Crate oxc_css_parser 

oxc-css-parser is a parser that can parse CSS, SCSS, Sass (indented syntax) and Less.

Basic Usage

This crate provides a simple API to get started.

First, create a parser, give it the source code and specify the syntax, then call the parse method:

use oxc_css_parser::{Allocator, Parser, Syntax, ast::Stylesheet};

let allocator = Allocator::default();
let mut parser = Parser::new(&allocator, "a {}", Syntax::Css); // syntax can also be `Scss`, `Sass` or `Less`
let result = parser.parse::<Stylesheet>();
match result {
    Ok(ast) => {
        // parsed successfully
        println!("{:#?}", ast);
    }
    Err(error) => {
        // it failed, error message and position can be accessed via `error`
        println!("{:#?}", error);
    }
}

Advanced Usage

Creating Parser with Builder

If you need to control parser with additional features, you can use ParserBuilder.

For example, to collect comments:

use oxc_css_parser::{Allocator, ParserBuilder, ast::Stylesheet};

let allocator = Allocator::default();
let builder = ParserBuilder::new(&allocator, "/* comment */ a {}").comments();
let mut parser = builder.build();
parser.parse::<Stylesheet>().unwrap();
let comments = parser.comments();

By default, syntax is CSS when using parser builder. You can customize it:

use oxc_css_parser::{Allocator, ParserBuilder, Syntax};

let allocator = Allocator::default();
let builder = ParserBuilder::new(&allocator, "a {}").syntax(Syntax::Scss);

Parser option: template_placeholder

By default, a backtick is a syntax error outside Less. Setting this option makes the parser recognize a backtick-delimited token of the shape `<prefix><decimal index>` as an atomic Placeholder node (in value, selector, and statement positions) carrying the parsed index. The token terminates at the closing backtick, so a following identifier re-lexes separately. This is designed for downstream formatters that substitute template interpolations (e.g. CSS-in-JS ${expr}) with such placeholders before parsing. It MUST be used with Syntax::Scss (backtick is Less’s inline-JS delimiter).

use oxc_css_parser::{Allocator, ParserBuilder, ParserOptions, Syntax, TemplatePlaceholder, ast::*};

let allocator = Allocator::default();
let options = ParserOptions {
    template_placeholder: Some(TemplatePlaceholder {
        prefix: "PLACEHOLDER-",
    }),
    ..Default::default()
};
let builder = ParserBuilder::new(&allocator, "a { width: `PLACEHOLDER-0`; }")
    .syntax(Syntax::Scss)
    .options(options);
let mut parser = builder.build();

assert!(parser.parse::<Stylesheet>().is_ok());

Parse Partial Structure

Sometimes you don’t want to parse a full stylesheet. Say you only need to parse a qualified rule or even a single declaration. All you need to do is to update the generics of the parse method.

use oxc_css_parser::{Allocator, Parser, Syntax, ast::QualifiedRule};

let allocator = Allocator::default();
let mut parser = Parser::new(&allocator, "a {}", Syntax::Css);
parser.parse::<QualifiedRule>();

and

use oxc_css_parser::{Allocator, Parser, Syntax, ast::Declaration};

let allocator = Allocator::default();
let mut parser = Parser::new(&allocator, "color: green", Syntax::Css);
parser.parse::<Declaration>();

Not all AST nodes support the usage above; technically, those nodes that implement Parse trait are supported.

Retrieve Recoverable Errors

There may be some recoverable errors which doesn’t affect on producing AST. To retrieve those errors, use recoverable_errors.

use oxc_css_parser::{Allocator, Parser, Syntax, ast::Stylesheet};

let allocator = Allocator::default();
let mut parser = Parser::new(&allocator, "@keyframes kf { invalid {} }", Syntax::Css);
let result = parser.parse::<Stylesheet>();
assert!(result.is_ok());
println!("{:?}", parser.recoverable_errors());

Serialization

Produced AST can be serialized by Serde, but this feature is disabled by default. You need to enable feature serialize manually:

oxc-css-parser = { version = "*", features = ["serialize"] }

Then you can pass AST to Serde.

Note that oxc-css-parser only supports serialization. Deserialization isn’t supported.

Re-exports

pub use pos::Span;

Modules

ast

All kinds of AST nodes are here.

error

Error management.

pos

token

All supported tokens, and with comments.

Structs

Allocator

A bump-allocated memory arena.

Parser

Create a parser with some source code, then parse it.

ParserBuilder

Parser builder is for building a parser while allowing us to control advanced behaviors.

ParserOptions

Parser options for customizing parser behaviors.

TemplatePlaceholder

Configuration for a backtick-delimited template placeholder.

Enums

Syntax

Supported syntax.

Traits

Parse