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

Simple parallelization for EcmaScript

import {IParallelTaskEnvironment} from "../";
/**
 * Performs the map operation
 * @param iterator the iterator of the previous step
 * @param iteratee the iteratee to apply to each element in the iterator
 * @param env the environment of the job
 * @param T the type of the input elements
 * @param TResult the type of the returned element of the iteratee
 * @returns a new iterator where each element has been mapped using the iteratee
 */
export function mapIterator<T, TResult>(iterator: Iterator<T>, iteratee: (this: void, value: T, env: IParallelTaskEnvironment) => TResult, env: IParallelTaskEnvironment): Iterator<TResult> {
    return {
        next(): IteratorResult<TResult> {
            const result = iterator.next();
            if (result.done) {
                return { done: true } as IteratorResult<TResult>;
            }
            return {
                done: result.done,
                value: iteratee(result.value, env)
            };
        }
    };
}