From tsiivola at cc.hut.fi Tue Dec 7 14:45:13 2004 From: tsiivola at cc.hut.fi (Nikodemus Siivola) Date: Tue, 7 Dec 2004 16:45:13 +0200 (EET) Subject: [threads-standard-discuss] MP standardization proposal In-Reply-To: <87acy9fgo8.fsf@noetbook.telent.net> References: <87acy9fgo8.fsf@noetbook.telent.net> Message-ID: I found this during my postponed-folder cleanup. It's ages past this was last talked about... but what the more general point remains valid: --snip-- On Fri, 9 Jul 2004, Daniel Barlow wrote: > atomic-incf reference [Function] > atomic-decf reference [Function] > > Increments (or decrements) the fixnum value referred to by reference > as a single, atomic operation. If the operation would take the value > out of fixnum range, behaviour is undefined. I'd propose "unspecified behaviour" instead, the essential difference being that heap corruption, crashes, etc aren't allowed. Implementations would still be allowed to wrap, zero the reference, signal an error, etc. --snap-- The "general point" being that "unspecified" and "undefined" have a nice distinction, and specifying something as unspecified behaviour instead of defining as undefined (sorry, couldn't resist) gives a useful promise of "not destrying the world" to the user. Whether that promise is something that can be given in this case, I do not know. Cheers, -- Nikodemus "Not as clumsy or random as a C++ or Java. An elegant weapon for a more civilized time."