iter-funcs

About

Utility functions for iterators. Inspired by Rust’s std::iter::Iterator trait. This library uses JavaScript native iterators, so it’s compatible with any library that uses them.

Difference from Array.prototype methods

This library’s functions are lazy. They don’t evaluate the whole iterator at once. They evaluate only the needed elements. This is useful when you have a large iterator and you only need a few elements from it.

Example

import {
  filter,
  forEach,
  map,
  pipe,
  take,
} from "https://deno.land/x/iter_funcs@1.5.0/mod.ts";

const array = [1, 2, 3, 4, 5, 6];

pipe(
  array.values(), // make iterator from array
  filter((x) => x % 2 === 0), // filter even numbers
  map((x) => x * 2), // multiply by 2
  take(2), // take first 2 elements
  forEach(console.log), // => 4, 8
);