✨ feat: Add swap and swapRanges.

Author: make-github-pseudonymous-again

README.md

@@ -4,12 +4,21 @@
 ArrayLike value swapping for JavaScript.
 See [docs](https://array-like.github.io/swap/index.html).
 
-> :building_construction: Caveat emptor! This is work in progress. Code may be
-> working. Documentation may be present. Coherence may be. Maybe.
+```js
+import {swapRanges} from '@array-like/swap';
+import {alloc} from '@array-like/alloc';
+import {iota} from '@array-like/iota';
 
-> :warning: Depending on your environment, the code may require
-> `regeneratorRuntime` to be defined, for instance by importing
-> [regenerator-runtime/runtime](https://www.npmjs.com/package/regenerator-runtime).
+const n = 6;
+const a = alloc(n);
+iota(a, 0, n, 0);
+const b = alloc(n);
+iota(b, 0, n, 0);
+
+swapRanges(a, 0, 3, b, 3);
+a; // 3 4 5 3 4 5
+b; // 0 1 2 0 1 2
+```
 
 [![License](https://img.shields.io/github/license/array-like/swap.svg)](https://raw.githubusercontent.com/array-like/swap/main/LICENSE)
 [![Version](https://img.shields.io/npm/v/@array-like/swap.svg)](https://www.npmjs.org/package/@array-like/swap)

doc/manual/usage.md

@@ -1,17 +1,6 @@
 # Usage
 
-> :warning: Depending on your environment, the code may require
-> `regeneratorRuntime` to be defined, for instance by importing
-> [regenerator-runtime/runtime](https://www.npmjs.com/package/regenerator-runtime).
-
-First, require the polyfill at the entry point of your application
-```js
-await import('regenerator-runtime/runtime.js');
-// or
-import 'regenerator-runtime/runtime.js';
-```
-
-Then, import the library where needed
+Import the library where needed
 ```js
 const swap = await import('@array-like/swap');
 // or

package.json

@@ -61,11 +61,13 @@
   },
   "dependencies": {},
   "devDependencies": {
+    "@array-like/alloc": "^0.0.1",
     "@babel/core": "7.14.8",
     "@babel/preset-env": "7.14.8",
     "@babel/register": "7.14.5",
     "@commitlint/cli": "13.1.0",
     "@js-library/commitlint-config": "0.0.4",
+    "@randomized/random": "^4.0.0",
     "ava": "3.15.0",
     "babel-plugin-transform-remove-console": "6.9.4",
     "babel-plugin-unassert": "3.1.0",

src/index.js

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

src/swap.js

@@ -0,0 +1,14 @@
+/**
+ * Swap.
+ *
+ * @param {{[x: number]: any}} a
+ * @param {number} i
+ * @param {number} j
+ */
+const swap = (a, i, j) => {
+	const ai = a[i];
+	a[i] = a[j];
+	a[j] = ai;
+};
+
+export default swap;

src/swapRanges.js

@@ -0,0 +1,18 @@
+/**
+ * SwapRanges.
+ *
+ * @param {{[x: number]: any}} a
+ * @param {number} ai
+ * @param {number} aj
+ * @param {{[x: number]: any}} b
+ * @param {number} bi
+ */
+const swapRanges = (a, ai, aj, b, bi) => {
+	for (; ai < aj; ++ai, ++bi) {
+		const temporary = a[ai];
+		a[ai] = b[bi];
+		b[bi] = temporary;
+	}
+};
+
+export default swapRanges;

test/src/_fixtures.js

@@ -0,0 +1,12 @@
+export const arrayTypes = [
+	Array,
+	Int8Array,
+	Int16Array,
+	Int32Array,
+	Uint8Array,
+	Uint16Array,
+	Uint32Array,
+	Uint8ClampedArray,
+	Float32Array,
+	Float64Array,
+];

test/src/api.js

@@ -0,0 +1,47 @@
+import test from 'ava';
+
+import {_calloc} from '@array-like/alloc';
+import {randint} from '@randomized/random';
+
+import {swap} from '../../src/index.js';
+
+import {arrayTypes} from './_fixtures.js';
+
+const macro = (t, Constructor) => {
+	const calloc = _calloc(Constructor);
+
+	const n = 100;
+	const ai = 23;
+	const aj = 73;
+
+	const a = calloc(n);
+	const b = calloc(n);
+
+	for (let i = 0; i < n; ++i) {
+		a[i] = randint(1, 2 ** 31);
+		b[i] = a[i];
+	}
+
+	swap(a, ai, aj);
+
+	for (let i = 0; i < n; ++i) {
+		if (i === ai || i === aj) {
+			const j = ai + aj - i;
+			t.deepEqual(a[i], b[j], `a[${i}] === b[${j}]`);
+		} else {
+			t.deepEqual(a[i], b[i], `a[${i}] === b[${i}]`);
+		}
+	}
+
+	swap(a, ai, aj);
+
+	t.deepEqual(a, b, 'swap back');
+
+	swap(a, ai, ai);
+
+	t.deepEqual(a, b, 'swap');
+};
+
+macro.title = (title, Constructor) => title ?? Constructor.name;
+
+for (const arrayType of arrayTypes) test(macro, arrayType);

test/src/swap.js

@@ -0,0 +1,60 @@
+import test from 'ava';
+
+import {_calloc} from '@array-like/alloc';
+import {randint} from '@randomized/random';
+
+import {swapRanges} from '../../src/index.js';
+
+import {arrayTypes} from './_fixtures.js';
+
+const macro = (t, Constructor) => {
+	const calloc = _calloc(Constructor);
+
+	const n = 100;
+	const ai = 23;
+	const aj = 73;
+	const bi = 49;
+
+	const a = calloc(n);
+	const b = calloc(n);
+	const c = calloc(n);
+	const d = calloc(n);
+
+	for (let i = 0; i < n; ++i) {
+		a[i] = randint(1, 2 ** 31);
+		b[i] = randint(1, 2 ** 31);
+		c[i] = a[i];
+		d[i] = b[i];
+	}
+
+	swapRanges(a, ai, aj, b, bi);
+
+	for (let i = 0; i < n; ++i) {
+		if (i < ai || i >= aj) {
+			t.deepEqual(a[i], c[i], `a[${i}] === c[${i}]`);
+		} else {
+			const j = i - ai + bi;
+			t.deepEqual(a[i], d[j], `a[${i}] === d[${j}]`);
+		}
+
+		if (i < bi || i >= bi + aj - ai) {
+			t.deepEqual(b[i], d[i], `b[${i}] === d[${i}]`);
+		} else {
+			const j = i - bi + ai;
+			t.deepEqual(b[i], c[j], `b[${i}] === c[${j}]`);
+		}
+	}
+
+	swapRanges(a, ai, aj, b, bi);
+
+	t.deepEqual(a, c, 'swapranges back check a');
+	t.deepEqual(b, d, 'swapranges back check b');
+
+	swapRanges(a, ai, aj, a, ai);
+
+	t.deepEqual(a, c, 'swapranges self check a');
+};
+
+macro.title = (title, Constructor) => title ?? Constructor.name;
+
+for (const arrayType of arrayTypes) test(macro, arrayType);