defer, skipUntil & combine

[hoc081098]

@Suppress("UNCHECKED_CAST")
public fun <T1, T2, T3, T4, T5, T6, R> combine(
  flow: Flow<T1>,
  flow2: Flow<T2>,
  flow3: Flow<T3>,
  flow4: Flow<T4>,
  flow5: Flow<T5>,
  flow6: Flow<T6>,
  transform: suspend (T1, T2, T3, T4, T5, T6) -> R,
): Flow<R> = combine(flow, flow2, flow3, flow4, flow5, flow6) { args: Array<*> ->
  transform(
    args[0] as T1,
    args[1] as T2,
    args[2] as T3,
    args[3] as T4,
    args[4] as T5,
    args[5] as T6,
  )
}

@Suppress("UNCHECKED_CAST")
public fun <T1, T2, T3, T4, T5, T6, T7, R> combine(
  flow: Flow<T1>,
  flow2: Flow<T2>,
  flow3: Flow<T3>,
  flow4: Flow<T4>,
  flow5: Flow<T5>,
  flow6: Flow<T6>,
  flow7: Flow<T7>,
  transform: suspend (T1, T2, T3, T4, T5, T6, T7) -> R,
): Flow<R> = combine(flow, flow2, flow3, flow4, flow5, flow6, flow7) { args: Array<*> ->
  transform(
    args[0] as T1,
    args[1] as T2,
    args[2] as T3,
    args[3] as T4,
    args[4] as T5,
    args[5] as T6,
    args[6] as T7,
  )
}

@Suppress("UNCHECKED_CAST")
public fun <T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, R> combine(
  flow: Flow<T1>,
  flow2: Flow<T2>,
  flow3: Flow<T3>,
  flow4: Flow<T4>,
  flow5: Flow<T5>,
  flow6: Flow<T6>,
  flow7: Flow<T7>,
  flow8: Flow<T8>,
  flow9: Flow<T9>,
  flow10: Flow<T10>,
  flow11: Flow<T11>,
  transform: suspend (T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11) -> R,
): Flow<R> = combine(
  flow,
  flow2,
  flow3,
  flow4,
  flow5,
  flow6,
  flow7,
  flow8,
  flow9,
  flow10,
  flow11
) { args: Array<*> ->
  transform(
    args[0] as T1,
    args[1] as T2,
    args[2] as T3,
    args[3] as T4,
    args[4] as T5,
    args[5] as T6,
    args[6] as T7,
    args[7] as T8,
    args[8] as T9,
    args[9] as T10,
    args[10] as T11
  )
}

fun <T> defer(flowFactory: () -> Flow<T>): Flow<T> = flow { emitAll(flowFactory()) }

fun <T> Flow<T>.skipUntil(notifier: Flow<Any?>): Flow<T> = flow {
  coroutineScope {
    val shouldEmit = AtomicBoolean(false)

    launch(start = CoroutineStart.UNDISPATCHED) {
      notifier
        .take(1)
        .collect()
      shouldEmit.set(true)
    }

    collect {
      if (shouldEmit.get()) {
        emit(it)
      }
    }
  }
}

• defer
• skipUntil / dropUntil
• combine...