MZC/KnowMathBot/frontend/node_modules/micromark-factory-space/index.js

/**
 * @import {Effects, State, TokenType} from 'micromark-util-types'
 */

import { markdownSpace } from 'micromark-util-character';

// To do: implement `spaceOrTab`, `spaceOrTabMinMax`, `spaceOrTabWithOptions`.

/**
 * Parse spaces and tabs.
 *
 * There is no `nok` parameter:
 *
 * *   spaces in markdown are often optional, in which case this factory can be
 *     used and `ok` will be switched to whether spaces were found or not
 * *   one line ending or space can be detected with `markdownSpace(code)` right
 *     before using `factorySpace`
 *
 * ###### Examples
 *
 * Where `␉` represents a tab (plus how much it expands) and `␠` represents a
 * single space.
 *
 * ```markdown
 * ␉
 * ␠␠␠␠
 * ␉␠
 * ```
 *
 * @param {Effects} effects
 *   Context.
 * @param {State} ok
 *   State switched to when successful.
 * @param {TokenType} type
 *   Type (`' \t'`).
 * @param {number | undefined} [max=Infinity]
 *   Max (exclusive).
 * @returns {State}
 *   Start state.
 */
export function factorySpace(effects, ok, type, max) {
  const limit = max ? max - 1 : Number.POSITIVE_INFINITY;
  let size = 0;
  return start;

  /** @type {State} */
  function start(code) {
    if (markdownSpace(code)) {
      effects.enter(type);
      return prefix(code);
    }
    return ok(code);
  }

  /** @type {State} */
  function prefix(code) {
    if (markdownSpace(code) && size++ < limit) {
      effects.consume(code);
      return prefix;
    }
    effects.exit(type);
    return ok(code);
  }
}