\section[RnSource]{Main pass of renamer}
\begin{code}
-module RnSource ( rnDecl, rnSourceDecls, rnHsType, rnHsSigType ) where
+module RnSource ( rnDecl, rnSourceDecls, rnHsType, rnHsSigType, rnHsPolyType ) where
#include "HsVersions.h"
rnDecl (SigD (IfaceSig name ty id_infos loc))
= pushSrcLocRn loc $
lookupBndrRn name `thenRn` \ name' ->
- rnHsType doc_str ty `thenRn` \ (ty',fvs1) ->
+ rnHsPolyType doc_str ty `thenRn` \ (ty',fvs1) ->
mapFvRn rnIdInfo id_infos `thenRn` \ (id_infos', fvs2) ->
returnRn (SigD (IfaceSig name' ty' id_infos' loc), fvs1 `plusFV` fvs2)
where
get_var (RuleBndrSig v _) = v
rn_var (RuleBndr v, id) = returnRn (RuleBndr id, emptyFVs)
- rn_var (RuleBndrSig v t, id) = rnHsType doc t `thenRn` \ (t', fvs) ->
+ rn_var (RuleBndrSig v t, id) = rnHsPolyType doc t `thenRn` \ (t', fvs) ->
returnRn (RuleBndrSig id t', fvs)
\end{code}
returnRn (InfixCon new_ty1 new_ty2, fvs1 `plusFV` fvs2)
rnConDetails doc locn (NewCon ty mb_field)
- = rnHsType doc ty `thenRn` \ (new_ty, fvs) ->
+ = rnHsPolyType doc ty `thenRn` \ (new_ty, fvs) ->
rn_field mb_field `thenRn` \ new_mb_field ->
returnRn (NewCon new_ty new_mb_field, fvs)
where
returnRn ((new_names, new_ty), fvs)
rnBangTy doc (Banged ty)
- = rnHsType doc ty `thenRn` \ (new_ty, fvs) ->
+ = rnHsPolyType doc ty `thenRn` \ (new_ty, fvs) ->
returnRn (Banged new_ty, fvs)
rnBangTy doc (Unbanged ty)
- = rnHsType doc ty `thenRn` \ (new_ty, fvs) ->
+ = rnHsPolyType doc ty `thenRn` \ (new_ty, fvs) ->
returnRn (Unbanged new_ty, fvs)
rnBangTy doc (Unpacked ty)
- = rnHsType doc ty `thenRn` \ (new_ty, fvs) ->
+ = rnHsPolyType doc ty `thenRn` \ (new_ty, fvs) ->
returnRn (Unpacked new_ty, fvs)
-- This data decl will parse OK
-- rnHsSigType is used for source-language type signatures,
-- which use *implicit* universal quantification.
rnHsSigType doc_str ty
- = rnHsType (text "the type signature for" <+> doc_str) ty
+ = rnHsPolyType (text "the type signature for" <+> doc_str) ty
-rnForAll doc forall_tyvars ctxt ty
- = bindTyVarsFVRn doc forall_tyvars $ \ new_tyvars ->
- rnContext doc ctxt `thenRn` \ (new_ctxt, cxt_fvs) ->
- rnHsType doc ty `thenRn` \ (new_ty, ty_fvs) ->
- returnRn (mkHsForAllTy new_tyvars new_ctxt new_ty,
- cxt_fvs `plusFV` ty_fvs)
-
--- Check that each constraint mentions at least one of the forall'd type variables
--- Since the forall'd type variables are a subset of the free tyvars
--- of the tau-type part, this guarantees that every constraint mentions
--- at least one of the free tyvars in ty
-checkConstraints explicit_forall doc forall_tyvars ctxt ty
- = mapRn check ctxt `thenRn` \ maybe_ctxt' ->
- returnRn (catMaybes maybe_ctxt')
- -- Remove problem ones, to avoid duplicate error message.
- where
- check ct@(_,tys)
- | forall_mentioned = returnRn (Just ct)
- | otherwise = addErrRn (ctxtErr explicit_forall doc forall_tyvars ct ty)
- `thenRn_` returnRn Nothing
- where
- forall_mentioned = foldr ((||) . any (`elem` forall_tyvars) . extractHsTyRdrTyVars)
- False
- tys
+---------------------------------------
+rnHsPolyType, rnHsType :: SDoc -> RdrNameHsType -> RnMS (RenamedHsType, FreeVars)
+-- rnHsPolyType is prepared to see a for-all; rnHsType is not
+-- The former is called for the top level of type sigs and function args.
-rnHsType :: SDoc -> RdrNameHsType -> RnMS (RenamedHsType, FreeVars)
-
-rnHsType doc (HsForAllTy Nothing ctxt ty)
+---------------------------------------
+rnHsPolyType doc (HsForAllTy Nothing ctxt ty)
-- From source code (no kinds on tyvars)
-- Given the signature C => T we universally quantify
-- over FV(T) \ {in-scope-tyvars}
checkConstraints False doc forall_tyvars ctxt ty `thenRn` \ ctxt' ->
rnForAll doc (map UserTyVar forall_tyvars) ctxt' ty
-rnHsType doc (HsForAllTy (Just forall_tyvars) ctxt tau)
+rnHsPolyType doc (HsForAllTy (Just forall_tyvars) ctxt tau)
-- Explicit quantification.
-- Check that the forall'd tyvars are a subset of the
-- free tyvars in the tau-type part
checkConstraints True doc forall_tyvar_names ctxt tau `thenRn` \ ctxt' ->
rnForAll doc forall_tyvars ctxt' tau
+rnHsPolyType doc other_ty = rnHsType doc other_ty
+
+
+-- Check that each constraint mentions at least one of the forall'd type variables
+-- Since the forall'd type variables are a subset of the free tyvars
+-- of the tau-type part, this guarantees that every constraint mentions
+-- at least one of the free tyvars in ty
+checkConstraints explicit_forall doc forall_tyvars ctxt ty
+ = mapRn check ctxt `thenRn` \ maybe_ctxt' ->
+ returnRn (catMaybes maybe_ctxt')
+ -- Remove problem ones, to avoid duplicate error message.
+ where
+ check ct@(_,tys)
+ | forall_mentioned = returnRn (Just ct)
+ | otherwise = addErrRn (ctxtErr explicit_forall doc forall_tyvars ct ty)
+ `thenRn_` returnRn Nothing
+ where
+ forall_mentioned = foldr ((||) . any (`elem` forall_tyvars) . extractHsTyRdrTyVars)
+ False
+ tys
+
+rnForAll doc forall_tyvars ctxt ty
+ = bindTyVarsFVRn doc forall_tyvars $ \ new_tyvars ->
+ rnContext doc ctxt `thenRn` \ (new_ctxt, cxt_fvs) ->
+ rnHsType doc ty `thenRn` \ (new_ty, ty_fvs) ->
+ returnRn (mkHsForAllTy (Just new_tyvars) new_ctxt new_ty,
+ cxt_fvs `plusFV` ty_fvs)
+
+---------------------------------------
+rnHsType doc ty@(HsForAllTy _ _ inner_ty)
+ = addErrRn (unexpectedForAllTy ty) `thenRn_`
+ rnHsPolyType doc ty
+
rnHsType doc (MonoTyVar tyvar)
= lookupOccRn tyvar `thenRn` \ tyvar' ->
returnRn (MonoTyVar tyvar', unitFV tyvar')
rnHsType doc (MonoFunTy ty1 ty2)
- = rnHsType doc ty1 `thenRn` \ (ty1', fvs1) ->
- rnHsType doc ty2 `thenRn` \ (ty2', fvs2) ->
+ = rnHsPolyType doc ty1 `thenRn` \ (ty1', fvs1) ->
+ -- Might find a for-all as the arg of a function type
+ rnHsPolyType doc ty2 `thenRn` \ (ty2', fvs2) ->
+ -- Or as the result. This happens when reading Prelude.hi
+ -- when we find return :: forall m. Monad m -> forall a. a -> m a
returnRn (MonoFunTy ty1' ty2', fvs1 `plusFV` fvs2)
rnHsType doc (MonoListTy ty)
\begin{code}
rnCoreExpr (UfType ty)
- = rnHsType (text "unfolding type") ty `thenRn` \ (ty', fvs) ->
+ = rnHsPolyType (text "unfolding type") ty `thenRn` \ (ty', fvs) ->
returnRn (UfType ty', fvs)
rnCoreExpr (UfVar v)
\begin{code}
rnCoreBndr (UfValBinder name ty) thing_inside
- = rnHsType doc ty `thenRn` \ (ty', fvs1) ->
+ = rnHsPolyType doc ty `thenRn` \ (ty', fvs1) ->
bindCoreLocalFVRn name ( \ name' ->
thing_inside (UfValBinder name' ty')
) `thenRn` \ (result, fvs2) ->
returnRn (result, fvs1 `plusFV` fvs3)
rnNote (UfCoerce ty)
- = rnHsType (text "unfolding coerce") ty `thenRn` \ (ty', fvs) ->
+ = rnHsPolyType (text "unfolding coerce") ty `thenRn` \ (ty', fvs) ->
returnRn (UfCoerce ty', fvs)
rnNote (UfSCC cc) = returnRn (UfSCC cc, emptyFVs)
= returnRn (UfLitCon lit, emptyFVs)
rnUfCon (UfLitLitCon lit ty)
- = rnHsType (text "litlit") ty `thenRn` \ (ty', fvs) ->
+ = rnHsPolyType (text "litlit") ty `thenRn` \ (ty', fvs) ->
returnRn (UfLitLitCon lit ty', fvs)
rnUfCon (UfPrimOp op)
$$
(ptext SLIT("In") <+> doc)
+unexpectedForAllTy ty
+ = ptext SLIT("Unexpected forall type:") <+> ppr ty
+
badRuleLhsErr name lhs
= sep [ptext SLIT("Rule") <+> ptext name <> colon,
nest 4 (ptext SLIT("Illegal left-hand side:") <+> ppr lhs)]
projects / ghc-hetmet.git / blobdiff