tcGetGlobalTyVars,
-- Template Haskell stuff
- checkWellStaged, spliceOK, bracketOK, tcMetaTy, thLevel,
+ checkWellStaged, tcMetaTy, thLevel,
topIdLvl, thTopLevelId, thRnBrack, isBrackStage,
-- New Ids
import Class
import Name
import NameEnv
-import OccName
import HscTypes
import SrcLoc
import Outputable
-import Maybes
import Unique
import FastString
\end{code}
-- Look up the instance tycon of a family instance.
--
--- The match must be unique - ie, match exactly one instance - but the
--- type arguments used for matching may be more specific than those of
--- the family instance declaration.
+-- The match may be ambiguous (as we know that overlapping instances have
+-- identical right-hand sides under overlapping substitutions - see
+-- 'FamInstEnv.lookupFamInstEnvConflicts'). However, the type arguments used
+-- for matching must be equal to or be more specific than those of the family
+-- instance declaration. We pick one of the matches in case of ambiguity; as
+-- the right-hand sides are identical under the match substitution, the choice
+-- does not matter.
--
-- Return the instance tycon and its type instance. For example, if we have
--
; eps <- getEps
; let instEnv = (eps_fam_inst_env eps, tcg_fam_inst_env env)
; case lookupFamInstEnv instEnv tycon tys of
- [(fam_inst, rep_tys)] -> return $ Just (famInstTyCon fam_inst,
- rep_tys)
- _ -> return Nothing
+ [] -> return Nothing
+ ((fam_inst, rep_tys):_)
+ -> return $ Just (famInstTyCon fam_inst, rep_tys)
}
\end{code}
tcl_tyvars = gtvs,
tcl_rdr = rdr_env}) <- getLclEnv
let
- rdr_env' = extendLocalRdrEnv rdr_env (map fst binds)
+ rdr_env' = extendLocalRdrEnvList rdr_env (map fst binds)
new_tv_set = tcTyVarsOfTypes (map snd binds)
le' = extendNameEnvList le [(name, ATyVar name ty) | (name, ty) <- binds]
_ -> Wobbly})
| (name,id) <- names_w_ids, let id_ty = idType id]
le' = extendNameEnvList (tcl_env env) extra_env
- rdr_env' = extendLocalRdrEnv (tcl_rdr env) [name | (name,_) <- names_w_ids]
+ rdr_env' = extendLocalRdrEnvList (tcl_rdr env) [name | (name,_) <- names_w_ids]
\end{code}
%************************************************************************
\begin{code}
-instance Outputable ThStage where
- ppr (Comp l) = text "Comp" <+> int l
- ppr (Brack l _ _) = text "Brack" <+> int l
- ppr (Splice l) = text "Splice" <+> int l
-
-
-thLevel :: ThStage -> ThLevel
-thLevel (Comp l) = l
-thLevel (Splice l) = l
-thLevel (Brack l _ _) = l
-
-
checkWellStaged :: SDoc -- What the stage check is for
-> ThLevel -- Binding level (increases inside brackets)
- -> ThStage -- Use stage
+ -> ThLevel -- Use stage
-> TcM () -- Fail if badly staged, adding an error
-checkWellStaged pp_thing bind_lvl use_stage
+checkWellStaged pp_thing bind_lvl use_lvl
| use_lvl >= bind_lvl -- OK! Used later than bound
= return () -- E.g. \x -> [| $(f x) |]
- | bind_lvl == topLevel -- GHC restriction on top level splices
+ | bind_lvl == outerLevel -- GHC restriction on top level splices
= failWithTc $
sep [ptext (sLit "GHC stage restriction:") <+> pp_thing,
- nest 2 (ptext (sLit "is used in") <+> use_lvl_doc <> ptext (sLit ", and must be imported, not defined locally"))]
+ nest 2 (vcat [ ptext (sLit "is used in a top-level splice or annotation,")
+ , ptext (sLit "and must be imported, not defined locally")])]
| otherwise -- Badly staged
= failWithTc $ -- E.g. \x -> $(f x)
ptext (sLit "Stage error:") <+> pp_thing <+>
hsep [ptext (sLit "is bound at stage") <+> ppr bind_lvl,
ptext (sLit "but used at stage") <+> ppr use_lvl]
- where
- use_lvl = thLevel use_stage
- use_lvl_doc | use_lvl == thLevel topStage = ptext (sLit "a top-level splice")
- | use_lvl == thLevel topAnnStage = ptext (sLit "an annotation")
- | otherwise = panic "checkWellStaged"
topIdLvl :: Id -> ThLevel
-- Globals may either be imported, or may be from an earlier "chunk"
-- $( f x )
-- By the time we are prcessing the $(f x), the binding for "x"
-- will be in the global env, not the local one.
-topIdLvl id | isLocalId id = topLevel
+topIdLvl id | isLocalId id = outerLevel
| otherwise = impLevel
--- Indicates the legal transitions on bracket( [| |] ).
-bracketOK :: ThStage -> Maybe ThLevel
-bracketOK (Brack _ _ _) = Nothing -- Bracket illegal inside a bracket
-bracketOK stage = Just (thLevel stage + 1)
-
--- Indicates the legal transitions on splice($).
-spliceOK :: ThStage -> Maybe ThLevel
-spliceOK (Splice _) = Nothing -- Splice illegal inside splice
-spliceOK stage = Just (thLevel stage - 1)
-
tcMetaTy :: Name -> TcM Type
-- Given the name of a Template Haskell data type,
-- return the type
(LHsBinds a) -- Bindings for the instance methods
[LSig a] -- User pragmas recorded for generating
-- specialised instances
+ Bool -- True <=> This code came from a standalone deriving clause
| NewTypeDerived -- Used for deriving instances of newtypes, where the
CoercionI -- witness dictionary is identical to the argument
pprInstInfoDetails :: OutputableBndr a => InstInfo a -> SDoc
pprInstInfoDetails info = pprInstInfo info $$ nest 2 (details (iBinds info))
where
- details (VanillaInst b _) = pprLHsBinds b
- details (NewTypeDerived _) = text "Derived from the representation type"
+ details (VanillaInst b _ _) = pprLHsBinds b
+ details (NewTypeDerived _) = text "Derived from the representation type"
simpleInstInfoClsTy :: InstInfo a -> (Class, Type)
simpleInstInfoClsTy info = case instanceHead (iSpec info) of
\begin{code}
newDFunName :: Class -> [Type] -> SrcSpan -> TcM Name
-newDFunName clas (ty:_) loc
- = do { index <- nextDFunIndex
- ; is_boot <- tcIsHsBoot
+newDFunName clas tys loc
+ = do { is_boot <- tcIsHsBoot
; mod <- getModule
; let info_string = occNameString (getOccName clas) ++
- occNameString (getDFunTyKey ty)
- dfun_occ = mkDFunOcc info_string is_boot index
-
+ concatMap (occNameString.getDFunTyKey) tys
+ ; dfun_occ <- chooseUniqueOccTc (mkDFunOcc info_string is_boot)
; newGlobalBinder mod dfun_occ loc }
-
-newDFunName clas [] loc = pprPanic "newDFunName" (ppr clas <+> ppr loc)
\end{code}
Make a name for the representation tycon of a family instance. It's an
newGlobalBinder.
\begin{code}
-newFamInstTyConName :: Name -> SrcSpan -> TcM Name
-newFamInstTyConName tc_name loc
- = do { index <- nextDFunIndex
- ; mod <- getModule
- ; let occ = nameOccName tc_name
- ; newGlobalBinder mod (mkInstTyTcOcc index occ) loc }
+newFamInstTyConName :: Name -> [Type] -> SrcSpan -> TcM Name
+newFamInstTyConName tc_name tys loc
+ = do { mod <- getModule
+ ; let info_string = occNameString (getOccName tc_name) ++
+ concatMap (occNameString.getDFunTyKey) tys
+ ; occ <- chooseUniqueOccTc (mkInstTyTcOcc info_string)
+ ; newGlobalBinder mod occ loc }
\end{code}
Stable names used for foreign exports and annotations.
projects / ghc-hetmet.git / blobdiff