cssselect

Translate CSS3 selectors into XPath 1.0 expression strings.

This crate parses a CSS group of selectors and emits XPath 1.0 strings. The whole library is a pure string to string transformation. It needs alloc but not std, so it builds for no_std and wasm32 targets with zero runtime dependencies.

Installation

[dependencies]
cssselect = "0.1"

Usage

use cssselect::GenericTranslator;

let xpath = GenericTranslator::new()
    .css_to_xpath("a#bar")
    .unwrap();
assert_eq!(xpath, "descendant-or-self::a[@id = 'bar']");

GenericTranslator targets generic XML. HtmlTranslator targets (X)HTML with case-insensitive names and HTML-aware results for :checked, :disabled, :enabled, :link, and :lang().

Call parse directly when you need the parsed tree, the canonical CSS form, or the specificity:

use cssselect::parse;

let selector = &parse(":is(.foo, #bar)").unwrap()[0];
assert_eq!(selector.canonical(), ":is(.foo, #bar)");
assert_eq!(selector.specificity(), (1, 0, 0));

Supported selectors

Type, universal, namespace, class, id, and attribute selectors with the =, ~=, |=, ^=, $=, *=, and != operators. Structural pseudo-classes including the :nth-* family, :not(), :is(), :matches(), :where(), :has(), and :scope. Pseudo-elements with one or two colons. The four combinators: descendant, >, +, and ~.

Tests

cargo test runs the string-parity suite with no dependencies. The optional selection tier runs generated XPath against a real engine:

cargo test --features xpath-engine-tests

License

Licensed under the BSD 3-Clause license.