💥 BREAKING CHANGE: Move to more functional API.

README.md

@@ -4,13 +4,19 @@
 Pseudorandom number generators for JavaScript.
 See [docs](https://aureooms.github.io/js-pseudo-random/index.html).
 
+> :warning: The code requires `regeneratorRuntime` to be defined, for instance by importing
+> [regenerator-runtime/runtime](https://www.npmjs.com/package/regenerator-runtime).
 ```js
-import {SplitMix64} from '@aureooms/js-pseudo-random';
+import {
+  splitmix64,
+  nextFloat,
+  nextUint64,
+} from '@aureooms/js-pseudo-random';
 
 const seed = [0, 0]; // Two 32-bit signed integers.
-const prng = new SplitMix64(seed);
-prng.next(); // 64 random bits as two 32-bit signed integers.
-prng.nextFloat(); // a random float in the range [0, 1[
+const prng = splitmix64(seed);
+nextUint64(prng); // 64 random bits as two 32-bit signed integers (compatible with @aureooms/js-uint64).
+nextFloat(prng); // A random float in the range [0, 1[.
 ```
 
 [![License](https://img.shields.io/github/license/aureooms/js-pseudo-random.svg)](https://raw.githubusercontent.com/aureooms/js-pseudo-random/main/LICENSE)

doc/manual/usage.md

@@ -1,6 +1,16 @@
 # Usage
 
-Import the library where needed
+> :warning: The code requires `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
+require( 'regenerator-runtime/runtime' );
+// or
+import 'regenerator-runtime/runtime.js' ;
+```
+
+Then, import the library where needed
 ```js
 const pseudorandom = require( '@aureooms/js-pseudo-random' ) ;
 // or

src/index.js

@@ -1,8 +1,12 @@
-import SplitMix64 from './SplitMix64';
+import nextFloat from './nextFloat';
+import nextUint64 from './nextUint64';
+import splitmix64 from './splitmix64';
 
 /* eslint import/no-anonymous-default-export: [2, {"allowObject": true}] */
 export default {
-	SplitMix64,
+	nextFloat,
+	nextUint64,
+	splitmix64,
 };
 
-export {SplitMix64};
+export {nextFloat, nextUint64, splitmix64};

src/nextFloat.js

@@ -0,0 +1,5 @@
+export default function nextFloat(prng) {
+	const a = prng.next().value;
+	const b = prng.next().value;
+	return (a >>> 0) / 2 ** 32 + (b >>> 0) / 2 ** 64;
+}

src/nextUint64.js

@@ -0,0 +1,3 @@
+export default function nextUint64(prng) {
+	return [prng.next().value, prng.next().value];
+}

src/splitmix64.js

@@ -0,0 +1,12 @@
+import {add64, mul64, xor64, shr64, get64} from '@aureooms/js-uint64';
+
+export default function* splitmix64(seed) {
+	let state = get64(...seed);
+	while (true) {
+		state = add64(state, get64(0x9e3779b9, 0x7f4a7c15));
+		let z = state;
+		z = mul64(xor64(z, shr64(z, 30)), get64(0xbf58476d, 0x1ce4e5b9));
+		z = mul64(xor64(z, shr64(z, 27)), get64(0x94d049bb, 0x133111eb));
+		yield* xor64(z, shr64(z, 31));
+	}
+}

test/src/SplitMix64.js → test/src/splitmix64.js

@@ -1,19 +1,19 @@
 import test from 'ava';
 import {range, map} from '@aureooms/js-itertools';
 
-import {SplitMix64} from '../../src';
+import {splitmix64, nextUint64, nextFloat} from '../../src';
 
 test('https://rosettacode.org/wiki/Pseudo-random_numbers/Splitmix64 #1', (t) => {
 	/**
 	 * Show the first five integers generated using the seed 1234567.
 	 */
 	const seed = [0, 1234567];
-	const prng = new SplitMix64(seed);
-	t.deepEqual(prng.next(), [0x599ed017 | 0, 0xfb08fc85 | 0]); // 6457827717110365317
-	t.deepEqual(prng.next(), [0x2c73f084 | 0, 0x58540fa5 | 0]); // 3203168211198807973
-	t.deepEqual(prng.next(), [0x883ebce5 | 0, 0xa3f27c77 | 0]); // 9817491932198370423
-	t.deepEqual(prng.next(), [0x3fbef740 | 0, 0xe9177b3f | 0]); // 4593380528125082431
-	t.deepEqual(prng.next(), [0xe3b83467 | 0, 0x08cb5ecd | 0]); // 16408922859458223821
+	const prng = splitmix64(seed);
+	t.deepEqual(nextUint64(prng), [0x599ed017 | 0, 0xfb08fc85 | 0]); // 6457827717110365317
+	t.deepEqual(nextUint64(prng), [0x2c73f084 | 0, 0x58540fa5 | 0]); // 3203168211198807973
+	t.deepEqual(nextUint64(prng), [0x883ebce5 | 0, 0xa3f27c77 | 0]); // 9817491932198370423
+	t.deepEqual(nextUint64(prng), [0x3fbef740 | 0, 0xe9177b3f | 0]); // 4593380528125082431
+	t.deepEqual(nextUint64(prng), [0xe3b83467 | 0, 0x08cb5ecd | 0]); // 16408922859458223821
 });
 
 test('https://rosettacode.org/wiki/Pseudo-random_numbers/Splitmix64 #2', (t) => {
@@ -25,10 +25,10 @@ test('https://rosettacode.org/wiki/Pseudo-random_numbers/Splitmix64 #2', (t) =>
 	 */
 
 	const seed = [0, 987654321];
-	const prng = new SplitMix64(seed);
+	const prng = splitmix64(seed);
 	const histogram = new Array(5).fill(0);
 	for (const k of map(
-		() => Math.floor(prng.nextFloat() * 5) | 0,
+		() => Math.floor(nextFloat(prng) * 5) | 0,
 		range(100000),
 	)) {
 		++histogram[k];