On Nov 24, 2011, at 2:31 AM, Patrick Li wrote:
> Hello everyone, > > Does anyone know of a guide on how delimited continuations (reset/shift) can > be implemented using a CPS transform? There is a paper for doing this in > Scala, but I don't have a CS background and cannot understand the notation. > > I thought it might be similar to implementing full continuations using a CPS > transform (which I know how to do), but I'm not sure if my solution is the > cleanest. Normally, in the CPS transform, each function is extended to take > an extra continuation argument. My solution is to extend every function with > an additional return-to-reset continuation on top of the extra continuation > argument. This 2nd continuation is used by "shift" commands to return to the > enclosing "reset", and the original 1st continuation is used to return to the > caller. > > Does that sound sensible? Sure, that's how they created it in 1990. But you could also break the tail-call discipline of CPS and translate [shift e] as \k. (k [e](\x.x)) Or you can use our 'abstract' continuations to manipulate a stack of continuations directly. -- Matthias _________________________________________________ For list-related administrative tasks: http://lists.racket-lang.org/listinfo/users
