| 'use strict'; | 
| var call = require('../internals/function-call'); | 
| var aCallable = require('../internals/a-callable'); | 
| var anObject = require('../internals/an-object'); | 
| var getIteratorDirect = require('../internals/get-iterator-direct'); | 
| var createIteratorProxy = require('../internals/iterator-create-proxy'); | 
| var callWithSafeIterationClosing = require('../internals/call-with-safe-iteration-closing'); | 
|   | 
| var IteratorProxy = createIteratorProxy(function () { | 
|   var iterator = this.iterator; | 
|   var result = anObject(call(this.next, iterator)); | 
|   var done = this.done = !!result.done; | 
|   if (!done) return callWithSafeIterationClosing(iterator, this.mapper, [result.value, this.counter++], true); | 
| }); | 
|   | 
| // `Iterator.prototype.map` method | 
| // https://github.com/tc39/proposal-iterator-helpers | 
| module.exports = function map(mapper) { | 
|   anObject(this); | 
|   aCallable(mapper); | 
|   return new IteratorProxy(getIteratorDirect(this), { | 
|     mapper: mapper | 
|   }); | 
| }; |