/
set-intersection.js
46 lines (39 loc) · 1.23 KB
/
set-intersection.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
'use strict';
var SetHelpers = require('../internals/set-helpers');
var getSetRecord = require('../internals/get-set-record');
var iterateSimple = require('../internals/iterate-simple');
var Set = SetHelpers.Set;
var aSet = SetHelpers.aSet;
var add = SetHelpers.add;
var has = SetHelpers.has;
var size = SetHelpers.size;
var forEach = SetHelpers.forEach;
var nativeHas = SetHelpers.$has;
var nativeKeys = SetHelpers.$keys;
var isNativeSetRecord = function (record) {
return record.has === nativeHas && record.keys === nativeKeys;
};
// `Set.prototype.intersection` method
// https://github.com/tc39/proposal-set-methods
module.exports = function intersection(other) {
var O = aSet(this);
var otherRec = getSetRecord(other);
var result = new Set();
// observable side effects
if (!isNativeSetRecord(otherRec) && size(O) > otherRec.size) {
iterateSimple(otherRec.getIterator(), function (e) {
if (has(O, e)) add(result, e);
});
if (size(result) < 2) return result;
var disordered = result;
result = new Set();
forEach(O, function (e) {
if (has(disordered, e)) add(result, e);
});
} else {
forEach(O, function (e) {
if (otherRec.includes(e)) add(result, e);
});
}
return result;
};