export const reduceWhileEffect = <S, In, E, R>(
  initial: LazyArg<S>,
  predicate: Predicate<S>,
  f: (s: S, input: In) => Effect.Effect<S, E, R>
): Sink<S, In, In, E, R> =>
  fromTransform((upstream) => {
    let state = initial()
    let leftover: NonEmptyReadonlyArray<In> | undefined = undefined
    if (!predicate(state)) {
      return Effect.succeed([state] as const)
    }
    return upstream.pipe(
      Effect.flatMap((arr) => {
        let i = 0
        return Effect.whileLoop({
          while: () => i < arr.length,
          body: constant(Effect.flatMap(Effect.suspend(() => f(state, arr[i++])), (s) => {
            state = s
            if (!predicate(state)) {
              if (i < arr.length) {
                leftover = arr.slice(i) as any
              }
              return Cause.done()
            }
            return Effect.void
          })),
          step: constVoid
        })
      }),
      Effect.forever({ disableYield: true }),
      Pull.catchDone(() => Effect.succeed([state, leftover] as const))
    )
  })