\begin{code}
module BuildTyCl (
buildSynTyCon, buildAlgTyCon, buildDataCon,
- buildClass,
+ TcMethInfo, buildClass,
mkAbstractTyConRhs, mkOpenDataTyConRhs,
mkNewTyConRhs, mkDataTyConRhs, setAssocFamilyPermutation
) where
------------------------------------------------------
buildSynTyCon :: Name -> [TyVar]
-> SynTyConRhs
- -> Kind -- Kind of the RHS
- -> Maybe (TyCon, [Type]) -- family instance if applicable
+ -> Kind -- ^ Kind of the RHS
+ -> Maybe (TyCon, [Type]) -- ^ family instance if applicable
-> TcRnIf m n TyCon
buildSynTyCon tc_name tvs rhs@(OpenSynTyCon {}) rhs_kind _
------------------------------------------------------
buildAlgTyCon :: Name -> [TyVar]
- -> ThetaType -- Stupid theta
+ -> ThetaType -- ^ Stupid theta
-> AlgTyConRhs
-> RecFlag
- -> Bool -- True <=> want generics functions
- -> Bool -- True <=> was declared in GADT syntax
- -> Maybe (TyCon, [Type]) -- family instance if applicable
+ -> Bool -- ^ True <=> want generics functions
+ -> Bool -- ^ True <=> was declared in GADT syntax
+ -> Maybe (TyCon, [Type]) -- ^ family instance if applicable
-> TcRnIf m n TyCon
buildAlgTyCon tc_name tvs stupid_theta rhs is_rec want_generics gadt_syn
; return tycon
}
--- If a family tycon with instance types is given, the current tycon is an
+-- | If a family tycon with instance types is given, the current tycon is an
-- instance of that family and we need to
--
-- (1) create a coercion that identifies the family instance type and the
mkDataTyConRhs :: [DataCon] -> AlgTyConRhs
mkDataTyConRhs cons
- = DataTyCon { data_cons = cons, is_enum = all isNullarySrcDataCon cons }
+ = DataTyCon {
+ data_cons = cons,
+ is_enum = -- We define datatypes with no constructors to not be
+ -- enumerations; this fixes trac #2578, Otherwise we
+ -- end up generating an empty table for
+ -- <mod>_<type>_closure_tbl
+ -- which is used by tagToEnum# to map Int# to constructors
+ -- in an enumeration. The empty table apparently upset
+ -- the linker.
+ not (null cons) &&
+ all isNullarySrcDataCon cons
+ }
mkNewTyConRhs :: Name -> TyCon -> DataCon -> TcRnIf m n AlgTyConRhs
--- Monadic because it makes a Name for the coercion TyCon
--- We pass the Name of the parent TyCon, as well as the TyCon itself,
--- because the latter is part of a knot, whereas the former is not.
+-- ^ Monadic because it makes a Name for the coercion TyCon
+-- We pass the Name of the parent TyCon, as well as the TyCon itself,
+-- because the latter is part of a knot, whereas the former is not.
mkNewTyConRhs tycon_name tycon con
= do { co_tycon_name <- newImplicitBinder tycon_name mkNewTyCoOcc
; let co_tycon = mkNewTypeCoercion co_tycon_name tycon etad_tvs etad_rhs
------------------------------------------------------
buildDataCon :: Name -> Bool
- -> [StrictnessMark]
+ -> [HsBang]
-> [Name] -- Field labels
-> [TyVar] -> [TyVar] -- Univ and ext
-> [(TyVar,Type)] -- Equality spec
------------------------------------------------------
\begin{code}
+type TcMethInfo = (Name, DefMethSpec, Type) -- A temporary intermediate, to communicate
+ -- between tcClassSigs and buildClass
+
buildClass :: Bool -- True <=> do not include unfoldings
-- on dict selectors
-- Used when importing a class without -O
-> Name -> [TyVar] -> ThetaType
- -> [FunDep TyVar] -- Functional dependencies
- -> [TyThing] -- Associated types
- -> [(Name, DefMeth, Type)] -- Method info
- -> RecFlag -- Info for type constructor
+ -> [FunDep TyVar] -- Functional dependencies
+ -> [TyThing] -- Associated types
+ -> [TcMethInfo] -- Method info
+ -> RecFlag -- Info for type constructor
-> TcRnIf m n Class
buildClass no_unf class_name tvs sc_theta fds ats sig_stuff tc_isrec
; fixM (\ rec_clas -> do { -- Only name generation inside loop
- let { rec_tycon = classTyCon rec_clas
- ; op_tys = [ty | (_,_,ty) <- sig_stuff]
- ; op_names = [op | (op,_,_) <- sig_stuff]
- ; op_items = [ (mkDictSelId no_unf op_name rec_clas, dm_info)
- | (op_name, dm_info, _) <- sig_stuff ] }
+ ; op_items <- mapM (mk_op_item rec_clas) sig_stuff
-- Build the selector id and default method id
; let n_value_preds = count (not . isEqPred) sc_theta
-- as ordinary arguments. That means that in the case of
-- class C a => D a
-- we don't get a newtype with no arguments!
- args = sc_sel_names ++ op_names
- arg_tys = map mkPredTy sc_theta ++ op_tys
-
+ args = sc_sel_names ++ op_names
+ arg_tys = map mkPredTy sc_theta ++ op_tys
+ op_tys = [ty | (_,_,ty) <- sig_stuff]
+ op_names = [op | (op,_,_) <- sig_stuff]
+ rec_tycon = classTyCon rec_clas
+
; dict_con <- buildDataCon datacon_name
False -- Not declared infix
- (map (const NotMarkedStrict) args)
+ (map (const HsNoBang) args)
[{- No fields -}]
tvs [{- no existentials -}]
[{- No GADT equalities -}] [{- No theta -}]
; traceIf (text "buildClass" <+> ppr tycon)
; return result
})}
+ where
+ mk_op_item :: Class -> TcMethInfo -> TcRnIf n m ClassOpItem
+ mk_op_item rec_clas (op_name, dm_spec, _)
+ = do { dm_info <- case dm_spec of
+ NoDM -> return NoDefMeth
+ GenericDM -> return GenDefMeth
+ VanillaDM -> do { dm_name <- newImplicitBinder op_name mkDefaultMethodOcc
+ ; return (DefMeth dm_name) }
+ ; return (mkDictSelId no_unf op_name rec_clas, dm_info) }
\end{code}
Note [Class newtypes and equality predicates]