mut path = PathBuf::from(&self.cwd);
+
+                let (file_name, contents) = match *f {
+                    Stub::EmptyFile(name) => (name, "fake data".to_string()),
+                    Stub::FileWithContent(name, content) => (name, content.to_string()),
+                    Stub::FileWithContentToBeTrimmed(name, content) => (
+                        name,
+                        content
+                            .lines()
+                            .skip(1)
+                            .map(|line| line.trim())
+                            .collect::<Vec<&str>>()
+                            .join(&endl),
+                    ),
+                };
+
+                path.push(file_name);
+
+                std::fs::write(path, contents.as_bytes()).expect("can not create file");
+            })
+            .for_each(drop);
+        self.back_to_playground();
+        self
+    }
+
+    pub fn within(&mut self, directory: &str) -> &mut Self {
+        self.cwd.push(directory);
+        std::fs::create_dir(&self.cwd).expect("can not create directory");
+        self
+    }
+
+    pub fn glob_vec(pattern: &str) -> Vec<PathBuf> {
+        let glob = glob(pattern);
+
+        glob.expect("invalid pattern")
+            .map(|path| {
+                if let Ok(path) = path {
+                    path
+                } else {
+                    unreachable!()
+                }
+            })
+            .collect()
+    }
+}