Re: [Chicken-users] SRFIs 34, 35 and 36

[Felix Winkelmann]

Joerg F. Wittenberger wrote:
> > >To be frank, I don't particularly like SRFI-34. The semantics of `raise'
> > >are (IMHO) unnecessarily complicated, and
>
>
> Could you please expand a little what the compliaction is?  It could
> be that I failed to see things.

The `guard' form is specified in such a way that the exception
is re-raised (risen?) when no clause applies, in the same dynamic
environment /but with the exception-handler of the guard form/.
I'm not particularly sure how this should be done, and I find the
reference implementation rather confusing. But perhaps we can
handle it in a more low-level way.
Another point is that the difference between SRFI-18 raise and the
one in SRFI-34 has not been completely settled, yet (If I understand
the discussion on the SRFI-34 mailing list correctly), apparently
a compatibility comment has been removed after that issue - so it
looks like their incompatible.
It's not that I'm completely opposed to SRFI-34/35/36. It's certainly
better than nothing.

I will extend the current exception system to provide a more
find-grained hierarchy of exception kinds than we have currently.
Perhaps we can devise a convenient `case'-like macro that dispatches
on contition types.

> > >the whole idea of condition-type defining macros a la ML is not my
> > >idea of the "Scheme Way" (of which exist about as many as Scheme
> > >implementors ;-).
> >
> >        Well, I don't particularly care which one is available, though
> > I favor accepted standards by instinct when I have nothing else to go
> > on.  I just want more flexibility in error handling and reporting than
> > dynamic-wind offers.
>
>
> Same here.

Agreed.


cheers,
felix


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