2009/10/25 Paul Ishenin <webpi...@mail.ru>: > > To use it in the for-in loop you need to add a function MoveNext: Boolean > (you can choose any other name but you need to mark it using 'enumerator > MoveMext' modifier) and property Current: TObject (you can choose any other > name but you need to mark it using 'enumerator Current' modifier).
Thanks Paul, now I have a much better idea of for-in loop (I started getting confused during this message thread discussion and lost track). As I mentioned in my previous post, I did not expect my idea of Iterators to work with for-in. Looking at your examples, I still agree with my assessment. for-in can be considered a "lite" version of Iterators. The for-in syntax however does not replace the need for full Iterator support. By "full Iterator" I mean having a large set of methods that the user can use, like: PeakNext, PeakPrevious, Remove, JumpToBack, etc... So I will continue with my work of Iterator support in all RTL container classes and use the GetIterator method to create an Iterator instance. This means the user can decide which method they want to use to iterate over their container classes and how much control they need in the looping code. It they only need a front-to-back loop, they can use for-in syntax,but if they want more control, they can request a Iterator via GetIterator method. BTW: Reading that Delphi article about Enumerators, I must say that your Implementation seems a lot more flexible by not hard-coding method names etc... Clearly it pays to discuss ideas first before jumping into the implementation. CodeGear certainly can learn something from FPC developers! :-) -- Regards, - Graeme - _______________________________________________ fpGUI - a cross-platform Free Pascal GUI toolkit http://opensoft.homeip.net/fpgui/ _______________________________________________ fpc-devel maillist - fpc-devel@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-devel
