parallel-es/src/common/parallel/slave/range-iterator.ts

Simple parallelization for EcmaScript

/**
 * Generator function that creates an iterator containing all elements in the range [start, end) with a step size of step.
 * @param start start value of the range (inclusive)
 * @param end end value of the range (exclusive)
 * @param step step size between two values
 * @returns iterator with the values [start, end)
 */
export function rangeIterator(start: number, end: number, step: number): Iterator<number> {
    const distance = end - start;
    let length = Math.max(Math.floor(distance / (step || 1)), 0);
    let next = start;

    return {
        next(): IteratorResult<number> {
            const current = next;
            next = next + step;
            if (length-- !== 0) {
                return { done: false, value: current };
            }
            return { done: true } as IteratorResult<number>;
        }
    };
}