documentation/node_modules/micromark-extension-directive/lib/factory-label.js

/**
 * @typedef {import('micromark-util-types').Effects} Effects
 * @typedef {import('micromark-util-types').State} State
 * @typedef {import('micromark-util-types').Token} Token
 * @typedef {import('micromark-util-types').TokenType} TokenType
 */

import {markdownLineEnding} from 'micromark-util-character'
// This is a fork of:
// <https://github.com/micromark/micromark/tree/main/packages/micromark-factory-label>
// to allow empty labels, balanced brackets (such as for nested directives),
// text instead of strings, and optionally disallows EOLs.
/**
 * @param {Effects} effects
 * @param {State} ok
 * @param {State} nok
 * @param {TokenType} type
 * @param {TokenType} markerType
 * @param {TokenType} stringType
 * @param {boolean | undefined} [disallowEol=false]
 */
export function factoryLabel(
  effects,
  ok,
  nok,
  type,
  markerType,
  stringType,
  disallowEol
) {
  let size = 0
  let balance = 0
  /** @type {Token | undefined} */
  let previous
  return start

  /** @type {State} */
  function start(code) {
    effects.enter(type)
    effects.enter(markerType)
    effects.consume(code)
    effects.exit(markerType)
    return afterStart
  }

  /** @type {State} */
  function afterStart(code) {
    if (code === 93) {
      effects.enter(markerType)
      effects.consume(code)
      effects.exit(markerType)
      effects.exit(type)
      return ok
    }
    effects.enter(stringType)
    return lineStart(code)
  }

  /** @type {State} */
  function lineStart(code) {
    if (code === 93 && !balance) {
      return atClosingBrace(code)
    }
    const token = effects.enter('chunkText', {
      contentType: 'text',
      previous
    })
    if (previous) previous.next = token
    previous = token
    return data(code)
  }

  /** @type {State} */
  function data(code) {
    if (code === null || size > 999) {
      return nok(code)
    }
    if (code === 91 && ++balance > 32) {
      return nok(code)
    }
    if (code === 93 && !balance--) {
      effects.exit('chunkText')
      return atClosingBrace(code)
    }
    if (markdownLineEnding(code)) {
      if (disallowEol) {
        return nok(code)
      }
      effects.consume(code)
      effects.exit('chunkText')
      return lineStart
    }
    effects.consume(code)
    return code === 92 ? dataEscape : data
  }

  /** @type {State} */
  function dataEscape(code) {
    if (code === 91 || code === 92 || code === 93) {
      effects.consume(code)
      size++
      return data
    }
    return data(code)
  }

  /** @type {State} */
  function atClosingBrace(code) {
    effects.exit(stringType)
    effects.enter(markerType)
    effects.consume(code)
    effects.exit(markerType)
    effects.exit(type)
    return ok
  }
}