summaryrefslogtreecommitdiffstats
path: root/node_modules/webpack/lib/util/SetHelpers.js
diff options
context:
space:
mode:
Diffstat (limited to 'node_modules/webpack/lib/util/SetHelpers.js')
-rw-r--r--node_modules/webpack/lib/util/SetHelpers.js48
1 files changed, 48 insertions, 0 deletions
diff --git a/node_modules/webpack/lib/util/SetHelpers.js b/node_modules/webpack/lib/util/SetHelpers.js
new file mode 100644
index 0000000..96c063c
--- /dev/null
+++ b/node_modules/webpack/lib/util/SetHelpers.js
@@ -0,0 +1,48 @@
+"use strict";
+
+/**
+ * intersect creates Set containing the intersection of elements between all sets
+ * @param {Set[]} sets an array of sets being checked for shared elements
+ * @returns {Set<TODO>} returns a new Set containing the intersecting items
+ */
+const 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;
+};
+
+/**
+ * Checks if a set is the subset of another set
+ * @param {Set<TODO>} bigSet a Set which contains the original elements to compare against
+ * @param {Set<TODO>} smallSet the set whos elements might be contained inside of bigSet
+ * @returns {boolean} returns true if smallSet contains all elements inside of the bigSet
+ */
+const isSubset = (bigSet, smallSet) => {
+ if (bigSet.size < smallSet.size) return false;
+ for (const item of smallSet) {
+ if (!bigSet.has(item)) return false;
+ }
+ return true;
+};
+
+exports.intersect = intersect;
+exports.isSubset = isSubset;