Benjamin Franksen wrote:
Adrian Hey wrote:
apfelmus wrote:
The Ord-constraint is too limiting for tries. Well it isn't going to disappear while I'm in charge of GT class :-) Why do you object to it? Ultimately we must be able to test keys for equality at least. Is there a type that is an instance of Eq, but not Ord (or could not reasonably be made an instance of Ord)?
Data.Typeable.TypeRep
Interesting problem, but I don't see any reason why this could not be an instance of Ord. Because of the weird Key hack that's there I guess you'd have to hand write this instance, not derive it. Then for GT you'd have to either hand write a matching GT instance or fall back on the less efficient but general purpose OrdGT.. http://darcs.haskell.org/packages/collections-ghc6.6/Data.Trie.General/Data/... Regards -- Adrian Hey