I sense confusion between "closure", "continuation" and "coroutine".
http://c2.com/cgi/wiki?ContinuationExplanation http://c2.com/cgi/wiki?ContinuationsAndCoroutines http://c2.com/cgi/wiki?CoRoutine http://c2.com/cgi/wiki?LexicalClosure Cheers, Michael On Thu, 04 Nov 2004 22:11:07 +0100, Klaas-Jan Stol <[EMAIL PROTECTED]> wrote: > > >Well, I don't know how "true" coroutines are defined, but Parrot, as > >it's CPS based, has no problems with coroutines and there are no > >restrictions to coroutines, AFAIK. > > > > > To be honest, I hadn't thought of this, either (this "true"-ness of > coroutines), but then again, I'm no expert on these things. > > >How coroutines finally really behave WRT argument passing isn't really > >layed out. There is a good article in Dan's blog IIRC. > > > > > I'll read it again. > > > > > > > > >>co = coroutine.create(function () > >> for i=1,10 do > >> print("co", i) > >> coroutine.yield() > >> end > >> end) > >> > >> > > > >In Parrot's enough to include a .yield() ... > > > >,--[ simplest usage ]- > >| $ cat coro.imc > >| .sub main @MAIN > >| $I0 = coro() > >| print $I0 > >| $I0 = coro() > >| print $I0 > >| .end > >| .sub coro > >| .yield(4) > >| .yield(2) > >| .end > >| > >| $ ./parrot coro.imc > >| 42 > >`--------------------- > > > > > > > I hadn't seen ".yield(x)" > Is > .yield(x) > > the same as: > > .pcc_begin_yield > .return x > .pcc_end_yield > ? > > >to get a static coroutine. Above Lua snippet would use the C<newsub> > >opcode to create a Coroutine function object. Such objects act as > >closures too (modulo untested, unimplemented features ;) > > > > > > > So, correct me if I'm wrong, a Coroutine is also a closure? > In that case, anytime you would create a closure, you could also create > a coroutine? > > I've also included the reply I got from Roberto: > <quote> > > Untested code: > -------------------------------------------------------- > function f(x) > A = function () > x=x+1 > end > > B = coroutine.wrap( > function (y) > C = coroutine.wrap( > function (z) > while true do > coroutine.yield(x+y+z) > end > end) > > while true do > y=y+1 > coroutine.yield() > end > end) > end > > X = f() > ---------------------------------------------------------- > Now we have: > > - function A: each call increments x (in the main thread) > > - coroutine B: each call increments y (in that coroutine) > > - coroutine C: each call returns x+y+z (each in a different coroutine) > > Of course, all this wold be more fun with recursion :) > -- Roberto > > </quote> > > Do you think the above code snippet could work? That is, without much > special code, can this be done in PIR? > (Of course, why would one ever want to write /such/ code :-P, but that's > another issue) > > Thanks, > Klaas-Jan > >
