Re: [Cardinal-dev] Continuation questions.

[Dan Sugalski]

At 8:20 PM +0200 5/2/02, Erik Bågfors wrote:
> On Thu, 2002-05-02 at 16:29, Dan Sugalski wrote:
>  > At 12:40 PM +0200 5/2/02, Erik Bågfors wrote:
>  > Or 3) I wasn't clear about being an opcode function. :)
>
> Ahh .. the magic third choice.  :)

Never leave home without one!

>  > One of the things we're shooting for is to be able to have the
> >  functions for opcodes (the stuff currently in core.ops) be writable
> >  in Parrot assembly as well as C. If you're inside of one of those,
> >  you can't take a continuation.
> >
> >  Or, to be more clear, assume you wrote the code to implement the
> >  set_i_ic op. (The one that puts an integer constant inside an integer
> >  register) In *that* function, you can't take a continuation. Inside
> >  normal code--for example, inside a regular function, method call,
> >  whatever--it's perfectly fine to take a continuation.
>
> Ahh.. now I see.  That makes perfect sense :)  I assume "Inside normal
> code" includes inside C-code as well?

Yes. I think the rule's going to be "Continuations always take up at
the start of the next opcode", but that's kind of a no-brainer. You'd
want to make sure you had your stacks and registers and all in proper
shape before you took the continuation, but that's a no-brainer.
(Taking a continuation with the system in an inconsistent state would
be... bad. Something we'll have to watch out for somehow with the
safe mode interpreter)

> Any idea when you will have function/method calls working in parrot? :)

We've a mostly-working hash implementation and, while it's not what I
ultimately want, it's good enough to use if its hidden properly.
Since the variable fetching and method calling protocols are
implementation independent, we may be able to go with it soon.
('Specially as we finally have the sub/method calling convention down)

This'll probably be in within a point release or two of parrot. If
not 0.0.6, 0.0.7. (0.0.6 may well be out next week if the reworked
assembler's done by then)
--
                                        Dan

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Dan Sugalski                          even samurai
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