module Data.Comp.Derive.Utils where
import Language.Haskell.TH
import Language.Haskell.TH.Syntax
import Control.Monad
import Language.Haskell.TH.ExpandSyns
abstractNewtypeQ :: Q Info -> Q Info
abstractNewtypeQ = liftM abstractNewtype
abstractNewtype :: Info -> Info
abstractNewtype (TyConI (NewtypeD cxt name args constr derive))
= TyConI (DataD cxt name args [constr] derive)
abstractNewtype owise = owise
normalCon :: Con -> (Name,[StrictType])
normalCon (NormalC constr args) = (constr, args)
normalCon (RecC constr args) = (constr, map (\(_,s,t) -> (s,t)) args)
normalCon (InfixC a constr b) = (constr, [a,b])
normalCon (ForallC _ _ constr) = normalCon constr
normalCon' :: Con -> (Name,[Type])
normalCon' = fmap (map snd) . normalCon
normalConExp :: Con -> Q (Name,[Type])
normalConExp c = do
let (n,ts) = normalCon' c
ts' <- mapM expandSyns ts
return (n, ts')
abstractConType :: Con -> (Name,Int)
abstractConType (NormalC constr args) = (constr, length args)
abstractConType (RecC constr args) = (constr, length args)
abstractConType (InfixC _ constr _) = (constr, 2)
abstractConType (ForallC _ _ constr) = abstractConType constr
tyVarBndrName (PlainTV n) = n
tyVarBndrName (KindedTV n _) = n
containsType :: Type -> Type -> Bool
containsType s t
| s == t = True
| otherwise = case s of
ForallT _ _ s' -> containsType s' t
AppT s1 s2 -> containsType s1 t || containsType s2 t
SigT s' _ -> containsType s' t
_ -> False
containsType' :: Type -> Type -> [Int]
containsType' = run 0
where run n s t
| s == t = [n]
| otherwise = case s of
ForallT _ _ s' -> run n s' t
AppT s1 s2 -> run n s1 t ++ run (n+1) s2 t
SigT s' _ -> run n s' t
_ -> []
newNames :: Int -> String -> Q [Name]
newNames n name = replicateM n (newName name)
tupleTypes n m = map tupleTypeName [n..m]
derive :: [Name -> Q [Dec]] -> [Name] -> Q [Dec]
derive ders names = liftM concat $ sequence [der name | der <- ders, name <- names]