dahlia/aitertools

Well-tested utility functions dealing with async iterables

aitertools

This library provides a well-tested collection of small utility functions dealing with async iterables. You can think of it as .NET LINQ or Python aitertools for Deno & Node.js.

Functions

For the complete list of functions, see the complete API reference.

• concat(...sources): Concatenate multiple async iterables into one.
• take(source, count): Take the first count items from the source.
• drop(source, count): Drop the first count items from the source.
• takeWhile(source, predicate): Take items from the source while the predicate returns true.
• dropWhile(source, predicate): Drop items from the source while the predicate returns true.
• takeEnd(source, count): Take the last count items from the source.
• dropEnd(source, count): Drop the last count items from the source.
• map(mapper, ...sources): Apply the mapper to each item in the sources.
• filter(predicate, ...sources): Filter items in the sources by the predicate.
• reduce(reducer, source, initial?): Reduce the source to a single value by the reducer, optionally with the initial value.
• tee(source, number): Effectively duplicate the source into number of async iterables.
• groupBy(source, keySelector): Group items in the source by the keySelector.
• unique(source, keySelector?): Eliminate duplicate items in the source, optionally by the keySelector.
• range(start?, stop, step?): Generate a sequence of numbers from start to stop by step.
• count(start?, step?): Generate a sequence of numbers from start by step infinitely.
• cycle(source): Cycle the source infinitely.
• repeat(value, times?): Repeat the value for times times, or infinitely if times is not specified.
• fromIterable(source): Convert an iterable to an async iterable.
• toArray(source): Convert an async iterable to an array.
• toSet(source): Convert an async iterable to a Set.
• toMap(source, keySelector, valueSelector?): Convert an async iterable to a Map.
• assertStreams(actual, expected, msg?): Asset that an async iterable actual is equal to an array expected.
• assertStreamStartsWith(actual, expected, msg?): Asset that an async iterable actual (which is possibly infinite) starts with an array expected.

Usage

In Deno:

$ deno add @hongminhee/aitertools

import * as aitertools from "@hongminhee/aitertools";

In Node.js:

$ npm add aitertools

import * as aitertools from "aitertools";

Changelog

See CHANGES.md file. Note that unreleased versions are also available on JSR for Deno:

deno add @hongminhee/aitertools@0.6.0-dev.36+9aa783c

… and on npm with dev tag for Node.js:

$ npm add aitertools@dev