Stephen Colebourne typed the following on 07:48 PM 5/26/2002 +0100 >> > > 4. Must tree iterators be depth-first? The ordered >> > > traversal for a heap tree isn't depth-first. >> > >> > No, but depth first is the one I needed ;-) There are two possibilities >> > here, >> > a) Add extra methods for different iteration types >> > b) Remove the comment that specifies how the iteration is done. >> >> I think, personally, for things like trees, either having >> >> depthFirstIterator() >> bredthFirstIterator() >> >> or removing all iteration from the tree directly, and require >> folks to do: >> >> Iterator iter = new DepthFirstIterator( tree ); >> >> or >> >> Iterator iter = new BredthFirstIterator( tree ); >> >> Just because there's no -default- way to iterate a tree, I don't >> think having just a plain iterator() method is sufficient. > >I would rather keep the iterator on TreeNode. If there are only two standard >ways to iterate then two methods would seem appropriate. But are there more >than two ways??
I favor a single iterator() method on the interface which returns the nodes in an unspecified order. I'm ambivalent about having the specific breadth/depth iterator methods on the Interface, but if it seems like there will be more than that, forget it; keep just a single iterator() method and leave other options to implementations rather than clutter the interface. There's nothing wrong with having a plain iterator() method even if there's no default way it needs to be implemented; other Collection (non-List) classes have iterators whose return order is unspecified. Kief -- To unsubscribe, e-mail: <mailto:[EMAIL PROTECTED]> For additional commands, e-mail: <mailto:[EMAIL PROTECTED]>
