[R6RS] Semantics of `raise'

William D Clinger will at ccs.neu.edu
Tue Mar 7 07:57:15 EST 2006


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.

If the R6RS semantics for raise were to specify that
the exception handler is called with the continuation
of the call to raise, then raise would indeed be useful
for continuable exceptions.

I apologize for my misunderstandings.

Will



More information about the R6RS mailing list