He-Pin(kerr)

The current `in` `out` looks like a primary student and verbose. Kotlin and C# is using `in` and `out` too，but reads badly.

repeat the `in` 、`out` and `inout` here and there make me looks like a fool; why not make use of `inputParameter T ` `outputParameterR`?

@leafpetersen I think the `-` and `+` style are more concise and the `in` and `out` style are more easy to understand.

Highly needed, my friend @WayneWang12 can't use scala-native for the competition of alicloud...

Any update on this? Would be very interesting to implement out tql with this.

@wsargent first you need a paradox-play plugin:)

I currently busy on translating two books (Pragmatic Scala and Reactive Design Patterns), sorry :( @wsargent @marcospereira

I think this could be part of Play 2.8 too. @dwijnand

@osi I'm trying to use this operator too, I'm currently using akka stream's [mergePrioritized](https://doc.akka.io/docs/akka/current/stream/operators/Source-or-Flow/mergePrioritized.html) which gives you ： ``` spot barley goodboy sammy doug pickles leela girl meatloaf henry ```...

@exoego I just come up with this idea too, any progress?