初始化

康凯

2022-05-20 aa4c235a8ca67ea8b731f90c951a465e92c0a865

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
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
import {
  noop,
  resolve,
  handleMaybeThenable,
  reject,
  fulfill,
  subscribe,
  FULFILLED,
  REJECTED,
  PENDING,
} from './-internal';
 
import { default as OwnPromise } from './promise';
import ownThen from './then';
import ownResolve from './promise/resolve';
 
export default class Enumerator {
  constructor(Constructor, input, abortOnReject, label) {
    this._instanceConstructor = Constructor;
    this.promise = new Constructor(noop, label);
    this._abortOnReject = abortOnReject;
    this._isUsingOwnPromise = Constructor === OwnPromise;
    this._isUsingOwnResolve = Constructor.resolve === ownResolve;
 
    this._init(...arguments);
  }
 
  _init(Constructor, input) {
    let len = input.length || 0;
    this.length     = len;
    this._remaining = len;
    this._result = new Array(len);
 
    this._enumerate(input);
  }
 
  _enumerate(input) {
    let length  = this.length;
    let promise = this.promise;
 
    for (let i = 0; promise._state === PENDING && i < length; i++) {
      this._eachEntry(input[i], i, true);
    }
    this._checkFullfillment();
  }
 
  _checkFullfillment() {
    if (this._remaining === 0) {
      let result = this._result;
      fulfill(this.promise, result);
      this._result = null
    }
  }
 
  _settleMaybeThenable(entry, i, firstPass) {
    let c = this._instanceConstructor;
 
    if (this._isUsingOwnResolve) {
      let then, error, succeeded = true;
      try {
        then = entry.then;
      } catch (e) {
        succeeded = false;
        error = e;
      }
 
      if (then === ownThen && entry._state !== PENDING) {
        entry._onError = null;
        this._settledAt(entry._state, i, entry._result, firstPass);
      } else if (typeof then !== 'function') {
        this._settledAt(FULFILLED, i, entry, firstPass);
      } else if (this._isUsingOwnPromise) {
        let promise = new c(noop);
        if (succeeded === false) {
          reject(promise, error);
        } else {
          handleMaybeThenable(promise, entry, then);
          this._willSettleAt(promise, i, firstPass);
        }
      } else {
        this._willSettleAt(new c(resolve => resolve(entry)), i, firstPass);
      }
    } else {
      this._willSettleAt(c.resolve(entry), i, firstPass);
    }
  }
 
  _eachEntry(entry, i, firstPass) {
    if (entry !== null && typeof entry === 'object') {
      this._settleMaybeThenable(entry, i, firstPass);
    } else {
      this._setResultAt(FULFILLED, i, entry, firstPass);
    }
  }
 
  _settledAt(state, i, value, firstPass) {
    let promise = this.promise;
 
    if (promise._state === PENDING) {
      if (this._abortOnReject && state === REJECTED) {
        reject(promise, value);
      } else {
        this._setResultAt(state, i, value, firstPass);
        this._checkFullfillment();
      }
    }
  }
 
  _setResultAt(state, i, value, firstPass) {
    this._remaining--;
    this._result[i] = value;
  }
 
  _willSettleAt(promise, i, firstPass) {
    subscribe(
      promise, undefined,
      value  => this._settledAt(FULFILLED, i, value, firstPass),
      reason => this._settledAt(REJECTED,  i, reason, firstPass)
    );
  }
}
 
export function setSettledResult(state, i, value) {
  this._remaining--;
  if (state === FULFILLED) {
    this._result[i] = {
      state: 'fulfilled',
      value: value
    };
  } else {
     this._result[i] = {
      state: 'rejected',
      reason: value
    };
  }
}