2 files changed, 14 insertions, 0 deletions
diff --git a/util/array.ts b/util/array.ts
index 5b8c512..f032935 100644
--- a/util/array.ts
+++ b/util/array.ts
@@ -6,6 +6,8 @@ declare global {
 		peek(): T;
 		/** @summary create Set from this array */
 		set(): Set<T>;
+		/** @summary clear array */
+		clear(): void;
 	}
 }
 
@@ -21,3 +23,7 @@ Array.prototype.set = function() {
 	return new Set(this);
 }
 
+Array.prototype.clear = function() {
+	while (this.length > 0) this.pop();
+}
+
diff --git a/util/types.ts b/util/types.ts
new file mode 100644
index 0000000..f03a242
--- /dev/null
+++ b/util/types.ts
@@ -0,0 +1,8 @@
+/**
+ * @type DeepPartial<T>  makes all properties of type T optional, but keep
+ * array types intact
+ */
+export type DeepPartial<T> = {
+	[K in keyof T]?: T[K] extends Array<infer U> ? Array<U> : DeepPartial<T[K]>;
+};
+