feat(transducers-async): add range() & tests

Author: postspectacular

packages/transducers-async/src/index.ts

@@ -14,6 +14,7 @@ export * from "./multiplex.js";
 export * from "./multiplex-obj.js";
 export * from "./partition.js";
 export * from "./push.js";
+export * from "./range.js";
 export * from "./reduce.js";
 export * from "./repeatedly.js";
 export * from "./run.js";

packages/transducers-async/src/range.ts

@@ -0,0 +1,31 @@
+import { delayed } from "@thi.ng/compose/delayed";
+import { Range } from "@thi.ng/transducers/range";
+
+/**
+ * Async version of [thi.ng/transducers
+ * range()](https://docs.thi.ng/umbrella/transducers/functions/range-1.html),
+ * taking an additional `delay` argument for specifying the number of
+ * milliseconds between each generated value.
+ *
+ * @param delay
+ */
+export function range(delay: number): AsyncIterableIterator<number>;
+export function range(to: number, delay: number): AsyncIterableIterator<number>;
+export function range(
+	from: number,
+	to: number,
+	delay: number
+): AsyncIterableIterator<number>;
+export function range(
+	from: number,
+	to: number,
+	step: number,
+	delay: number
+): AsyncIterableIterator<number>;
+export async function* range(...args: number[]) {
+	const delay = args.pop()!;
+	for (let x of new Range(...(<[number]>args))) {
+		yield x;
+		await delayed(null, delay);
+	}
+}

packages/transducers-async/test/main.test.ts

@@ -11,6 +11,7 @@ import {
 	multiplexObj,
 	partition,
 	push,
+	range,
 	repeatedly,
 	run,
 	step,
@@ -151,6 +152,16 @@ test("partition", async (done) => {
 	done();
 });
 
+test("range", async (done) => {
+	expect(await push(take(3, range(5)))).toEqual([0, 1, 2]);
+	expect(await push(range(3, 5))).toEqual([0, 1, 2]);
+	expect(await push(range(1, 3, 5))).toEqual([1, 2]);
+	expect(await push(range(1, 10, 2, 5))).toEqual([1, 3, 5, 7, 9]);
+	expect(await push(range(3, 0, 5))).toEqual([3, 2, 1]);
+	expect(await push(range(10, -1, -3, 5))).toEqual([10, 7, 4, 1]);
+	done();
+});
+
 test("repeatedly", async (done) => {
 	expect(await push(repeatedly(async (i) => i * 10, 3, 10))).toEqual([
 		0, 10, 20,