raise should not change continuation
Marc Feeley
(12 Aug 2002 12:09 UTC)
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Re: raise should not change continuation
sperber@xxxxxx
(12 Aug 2002 12:45 UTC)
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Re: raise should not change continuation
Marc Feeley
(12 Aug 2002 14:22 UTC)
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Re: raise should not change continuation sperber@xxxxxx (12 Aug 2002 14:35 UTC)
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Re: raise should not change continuation
Marc Feeley
(12 Aug 2002 14:57 UTC)
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Re: raise should not change continuation
sperber@xxxxxx
(12 Aug 2002 15:08 UTC)
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Re: raise should not change continuation
Richard Kelsey
(13 Aug 2002 01:17 UTC)
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Re: raise should not change continuation sperber@xxxxxx 12 Aug 2002 14:35 UTC
>>>>> "Marc" == Marc Feeley <xxxxxx@IRO.UMontreal.CA> writes: Marc> In SRFI 18 the exception handler must be called with the same Marc> continuation as "raise" (and consequently the same dynamic Marc> environment and exception handler). >> >> Why is this inconsistent? SRFI 34 doesn't specify a behavior >> different from that of SRFI 18. It merely leaves part of the behavior >> unspecified. Marc> No, SRFI 34 says: Marc> (raise obj) Invokes the current exception handler on obj . The Marc> handler is called in the dynamic environment of the call to raise , Marc> **** except that the current exception handler is that in place for Marc> the call to with-exception-handler that installed the handler being Marc> called. The handler's continuation is otherwise unspecified. **** Marc> According to this, the continuation of the exception handler can't Marc> be the ***same*** as the continuation of raise because the dynamic Marc> environment is different (recall that the dynamic environment is Marc> part of the continuation). The text in SRFI 18 you're referring to talks about primitives. SRFI 34 doesn't say anything about how primitives raise exceptions. The specifications of RAISE and WITH-EXCEPTION-HANDLER in SRFI 18 don't say anything about the dynamic environment or the continuation of the exception handler. The single example given doesn't constrain this further, either. -- Cheers =8-} Mike Friede, Völkerverständigung und überhaupt blabla