/*

* 格式化

* */

var pretty_format = function (obj, indent) {

  if (obj === null) return 'null';

  if (obj === undefined) return 'undefined';

  if (typeof obj === 'string') return '"' + obj + '"';

  if (typeof obj !== 'object') return String(obj);

  if (indent == undefined) indent = '';

  var result = '{\n';

  for (var key in obj) {

    result += indent + ' ' + key + ' = ';

    result += format_pretty(obj[key], indent + ' ') + '\n';

  }

  return result + indent + '}';

}