[fpc-devel] Debug compiler
pascaldragon at googlemail.com
Mon Nov 2 20:08:46 CET 2015
On 02.11.2015 16:12, Ondrej Pokorny wrote:
> On 01.11.2015 21:03, Ondrej Pokorny wrote:
>> You cannot assign an array property to a variable. It does not exist
>> without the index parameter.
> OK, there is a bug in ppc that allows to use an array property with *any
> paramete**r(s)* (also no parameter). Delphi does not allow it.
> Actually ppc doesn't check if *MyProp[Index]* matches the property
> declaration but if there is an (overloaded) function that matches the
> Index parameter. Therefore you can declare a parameterless function with
> property getter's name that returns the enumerator and it will be used
> in the for-in loop!
> I still think that it is a ppc bug and it would be better to have a
> clean way to do that. But if you don't like to extend the compiler,
> please don't fix this bug either.
It's not a general compiler bug, but only in relationship with helpers
(I can't trigger it if I have a class constructed that way without a
helper). Nevertheless it's a bug and it should be fixed. As I have
written the bug report: would you please report it as a separate bug?
> It was still a good practice for me to play with the compiler. I
> wouldn't have found the bug without studying the compiler code. You can
> find demo code that shows how to create an array property enumerator in
> the issue report: http://bugs.freepascal.org/view.php?id=28820#c87065
> Sven Barth & Michael Van Canneyt: you also showed an interest. What is
> your opinion about it?
I personally prefer the "enumerator" approach. You'll hear from me in a
moment regarding your patch (I was a bit busy at the weekend otherwise I
would have answered earlier).
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