Polyethylene is a wrapping layer around iterators and async iterators that lets you chain functional operators in a similar way you do with arrays but without the memory overhead or having to wait for an asynchronous iteration to end.
The default export of polyethylene
(named Poly
throughout the documentation) is the main entry point.
You would typically create an "augmented" iterable object using Poly.asyncFrom
or Poly.syncFrom
, then you start
calling transform methods like .map
, .filter
, etc. in the returned object, ending with a leaf method like
.reduce
or .forEach
.
In this way, polyethylene objects behave very similarly to Array
s, but they are fundamentally different because they
don't store their elements anywhere, instead processing them one by one.
The following is a very simple, fictitious example of using polyethylene:
import Poly from 'polyethylene';
import {findUsers, findUserPosts} from 'some-api-lib'
// Print the first 10 posts of each user
await Poly.asyncFrom(findUsers())
.flatMap(user => Poly.asyncFrom(findUserPosts(user)).take(10))
.forEach(post => console.log(post));
This package is designed as an ECMAScript Module from the get go, but since 2.1.0 a CommonJS version is provided.
All named exports are supported, but the default export must be accessed via the default
or Poly
exports:
const Poly = require('polyethylene').default
const {Poly} = require('polyethylene')
See the API Documentation.
Polyethylene is released under the MIT License