1
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var AwaitValue = require("./AwaitValue");
|
2
|
|
3
|
function AsyncGenerator(gen) {
|
4
|
var front, back;
|
5
|
|
6
|
function send(key, arg) {
|
7
|
return new Promise(function (resolve, reject) {
|
8
|
var request = {
|
9
|
key: key,
|
10
|
arg: arg,
|
11
|
resolve: resolve,
|
12
|
reject: reject,
|
13
|
next: null
|
14
|
};
|
15
|
|
16
|
if (back) {
|
17
|
back = back.next = request;
|
18
|
} else {
|
19
|
front = back = request;
|
20
|
resume(key, arg);
|
21
|
}
|
22
|
});
|
23
|
}
|
24
|
|
25
|
function resume(key, arg) {
|
26
|
try {
|
27
|
var result = gen[key](arg);
|
28
|
var value = result.value;
|
29
|
var wrappedAwait = value instanceof AwaitValue;
|
30
|
Promise.resolve(wrappedAwait ? value.wrapped : value).then(function (arg) {
|
31
|
if (wrappedAwait) {
|
32
|
resume(key === "return" ? "return" : "next", arg);
|
33
|
return;
|
34
|
}
|
35
|
|
36
|
settle(result.done ? "return" : "normal", arg);
|
37
|
}, function (err) {
|
38
|
resume("throw", err);
|
39
|
});
|
40
|
} catch (err) {
|
41
|
settle("throw", err);
|
42
|
}
|
43
|
}
|
44
|
|
45
|
function settle(type, value) {
|
46
|
switch (type) {
|
47
|
case "return":
|
48
|
front.resolve({
|
49
|
value: value,
|
50
|
done: true
|
51
|
});
|
52
|
break;
|
53
|
|
54
|
case "throw":
|
55
|
front.reject(value);
|
56
|
break;
|
57
|
|
58
|
default:
|
59
|
front.resolve({
|
60
|
value: value,
|
61
|
done: false
|
62
|
});
|
63
|
break;
|
64
|
}
|
65
|
|
66
|
front = front.next;
|
67
|
|
68
|
if (front) {
|
69
|
resume(front.key, front.arg);
|
70
|
} else {
|
71
|
back = null;
|
72
|
}
|
73
|
}
|
74
|
|
75
|
this._invoke = send;
|
76
|
|
77
|
if (typeof gen["return"] !== "function") {
|
78
|
this["return"] = undefined;
|
79
|
}
|
80
|
}
|
81
|
|
82
|
if (typeof Symbol === "function" && Symbol.asyncIterator) {
|
83
|
AsyncGenerator.prototype[Symbol.asyncIterator] = function () {
|
84
|
return this;
|
85
|
};
|
86
|
}
|
87
|
|
88
|
AsyncGenerator.prototype.next = function (arg) {
|
89
|
return this._invoke("next", arg);
|
90
|
};
|
91
|
|
92
|
AsyncGenerator.prototype["throw"] = function (arg) {
|
93
|
return this._invoke("throw", arg);
|
94
|
};
|
95
|
|
96
|
AsyncGenerator.prototype["return"] = function (arg) {
|
97
|
return this._invoke("return", arg);
|
98
|
};
|
99
|
|
100
|
module.exports = AsyncGenerator;
|