micromark-util-classify-character

What is micromark-util-classify-character?

The micromark-util-classify-character package is a utility for classifying characters in the context of micromark, a markdown parser. It helps in identifying character types such as whitespace, punctuation, and more, which is essential for parsing and tokenizing markdown content.

What are micromark-util-classify-character's main functionalities?

Whitespace Classification

This feature allows you to check if a character is a whitespace character. It returns true for spaces, newlines, and other whitespace characters, and false otherwise.

const { isWhitespace } = require('micromark-util-classify-character');

console.log(isWhitespace(' ')); // true
console.log(isWhitespace('\n')); // true
console.log(isWhitespace('a')); // false

Punctuation Classification

This feature allows you to check if a character is a punctuation character. It returns true for characters like periods, commas, and other punctuation marks, and false otherwise.

const { isPunctuation } = require('micromark-util-classify-character');

console.log(isPunctuation('.')); // true
console.log(isPunctuation(',')); // true
console.log(isPunctuation('a')); // false

Identifier Classification

This feature allows you to check if a character can start or continue an identifier. It returns true for valid identifier start characters (like letters and underscores) and valid identifier continuation characters (like letters, digits, and underscores).

const { isIdentifierStart, isIdentifierContinue } = require('micromark-util-classify-character');

console.log(isIdentifierStart('a')); // true
console.log(isIdentifierStart('_')); // true
console.log(isIdentifierStart('1')); // false
console.log(isIdentifierContinue('1')); // true
console.log(isIdentifierContinue('-')); // false

Other packages similar to micromark-util-classify-character

is-whitespace

The is-whitespace package provides a simple utility to check if a character is a whitespace character. It is more focused and less comprehensive compared to micromark-util-classify-character, which offers a broader range of character classification utilities.

is-punctuation

The is-punctuation package allows you to check if a character is a punctuation mark. Similar to is-whitespace, it is more specialized and does not offer the wide range of character classifications that micromark-util-classify-character does.

char-regex

The char-regex package provides regular expressions for different character classes, such as whitespace, punctuation, and identifiers. While it offers similar functionality, it uses regular expressions rather than direct utility functions, which might be less convenient for some use cases.

README

micromark-util-classify-character

micromark utility to classify whether a character is whitespace or punctuation.

Contents

• What is this?
• When should I use this?
• Install
• Use
• API
  • classifyCharacter(code)
• Types
• Compatibility
• Security
• Contribute
• License

What is this?

This package exposes an algorithm to classify characters into 3 categories.

When should I use this?

This package might be useful when you are making your own micromark extensions.

Install

This package is ESM only. In Node.js (version 16+), install with npm:

npm install micromark-util-classify-character

In Deno with esm.sh:

import {classifyCharacter} from 'https://esm.sh/micromark-util-classify-character@1'

In browsers with esm.sh:

<script type="module">
  import {classifyCharacter} from 'https://esm.sh/micromark-util-classify-character@1?bundle'
</script>

Use

/**
 * @this {TokenizeContext}
 *   Context.
 * @type {Tokenizer}
 */
function tokenizeAttention(effects, ok) {
  return start

  // …

  /** @type {State} */
  function sequence(code) {
    if (code === marker) {
      // …
    }

    const token = effects.exit('attentionSequence')
    const after = classifyCharacter(code)
    const open =
      !after || (after === constants.characterGroupPunctuation && before)
    const close =
      !before || (before === constants.characterGroupPunctuation && after)
    // …
  }

  // …
}

API

This module exports the identifier classifyCharacter. There is no default export.

classifyCharacter(code)

Classify whether a code represents whitespace, punctuation, or something else.

Used for attention (emphasis, strong), whose sequences can open or close based on the class of surrounding characters.

👉 Note: eof (null) is seen as whitespace.

Parameters

• code (Code) — code

Returns

Group (constants.characterGroupWhitespace, constants.characterGroupPunctuation, or undefined).

Types

This package is fully typed with TypeScript. It exports no additional types.

Compatibility

Projects maintained by the unified collective are compatible with maintained versions of Node.js.

When we cut a new major release, we drop support for unmaintained versions of Node. This means we try to keep the current release line, micromark-util-classify-character@2, compatible with Node.js 16. This package works with micromark@3.

Security

This package is safe. See security.md in micromark/.github for how to submit a security report.

Contribute

See contributing.md in micromark/.github for ways to get started. See support.md for ways to get help.

This project has a code of conduct. By interacting with this repository, organisation, or community you agree to abide by its terms.

License

MIT © Titus Wormer