Am Freitag, 13. Juni 2003 17:12 schrieb George Russell: > Keith wrote (snipped) > > > But George Russell's implementation relied on looking up something in > > one map with a key obtained from another map. I thought type-safe > > MRefs should disallow this. > > However if you disallow lookup up in one map with a key from another, > then Ralf Hinze's solution of putting the value inside the key > uses no type extentions and works perfectly well (though is probably > not quite what was intended).
Here is the modified version of `update': update :: (Typable b) => FM k -> Key k a -> a -> FM k update (FM bs) (Key k r) b = FM ((k, Dyn r b) : bs) _______________________________________________ Haskell mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell
