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"use strict";
var clear = require("es5-ext/array/#/clear")
, assign = require("es5-ext/object/assign")
, callable = require("es5-ext/object/valid-callable")
, value = require("es5-ext/object/valid-value")
, d = require("d")
, autoBind = require("d/auto-bind")
, Symbol = require("es6-symbol");
var defineProperty = Object.defineProperty, defineProperties = Object.defineProperties, Iterator;
module.exports = Iterator = function (list, context) {
if (!(this instanceof Iterator)) throw new TypeError("Constructor requires 'new'");
defineProperties(this, {
__list__: d("w", value(list)),
__context__: d("w", context),
__nextIndex__: d("w", 0)
});
if (!context) return;
callable(context.on);
context.on("_add", this._onAdd);
context.on("_delete", this._onDelete);
context.on("_clear", this._onClear);
};
// Internal %IteratorPrototype% doesn't expose its constructor
delete Iterator.prototype.constructor;
defineProperties(
Iterator.prototype,
assign(
{
_next: d(function () {
var i;
if (!this.__list__) return undefined;
if (this.__redo__) {
i = this.__redo__.shift();
if (i !== undefined) return i;
}
if (this.__nextIndex__ < this.__list__.length) return this.__nextIndex__++;
this._unBind();
return undefined;
}),
next: d(function () {
return this._createResult(this._next());
}),
_createResult: d(function (i) {
if (i === undefined) return { done: true, value: undefined };
return { done: false, value: this._resolve(i) };
}),
_resolve: d(function (i) {
return this.__list__[i];
}),
_unBind: d(function () {
this.__list__ = null;
delete this.__redo__;
if (!this.__context__) return;
this.__context__.off("_add", this._onAdd);
this.__context__.off("_delete", this._onDelete);
this.__context__.off("_clear", this._onClear);
this.__context__ = null;
}),
toString: d(function () {
return "[object " + (this[Symbol.toStringTag] || "Object") + "]";
})
},
autoBind({
_onAdd: d(function (index) {
if (index >= this.__nextIndex__) return;
++this.__nextIndex__;
if (!this.__redo__) {
defineProperty(this, "__redo__", d("c", [index]));
return;
}
this.__redo__.forEach(function (redo, i) {
if (redo >= index) this.__redo__[i] = ++redo;
}, this);
this.__redo__.push(index);
}),
_onDelete: d(function (index) {
var i;
if (index >= this.__nextIndex__) return;
--this.__nextIndex__;
if (!this.__redo__) return;
i = this.__redo__.indexOf(index);
if (i !== -1) this.__redo__.splice(i, 1);
this.__redo__.forEach(function (redo, j) {
if (redo > index) this.__redo__[j] = --redo;
}, this);
}),
_onClear: d(function () {
if (this.__redo__) clear.call(this.__redo__);
this.__nextIndex__ = 0;
})
})
)
);
defineProperty(
Iterator.prototype,
Symbol.iterator,
d(function () {
return this;
})
);