Re: Replacement for SCM_SETJMPBUF?

[Rob Browning]

Gary Houston <address@hidden> writes:

>>   (call-with-dynamic-root . unwind?)
>> 
>> with a default value of #t.
>
> See also:
>
> http://sources.redhat.com/ml/guile/1998-12/msg00304.html
>
> and follow ups:
>
> http://sources.redhat.com/ml/guile/1998-12/msg00306.html
> http://sources.redhat.com/ml/guile/1998-12/msg00305.html

OK, so Marius, and others, it looks like what's needed (by at least
scwm and guppi -- and now that I think about it, perhaps gnucash as
well) is a way for C code to call scheme callbacks, preserving the
dynamic-wind context, but blocking continuations and exceptions.

So instead of adding (call-with-dynamic-root . unwind?), another
possibility, suggested by Mikael in the msgs referenced above would to
leave call-with-dynamic-root alone and add a new
call-with-dynamic-context (or perhaps just
scm_call_with_dynamic_context) that doesn't rewind the dynamic-wind
chain.

More directly, what should I do right now?  Do we know enough to think
that adding scm_call_with_dynamic_context to root.[hc] is the right
idea[1], or should guppi, scwm, etc. just do another copy/paste from
libguile/root.c into their own source?

Thanks

[1] An answer of yes here would only be relevant if it's a yes for
    adding it to 1.5.2, since otherwise I'd still have to copy/paste
    into guppi to bring it up to speed.

-- 
Rob Browning
rlb @defaultvalue.org, @linuxdevel.com, and @debian.org
Previously @cs.utexas.edu
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