Convert Wesnoth WML file into JSON

wmlreader.js

/* wmlreader.js
 *
 * Read a Wesnoth WML file and parse it, save it as a JSON string.
 *
 * This depends on jQuery to read in the file. If you already have the file as a string
 * you can skip readConfigFile() and just use readWML().
 *
 * This isn’t quite valid JSON. It has duplicate entries. I’ll need to turn those into arrays or something.
 *
 * last updated 13 May 12
 */

function readConfigFile(title) {
  result = "";
  $.ajax({
    url: title,
    async: false,
    success: function(data) {
      result = data;
    }
  });
  return result;
}

function readWML(data) {
  var file = data.toString().split('\n');
  
  for (var i = 0; i < file.length; i++) {
    var that = file[i];
    
    that = that.replace(/\'/g, "\\'");
    that = that.replace(/\"/g, "");
    that = that.trim();
    
    if (that.search(/\[[_A-Za-z]+\]/) != -1) {
      file[i] = that.replace(/[\[\]]+/g, '"');
      file[i] = file[i] + ': {';
    } else if (that.search(/\[\/[_A-Za-z]+\]/) != -1) {
      if (file[i-1].charAt(file[i-1].length-1) == ',') {
        file[i-1] = file[i-1].substring(0,file[i-1].length-1);
      }
      file[i] = '},';
    } else if (that.indexOf('=') != -1) {
      that = that.split('=');
      file[i] = '"' + that[0].trim() + '":"' + that[1].trim() + '",';
    } else {
      file[i] = '';
    }
  }
  
  // Delete that hanging comma. (There’s probably a more elegant way to do this.)
  if (file[file.length-2].charAt(file[file.length-2].length-1) == ',') {
    file[file.length-2] = file[file.length-2].substring(0,file[file.length-2].length-1);
  }

  return '{' + file.join('') + '}';
}

// For older browsers:
if (typeof String.prototype.trim != 'function') {
  String.prototype.trim = function() {
    return this.replace(/^\s+/, '').replace(/\s+$/, '');
  };
}