Re: [Chicken-users] Re: srfi-18 and dynamic wind problem

[Hans Bulfone]

hi,

On Mon, Apr 07, 2008 at 11:18:51PM +0100, Alaric Snell-Pym wrote:
>
> On 7 Apr 2008, at 11:15 pm, Hans Bulfone wrote:
>
>> and i'd find it even better if we could change the behaviour of the
>> default exception handler to unwind the dynamic-wind stack before
>> exiting or terminating the thread.  i think it's a more useful default
>> behaviour... but i don't know if it's easily doable...
>
> Can it not be done by wrapping every thread (even the primordial one)
> in a conventional exception catching block, which then generates a
> normal exception handler which calls to a continuation up in the
> dynamic scope of the catching block, thus unwinding the stack? Then
> it can just catch the exception and report exceptional thread
> termination, or in the normal course of events cleanly shut the
> thread down.
>
> Should be an easy fix, no?

semantically you are right but i don't know how easy this is for the
default handler which is probably just a procedure and not defined
with handle-exceptions or something.

at least you can't just wrap everything the compiler sees in a
handle-exceptions because then there would be no more toplevel
expressions :)

perhaps it's possible to somehow wrap the call to the main toplevel in
a handle-exceptions but i don't know how this looks like.

it requires some sort of process-exit-continuation... where the
continuation would actually be the process who wait()s for the exit
status of the chicken process :)

bye,
hans.