Jamie Brandon wrote:
Ive put up the haddock api at http://code.haskell.org/gmap/api/GMap.html
The interface is now split into GMap which make no guarantees on ordering and OrderedGMap which provides a compareKey function as well as ordered folds etc.
Because all maps ought to be traversable.
Thats a good point. Traversable requires Foldable. Do people expect Foldable to imply some ordering? I can put it into OrderedGMap at least.
Foldable does, trivially, imply ordering: "fold" can distinguish the order. So you might have to be careful about breaking referential transparency (at least if you want "==" GMaps to always be extensionally equivalent). But obviously a container without some concept of ordering will probably not be in any particularly *meaningful* order! It should still be Foldable if there's no reason not to (which is useful at least for commutative+associative ops like "+"). All IMHO. -Isaac