[m-rev.] for post-commit review: add new float classification predicates

[Julien Fischer]

On Wed, Sep 17, 2014 at 3:28 PM, Paul Bone <paul at bone.id.au> wrote:

> On Wed, Sep 17, 2014 at 02:41:42PM +1000, Julien Fischer wrote:
> > diff --git a/library/float.m b/library/float.m
> > index bc263e3..bb3fd2b 100644
> > --- a/library/float.m
> > +++ b/library/float.m
> > @@ -173,36 +181,45 @@
> >      %
> >  :- pred is_inf(float::in) is semidet.
> >
> > -    % Is the floating point number not a number?
> > +    % True iff the argument is not-a-number (NaN).
> >      %
> >  :- pred is_nan(float::in) is semidet.
> >
> > -     % Is the floating point number not a number or of infinite
> magnitude?
> > +    % True iff the argument is of infinite magnitude or not-a-number
> (NaN).
> >      %
> >  :- pred is_nan_or_infinite(float::in) is semidet.
> >
> > -    % Synonym for is_nan_or_inf/1.
> > +    % Synonym for above.
> >      %
> >  :- pred is_nan_or_inf(float::in) is semidet.
>
> "Synonym for *the* above"


Fixed.


> > @@ -722,6 +739,20 @@ is_infinite(F) :-
> >      SUCCESS_INDICATOR = false
> >  ").
> >
> > +:- pragma foreign_proc("C",
> > +    is_finite(Flt::in),
> > +    [will_not_call_mercury, promise_pure, thread_safe,
> will_not_modify_trail,
> > +        does_not_affect_liveness],
> > +"
> > +    SUCCESS_INDICATOR = MR_is_finite(Flt);
> > +").
> > +
> > +is_finite(F) :-
> > +    not is_infinite(F),
> > +    not is_nan(F).
> > +
> > +is_zero(0.0).
> > +
>
> I'm no floating point expert, but is -0.0 different from 0.0


Depends what you mean by different.


> and if so do we
> need to test for it explicity or does floating point comparison take care
> of
> this for us?
>

No, IEEE 754 says 0.0 and -0.0 compare as equal.

> @@ -298,6 +298,7 @@
> >  **   MR_HAVE_ISINF           we have the isinf() function.
> >  **   MR_HAVE_ISINFF          we have the isinff() function.
> >  **   MR_HAVE_FINITE          we have the finite() function.
> > +**   MR_HAVE_ISFINITE        we have the isfinite() function.
> >  **   MR_HAVE_FESETROUND      we have the fesetround() function.
> >  **   MR_HAVE_FMA             we have the fma() function.
> >  */
>
> The use of tabe and spaces is inconsistent here.
>

No it isn't.  (In any case it's just doing what the surrounding lines do)

Thanks for that!

Cheers,
Julien.
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