Hi doug

roel will reply soon but in essence the problem is not that you do not 
catch but that
you get an unhandledException when you catch it forcing the client to 
do isKindOf: to
distinguish. Roel checked also that this is not like that in VW.

Stef


On Sunday, August 24, 2003, at 05:04 AM, Doug Way wrote:

>
> I was looking at approving this changeset after Roel reviewed it, but 
> I have one question... it would appear based on this simple test that 
> Exception *does* currently handle a halt (without filing in Anthony's 
> changeset):
>
> [3 + 4. self halt] on: Exception do: [Transcript show: 'pickles'; cr]
> "shows 'pickles'"
>
> [3 + 4. self halt] on: Error do: [Transcript show: 'pickles'; cr]
> "halts, does not show 'pickles'"
>
> [3 + 4. self halt] on: Halt do: [Transcript show: 'pickles'; cr]
> "shows 'pickles'"
>
> After filing in this changeset, the behavior for these tests is the 
> same.
>
> Possibly my tests are missing something, though?
>
> But anyway, moving Halt to be a subclass of Exception (not Error) 
> seems like the right thing to do.
>
> - Doug
>
>
> On Tuesday, August 5, 2003, at 11:56 AM, Anthony Hannan wrote:
>
>>> From preamble:
>> Halt was being treated as a special case in Exception class >> 
>> #handles:
>> to avoid being handled by error handlers.  This changeset removes Halt
>> as a subclass of Error making it an indendent exception class (direct
>> subclass of Exception), and removes the special case test from
>> #handles:.
>>
>> Roel Wuyts <wuyts at iam.unibe.ch> wrote:
>>> Aha. So who would be willing to change it? I don't feel comfortable 
>>> with
>>> doing it myself, unless there are enough unit tests around...
>>>
>>> On Monday, Aug 4, 2003, at 19:00 Europe/Zurich, Anthony Hannan wrote:
>>>>>> The most important point however is that Exception DOES NOT
>>>>>> handle Halt (in spite of the fact that Halt is a subclass of
>>>>>> Exception.)
>>>>> Can somebody motivate this decision (or whether it is an 
>>>>> unintentional
>>>>> bug)?
>>>>
>>>> I'm not the author but I believe the reason is so "self halt" will
>>>> always halt and not be accidentally handled by a earlier Error 
>>>> handler.
>>>> The better solution is probably to not make Halt a subclass of Error
>>>> but just a direct subclass of Exception.
>>
>> <HaltNotAnError-ajh.cs>
>
>