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Version: 2.x

Leftovers

Collecting Leftovers​

A sink consumes a variable amount of I elements (zero or more) from the upstream. If the upstream is finite, we can collect leftover values by calling ZSink#collectLeftover. It returns a tuple that contains the result of the previous sink and its leftovers:

val s1: ZIO[Any, Nothing, (Chunk[Int], Chunk[Int])] =
  ZStream(1, 2, 3, 4, 5).run(
    ZSink.take(3).collectLeftover
  )
// Output: (Chunk(1, 2, 3), Chunk(4, 5))


val s2: ZIO[Any, Nothing, (Option[Int], Chunk[Int])] =
  ZStream(1, 2, 3, 4, 5).run(
    ZSink.head[Int].collectLeftover
  )
// Output: (Some(1), Chunk(2, 3, 4, 5))

Ignoring Leftovers​

If we don't need leftovers, we can drop them by using ZSink#ignoreLeftover:

ZSink.take[Int](3).ignoreLeftover