Re: [fpc-pascal] bug or feature?
> On Feb 12, 2022, at 11:40 PM, Jonas Maebe via fpc-pascal > wrote: > > I wouldn't consider this to be working by design, but rather because of > implementation limitations. I agree and it should be fixed probably. Regards, Ryan Joseph ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org https://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] bug or feature?
On Sat, 12 Feb 2022 17:58:27 +0100 Jonas Maebe via fpc-pascal wrote: >[...] > >> I wouldn't consider this to be working by design, but rather > >> because of implementation limitations. +1 pas2js complained. That's how I found out. Someone renamed a class, added an alias for compatibility, forgot to rename the implementation, and fpc did not complain. > > Why do you consider it a limitation ? > > > > Because the compiler currently has no way to distinguish the types > > when resolving the > > name "T" (as used in my example)? > > Indeed. > > > Then it is a strange coincidence that Delphi has it too :-) > > The simplest way to implement alias types is to just have them refer > to the original type... Actually pas2js did an even simpler approach here: Look up the identifier without resolving the original type ;) Mattias ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org https://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] bug or feature?
On 12/02/2022 17:47, Michael Van Canneyt via fpc-pascal wrote: On Sat, 12 Feb 2022, Jonas Maebe via fpc-pascal wrote: On 12/02/2022 17:36, Michael Van Canneyt via fpc-pascal wrote: PS. Just tested, the compiler accepts both... Amazing, I never thought this would be possible. I'd better update the docs :-) I wouldn't consider this to be working by design, but rather because of implementation limitations. Why do you consider it a limitation ? Because the compiler currently has no way to distinguish the types when resolving the name "T" (as used in my example)? Indeed. Then it is a strange coincidence that Delphi has it too :-) The simplest way to implement alias types is to just have them refer to the original type... Jonas ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org https://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] bug or feature?
On Sat, 12 Feb 2022, Jonas Maebe via fpc-pascal wrote: On 12/02/2022 17:36, Michael Van Canneyt via fpc-pascal wrote: PS. Just tested, the compiler accepts both... Amazing, I never thought this would be possible. I'd better update the docs :-) I wouldn't consider this to be working by design, but rather because of implementation limitations. Why do you consider it a limitation ? Because the compiler currently has no way to distinguish the types when resolving the name "T" (as used in my example)? Then it is a strange coincidence that Delphi has it too :-) Michael. ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org https://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] bug or feature?
On 12/02/2022 17:36, Michael Van Canneyt via fpc-pascal wrote: PS. Just tested, the compiler accepts both... Amazing, I never thought this would be possible. I'd better update the docs :-) I wouldn't consider this to be working by design, but rather because of implementation limitations. Jonas ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org https://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] bug or feature?
On Sat, 12 Feb 2022, Sven Barth via fpc-pascal wrote:
Michael Van Canneyt via fpc-pascal
schrieb am Sa., 12. Feb. 2022, 12:14:
On Sat, 12 Feb 2022, Mattias Gaertner via fpc-pascal wrote:
Hi,
This can't be right, can it?
type
TBird = class
procedure Fly;
end;
TEagle = TBird; // alias
procedure TEagle.Fly;
begin
end;
Personally, I would not allow this.
But Delphi compiles and runs it...
Maybe something to check for {$mode objfpc} =-)
The compiler does not have any real tracking for non-type aliases... As far
as the compiler is concerned these are interchangeable...
I think Mattias just got some more gray hairs :-)
So if I understand this correctly, I can do
---
Interface
Type
TSomeReallyAnnoyingIncrediblyLongClassName = Class
Procedure DoSomething;
end;
implementation
Type
T1 = TSomeReallyAnnoyingUltraLongClassName;
procedure T1.DoSomething;
begin
end;
---
And consequently also
---
Interface
Type
TSomeReallyAnnoyingIncrediblyLongClassName = Class
Type
TSomeReallyAnnoyingSubClass = class
Procedure DoSomething;
end;
end;
implementation
Type
T1 = TSomeReallyAnnoyingIncrediblyLongClassName.TSomeReallyAnnoyingSubClass;
procedure T1.DoSomething;
begin
end;
---
The lazarus code tools maintainer will have a field day with this one ;-)
Michael.
PS. Just tested, the compiler accepts both... Amazing, I never thought this
would be possible. I'd better update the docs :-)
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Re: [fpc-pascal] bug or feature?
Michael Van Canneyt via fpc-pascal
schrieb am Sa., 12. Feb. 2022, 12:14:
>
>
> On Sat, 12 Feb 2022, Mattias Gaertner via fpc-pascal wrote:
>
> > Hi,
> >
> > This can't be right, can it?
> >
> > type
> > TBird = class
> >procedure Fly;
> > end;
> > TEagle = TBird; // alias
> >
> > procedure TEagle.Fly;
> > begin
> > end;
>
> Personally, I would not allow this.
> But Delphi compiles and runs it...
>
> Maybe something to check for {$mode objfpc} =-)
>
The compiler does not have any real tracking for non-type aliases... As far
as the compiler is concerned these are interchangeable...
Regards,
Sven
>
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Re: [fpc-pascal] bug or feature?
On Sat, 12 Feb 2022, Mattias Gaertner via fpc-pascal wrote:
Hi,
This can't be right, can it?
type
TBird = class
procedure Fly;
end;
TEagle = TBird; // alias
procedure TEagle.Fly;
begin
end;
Personally, I would not allow this.
But Delphi compiles and runs it...
Maybe something to check for {$mode objfpc} =-)
Michael.
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[fpc-pascal] bug or feature?
Hi, This can't be right, can it? type TBird = class procedure Fly; end; TEagle = TBird; // alias procedure TEagle.Fly; begin end; Mattias ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org https://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
