showdown/src/subParsers/unescapeSpecialChars.js

/**
 * Swap back in all the special characters we've hidden.
 */
showdown.subParser('unescapeSpecialChars', function (text) {
  'use strict';

  text = text.replace(/~E(\d+)E/g, function (wholeMatch, m1) {
    var charCodeToReplace = parseInt(m1);
    return String.fromCharCode(charCodeToReplace);
  });
  return text;
});