please help: I think I knotted my brain into a loop!

I should probably just go to sleep and dream it up, but this has got me puzzled: in an actor, I would like to have a “var” which holds an Option[Function1[_, _]] which is applied to each incoming message to obtain the function for the next message. While I can describe it easily in words, and also imagine how the code shall look like (autopilot = autopilot flatMap (_(msg))), I cannot figure out what the actual type should be to make this compile. Since the type system is Turing complete, there must be a way, but how do I create a recursive type?

Regards,

Roland

On Sat, Feb 18, 2012 at 10:56 PM, rkuhn <google@rkuhn.info> wrote:

I should probably just go to sleep and dream it up, but this has got me puzzled: in an actor, I would like to have a “var” which holds an Option[Function1[_, _]] which is applied to each incoming message to obtain the function for the next message. While I can describe it easily in words, and also imagine how the code shall look like (autopilot = autopilot flatMap (_(msg))), I cannot figure out what the actual type should be to make this compile. Since the type system is Turing complete, there must be a way, but how do I create a recursive type?

You can express it with a trait. I've tinkered with this in my pursuit to implement actors on top of Iteratees.