init

lib/utils.ts

@@ -0,0 +1,14 @@
+export function* zip<A, B>(a: Iterable<A>, b: Iterable<B>): Generator<[A, B], void, void> {
+    const iter_a = a[Symbol.iterator](), iter_b = b[Symbol.iterator]();
+    while (true) {
+        const next_a = next(iter_a), next_b = next(iter_b);
+        if (next_a === null || next_b === null) return;
+        yield [next_a, next_b];
+    }
+}
+
+export function next<T>(iterator: Iterator<T>) {
+    const result = iterator.next().value;
+    if (result === undefined) return null;
+    else return result as T;
+}