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
|
for (var constructor of anyTypedArrayConstructors) {
// If the mapfn argument to %TypedArray%.from is undefined, don't map.
assertDeepEq(constructor.from([3, 4, 5], undefined), new constructor([3, 4, 5]));
assertDeepEq(constructor.from([4, 5, 6], undefined, Math), new constructor([4, 5, 6]));
// mapfn is called with two arguments: value and index.
var log = [];
function f(...args) {
log.push(args);
return log.length;
}
assertDeepEq(constructor.from(['a', 'e', 'i', 'o', 'u'], f), new constructor([1, 2, 3, 4, 5]));
assertDeepEq(log, [['a', 0], ['e', 1], ['i', 2], ['o', 3], ['u', 4]]);
// If the object to be copied is non-iterable, mapfn is still called with two
// arguments.
log = [];
assertDeepEq(constructor.from({0: "zero", 1: "one", length: 2}, f), new constructor([1, 2]));
assertDeepEq(log, [["zero", 0], ["one", 1]]);
// If the object to be copied is iterable and the constructor is not Array,
// mapfn is still called with two arguments.
log = [];
function C(...rest) {
return new constructor(...rest);
}
C.from = constructor.from;
var c = new C(2);
c[0] = 1;
c[1] = 2;
assertDeepEq(C.from(["zero", "one"], f), c);
assertDeepEq(log, [["zero", 0], ["one", 1]]);
// The mapfn is called even if the value to be mapped is undefined.
assertDeepEq(constructor.from([0, 1, , 3], String), new constructor(["0", "1", "undefined", "3"]));
var arraylike = {length: 4, "0": 0, "1": 1, "3": 3};
assertDeepEq(constructor.from(arraylike, String), new constructor(["0", "1", "undefined", "3"]));
}
// %TypedArray%.from(obj, map) is not exactly the same as %TypedArray%.from(obj).map(mapFn).
assertDeepEq(Int8Array.from([150], v => v / 2), new Int8Array([75]));
assertDeepEq(Int8Array.from([150]).map(v => v / 2), new Int8Array([-53]));
if (typeof reportCompare === "function")
reportCompare(true, true);
|
