Array

const map: <A, B>(f: (a: A, i: number) => B) => (self: ReadonlyArray<A>) => Array<B>

const filter: <A>(predicate: Predicate<A>) => (self: ReadonlyArray<A>) => Array<A>

const flatMap: <A, B>(f: (a: A, i: number) => ReadonlyArray<B>) => (self: ReadonlyArray<A>) => Array<B>

const reduce: <B, A>(b: B, f: (b: B, a: A, i: number) => B) => (self: ReadonlyArray<A>) => B

const partition: <A>(predicate: Predicate<A>) => (self: ReadonlyArray<A>) => [excluded: Array<A>, satisfying: Array<A>]

const groupBy: <A, K extends string | symbol>(f: (a: A) => K) => (self: ReadonlyArray<A>) => Record<K, Array<A>>

import { Array } from "effect"

const numbers = [1, 2, 3, 4, 5]

const result = numbers.pipe(
  Array.filter(n => n % 2 === 0),
  Array.map(n => n * 2)
)
console.log(result) // [4, 8]