JavaScriptExample
diff --git a/‎lib/util/SortableSet.js‎
Lines changed: 30 additions & 1 deletion b/‎lib/util/SortableSet.js‎
Lines changed: 30 additions & 1 deletion
@@ -5,18 +5,47 @@ module.exports = class SortableSet extends Set {
 	constructor(initialIterable, defaultSort) {
 		super(initialIterable);
 		this._sortFn = defaultSort;
+		this._lastActiveSortFn = null;
+		this._isSorted = false;
+	}
+
+	/**
+	 * @param {any} value - value to add to set
+	 * @returns {SortableSet} - returns itself
+	 */
+	add(value) {
+		this._lastActiveSortFn = null;
+		this._isSorted = false;
+		super.add(value);
+		return this;
+	}
+
+	/**
+	 * @returns {void}
+	 */
+	clear() {
+		this._lastActiveSortFn = null;
+		this._isSorted = false;
+		super.clear();
 	}
 
 	/**
 	 * @param {Function} sortFn - function to sort the set
 	 * @returns {void}
 	 */
 	sortWith(sortFn) {
+		if(this._isSorted && sortFn === this._lastActiveSortFn) {
+			// already sorted - nothing to do
+			return;
+		}
+
 		const sortedArray = Array.from(this).sort(sortFn);
-		this.clear();
+		super.clear();
 		for(let i = 0; i < sortedArray.length; i += 1) {
 			this.add(sortedArray[i]);
 		}
+		this._lastActiveSortFn = sortFn;
+		this._isSorted = true;
 	}
 
 	/**