@lou.codes/iterables/dist/asynchronous/reduce.js

🔁 Iterable and AsyncIterable utils

import { awaitableHandler } from "@lou.codes/utils";
import { forEach } from "./forEach.js";
/**
 * Reducer function for iterables and asynchronous iterables.
 *
 * @category Asynchronous Reducers
 * @example
 * ```typescript
 * const sum = Accumulator<number>(item => total => total + item);
 * const sumFrom0 = sum(0);
 *
 * sumFrom0([1, 2, 3]); // 6
 * ```
 * @param reducer Reducer function.
 * @returns Curried function with `reducer` in context.
 */
export const reduce = reducer => initialValue => iterable => {
	let accumulator = initialValue;
	return awaitableHandler(_ => accumulator)(
		forEach(
			async item => void (accumulator = await reducer(item)(accumulator)),
		)(iterable),
	);
};