[Haskell-cafe] function result caching

[Tomasz Zielonka]

On Fri, Oct 13, 2006 at 08:52:09AM -0400, Jan-Willem Maessen wrote:
> >I guess the reason is balancing. I can't think of any way of  
> >balancing a
> >lazy tree that wouldn't break abstraction.
> 
> Uh, Patricia trees aren't balanced in the usual sense.

> There is  exactly one tree structure for a given set of keys,
> regardless of  insertion order etc.  (IntSet and IntMap workes
> approximately as Carl  Witty described last I checked, though I won't
> swear to whether bits  are taken low to high or vice versa.)

Ah, IntMaps! Forget what I said.

Best regards
Tomasz