prando/dist/Prando.d.ts

Deterministic pseudo-random number generator for JavaScript and TypeScript

export default class Prando {
    private static readonly MIN;
    private static readonly MAX;
    private _seed;
    private _value;
    /**
     * Generate a new Prando pseudo-random number generator.
     *
     * @param seed - A number or string seed that determines which pseudo-random number sequence will be created. Defaults to a random seed based on `Math.random()`.
     */
    constructor(seed?: number | string);
    /**
     * Generates a pseudo-random number between a lower (inclusive) and a higher (exclusive) bounds.
     *
     * @param min - The minimum number that can be randomly generated.
     * @param pseudoMax - The maximum number that can be randomly generated (exclusive).
     * @return The generated pseudo-random number.
     */
    next(min?: number, pseudoMax?: number): number;
    /**
     * Generates a pseudo-random integer number in a range (inclusive).
     *
     * @param min - The minimum number that can be randomly generated.
     * @param max - The maximum number that can be randomly generated.
     * @return The generated pseudo-random number.
     */
    nextInt(min?: number, max?: number): number;
    /**
     * Generates a pseudo-random string sequence of a particular length from a specific character range.
     *
     * Note: keep in mind that creating a random string sequence does not guarantee uniqueness; there is always a
     * 1 in (char_length^string_length) chance of collision. For real unique string ids, always check for
     * pre-existing ids, or employ a robust GUID/UUID generator.
     *
     * @param length - Length of the string to be generated.
     * @param chars - Characters that are used when creating the random string. Defaults to all alphanumeric chars (A-Z, a-z, 0-9).
     * @return The generated string sequence.
     */
    nextString(length?: number, chars?: string): string;
    /**
     * Generates a pseudo-random string of 1 character specific character range.
     *
     * @param chars - Characters that are used when creating the random string. Defaults to all alphanumeric chars (A-Z, a-z, 0-9).
     * @return The generated character.
     */
    nextChar(chars?: string): string;
    /**
     * Picks a pseudo-random item from an array. The array is left unmodified.
     *
     * Note: keep in mind that while the returned item will be random enough, picking one item from the array at a time
     * does not guarantee nor imply that a sequence of random non-repeating items will be picked. If you want to
     * *pick items in a random order* from an array, instead of *pick one random item from an array*, it's best to
     * apply a *shuffle* transformation to the array instead, then read it linearly.
     *
     * @param array - Array of any type containing one or more candidates for random picking.
     * @return An item from the array.
     */
    nextArrayItem<T>(array: T[]): T;
    /**
     * Generates a pseudo-random boolean.
     *
     * @return A value of true or false.
     */
    nextBoolean(): boolean;
    /**
     * Skips ahead in the sequence of numbers that are being generated. This is equivalent to
     * calling next() a specified number of times, but faster since it doesn't need to map the
     * new random numbers to a range and return it.
     *
     * @param iterations - The number of items to skip ahead.
     */
    skip(iterations?: number): void;
    /**
     * Reset the pseudo-random number sequence back to its starting seed. Further calls to next()
     * will then produce the same sequence of numbers it had produced before. This is equivalent to
     * creating a new Prando instance with the same seed as another Prando instance.
     *
     * Example:
     * let rng = new Prando(12345678);
     * console.log(rng.next()); // 0.6177754114889017
     * console.log(rng.next()); // 0.5784605181725837
     * rng.reset();
     * console.log(rng.next()); // 0.6177754114889017 again
     * console.log(rng.next()); // 0.5784605181725837 again
     */
    reset(): void;
    private recalculate;
    private xorshift;
    private map;
    private hashCode;
    private getSafeSeed;
}