On 21/02/2016 11:15, Sven Barth wrote:
Would it be possible to implement? Yes
Would that mean that instance pointers would be handled as ordinal
values? No, because "case" is merely a parser construct. In principle
the condition and the case labels could be anything. String constants
aren't ordinal values after all either.
It might look logical but it would be a complete paradigm shift for
case-statements, because the case labels are supposed to be constant
values (ordinal, including enums and string constants) while variables
(local, global, fields) are not constants however.
And there lies the problem.
Case labels do not allow duplicates. But if they are variables, then
this can not be checked at compile time.
So this must either throw an exception, or add/change the evaluation of
the "case" to have a precedence between the "labels", and decide if only
the first or all matches are executed.
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;
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