effect-io-ai

Package: effect
Module: Stream

Stream.scan

Statefully maps over the elements of this stream to produce all intermediate results of type S given an initial S.

Example

import { Effect, Stream } from "effect"

const stream = Stream.range(1, 6).pipe(Stream.scan(0, (a, b) => a + b))

Effect.runPromise(Stream.runCollect(stream)).then(console.log)
// { _id: 'Chunk', values: [ 0,  1,  3, 6, 10, 15, 21 ] }

Signature

declare const scan: { <S, A>(s: S, f: (s: S, a: A) => S): <E, R>(self: Stream<A, E, R>) => Stream<S, E, R>; <A, E, R, S>(self: Stream<A, E, R>, s: S, f: (s: S, a: A) => S): Stream<S, E, R>; }

Source

Since v2.0.0