rewrite parsing, evaluation, and serialization (#67)

Adds support for the indented syntax, plain CSS imports, `@forward`, and many other previously missing features.

.github/ISSUE_TEMPLATE/incorrect-sass-output.md

@@ -1,19 +1,20 @@
 ---
-name: Incorrect SASS Output
-about: There exists a differential between the output of grass and dart-sass
+name: Incorrect Sass Output
+about: `grass` and `dart-sass` differ in output or `grass` reports and error for a valid style sheet
 title: ''
 labels: bug
 assignees: connorskees
 
 ---
 
-**Minimal Reproducible Example**:
+**Failing Sass**:
 ```
 a {
   color: red;
 }
 ```
 
+<!-- Showing output from both tools is optional, but does help in debugging -->
 **`grass` Output**:
 ```
 a {

.github/workflows/tests.yml

@@ -73,10 +73,10 @@ jobs:
       - name: Build
         run: cargo build
 
-      - name: Install dart-sass 1.36.0
+      - name: Install dart-sass 1.54.3
         run: |
-          wget https://github.com/sass/dart-sass/releases/download/1.36.0/dart-sass-1.36.0-linux-x64.tar.gz
-          tar -xzvf dart-sass-1.36.0-linux-x64.tar.gz
+          wget https://github.com/sass/dart-sass/releases/download/1.54.3/dart-sass-1.54.3-linux-x64.tar.gz
+          tar -xzvf dart-sass-1.54.3-linux-x64.tar.gz
 
       - name: Install bootstrap
         run: git clone --depth=1 --branch v5.0.2 https://github.com/twbs/bootstrap.git

CHANGELOG.md

@@ -1,3 +1,55 @@
+# TBD
+
+- complete rewrite of parsing, evaluation, and serialization steps
+- **implement the indented syntax**
+- **implement plain CSS imports**
+- support for custom properties
+- represent all numbers as f64, rather than using arbitrary precision
+- implement media query merging
+- implement builtin function `keywords`
+- implement Infinity and -Infinity
+- implement the `@forward` rule
+- feature complete parsing of `@supports` conditions
+- support media queries level 4
+- implement calculation simplification and the calculation value type
+- implement builtin fns `calc-args`, `calc-name`
+- add builtin math module variables `$epsilon`, `$max-safe-integer`, `$min-safe-integer`, `$max-number`, `$min-number`
+- allow angle units `turn` and `grad` in builtin trigonometry functions
+- implement `@at-root` conditions
+- implement `@import` conditions
+- remove dependency on `num-rational` and `beef`
+- support control flow inside declaration blocks
+For example:
+```scss
+a {
+  -webkit-: {
+    @if 1 == 1 {
+      scrollbar: red
+    }
+  }
+}
+```
+
+will now emit
+
+```css
+a {
+  -webkit-scrollbar: red;
+}
+```
+- always emit `rgb`/`rgba`/`hsl`/`hsla` for colors declared as such in expanded mode
+- more efficiently compress colors in compressed mode
+- treat `:where` the same as `:is` in extension
+- support "import-only" files
+- treat `@elseif` the same as `@else if`
+- implement division of non-comparable units and feature complete support for complex units
+- support 1 arg color.hwb()
+
+UPCOMING:
+
+- error when `@extend` is used across `@media` boundaries
+- more robust support for NaN in builtin functions
+
 # 0.11.2
 
 - make `grass::Error` a `Send` type

Cargo.toml

@@ -23,63 +23,32 @@ path = "src/lib.rs"
 # crate-type = ["cdylib", "rlib"]
 bench = false
 
-[[bench]]
-path = "benches/variables.rs"
-name = "variables"
-harness = false
-
-[[bench]]
-path = "benches/colors.rs"
-name = "colors"
-harness = false
-
-[[bench]]
-path = "benches/numbers.rs"
-name = "numbers"
-harness = false
-
-[[bench]]
-path = "benches/control_flow.rs"
-name = "control_flow"
-harness = false
-
-[[bench]]
-path = "benches/styles.rs"
-name = "styles"
-harness = false
-
-
 [dependencies]
 clap = { version = "2.34.0", optional = true }
-num-rational = "0.4"
-num-bigint = "0.4"
-num-traits = "0.2.14"
+# todo: use lazy_static
 once_cell = "1.15.0"
+# todo: use xorshift for random numbers
 rand = { version = "0.8", optional = true }
+# todo: update to use asref<path>
+# todo: update to expose more info (for eww)
+# todo: update to use text_size::TextRange
 codemap = "0.1.3"
 wasm-bindgen = { version = "0.2.68", optional = true }
-beef = "0.5"
+# todo: use phf for global functions
 phf = { version = "0.11", features = ["macros"] }
-# criterion is not a dev-dependency because it makes tests take too
-# long to compile, and you cannot make dev-dependencies optional
-criterion = { version = "0.4.0", optional = true }
-indexmap = "1.9.1"
+indexmap = "1.9.0"
+# todo: do we really need interning for things?
 lasso = "0.6"
 
 [features]
+# todo: no commandline by default
 default = ["commandline", "random"]
 # Option (enabled by default): build a binary using clap
 commandline = ["clap"]
-# Option: enable nightly-only features (for right now, only the `track_caller` attribute) 
-nightly = []
 # Option (enabled by default): enable the builtin functions `random([$limit])` and `unique-id()`
 random = ["rand"]
 # Option: expose JavaScript-friendly WebAssembly exports
 wasm-exports = ["wasm-bindgen"]
-# Option: enable features that assist in profiling (e.g. inline(never))
-profiling = []
-# Option: enable criterion for benchmarking
-bench = ["criterion"]
 
 [dev-dependencies]
 tempfile = "3.3.0"

README.md

@@ -3,17 +3,12 @@
 This crate aims to provide a high level interface for compiling Sass into
 plain CSS. It offers a very limited API, currently exposing only 2 functions.
 
-In addition to a library, also included is a binary that is intended to act as an invisible
+In addition to a library, this crate also includes a binary that is intended to act as an invisible
 replacement to the Sass commandline executable.
 
 This crate aims to achieve complete feature parity with the `dart-sass` reference
 implementation. A deviation from the `dart-sass` implementation can be considered
-a bug except for in the following situations:
-
-- Error messages
-- Error spans
-- Certain aspects of the indented syntax
-- Potentially others in the future
+a bug except for in the case of error message and error spans.
 
 [Documentation](https://docs.rs/grass/)  
 [crates.io](https://crates.io/crates/grass)
@@ -24,17 +19,7 @@ a bug except for in the following situations:
 
 Every commit of `grass` is tested against bootstrap v5.0.2, and every release is tested against the last 2,500 commits of bootstrap's `main` branch.
 
-That said, there are a number of known missing features and bugs. The notable features remaining are
-
-```
-indented syntax
-@forward and more complex uses of @use
-@at-root and @import media queries
-@media query merging
-/ as a separator in color functions, e.g. rgba(255, 255, 255 / 0)
-Infinity and -Infinity
-builtin meta function `keywords`
-```
+That said, there are a number of known missing features and bugs. The rough edges of `grass` largely include `@forward` and more complex uses of `@uses`. We support basic usage of these rules, but more advanced features such as `@import`ing modules containing `@forward` with prefixes may not behave as expected.
 
 All known missing features and bugs are tracked in [#19](https://github.com/connorskees/grass/issues/19).
 
@@ -44,11 +29,10 @@ All known missing features and bugs are tracked in [#19](https://github.com/conn
 
 `grass` experimentally releases a
 [WASM version of the library to npm](https://www.npmjs.com/package/@connorskees/grass),
-compiled using wasm-bindgen. To use `grass` in your JavaScript projects, just run
-`npm install @connorskees/grass` to add it to your package.json. Better documentation
-for this version will be provided when the library becomes more stable.
+compiled using wasm-bindgen. To use `grass` in your JavaScript projects, run
+`npm install @connorskees/grass` to add it to your package.json. This version of grass is not currently well documented, but one can find example usage in the [`grassmeister` repository](https://github.com/connorskees/grassmeister).
 
-## Features
+## Cargo Features
 
 ### commandline
 
@@ -73,28 +57,16 @@ are in the official spec.
 
 Having said that, to run the official test suite,
 
-```bash
-git clone https://github.com/connorskees/grass --recursive
-cd grass
-cargo b --release
-./sass-spec/sass-spec.rb -c './target/release/grass'
-```
-
-Note: you will have to install [ruby](https://www.ruby-lang.org/en/downloads/),
-[bundler](https://bundler.io/) and run `bundle install` in `./sass-spec/`.
-This might also require you to install the requirements separately
-for [curses](https://github.com/ruby/curses).
-
-Alternatively, it is possible to use nodejs to run the spec,
-
 ```bash
 # This script expects node >=v14.14.0. Check version with `node --version`
 git clone https://github.com/connorskees/grass --recursive
 cd grass && cargo b --release
 cd sass-spec && npm install
-npm run sass-spec -- --command '../target/release/grass'
+npm run sass-spec -- --impl=dart-sass --command '../target/release/grass'
 ```
 
+The spec runner does not work on Windows.
+
 These numbers come from a default run of the Sass specification as shown above.
 
 ```
@@ -103,3 +75,5 @@ PASSING: 4205
 FAILING: 2051
 TOTAL: 6256
 ```
+
+<!-- todo: msrv 1.41.1 -->