[fpc-devel] Ability to handle instance pointers as ordinal type.

[Nikolai Zhubr]

Hi,
21.02.2016 13:37, thaddy at thaddy.com:
[...]
>          x := (Sender As TComboBox);
>    8.
>    9.
>       case x.Name of
>   10.
>       'ComboBox01':if x.ItemIndex = -1 then x.ItemIndex := PrjIndex else
>   11.
>       begin

And what's wrong with just this:

if Sender = Combobox1 then
  ...
else if Sender = Combobox2 then
  ...
else


Regards,
Nikolai

>   12.
>       end;
>   13.
>       'ComboBox02':if x.ItemIndex = -1 then x.ItemIndex := HubIndex else
>   14.
>       begin
>   15.
>       end;
>   16.
>       'ComboBox03':if x.ItemIndex = -1 then x.ItemIndex := RimIndex else
>   17.
>       begin
>   18.
>       end;
>   19.
>       'ComboBox04':if x.ItemIndex = -1 then x.ItemIndex := SpkIndex else
>   20.
>       begin
>   21.
>       end;
>   22.
>       end;
>   23.
>       End;
>   24.
>       end;
>   25.
>   26.
>
>   Now how much nicer it would be if you could write someting along the
> lines of:
>
>    1.
>       procedure TFrame00.ComboBoxChanged(Sender: TObject);
>    2.
>       begin
>    3.
>       If Sender Is TComboBox Then
>    4.
>       case TCombobox(sender) of
>    5.
>            Combobox1:;
>    6.
>            ComboBox2:;
>    7.
>            ComboBox3:;
>    8.
>       end;
>    9.
>       end;
>
> In other words, use the instance pointer as an ordinal value.
> It looks a lot more logical but as it stands it is of course invalid syntax.
> Is it possible to implement?
> If so, has it any value? To me at least it looks feasable and less like
> syntactic sugar than some features.
>
>
>
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