44 lines
1.4 KiB
JavaScript
Executable file
44 lines
1.4 KiB
JavaScript
Executable file
'use strict';
|
|
// https://github.com/tc39/proposal-iterator-helpers
|
|
var $ = require('../internals/export');
|
|
var apply = require('../internals/function-apply');
|
|
var aCallable = require('../internals/a-callable');
|
|
var anObject = require('../internals/an-object');
|
|
var createAsyncIteratorProxy = require('../internals/async-iterator-create-proxy');
|
|
|
|
var AsyncIteratorProxy = createAsyncIteratorProxy(function (Promise, args) {
|
|
var state = this;
|
|
var filterer = state.filterer;
|
|
|
|
return new Promise(function (resolve, reject) {
|
|
var loop = function () {
|
|
try {
|
|
Promise.resolve(anObject(apply(state.next, state.iterator, args))).then(function (step) {
|
|
try {
|
|
if (anObject(step).done) {
|
|
state.done = true;
|
|
resolve({ done: true, value: undefined });
|
|
} else {
|
|
var value = step.value;
|
|
Promise.resolve(filterer(value)).then(function (selected) {
|
|
selected ? resolve({ done: false, value: value }) : loop();
|
|
}, reject);
|
|
}
|
|
} catch (err) { reject(err); }
|
|
}, reject);
|
|
} catch (error) { reject(error); }
|
|
};
|
|
|
|
loop();
|
|
});
|
|
});
|
|
|
|
$({ target: 'AsyncIterator', proto: true, real: true }, {
|
|
filter: function filter(filterer) {
|
|
return new AsyncIteratorProxy({
|
|
iterator: anObject(this),
|
|
filterer: aCallable(filterer)
|
|
});
|
|
}
|
|
});
|