-- from each type declaration, so this is emptyBag
; gen_binds <- return emptyBag -- mkGenericBinds is_boot tycl_decls
-{-
- -- Generate the Generic instances
- -- from each type declaration
- ; repInstsMeta <- genGenericAlls is_boot tycl_decls
-
- ; let repInsts = concat (map (\(a,_,_) -> a) repInstsMeta)
- repMetaTys = map (\(_,b,_) -> b) repInstsMeta
- repTyCons = map (\(_,_,c) -> c) repInstsMeta
--}
; (inst_info, rn_binds, rn_dus)
- <- renameDeriv is_boot gen_binds (insts1 ++ insts2 ++ concat metaInsts {- ++ repInsts -})
+ <- renameDeriv is_boot gen_binds (insts1 ++ insts2 ++ concat metaInsts)
; dflags <- getDOpts
; liftIO (dumpIfSet_dyn dflags Opt_D_dump_deriv "Derived instances"
- (ddump_deriving inst_info rn_binds))
+ (ddump_deriving inst_info rn_binds repMetaTys repTyCons metaInsts))
{-
; when (not (null inst_info)) $
dumpDerivingInfo (ddump_deriving inst_info rn_binds)
; return ( inst_info, rn_binds, rn_dus
, concat (map metaTyCons2TyCons repMetaTys), repTyCons) }
where
- ddump_deriving :: [InstInfo Name] -> HsValBinds Name -> SDoc
- ddump_deriving inst_infos extra_binds
- = hang (ptext (sLit "Derived instances"))
- 2 (vcat (map (\i -> pprInstInfoDetails i $$ text "") inst_infos)
- $$ ppr extra_binds)
+ ddump_deriving :: [InstInfo Name] -> HsValBinds Name
+ -> [MetaTyCons] -- ^ Empty data constructors
+ -> [TyCon] -- ^ Rep type family instances
+ -> [[(InstInfo RdrName, DerivAuxBinds)]]
+ -- ^ Instances for the repMetaTys
+ -> SDoc
+ ddump_deriving inst_infos extra_binds repMetaTys repTyCons metaInsts
+ = hang (ptext (sLit "Derived instances"))
+ 2 (vcat (map (\i -> pprInstInfoDetails i $$ text "") inst_infos)
+ $$ ppr extra_binds)
+ $$ hangP "Generic representation" (
+ hangP "Generated datatypes for meta-information"
+ (vcat (map ppr repMetaTys))
+ -- The Outputable instance for TyCon unfortunately only prints the name...
+ $$ hangP "Representation types"
+ (vcat (map ppr repTyCons))
+ $$ hangP "Meta-information instances"
+ (vcat (map (pprInstInfoDetails . fst) (concat metaInsts))))
+
+ hangP s x = text "" $$ hang (ptext (sLit s)) 2 x
renameDeriv :: Bool -> LHsBinds RdrName
where
(tyvars,_, clas,_) = instanceHead inst
clas_nm = className clas
-
------------------------------------------
-{- Now unused
-mkGenericBinds :: Bool -> [LTyClDecl Name] -> TcM (LHsBinds RdrName)
-mkGenericBinds is_boot tycl_decls
- | is_boot
- = return emptyBag
- | otherwise
- = do { tcs <- mapM tcLookupTyCon [ tcdName d
- | L _ d <- tycl_decls, isDataDecl d ]
- ; return (unionManyBags [ mkTyConGenericBinds tc
- | tc <- tcs, tyConHasGenerics tc ]) }
- -- We are only interested in the data type declarations,
- -- and then only in the ones whose 'has-generics' flag is on
- -- The predicate tyConHasGenerics finds both of these
--}
\end{code}
Note [Newtype deriving and unused constructors]
@makeDerivSpecs@ fishes around to find the info about needed derived instances.
\begin{code}
-{-
--- Make the EarlyDerivSpec for Generic
-mkGenDerivSpec :: TyCon -> TcRn (EarlyDerivSpec)
-mkGenDerivSpec tc = do
- { cls <- tcLookupClass genClassName
- ; let tc_tvs = tyConTyVars tc
- ; let tc_app = mkTyConApp tc (mkTyVarTys tc_tvs)
- ; let cls_tys = []
- ; let mtheta = Just []
- ; ds <- mkEqnHelp StandAloneDerivOrigin tc_tvs cls cls_tys tc_app mtheta
- -- JPM TODO: StandAloneDerivOrigin?...
- ; return ds }
--}
-- Make the "extras" for the generic representation
mkGenDerivExtras :: TyCon
-> TcRn (MetaTyCons, TyCon, [(InstInfo RdrName, DerivAuxBinds)])
-> TcM ( [EarlyDerivSpec]
, [(MetaTyCons, TyCon, [(InstInfo RdrName, DerivAuxBinds)])])
makeDerivSpecs is_boot tycl_decls inst_decls deriv_decls
- | is_boot -- No 'deriving' at all in hs-boot files
- = do { mapM_ add_deriv_err deriv_locs
- ; return ([],[]) }
+ | is_boot -- No 'deriving' at all in hs-boot files
+ = do { mapM_ add_deriv_err deriv_locs
+ ; return ([],[]) }
| otherwise
- = do { eqns1 <- mapAndRecoverM deriveTyData all_tydata
- ; eqns2 <- mapAndRecoverM deriveStandalone deriv_decls
- -- Generate EarlyDerivSpec's for Generic, if asked for
- -- ; (xGenerics, xDerRep) <- genericsFlags
- ; xDerRep <- genericsFlag
- ; let allTyNames = [ tcdName d | L _ d <- tycl_decls, isDataDecl d ]
- -- ; allTyDecls <- mapM tcLookupTyCon allTyNames
+ = do { eqns1 <- mapAndRecoverM deriveTyData all_tydata
+ ; eqns2 <- mapAndRecoverM deriveStandalone deriv_decls
+
+ -- Generic representation stuff: we might need to add some "extras"
+ -- to the instances
+ ; xDerRep <- getDOpts >>= return . xopt Opt_DeriveGeneric
+ ; generic_extras_deriv <- if not xDerRep
+ -- No extras if the flag is off
+ then (return [])
+ else do {
+ let allTyNames = [ tcdName d | L _ d <- tycl_decls, isDataDecl d ]
-- Select only those types that derive Generic
; let sel_tydata = [ tcdName t | (L _ c, L _ t) <- all_tydata
, getClassName c == Just genClassName ]
(sel_tydata ++ sel_deriv_decls)) allTyNames
-- We need to generate the extras to add to what has
-- already been derived
- ; generic_extras_deriv <- mapM mkGenDerivExtras derTyDecls
- -- For the remaining types, if Generics is on, we need to
- -- generate both the instances and the extras, but only for the
- -- types we can represent.
-{-
- ; let repTyDecls = filter canDoGenerics allTyDecls
- ; let remTyDecls = filter (\x -> not (x `elem` derTyDecls)) repTyDecls
- ; generic_instances <- if xGenerics
- then mapM mkGenDerivSpec remTyDecls
- else return []
- ; generic_extras_flag <- if xGenerics
- then mapM mkGenDerivExtras remTyDecls
- else return []
--}
- -- Merge and return everything
- ; return ( eqns1 ++ eqns2 -- ++ generic_instances
- , generic_extras_deriv {- ++ generic_extras_flag -}) }
+ ; {- pprTrace "sel_tydata" (ppr sel_tydata) $
+ pprTrace "sel_deriv_decls" (ppr sel_deriv_decls) $
+ pprTrace "derTyDecls" (ppr derTyDecls) $
+ pprTrace "deriv_decls" (ppr deriv_decls) $ -}
+ mapM mkGenDerivExtras derTyDecls }
+
+ -- Merge and return
+ ; return ( eqns1 ++ eqns2, generic_extras_deriv) }
where
-- We need extras if the flag DeriveGeneric is on and this type is
-- deriving Generic
-- Extracts the name of the class in the deriving
getClassName :: HsType Name -> Maybe Name
- getClassName (HsPredTy (HsClassP n _)) = Just n
- getClassName _ = Nothing
+ getClassName (HsForAllTy _ _ _ (L _ n)) = getClassName n
+ getClassName (HsPredTy (HsClassP n _)) = Just n
+ getClassName _ = Nothing
-- Extracts the name of the type in the deriving
+ -- This function (and also getClassName above) is not really nice, and I
+ -- might not have covered all possible cases. I wonder if there is no easier
+ -- way to extract class and type name from a LDerivDecl...
getTypeName :: HsType Name -> Maybe Name
+ getTypeName (HsForAllTy _ _ _ (L _ n)) = getTypeName n
getTypeName (HsTyVar n) = Just n
getTypeName (HsOpTy _ (L _ n) _) = Just n
getTypeName (HsPredTy (HsClassP _ [L _ n])) = getTypeName n
+ getTypeName (HsAppTy (L _ n) _) = getTypeName n
+ getTypeName (HsParTy (L _ n)) = getTypeName n
+ getTypeName (HsKindSig (L _ n) _) = getTypeName n
getTypeName _ = Nothing
extractTyDataPreds decls
= [(p, d) | d@(L _ (TyData {tcdDerivs = Just preds})) <- decls, p <- preds]
all_tydata :: [(LHsType Name, LTyClDecl Name)]
- -- Derived predicate paired with its data type declaration
+ -- Derived predicate paired with its data type declaration
all_tydata = extractTyDataPreds (instDeclATs inst_decls ++ tycl_decls)
deriv_locs = map (getLoc . snd) all_tydata
- ++ map getLoc deriv_decls
+ ++ map getLoc deriv_decls
add_deriv_err loc = setSrcSpan loc $
- addErr (hang (ptext (sLit "Deriving not permitted in hs-boot file"))
- 2 (ptext (sLit "Use an instance declaration instead")))
-
-genericsFlag :: TcM Bool
-genericsFlag = do dOpts <- getDOpts
- return ( xopt Opt_Generics dOpts
- || xopt Opt_DeriveGeneric dOpts)
+ addErr (hang (ptext (sLit "Deriving not permitted in hs-boot file"))
+ 2 (ptext (sLit "Use an instance declaration instead")))
------------------------------------------------------------------
deriveStandalone :: LDerivDecl Name -> TcM EarlyDerivSpec
no_cons_why rep_tc = quotes (pprSourceTyCon rep_tc) <+>
ptext (sLit "must have at least one data constructor")
--- JPM TODO: should give better error message
cond_RepresentableOk :: Condition
-cond_RepresentableOk (_,t) | canDoGenerics t = Nothing
- | otherwise = Just (ptext (sLit "Cannot derive Generic for type") <+> ppr t)
+cond_RepresentableOk (_,t) = canDoGenerics t
cond_enumOrProduct :: Condition
cond_enumOrProduct = cond_isEnumeration `orCond`
; let tv_set = mkVarSet tyvars
weird_preds = [pred | pred <- deriv_rhs
- , not (tyVarsOfPred pred `subVarSet` tv_set)]
+ , not (tyVarsOfPred pred `subVarSet` tv_set)]
; mapM_ (addErrTc . badDerivedPred) weird_preds
; theta <- simplifyDeriv orig the_pred tyvars deriv_rhs
where
inst_spec = mkInstance oflag theta spec
co1 = case tyConFamilyCoercion_maybe rep_tycon of
- Just co_con -> ACo (mkTyConApp co_con rep_tc_args)
+ Just co_con -> mkAxInstCo co_con rep_tc_args
Nothing -> id_co
-- Not a family => rep_tycon = main tycon
- co2 = case newTyConCo_maybe rep_tycon of
- Just co_con -> ACo (mkTyConApp co_con rep_tc_args)
- Nothing -> id_co -- The newtype is transparent; no need for a cast
- co = co1 `mkTransCoI` co2
- id_co = IdCo (mkTyConApp rep_tycon rep_tc_args)
+ co2 = mkAxInstCo (newTyConCo rep_tycon) rep_tc_args
+ co = co1 `mkTransCo` co2
+ id_co = mkReflCo (mkTyConApp rep_tycon rep_tc_args)
-- Example: newtype instance N [a] = N1 (Tree a)
-- deriving instance Eq b => Eq (N [(b,b)])
let metaDts = MetaTyCons metaDTyCon metaCTyCons metaSTyCons
rep0_tycon <- tc_mkRepTyCon tc metaDts
-
+
+ -- pprTrace "rep0" (ppr rep0_tycon) $
return (metaDts, rep0_tycon)
{-
genGenericAll :: TyCon
projects / ghc-hetmet.git / blobdiff