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node_modules/@csstools/css-parser-algorithms/README.md

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+# CSS Parser Algorithms
+
+[<img alt="npm version" src="https://img.shields.io/npm/v/@csstools/css-parser-algorithms.svg" height="20">][npm-url]
+[<img alt="Build Status" src="https://github.com/csstools/postcss-plugins/workflows/test/badge.svg" height="20">][cli-url]
+[<img alt="Discord" src="https://shields.io/badge/Discord-5865F2?logo=discord&logoColor=white">][discord]
+
+Implemented from : https://www.w3.org/TR/2021/CRD-css-syntax-3-20211224/
+
+## API
+
+[Read the API docs](./docs/css-parser-algorithms.md)
+
+## Usage
+
+Add [CSS Parser Algorithms] to your project:
+
+```bash
+npm install @csstools/css-parser-algorithms @csstools/css-tokenizer --save-dev
+```
+
+[CSS Parser Algorithms] only accepts tokenized CSS.
+It must be used together with `@csstools/css-tokenizer`.
+
+
+```js
+import { tokenizer, TokenType } from '@csstools/css-tokenizer';
+import { parseComponentValue } from '@csstools/css-parser-algorithms';
+
+const myCSS =  `@media only screen and (min-width: 768rem) {
+	.foo {
+		content: 'Some content!' !important;
+	}
+}
+`;
+
+const t = tokenizer({
+	css: myCSS,
+});
+
+const tokens = [];
+
+{
+	while (!t.endOfFile()) {
+		tokens.push(t.nextToken());
+	}
+
+	tokens.push(t.nextToken()); // EOF-token
+}
+
+const options = {
+	onParseError: ((err) => {
+		throw err;
+	}),
+};
+
+const result = parseComponentValue(tokens, options);
+
+console.log(result);
+```
+
+### Available functions
+
+- [`parseComponentValue`](https://www.w3.org/TR/css-syntax-3/#parse-component-value)
+- [`parseListOfComponentValues`](https://www.w3.org/TR/css-syntax-3/#parse-list-of-component-values)
+- [`parseCommaSeparatedListOfComponentValues`](https://www.w3.org/TR/css-syntax-3/#parse-comma-separated-list-of-component-values)
+
+### Utilities
+
+#### `gatherNodeAncestry`
+
+The AST does not expose the entire ancestry of each node.
+The walker methods do provide access to the current parent, but also not the entire ancestry.
+
+To gather the entire ancestry for a a given sub tree of the AST you can use `gatherNodeAncestry`.
+The result is a `Map` with the child nodes as keys and the parents as values.
+This allows you to lookup any ancestor of any node.
+
+```js
+import { parseComponentValue } from '@csstools/css-parser-algorithms';
+
+const result = parseComponentValue(tokens, options);
+const ancestry = gatherNodeAncestry(result);
+```
+
+### Options
+
+```ts
+{
+	onParseError?: (error: ParseError) => void
+}
+```
+
+#### `onParseError`
+
+The parser algorithms are forgiving and won't stop when a parse error is encountered.
+Parse errors also aren't tokens.
+
+To receive parsing error information you can set a callback.
+
+Parser errors will try to inform you about the point in the parsing logic the error happened.
+This tells you the kind of error.
+
+## Goals and non-goals
+
+Things this package aims to be:
+- specification compliant CSS parser
+- a reliable low level package to be used in CSS sub-grammars
+
+What it is not:
+- opinionated
+- fast
+- small
+- a replacement for PostCSS (PostCSS is fast and also an ecosystem)
+
+[cli-url]: https://github.com/csstools/postcss-plugins/actions/workflows/test.yml?query=workflow/test
+[discord]: https://discord.gg/bUadyRwkJS
+[npm-url]: https://www.npmjs.com/package/@csstools/css-parser-algorithms
+
+[CSS Parser Algorithms]: https://github.com/csstools/postcss-plugins/tree/main/packages/css-parser-algorithms