Function scanLeft

packages/effect/test/Schedule.test.ts:1009–1017

(self: Chunk.Chunk<A>, b: B, f: (b: B, a: A) => B)

}
// TODO(Mike/Max): remove if added to `effect`
const scanLeft = <A, B>(self: Chunk.Chunk<A>, b: B, f: (b: B, a: A) => B): Chunk.Chunk<B> => {
  const len = self.length
  const out = Array.allocate<B>(len + 1) as Array<B>
  out[0] = b
  for (let i = 0; i < len; i++) {
    out[i + 1] = f(out[i], self.pipe(Chunk.unsafeGet(i)))
  }
  return Chunk.unsafeFromArray(out)
}