Graeme Geldenhuys wrote:
Just to recap... What exactly does the function GetEnumerator return?
Specifically for list type classes. Also what interface would that
enumerator support?
Valid return for now is object or class instance. I did not implement
interface support yet. But delphi has the next interface for this:
IEnumerator = interface(IInterface)
function GetCurrent: TObject;
function MoveNext: Boolean;
procedure Reset;
property Current: TObject read GetCurrent;
end;
The reason I ask... I would still like the full power of Iterator (as
discussed before) for all List type classes in the RTL (similar to my
code attachment of 4 days ago). I'm not sure if what you implemented
will conflict with what I want to implement in the RTL. The major
difference would be that mine is a implementation detail in the list
classes, whereas your implementation is a language feature. When I use
iterators, I would like to have the ability to use Current, HasNext,
HasPrevious, PeakNext, PeakPrevious, Reset, JumpToBack, pass a filter
to GetIterator... etc.
I don't argue but how do you think to use HasPrevious, PeakNext,
PeakPrevios, Reset, JumpToBack in the for-in loop? Can you suggest a syntax?
Also, I referred to them in my implementation as Iterators - as per
the Iterator design pattern. How does Enumerator differ from Iterator?
Delphi enumerator pattern is a structure with one boolean function
MoveNext and one property Current.
More info is here:
http://17slon.com/blogs/gabr/2007/03/fun-with-enumerators.html
Best regards,
Paul Ishenin.
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