[fpc-pascal]FP newbie

Demian Lessa demian at knowhow-online.com.br
Thu Nov 13 13:49:57 CET 2003


Thanks for clearing things a little further!

I see that many responses refer to Delphi compatibility. I understand 
that the FP compiler has a switch that tells it to compile the pascal 
code as Delphi code. In that sense, I'd expect FP to provide a superset 
of the Object Pascal dialect. And that is true indeed!

FP offers operator overloading, which is not an Object Pascal feature. 
I'm not yet familiar with the compiler but I guess many other features 
are also particular to FP.

Many of us (Delphi/Kylix developers) find many features missing in the 
Object Pascal compiler and we see FP is a real chance to get those 
features working. RTTI, for instance. Why shouldn't all objects have 
RTTI? Why should only TPersistent descendants have it? Class attributes 
is another missing part of the (language feature) puzzle. Why is it not 
supported by Object Pascal and FP? It really doesn't make sense to me. 
Unless, of course, this is so complex to implement...

I have hacked a way to get class attributes working- it does the job, 
but we should have a language construct to support this kind of thing. 
You can check this article to see how class attributes can be 
"implemented" the Delphi way:


It's good that you pointed out early that the main thought here is to 
keep Delphi compatibility. This way I won't dream of features that will 
"never" be part of FP.

Thanks again!


Peter Vreman wrote:

>>#A. Does FP support other class hierarchies other than those
>>    starting at TObject? I mean, any FP object is a TObject,
>>    right? I wonder if it would be possible to create a new
>>    object hierarchy from scratch, not based on TObject.
> This is not supported. The compiler requires knowledge about TObject for
> things like AfterConstruction and BeforeDestruction.
>>#B. Reflection support, as far as I understand, starts at
>>    TPersistent and relies on published properties. Is there
>>    any chance this could be made more flexible- I mean, let
>>    TObject properties support reflection?
> That will break compatibility with Delphi. Compatibility with Delphi is
> the most important issue, because that is what ppl expect how things work.
>>#C. Is there (planned) support for class attributes?
>>#D. Is there (planned) support for class templates?
> When it is not in Delphi then it is not (planned or) supported
>>#E. Is there (planned) support for wxWindows? I think this
>>    is a terrific abstraction layer for GUI. The best is
>>    that it is stable (10+ years), works on many plataforms,
>>    and as FP/Lazarus, it is OS. But it still doesn't have
>>    a Pascal port.
> The core developpers have no time for creating the bindings. But if
> somebody else creates them we can include them.
>>#F. I haven't seen any links or pages through which I could
>>    volunteer to help with FP/Lazarus- where do I find that?
> You can use the mailing lists. When you help FPC/Lazarus with a lot of
> patches you can get cvs write access. There is no standard procedure, it
> is not a professional job for which you have an interview and to sign a
> contract.
> Peter

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