AVL Trees available

[Adrian Hey]

Hello,

I've put my candidate for Data.Trees.AVL up here..

 http://homepages.nildram.co.uk/~ahey/HLibs/Local.Data.Trees.AVL/

It's not finished, but in the absence of any other AVL tree
offerings that I'm aware of, I would like to strike the Local
prefix from this library name and claim the currently vacant
Data.Trees.AVL slot in Simon M's hierarchy.

If you look at the code you'll see this is not Haskell at it's
most elegant. Most of tt's like assembler written in Haskell,
but it's fast :-)

I'd also like to book "Data.COrdering" too, if that's OK.

Regards
--
Adrian Hey