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