Piers Cawley <[EMAIL PROTECTED]> wrote: > I could be wrong here, but it seems to me that having a special > 'tailinvoke' operator which simply reuses the current return > continuation instead of creating a new one would make for rather faster > tail calls than fetching the current continuation out of the interpreter > structure, then invoking the target sub with with this new > continuation (ISTM that doing it this way means you're going to end up > doing a chunk of the work of creating a new return continuation anyway, > which rather defeats the purpose.)
Yep, that's true. We already have (unimplemented) C<tailcallmethod> opcodes. A plain C<tailcall> for functions is still missing. Anyway, if the current continuation has its location in the interpreter context, its simple to implement these opcodes. If a real continuation object is constructed or not is invisible then and can be considered as an implementation detail. Anyway, I think that the current continuation will be mostly invisible except in code like your backtracking example, where you explicitely request the (call-with-current-continuation ...). leo
