[fpc-devel] Templates / Generics

[Mattias Gaertner]

On Mon, 07 Nov 2005 22:41:06 +0100
Florian Klaempfl <florian at freepascal.org> wrote:

> Mattias Gaertner wrote:
> > On Mon, 07 Nov 2005 19:29:51 +0100
> > Bram Kuijvenhoven <kuifwaremailinglists at xs4all.nl> wrote:
> > 
> > 
> >>Micha Nelissen wrote:
> >>
> >>>On Mon, 07 Nov 2005 14:45:19 +0100
> >>>Bram Kuijvenhoven <kuifwaremailinglists at xs4all.nl> wrote:
> >>>
> >>>>Does <> for generics fit into Pascal? Well, we use [] for array
> >>>
> >>>indexing, and () for parameter passing to procedures/functions/methods.
> >>>So why not use <> for passing parameters to generic types? And, similar
> >>>to the case of function calls and array indexing, these <> could follow
> >>>the type identifier directly.
> >>>
> >>>You got a point here, but the "where T is Foo" stuff is crap then,
> >don't >>you agree?
> >>>
> >>>TGType<T: TBaseType> = class(...) ... end;
> >>>
> >>>is better then, when compared to your parameter example.
> >>
> >>I indeed don't like the "where T is foo" of Chrome :) So you are totally
> >>right, TGType<T : TBaseType> is a lot better and a lot more consistent
> >>(with e.g. function parameter syntaxis).
> > 
> > 
> > Let's sum up the different points for the syntax so far:
> > 
> > - <> will probably be used by Delphi
> > - <> bites the < operator
> 
> No, as I said, we should allow template instantiation only in type blocks.

type
  TMyType = boolean(a<b)..(a>b);

:)
 

> > - <> makes the parser more difficult and slow
> 
> See above.
> 
> > - <> makes pascal more ambigious
> 
> See above.
> 
> > - alternatives: modifiers or not yet used brackets like (! !) or (# #)
> 
> Ugly :)

Sure. But some people like emoticons. !)


 
> > It seems to me, it's a question of: Follow Delphi generics or not.
> > And we don't know, where Delphi will go. They will not have generics in
> > the next one and a half year and as always: They will do a few things
> > completely different than expected.
> > If we follow, then we will do, as Florian et al said.
> > If not, then the <> is not the best solution.
> > 
> > Is this correct so far?

Ok. So, FPC will follow chrome/Delphi?


Mattias