Re: Replacement for SCM_SETJMPBUF?

[Rob Browning]

Gary Houston <address@hidden> writes:

> It's just a slightly modified version of scm_internal_cwdr from root.c
> in guile-1.3.4 and earlier.  scm_internal_cwdr implements
> call-with-dynamic-root.  The change that's been made is to avoid
> unwinding/rewinding the caller's wind list around the callee
> procedure.

But I presume that the other properties still hold (i.e. can only
return from the call one time, errors can't throw past this point,
etc.)

> So a quick fix would be to take a new cut-and-paste from guile 1.5 and
> apply the change again (see below for some untested code).

OK.  Perhaps I'll try that, though in the long run, and as you suggest
below, I'd like to have a supported solution, or fix guppi to handle
things some other (more acceptable) way.

> If guppi and scwm both needed this ability then maybe it's a flaw in
> Guile that it's not provided.

Could be.  I guess it depends on exactly what semantics they really
need, and whether or not this is the most appropriate way to provide
them.  I don't know enough about what guppi needs to do here to say
for sure yet.

Thanks much.

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