Frama-C-discuss mailing list archives

This page gathers the archives of the old Frama-C-discuss archives, that was hosted by Inria's gforge before its demise at the end of 2020. To search for mails newer than September 2020, please visit the page of the new mailing list on Renater.

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[Frama-c-discuss] chained comparisons

Hi,

No, chained comparisons are not allowed as such in terms. From my
understanding, the syntax of ACSL terms was chosen to be as similar as
possible to the one of side-effects-free C expressions. In C, x < y < z is
parsed as the (misleading) (x < y) < z, which is too different from the
meaning we give to x < y < z in specifications.

That being said, as you noticed, x < y < z is indeed accepted in a term
position by Frama-C. In this case, the _predicate_ is cast from boolean to
integer, and used as a term. This is documented in section 2.2.3 of the
ACSL manual.

HTH,


On Sat, May 23, 2015 at 8:52 PM, cok at frontiernet.net <cok at frontiernet.net>
wrote:

> The ACSL1.9 document defines and discusses chained comparisons:
> Fig 2.2 gives a rule for pred as term ( rel-op term )+
>
> But Fig 2.1 does not give a corresponding rule for terms.
> It just says that a term can be  term bin-op term
>
> Is it intended that chained comparisons may be used only in predicate
> position?
> Or is it implicitly allowed for terms also  since term bin-op term bin-op
> term
> parses as an appropriate tree?
>
> Thanks,
>
> - David
>
> _______________________________________________
> Frama-c-discuss mailing list
> Frama-c-discuss at lists.gforge.inria.fr
> http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/frama-c-discuss
>



-- 
Boris
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.gforge.inria.fr/pipermail/frama-c-discuss/attachments/20150528/f1bb093c/attachment.html>