feat(transducers): add opt limit for cycle()

packages/transducers/src/iter/cycle.ts

@@ -1,23 +1,34 @@
 /**
  * Iterator which yields an infinite repetition of given `input`
- * iterable's values. Produces no values if `input` is empty.
+ * iterable's values. Produces no values if `input` is empty. If `num`
+ * is given, only that many cycles will be emitted.
+ *
+ * @remarks
+ * Also see {@link repeat}, {@link repeatedly} for related functions.
  *
  * @example
  * ```ts
+ * // take 5 from infinite sequence
  * [...take(5, cycle([1, 2, 3]))]
  * // [1, 2, 3, 1, 2]
+ *
+ * // only produce 2 cycles
+ * [...cycle(range(3), 2)]
+ * // [ 0, 1, 2, 0, 1, 2 ]
  * ```
  *
  * @param input -
+ * @param num -
  */
-export function* cycle<T>(input: Iterable<T>) {
+export function* cycle<T>(input: Iterable<T>, num = Infinity) {
+    if (num < 1) return;
     let cache: T[] = [];
     for (let i of input) {
         cache.push(i);
         yield i;
     }
     if (cache.length > 0) {
-        while (true) {
+        while (--num > 0) {
             yield* cache;
         }
     }