/
signal-structure.js
117 lines (98 loc) · 2.56 KB
/
signal-structure.js
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
function signal(initial) {
let value = initial;
const scribers = new Set();
const notify = () => scribers.forEach(s => s(value));
const subscribe = s => scribers.add(s); // for "hot" signal add s(value)
const add = incr => {
value = (value ?? 0) + incr;
notify();
};
return { subscribe, add };
}
function getCountSignal(initial) {
let value = initial;
const signal = new Signal();
const subscribe = signal.subscribe.bind(signal);
const add = incr => {
value = (value ?? 0) + incr;
signal.notify(value);
};
return { subscribe, add };
}
class Signal extends Set {
notify(payload) {
this.forEach(s => s(payload));
}
subscribe(s) {
this.add(s);
}
}
class ValueSignal {
constructor(initial) {
this.signal = new Signal();
this.value = initial;
}
subscribe(s) {
this.signal.subscribe(s);
// for "hot" signal add:
// s(this.value);
}
}
class CountSignal extends ValueSignal {
add(incr) {
this.signal.notify(this.value = (this.value ?? 0) + incr);
}
}
console.log('signal');
const { subscribe, add } = signal(0);
subscribe(console.log);
add(1);
add(3);
add(2);
console.log('CountSignal');
const countSignal = new CountSignal(5);
countSignal.subscribe(console.log);
countSignal.add(1);
countSignal.add(2);
countSignal.add(1);
console.log('getCountSignal');
const c2Signal = getCountSignal(3);
c2Signal.subscribe(console.log);
c2Signal.add(2);
c2Signal.add(2);
c2Signal.add(10);
async function* store(initial) {
let value = initial;
const change = newValue => value = newValue;
let request = yield await value;
while(true) {
change(request);
request = yield await value;
}
}
async function operator(initial) {
const iterator = store(initial);
const change = async nextValue => {
const { value } = await iterator.next(nextValue);
return value;
};
const value = await change();
return { change, value };
}
async function counter(count) {
let { change, value } = await operator(count);
const doChange = async amt => value = await change(value + amt);
return {
increment: () => doChange(1),
decrement: () => doChange(-1),
};
}
console.log('operator');
const { increment, decrement } = await counter(5);
console.log(await increment());
console.log(await increment());
console.log(await increment());
console.log(await decrement());
console.log(await decrement());
console.log(await decrement());
console.log(await increment());