[fpc-devel] Generics in FPC have many problems

[Anthony Walter]

On Mon, Aug 29, 2011 at 11:19 AM, Sven Barth <pascaldragon at googlemail.com>wrote:

> Hi!
>
> As Paul and Jonas already told you, I'm currently working on improving the
> compilers generic implementation. As you have noticed it currently doesn't
> support generic methods and constraints at all. Also the generic
> implementation in mode Delphi isn't working correctly as you've noticed.
> Inline specialications (those without using "type foobar = foo<bar>") don't
> work either.
>
> For this I have found the following tasks:
> * allow declaring and implementing generics with the Delphi syntax while
> keeping the FPC syntax supported (this is an important point regarding
> backwards compatibility); state: working
> * allow the declarations of multiple generics with the same name (e.g.
> foo<t> =... foo <t, s> = ...); state: mostly working
> * allow inline specializations; state: partly working inside
> implementations; inside declarations this needs to be tested
> * allow nested specializations: not started
> * allow nested generics: not started
> * implement generic methods: not started
> * implement constraints: not started
>
> My plan is to merge the changes from my branch to trunk after the first
> three points are done (the third one at least mostly as inline
> specializations are rather fragile) to reduce the differences between those
> to branches. Then I'll start working on either generic methods or
> constraints (depends on my mood then).
>
> Please keep in mind that working on the generics feature isn't an easy
> task, so I can't give you an estimate when the one or other improvement will
> be available.
>
> If you want you can test around with my branch, but please keep in mind
> that it's a work in progress and that compilation of the compiler or the RTL
> might also be broken from time to time (currently the fgl unit doesn't
> compiler for example).
>
>
>  And if someone ever does intent to fix generics in FPC, there are a whole
>> slew of errors that they already bring into the compiler. I'll make a list
>> of examples of those errors at a later time, but they inner workings of
>> generics should be redone to remove the specialization requirement before
>> those errors are addressed.
>>
>
> If you do such an error list then please provide a single program for each
> problem you encounter so that it might be integrated into FPC's test suite
> which will ease fixing the problem.
>
> Regards,
> Sven


Wow, Sven, thanks for the reply, and most definitely thanks for working on
FPC. Anything I can do to help I'll do. Last week I sent patches to fix
issues with Lazarus CodeTools and the new generic syntax which basically
caused a lot of problems in the IDE.

I'll be on freenode irc in both #fpc and #lararus-ide for the next few weeks
at least. Where do you want me to send some unit tests/test program source?
The issue tracker? One issue for each test that or all in all tests in one
issue?

Also be sure to let me know if there is anything I can do for you. I don't
have much experience with OSS collaboration, but am motivated to get things
done and done the right way.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.freepascal.org/pipermail/fpc-devel/attachments/20110829/47f754f7/attachment.html>