On Wed, 12 May 2010 17:19:57 +0200 Graeme Geldenhuys <graemeg.li...@gmail.com> wrote:
> 2010/5/12 spir ☣: > > > > * TFPList > > Is there another way to traverse a list than > > for i :=0 to (list.count - 1) do ... > > What about list.high? > > Yes, I use the Iterator design pattern. This allows me to write code as > follows: > > --------------- > var > itr: ITBStringIterator; > begin > ... > itr := gIteratorFactory.StringIterator(sl); > while itr.HasNext do > writeln(itr.Next); > ... > end; > --------------- > > I have created Iterators for all existing list types and the code (and > accompanied article explaining Iterators) are freely available at: > http://opensoft.homeip.net/articles/ > > Iterators have the added flexibility that I can even combine them with > regular expressions to creating a filtered list. > ----------- > fitr := gIteratorFactory.FilteredStringIterator(MyStringsCollection, > 'foob.*r'); > while fitr.HasNext do > begin > DoSomethingWithItem(fitr.Next); > ... > end; > ----------- > > I can also move backwards, forwards, peak back or forward, reverse the > iterating, reset the iteration etc. Iterators are very flexible. Oh, thank you for this pattern. This is a really nice feature, esp. in that it integrates so well with while loops? I'll have a look at your code as soon as I can. Denis ________________________________ vit esse estrany ☣ spir.wikidot.com _______________________________________________ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
