+
+-- | Is the given type a State type?
+isStateType :: Type.Type -> Bool
+-- Resolve any type synonyms remaining
+isStateType ty | Just ty' <- Type.tcView ty = isStateType ty'
+isStateType ty = Maybe.isJust $ do
+ -- Split the type. Don't use normal splitAppTy, since that looks through
+ -- newtypes, and we want to see the State newtype.
+ (typef, _) <- Type.repSplitAppTy_maybe ty
+ -- See if the applied type is a type constructor
+ (tycon, _) <- Type.splitTyConApp_maybe typef
+ if TyCon.isNewTyCon tycon && Name.getOccString tycon == "State"
+ then
+ Just ()
+ else
+ Nothing
+
+-- | Does the given expression have a State type?
+hasStateType :: CoreSyn.CoreExpr -> Bool
+hasStateType (CoreSyn.Type _) = False
+hasStateType expr = (isStateType . CoreUtils.exprType) expr