`Word' data type et al._(re)

Wed, 18 Jun 1997 18:10:55 -0700

Frank Heckenbach wrote:
> 
> If I understand it right, Integer and Cardinal have different sizes
> on 16 and 32 bit Delphi, right? This would be like in gpc (though
> not 16 bit, AFAIK, but 64 bit and perhaps more).

Exactly 16 bits in Delphi1, 32 bits in Delphi2.
In any case they are "the best suited signed and unsigned integers
for a given machine"

> I'd add {Short,Long,LongLong(?),Longest(?)}{Int,Card} here.

But this is much harder to standardize: they will have different
meanings on different systems, whence better to reject them in
XXcompat units: gpc being cross-platform it will be difficult to
give a general rule whereas the others are non ambiguous:

> > int8      card8   (=byte is the only case without doubt)
> > int16     card16
> > int32     card32
 
> I agree! Except for "integer", all types can be redeclared in these
> units. (I think, "integer" could be redeclared, too, but AFAIR it's
> not a good idea to do so, is it?)

certainly a bad idea in general,
but notice that in BP I frequenly used a defreal unit,
(referenced from the main and all other units) which
contains either

type real = single
or
type real = double
or
type real = extended
 
to have a quick way to see the effect of the size of reals on accuracy
or speed of some computations. But this is a purely private trick
which should be restricted to such peculiar purposes.

-- 
                     Maurice Lombardi
Lab. Spectrometrie Physique, Universite Joseph Fourier de Grenoble, BP87
        38402 Saint Martin d'Heres Cedex     FRANCE
Tel: (33) 4 7651 4751.                           Fax (33) 4 7651 4544.

Maurice Lombardi (Maurice.LOMBARDI@ujf-grenoble.fr)