// Thanks @mathiasbynens
// http://mathiasbynens.be/notes/javascript-unicode#iterating-over-symbols

'use strict';

var setPrototypeOf = require('es5-ext/object/set-prototype-of')
  , d              = require('d')
  , Iterator       = require('./')

  , defineProperty = Object.defineProperty
  , StringIterator;

StringIterator = module.exports = function (str) {
	if (!(this instanceof StringIterator)) return new StringIterator(str);
	str = String(str);
	Iterator.call(this, str);
	defineProperty(this, '__length__', d('', str.length));

};
if (setPrototypeOf) setPrototypeOf(StringIterator, Iterator);

StringIterator.prototype = Object.create(Iterator.prototype, {
	constructor: d(StringIterator),
	_next: d(function () {
		if (!this.__list__) return;
		if (this.__nextIndex__ < this.__length__) return this.__nextIndex__++;
		this._unBind();
	}),
	_resolve: d(function (i) {
		var char = this.__list__[i], code;
		if (this.__nextIndex__ === this.__length__) return char;
		code = char.charCodeAt(0);
		if ((code >= 0xD800) && (code <= 0xDBFF)) return char + this.__list__[this.__nextIndex__++];
		return char;
	}),
	toString: d(function () { return '[object String Iterator]'; })
});