Hello, I was wondering how to convert `IO` to `Mon...

# arrow

[Chris Kruczynski]

Hello, I was wondering how to convert IO to MonoK nicely, could anybody help?

[simon.vergauwen]

Hey Chris,

These are the methods you can use to transform between MonoK and IO. These should be added to Arrow Fx and its integration libs.

import arrow.core.Left
import arrow.core.Right
import <http://arrow.fx.IO|arrow.fx.IO>
import reactor.core.publisher.Mono

fun <A> IO<A>.toMonoK(): MonoK<A> =
  MonoK(Mono.create<A> { sink ->
    val dispose = unsafeRunAsyncCancellable { result ->
      result.fold(sink::error, sink::success)
    }
    sink.onCancel { dispose.invoke() }
  })

fun <A> MonoK<A>.toIO(): IO<A> =
  IO.cancelable { cb ->
    val dispose = value().subscribe({ a -> cb(Right(a)) }, { e -> cb(Left(e)) })
    IO { dispose.dispose() }
  }

[Chris Kruczynski]

Sweet, thanks very much!

[simon.vergauwen]

You’re welcome!