Function monotonicFactory

source/ulid.ts:155–169

(prng?: PRNG)

 *  ulid(); // "01HNZXD07M5CEN5XA66EMZSRZW"
 */
export function monotonicFactory(prng?: PRNG): ULIDFactory {
    const currentPRNG = prng || detectPRNG();
    let lastTime: number = 0,
        lastRandom: string;
    return function _ulid(seedTime?: number): ULID {
        const seed = !seedTime || isNaN(seedTime) ? Date.now() : seedTime;
        if (seed <= lastTime) {
            const incrementedRandom = (lastRandom = incrementBase32(lastRandom));
            return encodeTime(lastTime, TIME_LEN) + incrementedRandom;
        }
        lastTime = seed;
        const newRandom = (lastRandom = encodeRandom(RANDOM_LEN, currentPRNG));
        return encodeTime(seed, TIME_LEN) + newRandom;
    };
}

/**
 * Generate a ULID