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Re: shift and reset in ice-9 control
From: |
Andy Wingo |
Subject: |
Re: shift and reset in ice-9 control |
Date: |
Tue, 12 Apr 2011 11:51:04 +0200 |
User-agent: |
Gnus/5.13 (Gnus v5.13) Emacs/23.2 (gnu/linux) |
Hi Wolfgang,
Thanks for your note.
On Sat 02 Apr 2011 16:40, Wolfgang J Moeller <address@hidden> writes:
> Using the "direct" implementaion of reset/shift (mine seems to agree
> with Flatt et.al.), it goes into a loop since (dc "ignored.2")
> makes (f1) restore the full continuation that makes (dc "ignored.1")
> return one more time - "dc" isn't so "delimited" after all.
Have you tried this on Racket? I would expect that it would do the
right thing. The difference, AFAIK, is that a prompt delimits full
continuations there as well. That's why they call them "composable"
continuations instead of "delimited" continuations: because either kind
can be delimited; the real question is what properties do they have.
I think we're going to switch to do that in Guile 2.2 as well.
> (begin
> (define dummy1
> (eval
> ;;
> '(defmacro macro-case clauses
[...]
> (interaction-environment)))
> )
> ;;
> (macro-case
> (#f
> (define something #t)))
> Depending upon what I do with this snippet (auto-compile, load vs. include),
> it sometimes gets accepted by GUILE V2.0.0:
>
> auto,include auto,load noauto,include noauto,load
> ---------------------------------------------------------------------------
> @toplevel Error Error Error OK
> surroundes by
> BEGIN Error Error Error Error
> EVAL-WHEN OK OK OK Error
Indeed. If you need to evaluate previous expressions in order to expand
later ones, you need eval-when. That goes for forms within your
prelude, and for the "users" of your prelude; Guile doesn't know that
when it sees a `(load "prelude.scm")' that prelude.scm will define
syntax definitions, so it won't pull in those definitions at
compile-time, without an eval-when wrapping the load...
I don't understand the noauto,load case there though. Were some of your
files compiled and some not? Hmm...
Regards,
Andy
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