- returnM (mkLocalId var ty)
- new_id (RuleBndrSig var rn_ty) = tcHsSigType (RuleSigCtxt var) rn_ty `thenM` \ ty ->
- returnM (mkLocalId var ty)
-
-ruleLhsTvs :: TcExpr -> TcTyVarSet
--- We need to gather the type variables mentioned on the LHS so we can
--- quantify over them. Example:
--- data T a = C
---
--- foo :: T a -> Int
--- foo C = 1
---
--- {-# RULES "myrule" foo C = 1 #-}
---
--- After type checking the LHS becomes (foo a (C a))
--- and we do not want to zap the unbound tyvar 'a' to (), because
--- that limits the applicability of the rule. Instead, we
--- want to quantify over it!
---
--- Fortunately the form of the LHS is pretty limited (see RnSource.validRuleLhs)
--- so we don't need to deal with the whole of HsSyn.
---
--- Uh oh! validRuleLhs only checks the function part of rule LHSs!
-
-ruleLhsTvs (HsPar e) = ruleLhsTvs e
-ruleLhsTvs (HsLit e) = emptyVarSet
-ruleLhsTvs (HsOverLit e) = emptyVarSet
-ruleLhsTvs (HsVar v) = emptyVarSet -- I don't think we need the tyvars of the Id
-
-ruleLhsTvs (OpApp e1 op _ e2) = ruleLhsTvs e1 `unionVarSet` ruleLhsTvs op
- `unionVarSet` ruleLhsTvs e2
-ruleLhsTvs (HsApp e1 e2) = ruleLhsTvs e1 `unionVarSet` ruleLhsTvs e2
-ruleLhsTvs (TyApp e1 tys) = ruleLhsTvs e1 `unionVarSet` tyVarsOfTypes tys
-ruleLhsTvs (DictApp e ds) = ruleLhsTvs e
-ruleLhsTvs (NegApp e _) = ruleLhsTvs e
-ruleLhsTvs (ExplicitList ty es) = tyVarsOfType ty `unionVarSet` ruleLhsTvs_s es
-ruleLhsTvs (ExplicitTuple es _) = ruleLhsTvs_s es
-
--- Type abstractions can occur in rules like
--- "foldr k z (build g) = g k z"
-ruleLhsTvs (TyLam tvs e) = ruleLhsTvs e `delVarSetList` tvs
-ruleLhsTvs (DictLam ids e) = ruleLhsTvs e
-ruleLhsTvs e = pprPanic "ruleLhsTvs" (ppr e)
-
-ruleLhsTvs_s es = foldr (unionVarSet . ruleLhsTvs) emptyVarSet es