markdown-it/lib/rules_core/abbr.js

// Parse abbreviation definitions, i.e. `*[abbr]: description`
//

'use strict';


function parseAbbr(str, parserInline, options, env) {
  var pos, label, title, ch,
      max = str.length,
      labelEnd = -1;

  if (str.charCodeAt(0) !== 0x2A/* * */) { return -1; }
  if (str.charCodeAt(1) !== 0x5B/* [ */) { return -1; }

  if (str.indexOf(']:') === -1) { return -1; }

  for (pos = 2; pos < max; pos++) {
    ch = str.charCodeAt(pos);
    if (ch === 0x5B /* [ */) {
      return -1;
    } else if (ch === 0x5D /* ] */) {
      labelEnd = pos;
      break;
    } else if (ch === 0x5C /* \ */) {
      pos++;
    }
  }

  if (labelEnd < 0 || str.charCodeAt(labelEnd + 1) !== 0x3A/* : */) { return -1; }

  // abbr title is always one line, so looking for ending "\n" here
  for (pos = labelEnd + 2; pos < max; pos++) {
    if (str.charCodeAt(pos) === 0x0A) { break; }
  }

  label = str.slice(2, labelEnd).replace(/\\(.)/g, '$1');
  title = str.slice(labelEnd + 2, pos).trim();
  if (title.length === 0) { return -1; }
  if (!env.abbreviations) { env.abbreviations = {}; }
  // prepend ':' to avoid conflict with Object.prototype members
  if (typeof env.abbreviations[':' + label] === 'undefined') {
    env.abbreviations[':' + label] = title;
  }

  return pos;
}

module.exports = function abbr(state) {
  var tokens = state.tokens, i, l, content, pos;

  if (state.inlineMode) {
    return;
  }

  // Parse inlines
  for (i = 1, l = tokens.length - 1; i < l; i++) {
    if (tokens[i - 1].type === 'paragraph_open' &&
        tokens[i].type === 'inline' &&
        tokens[i + 1].type === 'paragraph_close') {

      content = tokens[i].content;
      while (content.length) {
        pos = parseAbbr(content, state.inline, state.options, state.env);
        if (pos < 0) { break; }
        content = content.slice(pos).trim();
      }

      tokens[i].content = content;
      if (!content.length) {
        tokens[i - 1].tight = true;
        tokens[i + 1].tight = true;
      }
    }
  }
};