When we are already discussing new language features, what about supporting iterators for array properties:

   TTest = class
     // ...
     property Objects[Index: Integer]: TObject read GetObject *iterator
GetObjectIterator*;
     property ObjectCount: Integer read GetObjectCount;
   end;

This would allow code like:

   for MyObject in Test.Objects do
     //...

In the LCL, e.g.:

procedure TForm1.Button1Click(Sender: TObject);
var
   Comp: TComponent;
begin
   for Comp in Components do
     //...
end;

This should actually be pretty OK and should not cause any regressions.

Ondrej

After a

sed s/iterator/enumerator/g

I'm all for it.

I've been looking how to implement names/objects/values enumerators in TStrings. This would be the almost perfect solution.

But your example is not well-chosen, since the enumerator for TComponent already exists:

Procedure TForm1.Button1Click(Sender: TObject);
  var
   Comp: TComponent;
  begin
   for Comp in Self do
     //...
  end;

Just as an aside...

Michael.

Yes, of course. I ment enumerator :)

   TTest = class
     // ...
     property Objects[Index: Integer]: TObject read GetObject
*enumerator GetObjectEnumerator*;
     property ObjectCount: Integer read GetObjectCount;
   end;

+ Yes, the "in Self" is supported. But this is not the problem here. The example still doesn't compile. A class can have more array properties. And even the default class enumerators can be redeclared and so hide enumerators from ancestor classes.

Maybe a better example:

*Procedure TForm1.Button1Click(Sender: TObject); ** ** var **
** Cont: TControl; **
** begin **
** for Cont in Controls do **
** //... **
** end; **
***
Ondrej

100% agreed :)

Michael.

Michael Van Canneyt wrote

100% agreed :)

Great!

I wrote a feature request in mantis for it so that we don't forget about it and can follow it there: http://bugs.freepascal.org/view.php?id=28820

Ondre

Oh, it would be so nice if default enumerator wasn't defined with the "GetEnumerator" function but with the default property:

   TTest = class
     // ...
     function GetObjectEnumerator: TTestObjectEnumerator;
     property Objects[Index: Integer]: TObject read GetObject enumerator
GetObjectEnumerator; default;
   end;

In this case the default enumerator would always correspond with the default property. Now they can be completely different. But Embarcadero already made the decision, so it doesn't matter :(

Ondrej

The class does not need to have a default property to begin with, so it is somewhere logical.

Michael.

Michael Van Canneyt wrote

The class does not need to have a default property to begin with, so it is somewhere logical.

Yes, in that case a default enumerator would not be allowed, which sounds (in contrary) logical to me: no default array property => no enumerator. But this depends on the point of view, I can understand that the meanings differ. And it is a pure off-topic because it has already been decided :)

Ondrej