split-lazy 🗡🦥

This package provides ways to split arrays, strings or other iterables (sync and async) lazily. It returns an iterable that calculates the result lazily (while iterating on it).

👉 Learn more about iterators here.

Installing

Use yarn or npm to install it.

npm install split-lazy

splitLazy

function splitLazy<I, T extends Iterable<I>>(
  iterable: T,
  separator: unknown
): Generator<I[], void, void>

First argument is iterable to search inside and split. Second argument is either an iterable or an element to look for in the given first argument.

separator can be an Iterable or anything else as an element. If separator is an iterable, it will be searched as a sub iterator.

Examples

import { splitLazy } from "split-lazy";

const arr = [1, 3, 5, 7, 9];
const result = splitLazy(arr, 5);

for (const item of result) {
    console.log(item);
}
// outputs:
// [1, 3]
// [7, 9]

import { splitLazy } from "split-lazy";

const arr = [1, 3, 5, 7, 9];
const iterable = splitLazy(arr, 5);

expect(iterable.next().value).toEqual([1, 3]); // ✅
expect(iterable.next().value).toEqual([7, 9]); // ✅

import { splitLazy } from "split-lazy";

function* generator() {
    yield 1;
    yield 3;
    yield 5;
    yield 7;
    yield 9;
}

const iterable = generator();
const result = splitLazy(iterable, 5);

for (const item of result) {
    console.log(item);
}
// outputs:
// [1, 3]
// [7, 9]

It can also search for sub-iterables in iterables:

import { splitLazy } from "split-lazy";

const arr = [1, 3, 5, 7, 9, 11];
const iterable = splitLazy(arr, [5, 7]);

expect(iterable.next().value).toEqual([1, 3]); // ✅
expect(iterable.next().value).toEqual([9, 11]); // ✅

asyncSplitLazy

async function* asyncSplitLazy<I, T extends AsyncIterable<I>>(
  iterable: T,
  separator: unknown
): AsyncGenerator<I[], void, void>

Iterable can be an AsyncIterable. Separator can be an Iterable, AsyncIterable or anything else as an element. If separator is an iterable, it will be searched as a sub iterator.

Note that if separator argument is an AsyncIterable, asyncSplitLazy fully iterates the given separator before it starts searching for it in the first argument (iterable).

Contributing

Help is needed for documentation in general. Adding/improving TSDoc, a better README, added/improved reference would be amazing 💫. Please open/find an issue to discuss.

Tests

Jest tests are set up to run with npm test.