effect-io-ai

Package: effect
Module: Array

Array.flatMap

Maps each element to an array and flattens the results into a single array.

When to use

Use to map each array element to zero or more values and concatenate the results in one pass.

Details

The function receives (element, index). This returns NonEmptyArray when both the input and mapped arrays are non-empty.

Example (Flat mapping an array)

import { Array } from "effect"

console.log(Array.flatMap([1, 2, 3], (x) => [x, x * 2])) // [1, 2, 2, 4, 3, 6]

See

• map — transform without flattening
• flatten — flatten without mapping

Signature

declare const flatMap: { <S extends ReadonlyArray<any>, T extends ReadonlyArray<any>>(f: (a: ReadonlyArray.Infer<S>, i: number) => T): (self: S) => ReadonlyArray.AndNonEmpty<S, T, ReadonlyArray.Infer<T>>; <A, B>(self: NonEmptyReadonlyArray<A>, f: (a: A, i: number) => NonEmptyReadonlyArray<B>): NonEmptyArray<B>; <A, B>(self: ReadonlyArray<A>, f: (a: A, i: number) => ReadonlyArray<B>): Array<B>; }

Source

Since v2.0.0