Hi. there is a demo example that is coming (somewhat) close to what you ask for: http://www.cs.vu.nl/boilerplate/testsuite/gzip/Main.hs Boilerplate paper II with some of the relevant background is found at: http://www.cs.vu.nl/boilerplate If you complete anything along the lines you describe, please let me know. Could be a nice entry in the boilerplate suite. Ralf
Hi
Has anybody done generic unification algorithm (e.g. using Data.Generics)?
The idea is to do the unifications in a state monad (like http://portal.acm.org/citation.cfm?id=507648&dl=ACM&coll=portal ), but without having to have two level types.
It would be cool to have a data type, e.g.
data Var a = Bound a | Unbound
data STVar s a = STRef s (Var a)
So then I could define my own data type, say person, with a mix of logical variables and constants:
data Person :: Person s { ssn :: Int, name :: STVar s String, spouse :: STVar s (Person s) }
So ssn would be a constant, while name and spouse would be logical variables.
unify would need to be a generic function, bringing together basic functions like:
unifyStringString :: String - > String -> ST s () unifyVarString :: STVar s String - > String -> ST s () (for basic types)
and
genericUnify :: a -> a -> ST s () genericVarActualUnify :: (STVar s a) -> a -> ST s () genericActualVarUnify :: a -> (STVar s a) -> ST s () genericVarVarUnify :: (STVar s a) -> (STVar s a) -> ST s ()
Cheers
John _______________________________________________ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users