@mapbox/jsxtreme-markdown/vendor/remark-parse/lib/tokenize/heading-atx.js

Transform Markdown into JSX or React component modules

'use strict';

module.exports = atxHeading;

var lineFeed = '\n';
var tab = '\t';
var space = ' ';
var numberSign = '#';

var maxFenceCount = 6;

function atxHeading(eat, value, silent) {
  var self = this;
  var pedantic = self.options.pedantic;
  var length = value.length + 1;
  var index = -1;
  var now = eat.now();
  var subvalue = '';
  var content = '';
  var character;
  var queue;
  var depth;

  // Eat initial spacing.
  while (++index < length) {
    character = value.charAt(index);

    if (character !== space && character !== tab) {
      index--;
      break;
    }

    subvalue += character;
  }

  // Eat hashes.
  depth = 0;

  while (++index <= length) {
    character = value.charAt(index);

    if (character !== numberSign) {
      index--;
      break;
    }

    subvalue += character;
    depth++;
  }

  if (depth > maxFenceCount) {
    return;
  }

  if (!depth || (!pedantic && value.charAt(index + 1) === numberSign)) {
    return;
  }

  length = value.length + 1;

  // Eat intermediate white-space.
  queue = '';

  while (++index < length) {
    character = value.charAt(index);

    if (character !== space && character !== tab) {
      index--;
      break;
    }

    queue += character;
  }

  // Exit when not in pedantic mode without spacing.
  if (!pedantic && queue.length === 0 && character && character !== lineFeed) {
    return;
  }

  if (silent) {
    return true;
  }

  // Eat content.
  subvalue += queue;
  queue = '';
  content = '';

  while (++index < length) {
    character = value.charAt(index);

    if (!character || character === lineFeed) {
      break;
    }

    if (character !== space && character !== tab && character !== numberSign) {
      content += queue + character;
      queue = '';
      continue;
    }

    while (character === space || character === tab) {
      queue += character;
      character = value.charAt(++index);
    }

    // `#` without a queue is part of the content.
    if (!pedantic && content && !queue && character === numberSign) {
      content += character;
      continue;
    }

    while (character === numberSign) {
      queue += character;
      character = value.charAt(++index);
    }

    while (character === space || character === tab) {
      queue += character;
      character = value.charAt(++index);
    }

    index--;
  }

  now.column += subvalue.length;
  now.offset += subvalue.length;
  subvalue += content + queue;

  return eat(subvalue)({
    type: 'heading',
    depth: depth,
    children: self.tokenizeInline(content, now),
  });
}