windowed (Functional Programming)

Creates a function that returns sliding windows from an array. Use it with pipe.

const result = pipe(array, windowed(size, step, options));

::: info

Prefer the original es-toolkit windowed in ordinary code. Use this fp variant when composing transformations with pipe.

:::

Usage

windowed returns sub-arrays of length size, moving forward by step each time. Full-window mode is lazy-capable inside pipe.

import { pipe, windowed } from 'es-toolkit/fp';

pipe([1, 2, 3, 4], windowed(2)); // => [[1, 2], [2, 3], [3, 4]]

pipe([1, 2, 3, 4], windowed(2, 2)); // => [[1, 2], [3, 4]]

Parameters

• size (number): The length of each window.
• step (number, optional): The number of positions to move between windows. Defaults to 1.
• options (WindowedOptions, optional): Options such as whether to include partial trailing windows.

Returns

((array: readonly T[]) => T[][]): A function that maps a readonly T[] to sliding windows.

Throws

Throws an error if size or step is not a positive integer.