RE: exception from inside false-if-exception?

[Attila Lendvai]

> >do i get this right? (with-exception-handler ... #:unwind? #f) installs a so 
> >called pre-unwind-handler, which takes priority over a false-if-exception, 
> >even if deeper in the stack, because f-i-e installs a post-unwind-handler?
> 
> It’s not post-unwind? If anything, I would call it pre-unwind. If 
> with-exception-handler were post all the unwinding, then it’s too late to let 
> raise-continuable return anything.


i didn't properly understand the meaning of pre-unwind and post-unwind handlers 
when i wrote the above. i thought they are something more peculiar than what 
they actually are.


> But other than that (“[it] takes priority over a false-if-exception, [...]), 
> that’s my understanding of things.
> 
> I guess what should be done, is it _not_ having priority, and instead it only 
> handling things when there noguard/catch/... inside has caught the exception.


what i didn't understand is that FALSE-IF-EXCEPTION is implemented with a 
simple CATCH, so its handler should have shadowed my handler. but what actually 
happens is more sinister, see my other mail with the test case.


> Going by < 9.1 Condition System Concepts | Common Lisp (New) Language 
> Reference (lisp-docs.github.io)>, the API and semantics of CL is pretty much 
> the same as guard/with-exception-handler/raise(-continuable) stuff(*).


yep. with the addendum that CL has two entirely different macros for unwinding 
and non-unwinding WITH-EXCEPTION-HANDLER. and the handlers are always 
uninstalled before they are called. and there's no multitude of duplicate 
primitives for almost identical functionality due to a single revision of the 
CL standard.


> (I haven’t found search results on what backtrace decorators are in CL.)


this is user code, sorry. it's something we added to be able to decorate 
backtraces with domain-specific data.

-- 
• attila lendvai
• PGP: 963F 5D5F 45C7 DFCD 0A39
--
<hcf> information we gather and create overflows our means of managing it
<hcf> our ppl r only happenstancely synergistic