1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
|
function _defineProperty(obj, key, value) { if (key in obj) { Object.defineProperty(obj, key, { value: value, enumerable: true, configurable: true, writable: true }); } else { obj[key] = value; } return obj; }
import { SYMBOL_ASYNC_ITERATOR } from "../polyfills/symbols.mjs";
/**
* Given an AsyncIterable and a callback function, return an AsyncIterator
* which produces values mapped via calling the callback function.
*/
export default function mapAsyncIterator(iterable, callback, rejectCallback) {
// $FlowFixMe[prop-missing]
var iteratorMethod = iterable[SYMBOL_ASYNC_ITERATOR];
var iterator = iteratorMethod.call(iterable);
var $return;
var abruptClose;
if (typeof iterator.return === 'function') {
$return = iterator.return;
abruptClose = function abruptClose(error) {
var rethrow = function rethrow() {
return Promise.reject(error);
};
return $return.call(iterator).then(rethrow, rethrow);
};
}
function mapResult(result) {
return result.done ? result : asyncMapValue(result.value, callback).then(iteratorResult, abruptClose);
}
var mapReject;
if (rejectCallback) {
// Capture rejectCallback to ensure it cannot be null.
var reject = rejectCallback;
mapReject = function mapReject(error) {
return asyncMapValue(error, reject).then(iteratorResult, abruptClose);
};
}
/* TODO: Flow doesn't support symbols as keys:
https://github.com/facebook/flow/issues/3258 */
return _defineProperty({
next: function next() {
return iterator.next().then(mapResult, mapReject);
},
return: function _return() {
return $return ? $return.call(iterator).then(mapResult, mapReject) : Promise.resolve({
value: undefined,
done: true
});
},
throw: function _throw(error) {
if (typeof iterator.throw === 'function') {
return iterator.throw(error).then(mapResult, mapReject);
}
return Promise.reject(error).catch(abruptClose);
}
}, SYMBOL_ASYNC_ITERATOR, function () {
return this;
});
}
function asyncMapValue(value, callback) {
return new Promise(function (resolve) {
return resolve(callback(value));
});
}
function iteratorResult(value) {
return {
value: value,
done: false
};
}
|
