🚧 progress: Import existing source from js-itertools.

Author: make-github-pseudonymous-again

README.md

@@ -11,6 +11,14 @@ See [docs](https://iterable-iterator.github.io/map/index.html).
 > `regeneratorRuntime` to be defined, for instance by importing
 > [regenerator-runtime/runtime](https://www.npmjs.com/package/regenerator-runtime).
 
+```js
+import {zip, count} from '@aureooms/js-itertools';
+import {truth, mul} from '@aureooms/js-operator';
+import {map, starmap} from '@iterable-itertools/map';
+map( truth , [ 0 , 1 , null , undefined , "A" ] ) ; // F T F F T
+starmap( mul , zip( count( 0 , 1 ) , count( 0 , 1 ) ) ) ; // 0 1 4 9 16 25 36 ...
+```
+
 [![License](https://img.shields.io/github/license/iterable-iterator/map.svg)](https://raw.githubusercontent.com/iterable-iterator/map/main/LICENSE)
 [![Version](https://img.shields.io/npm/v/@iterable-iterator/map.svg)](https://www.npmjs.org/package/@iterable-iterator/map)
 [![Tests](https://img.shields.io/github/workflow/status/iterable-iterator/map/ci:test?event=push&label=tests)](https://github.com/iterable-iterator/map/actions/workflows/ci:test.yml?query=branch:main)

package.json

@@ -61,6 +61,7 @@
   },
   "dependencies": {},
   "devDependencies": {
+    "@aureooms/js-operator": "^1.0.2",
     "@babel/core": "7.13.15",
     "@babel/preset-env": "7.13.15",
     "@babel/register": "7.13.14",

src/index.js

@@ -1,2 +1,2 @@
-const answer = 42;
-export default answer;
+export {default as map} from './map.js';
+export {default as starmap} from './starmap.js';

src/map.js

@@ -0,0 +1,16 @@
+/**
+ * Applies a given callable to each of the elements of the input iterable.
+ *
+ * @example
+ * // return [ 0 , 1 , 4 , 9 ]
+ * list( map( x => x**2 , range( 4 ) ) ) ;
+ *
+ * @param {Function} callable - The callable to use.
+ * @param {Iterable} iterable - The input iterable.
+ * @returns {IterableIterator}
+ */
+export default function* map(callable, iterable) {
+	for (const item of iterable) {
+		yield callable(item);
+	}
+}

src/starmap.js

@@ -0,0 +1,16 @@
+/**
+ * Same as {@link map} but allows multiple arguments callable functions.
+ *
+ * @example
+ * // return [ 0 , 1 , 4 , 9 ]
+ * list( starmap( ( x , y ) => x*y , zip( range( 4 ) , range( 4 ) ) ) ;
+ *
+ * @param {Function} callable - The callable to use.
+ * @param {Iterable} iterable - The input iterable.
+ * @returns {Iterator}
+ */
+export default function* starmap(callable, iterable) {
+	for (const args of iterable) {
+		yield callable(...args);
+	}
+}

test/src/api.js

@@ -0,0 +1,17 @@
+import test from 'ava';
+
+import {map} from '../../src/index.js';
+
+test('map', (t) => {
+	const x = function (callable, iterable, out) {
+		t.deepEqual(Array.from(map(callable, iterable)), out);
+	};
+
+	const pow2 = (x) => x * x;
+
+	x(pow2, [], []);
+	x(pow2, [1], [1]);
+	x(pow2, [1, 2, 3], [1, 4, 9]);
+	x(pow2, [1, 2, 3, 4, 5, 6], [1, 4, 9, 16, 25, 36]);
+	x(pow2, [1, 2, 3, 4, 5, 6, 7, 8, 9], [1, 4, 9, 16, 25, 36, 49, 64, 81]);
+});

test/src/map.js

@@ -0,0 +1,49 @@
+import test from 'ava';
+
+import {mul} from '@aureooms/js-operator';
+import {starmap} from '../../src/index.js';
+
+test('starmap', (t) => {
+	const x = (callable, iterable, out) => {
+		t.deepEqual(Array.from(starmap(callable, iterable)), out);
+	};
+
+	x(mul, [], []);
+	x(mul, [[1, 1]], [1]);
+	x(
+		mul,
+		[
+			[1, 1],
+			[2, 2],
+			[3, 3],
+		],
+		[1, 4, 9],
+	);
+	x(
+		mul,
+		[
+			[1, 1],
+			[2, 2],
+			[3, 3],
+			[4, 4],
+			[5, 5],
+			[6, 6],
+		],
+		[1, 4, 9, 16, 25, 36],
+	);
+	x(
+		mul,
+		[
+			[1, 1],
+			[2, 2],
+			[3, 3],
+			[4, 4],
+			[5, 5],
+			[6, 6],
+			[7, 7],
+			[8, 8],
+			[9, 9],
+		],
+		[1, 4, 9, 16, 25, 36, 49, 64, 81],
+	);
+});