'use strict';
|
// https://github.com/tc39/proposal-iterator-helpers
|
var $ = require('../internals/export');
|
var call = require('../internals/function-call');
|
var anObject = require('../internals/an-object');
|
var getIteratorDirect = require('../internals/get-iterator-direct');
|
var notANaN = require('../internals/not-a-nan');
|
var toPositiveInteger = require('../internals/to-positive-integer');
|
var createAsyncIteratorProxy = require('../internals/async-iterator-create-proxy');
|
var createIterResultObject = require('../internals/create-iter-result-object');
|
|
var AsyncIteratorProxy = createAsyncIteratorProxy(function (Promise) {
|
var state = this;
|
|
return new Promise(function (resolve, reject) {
|
var doneAndReject = function (error) {
|
state.done = true;
|
reject(error);
|
};
|
|
var loop = function () {
|
try {
|
Promise.resolve(anObject(call(state.next, state.iterator))).then(function (step) {
|
try {
|
if (anObject(step).done) {
|
state.done = true;
|
resolve(createIterResultObject(undefined, true));
|
} else if (state.remaining) {
|
state.remaining--;
|
loop();
|
} else resolve(createIterResultObject(step.value, false));
|
} catch (err) { doneAndReject(err); }
|
}, doneAndReject);
|
} catch (error) { doneAndReject(error); }
|
};
|
|
loop();
|
});
|
});
|
|
$({ target: 'AsyncIterator', proto: true, real: true, forced: true }, {
|
drop: function drop(limit) {
|
return new AsyncIteratorProxy(getIteratorDirect(this), {
|
remaining: toPositiveInteger(notANaN(+limit))
|
});
|
}
|
});
|