109 lines
2.3 KiB
Markdown
109 lines
2.3 KiB
Markdown
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# CSS Tokenizer
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[<img alt="npm version" src="https://img.shields.io/npm/v/@csstools/css-tokenizer.svg" height="20">][npm-url]
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[<img alt="Build Status" src="https://github.com/csstools/postcss-plugins/workflows/test/badge.svg" height="20">][cli-url]
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[<img alt="Discord" src="https://shields.io/badge/Discord-5865F2?logo=discord&logoColor=white">][discord]
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Implemented from : https://www.w3.org/TR/2021/CRD-css-syntax-3-20211224/
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## Usage
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Add [CSS Tokenizer] to your project:
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```bash
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npm install @csstools/css-tokenizer --save-dev
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```
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```js
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import { tokenizer, TokenType } from '@csstools/css-tokenizer';
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const myCSS = `@media only screen and (min-width: 768rem) {
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.foo {
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content: 'Some content!' !important;
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}
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}
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`;
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const t = tokenizer({
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css: myCSS,
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});
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while (true) {
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const token = t.nextToken();
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if (token[0] === TokenType.EOF) {
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break;
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}
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console.log(token);
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}
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```
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Or use the `tokenize` helper function:
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```js
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import { tokenize } from '@csstools/css-tokenizer';
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const myCSS = `@media only screen and (min-width: 768rem) {
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.foo {
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content: 'Some content!' !important;
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}
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}
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`;
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const tokens = tokenize({
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css: myCSS,
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});
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console.log(tokens);
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```
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### Options
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```ts
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{
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onParseError?: (error: ParseError) => void
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}
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```
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#### `onParseError`
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The tokenizer is forgiving and won't stop when a parse error is encountered.
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Parse errors also aren't tokens.
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To receive parsing error information you can set a callback.
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```js
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import { tokenizer, TokenType } from '@csstools/css-tokenizer';
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const t = tokenizer({
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css: '\\',
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}, { onParseError: (err) => console.warn(err) });
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while (true) {
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const token = t.nextToken();
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if (token[0] === TokenType.EOF) {
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break;
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}
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}
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```
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Parser errors will try to inform you about the point in the tokenizer logic the error happened.
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This tells you the kind of error.
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## Goals and non-goals
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Things this package aims to be:
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- specification compliant CSS tokenizer
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- a reliable low level package to be used in CSS parsers
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What it is not:
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- opinionated
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- fast
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- small
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[cli-url]: https://github.com/csstools/postcss-plugins/actions/workflows/test.yml?query=workflow/test
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[discord]: https://discord.gg/bUadyRwkJS
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[npm-url]: https://www.npmjs.com/package/@csstools/css-tokenizer
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[CSS Tokenizer]: https://github.com/csstools/postcss-plugins/tree/main/packages/css-tokenizer
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