webpack/lib/util/SetHelpers.js

35 lines
743 B
JavaScript

"use strict";
exports.intersect = sets => {
if(sets.length === 0) return new Set();
if(sets.length === 1) return new Set(sets[0]);
let minSize = Infinity;
let minIndex = -1;
for(let i = 0; i < sets.length; i++) {
const size = sets[i].size;
if(size < minSize) {
minIndex = i;
minSize = size;
}
}
const current = new Set(sets[minIndex]);
for(let i = 0; i < sets.length; i++) {
if(i === minIndex) continue;
const set = sets[i];
for(const item of current) {
if(!set.has(item)) {
current.delete(item);
}
}
}
return current;
};
exports.isSubset = (bigSet, smallSet) => {
if(bigSet.size < smallSet.size) return false;
for(const item of smallSet) {
if(!bigSet.has(item)) return false;
}
return true;
};