DRAFT: implement sequence

src/sequence/zip.ts

@@ -0,0 +1,9 @@
+export function* zip<T, B>(value: Iterable<T>, items: Iterable<B>): Iterable<[T, B]> {
+    const iteratorA = value[Symbol.iterator]();
+    const iteratorB = items[Symbol.iterator]();
+    let {value: itA, done: doneA} = iteratorA.next();
+    let {value: itB, done: doneB} = iteratorB.next();
+    while (!doneA && !doneB) {
+        yield [itA, itB];
+    }
+}