parseQueryParams - parse query string parameters into an object [non-jQuery version]

parseQueryParams.js

parseQueryParams = function (query) {
  var re = /([^&=]+)=?([^&]*)/g;
  var decodeRE = /\+/g;
  var decode = function (str) {
    return decodeURIComponent(str.replace(decodeRE, " "));
  };

  var params = {}, e;
  while (e = re.exec(query)) {
    var k = decode(e[1]), v = decode(e[2]);
    if (k.substring(k.length - 2) === '[]') {
      k = k.substring(0, k.length - 2);
      (params[k] || (params[k] = [])).push(v);
    } else params[k] = v;
  }

  return params;
};

Works with grouped[]=values, too