On Dec 5, 2007 12:16 AM, Aaron Denney <[EMAIL PROTECTED]> wrote: > On 2007-12-04, Paulo J. Matos <[EMAIL PROTECTED]> wrote: > > Hello all, > > > > As you might have possibly read in some previous blog posts: > > http://users.ecs.soton.ac.uk/pocm06r/fpsig/?p=10 > > http://users.ecs.soton.ac.uk/pocm06r/fpsig/?p=11 > > > > we (the FPSIG group) defined: > > data BTree a = Leaf a > > | Branch (BTree a) a (BTree a) > > Totally avoiding your question, but I'm curious as to why you > deliberately exclude empty trees. > > Come to think of it, how can you represent a tree with two elements? >
Good question. I think we were just trying to define a tree in the meeting and everyone agreed on this representation. > Wouldn't > > > data BTree a = Empty > > | Branch (BTree a) a (BTree a) > > be better? > Possibly :) I think that at the time nobody really cared about empty trees! But for a really application we would have had to define them probably. Now thinking about it, it seems like defining lists without Null, strange, isn't it? > -- > Aaron Denney > -><- > > > _______________________________________________ > Haskell-Cafe mailing list > Haskell-Cafe@haskell.org > http://www.haskell.org/mailman/listinfo/haskell-cafe > > > -- Paulo Jorge Matos - pocm at soton.ac.uk http://www.personal.soton.ac.uk/pocm PhD Student @ ECS University of Southampton, UK _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe