46 lines
1.4 KiB
JavaScript
46 lines
1.4 KiB
JavaScript
/**
|
|
* @since 2.0.0
|
|
*/
|
|
import { map } from './IO';
|
|
import { pipe } from './function';
|
|
/**
|
|
* Returns a random number between 0 (inclusive) and 1 (exclusive). This is a direct wrapper around JavaScript's
|
|
* `Math.random()`.
|
|
*
|
|
* @since 2.0.0
|
|
*/
|
|
export var random = function () { return Math.random(); };
|
|
/**
|
|
* Takes a range specified by `low` (the first argument) and `high` (the second), and returns a random integer uniformly
|
|
* distributed in the closed interval `[low, high]`. It is unspecified what happens if `low > high`, or if either of
|
|
* `low` or `high` is not an integer.
|
|
*
|
|
* @since 2.0.0
|
|
*/
|
|
export function randomInt(low, high) {
|
|
return pipe(random, map(function (n) { return Math.floor((high - low + 1) * n + low); }));
|
|
}
|
|
/**
|
|
* Returns a random number between a minimum value (inclusive) and a maximum value (exclusive). It is unspecified what
|
|
* happens if `maximum < minimum`.
|
|
*
|
|
* @since 2.0.0
|
|
*/
|
|
export function randomRange(min, max) {
|
|
return pipe(random, map(function (n) { return (max - min) * n + min; }));
|
|
}
|
|
/**
|
|
* Returns a random boolean value with an equal chance of being `true` or `false`
|
|
*
|
|
* @since 2.0.0
|
|
*/
|
|
export var randomBool = /*#__PURE__*/ pipe(random, map(function (n) { return n < 0.5; }));
|
|
/**
|
|
* Returns a random element of a `ReadonlyNonEmptyArray`.
|
|
*
|
|
* @since 2.10.0
|
|
*/
|
|
export var randomElem = function (as) {
|
|
return pipe(randomInt(0, as.length - 1), map(function (i) { return as[i]; }));
|
|
};
|