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
|
// @flow strict
/**
* Memoizes the provided three-argument function.
*/
export default function memoize3<
A1: { ... } | $ReadOnlyArray<mixed>,
A2: { ... } | $ReadOnlyArray<mixed>,
A3: { ... } | $ReadOnlyArray<mixed>,
R: mixed,
>(fn: (A1, A2, A3) => R): (A1, A2, A3) => R {
let cache0;
return function memoized(a1, a2, a3) {
if (!cache0) {
cache0 = new WeakMap();
}
let cache1 = cache0.get(a1);
let cache2;
if (cache1) {
cache2 = cache1.get(a2);
if (cache2) {
const cachedValue = cache2.get(a3);
if (cachedValue !== undefined) {
return cachedValue;
}
}
} else {
cache1 = new WeakMap();
cache0.set(a1, cache1);
}
if (!cache2) {
cache2 = new WeakMap();
cache1.set(a2, cache2);
}
const newValue = fn(a1, a2, a3);
cache2.set(a3, newValue);
return newValue;
};
}
|
