On 2017-07-21 07:16, Sven Barth via fpc-pascal wrote:
Am 21.07.2017 10:44 schrieb "Santiago A." <s...@ciberpiula.net>:
El 20/07/2017 a las 15:50, Sven Barth via fpc-pascal escribió:
Am 20.07.2017 13:01 schrieb "Bo Berglund" <bo.bergl...@gmail.com>:
>
> On Thu, 20 Jul 2017 11:11:50 +0200, Maciej Izak
> <hnb.c...@gmail.com> wrote:
>
> >2017-07-20 11:03 GMT+02:00 Bo Berglund <bo.bergl...@gmail.com>:
> >
> >> So since I don't really want to use a global, is it possible
to
> >> declare a local variable static in the sense that it retains
its
> >> values across calls to the procedure?
> >> If so how is it done?
> >>
> >
> >procedure foo;
> >{$PUSH}
> >const{$J+}
> > s : string ='';
> >{$POP}
>
> Thanks,
> but it looks a bit involved, probably better to use an object
field
> variable instead only accessible from the internal methods.
If you don't want to use $push/$pop then you can also simply enable
$J+ for the whole unit. But this will also mean that global constants
are writable.
Well, I'm an old dog so I prefer old fashion ways. A variable that
retains its value is, from memory point of view, a global variable. I
mean, the memory is never freed, it's not freed when it goes out of
scope. So, the problem is what to do to limit the visibility to the
procedure.
Writable constants *are* the old fashion way, cause this kind of usage
stems from Turbo Pascal and allowed to restrict the visibility of
symbols.
Regards,
Sven
Except really old fashioned might mean Modula
That's a neat idea to create a new module, and use it sort of like a
private object or static object just for the purpose of storing a global
variable in the private implementation section.
One disadvantage of modules (units) is that they add extra bytes to the
Exe, but is generally not an issue in desktop software. Previously when
people have asked for static C type things in fpc they were working with
embedded systems where every last byte counted and size of the program
was an issue. But, I don't know the use case in this episode..
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