✨ feat(api): Expose random, _randint, and randfloat.

Fixes #89.

Author: make-github-pseudonymous-again

src/api/randfloat.js

@@ -1,7 +1,15 @@
+import random from './random.js';
+import _randfloat from '../kernel/_randfloat.js';
+
 /**
- * Returns a floating point number in interval [i, j[ (i included, j excluded)
+ * Returns a double in interval [i, j[ (i included, j excluded)
  * according to a uniform distribution.
+ *
+ * @function
+ * @param {number} i The inclusive left bound
+ * @param {number} j The non-inclusive right bound
+ * @return {number} A double in the interval [i, j[ taken uniformly at
+ * random.
  */
-
-const randfloat = (i, j) => i + Math.random() * (j - i);
+const randfloat = _randfloat(random);
 export default randfloat;

src/api/randint.js

@@ -1,7 +1,15 @@
+import random from './random.js';
+import _randint from '../kernel/_randint.js';
+
 /**
  * Returns an integer in interval [i, j[ (i included, j excluded)
  * according to a uniform distribution.
+ *
+ * @function
+ * @param {number} i The inclusive left bound
+ * @param {number} j The non-inclusive right bound
+ * @return {number} An integer in the interval [i, j[ taken uniformly at
+ * random.
  */
-
-const randint = (i, j) => i + Math.floor(Math.random() * (j - i));
+const randint = _randint(random);
 export default randint;

src/api/random.js

@@ -0,0 +1,9 @@
+/**
+ * Returns a double in the interval [0, 1) using JavaScript Math.random().
+ * @return {number}
+ */
+const random = () => {
+	return Math.random();
+};
+
+export default random;

src/index.js

@@ -1,7 +1,10 @@
 export {default as randfloat} from './api/randfloat.js';
 export {default as randint} from './api/randint.js';
+export {default as random} from './api/random.js';
 export {default as randrange} from './api/randrange.js';
 export {default as sample} from './api/sample.js';
 export {default as shuffle} from './api/shuffle.js';
 export {default as _fisheryates} from './kernel/_fisheryates.js';
+export {default as _randfloat} from './kernel/_randfloat.js';
+export {default as _randint} from './kernel/_randint.js';
 export {default as _shuffle} from './kernel/_shuffle.js';

src/kernel/_randfloat.js

@@ -0,0 +1,23 @@
+/**
+ * Builds a randfloat function given a random number generator.
+ *
+ * @param {Function} random A function taking no arguments that returns a
+ * double uniformly at random in the interval [0, 1).
+ *
+ * @return {Function} A randfloat function.
+ */
+const _randfloat = (random) => {
+	/**
+	 * Returns a double in interval [i, j[ (i included, j excluded)
+	 * according to a uniform distribution.
+	 *
+	 * @param {number} i The inclusive left bound
+	 * @param {number} j The non-inclusive right bound
+	 * @return {number} A double in the interval [i, j[ taken uniformly at
+	 * random.
+	 */
+	const randfloat = (i, j) => i + random() * (j - i);
+	return randfloat;
+};
+
+export default _randfloat;

src/kernel/_randint.js

@@ -0,0 +1,23 @@
+/**
+ * Builds a randint function given a random number generator.
+ *
+ * @param {Function} random A function taking no arguments that returns a
+ * double uniformly at random in the interval [0, 1).
+ *
+ * @return {Function} A randint function.
+ */
+const _randint = (random) => {
+	/**
+	 * Returns an integer in interval [i, j[ (i included, j excluded)
+	 * according to a uniform distribution.
+	 *
+	 * @param {number} i The inclusive left bound
+	 * @param {number} j The non-inclusive right bound
+	 * @return {number} An integer in the interval [i, j[ taken uniformly at
+	 * random.
+	 */
+	const randint = (i, j) => i + Math.floor(random() * (j - i));
+	return randint;
+};
+
+export default _randint;