does anyone know if it would be viable to implement "real" continuations as an SBCL extension?. I know there are CPS transformation libraries there, but they have limitations, specially when interacting with code not written in CPS. So I was thinking something like Smalltalk stack manipulation or Scheme continuations, but I don't know if that would be possible to implement. A good implementation of continuations would be useful for things like asynchronous programming, generators, co-routines, web continuations, an so on, without the limitations of the current implementations of those things.