[R6RS] Semantics of `raise'

Michael Sperber sperber at informatik.uni-tuebingen.de
Tue Mar 7 13:08:50 EST 2006


William D Clinger <will at ccs.neu.edu> writes:

> Mike wrote:
>> > The SRFI 34 semantics for raise changes the current exception
>> > handler.  To repair the cause of the exception, and to continue
>> > from it, there would have to be some way to reinstall the
>> > exception handler that was removed by raise.
>>
>> The repair is implicitly done by returning from the exception handler.
>> Maybe the wording says that poorly, but that was certainly the
>> intention, and is the semantics of the obvious implementation.
>
> Ah, I didn't realize that returning from the exception
> would reinstall the exception handler.  I don't think
> this is a very useful thing to know with SRFI 34, which
> doesn't specify the continuation to which you would be
> returning.

No, but at the beginning of this thread I suggested tightening up the
specification to that effect, i.e. to call the handler with a
continuation equivalent to that of raise except for its exception
handler.  That's what I was referring to.

-- 
Cheers =8-} Mike
Friede, Völkerverständigung und überhaupt blabla



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