'use strict';
  
  var toArray  = require('./to-array')
    , isDate   = require('../date/is-date')
    , isRegExp = require('../reg-exp/is-reg-exp')
  
    , isArray = Array.isArray, stringify = JSON.stringify
    , keyValueToString = function (value, key) { return stringify(key) + ':' + exports(value); };
  
  var sparseMap = function (arr) {
  	var i, l = arr.length, result = new Array(l);
  	for (i = 0; i < l; ++i) {
  		if (!arr.hasOwnProperty(i)) continue;
  		result[i] = exports(arr[i]);
  	}
  	return result;
  };
  
  module.exports = exports = function (obj) {
  	if (obj == null) return String(obj);
  	switch (typeof obj) {
  	case 'string':
  		return stringify(obj);
  	case 'number':
  	case 'boolean':
  	case 'function':
  		return String(obj);
  	case 'object':
  		if (isArray(obj)) return '[' + sparseMap(obj) + ']';
  		if (isRegExp(obj)) return String(obj);
  		if (isDate(obj)) return 'new Date(' + obj.valueOf() + ')';
  		return '{' + toArray(obj, keyValueToString) + '}';
  	default:
  		throw new TypeError("Serialization of " + String(obj) + "is unsupported");
  	}
  };