X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2Fiface%2FBuildTyCl.lhs;h=242772fecb43cd01f32a38e4be385c10f163bc5d;hp=864cb1950f0ed7e19b82fb4892374dbed8727faa;hb=ad94d40948668032189ad22a0ad741ac1f645f50;hpb=604afcb5b9c06bee56d3a89f5d0bcdb793bbfb10 diff --git a/compiler/iface/BuildTyCl.lhs b/compiler/iface/BuildTyCl.lhs index 864cb19..242772f 100644 --- a/compiler/iface/BuildTyCl.lhs +++ b/compiler/iface/BuildTyCl.lhs @@ -4,10 +4,17 @@ % \begin{code} +{-# OPTIONS -w #-} +-- The above warning supression flag is a temporary kludge. +-- While working on this module you are encouraged to remove it and fix +-- any warnings in the module. See +-- http://hackage.haskell.org/trac/ghc/wiki/CodingStyle#Warnings +-- for details + module BuildTyCl ( buildSynTyCon, buildAlgTyCon, buildDataCon, buildClass, - mkAbstractTyConRhs, mkOpenDataTyConRhs, mkOpenNewTyConRhs, + mkAbstractTyConRhs, mkOpenDataTyConRhs, mkNewTyConRhs, mkDataTyConRhs ) where @@ -28,6 +35,8 @@ import Class import TyCon import Type import Coercion + +import TcRnMonad import Outputable import Data.List @@ -36,16 +45,29 @@ import Data.List \begin{code} ------------------------------------------------------ -buildSynTyCon :: Name -> [TyVar] -> SynTyConRhs -> TyCon -buildSynTyCon name tvs rhs@(OpenSynTyCon rhs_ki) - = mkSynTyCon name kind tvs rhs - where - kind = mkArrowKinds (map tyVarKind tvs) rhs_ki -buildSynTyCon name tvs rhs@(SynonymTyCon rhs_ty) - = mkSynTyCon name kind tvs rhs - where - kind = mkArrowKinds (map tyVarKind tvs) (typeKind rhs_ty) +buildSynTyCon :: Name -> [TyVar] + -> SynTyConRhs + -> Maybe (TyCon, [Type]) -- family instance if applicable + -> TcRnIf m n TyCon +buildSynTyCon tc_name tvs rhs@(OpenSynTyCon rhs_ki _) _ + = let + kind = mkArrowKinds (map tyVarKind tvs) rhs_ki + in + return $ mkSynTyCon tc_name kind tvs rhs NoParentTyCon + +buildSynTyCon tc_name tvs rhs@(SynonymTyCon rhs_ty) mb_family + = do { -- We need to tie a knot as the coercion of a data instance depends + -- on the instance representation tycon and vice versa. + ; tycon <- fixM (\ tycon_rec -> do + { parent <- mkParentInfo mb_family tc_name tvs tycon_rec + ; let { tycon = mkSynTyCon tc_name kind tvs rhs parent + ; kind = mkArrowKinds (map tyVarKind tvs) (typeKind rhs_ty) + } + ; return tycon + }) + ; return tycon + } ------------------------------------------------------ buildAlgTyCon :: Name -> [TyVar] @@ -62,7 +84,7 @@ buildAlgTyCon tc_name tvs stupid_theta rhs is_rec want_generics gadt_syn = do { -- We need to tie a knot as the coercion of a data instance depends -- on the instance representation tycon and vice versa. ; tycon <- fixM (\ tycon_rec -> do - { parent <- parentInfo mb_family tycon_rec + { parent <- mkParentInfo mb_family tc_name tvs tycon_rec ; let { tycon = mkAlgTyCon tc_name kind tvs stupid_theta rhs fields parent is_rec want_generics gadt_syn ; kind = mkArrowKinds (map tyVarKind tvs) liftedTypeKind @@ -72,38 +94,38 @@ buildAlgTyCon tc_name tvs stupid_theta rhs is_rec want_generics gadt_syn }) ; return tycon } - where - -- 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 - -- representation type from Step (1); ie, it is of the form - -- `Co tvs :: F ts :=: R tvs', where `Co' is the name of the coercion, - -- `F' the family tycon and `R' the (derived) representation tycon, - -- and - -- (2) produce a `AlgTyConParent' value containing the parent and coercion - -- information. - -- - parentInfo Nothing rep_tycon = - return NoParentTyCon - parentInfo (Just (family, instTys)) rep_tycon = - do { -- Create the coercion - ; co_tycon_name <- newImplicitBinder tc_name mkInstTyCoOcc - ; let co_tycon = mkDataInstCoercion co_tycon_name tvs - family instTys rep_tycon - ; return $ FamilyTyCon family instTys co_tycon - } - +-- 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 +-- representation type from Step (1); ie, it is of the form +-- `Co tvs :: F ts :=: R tvs', where `Co' is the name of the coercion, +-- `F' the family tycon and `R' the (derived) representation tycon, +-- and +-- (2) produce a `TyConParent' value containing the parent and coercion +-- information. +-- +mkParentInfo :: Maybe (TyCon, [Type]) + -> Name -> [TyVar] + -> TyCon + -> TcRnIf m n TyConParent +mkParentInfo Nothing _ _ _ = + return NoParentTyCon +mkParentInfo (Just (family, instTys)) tc_name tvs rep_tycon = + do { -- Create the coercion + ; co_tycon_name <- newImplicitBinder tc_name mkInstTyCoOcc + ; let co_tycon = mkFamInstCoercion co_tycon_name tvs + family instTys rep_tycon + ; return $ FamilyTyCon family instTys co_tycon + } + ------------------------------------------------------ mkAbstractTyConRhs :: AlgTyConRhs mkAbstractTyConRhs = AbstractTyCon mkOpenDataTyConRhs :: AlgTyConRhs -mkOpenDataTyConRhs = OpenDataTyCon - -mkOpenNewTyConRhs :: AlgTyConRhs -mkOpenNewTyConRhs = OpenNewTyCon +mkOpenDataTyConRhs = OpenTyCon Nothing mkDataTyConRhs :: [DataCon] -> AlgTyConRhs mkDataTyConRhs cons @@ -120,6 +142,7 @@ mkNewTyConRhs tycon_name tycon con = Just co_tycon | otherwise = Nothing + ; traceIf (text "mkNewTyConRhs" <+> ppr cocon_maybe) ; return (NewTyCon { data_con = con, nt_rhs = rhs_ty, nt_etad_rhs = (etad_tvs, etad_rhs), @@ -133,9 +156,13 @@ mkNewTyConRhs tycon_name tycon con -- non-recursive newtypes all_coercions = True tvs = tyConTyVars tycon - rhs_ty = head (dataConInstOrigArgTys con (mkTyVarTys tvs)) + rhs_ty = ASSERT(not (null (dataConInstOrigDictsAndArgTys con (mkTyVarTys tvs)))) + -- head (dataConInstOrigArgTys con (mkTyVarTys tvs)) + head (dataConInstOrigDictsAndArgTys con (mkTyVarTys tvs)) -- Instantiate the data con with the -- type variables from the tycon + -- NB: a newtype DataCon has no existentials; hence the + -- call to dataConInstOrigArgTys has the right type args etad_tvs :: [TyVar] -- Matched lazily, so that mkNewTypeCoercion can etad_rhs :: Type -- return a TyCon without pulling on rhs_ty @@ -260,44 +287,48 @@ buildClass :: Name -> [TyVar] -> ThetaType -> TcRnIf m n Class buildClass class_name tvs sc_theta fds ats sig_stuff tc_isrec - = do { tycon_name <- newImplicitBinder class_name mkClassTyConOcc + = do { traceIf (text "buildClass") + ; tycon_name <- newImplicitBinder class_name mkClassTyConOcc ; datacon_name <- newImplicitBinder class_name mkClassDataConOcc -- The class name is the 'parent' for this datacon, not its tycon, -- because one should import the class to get the binding for -- the datacon - ; sc_sel_names <- mapM (newImplicitBinder class_name . mkSuperDictSelOcc) - [1..length sc_theta] - -- We number off the superclass selectors, 1, 2, 3 etc so that we - -- can construct names for the selectors. Thus - -- class (C a, C b) => D a b where ... - -- gives superclass selectors - -- D_sc1, D_sc2 - -- (We used to call them D_C, but now we can have two different - -- superclasses both called C!) ; fixM (\ rec_clas -> do { -- Only name generation inside loop - let { rec_tycon = classTyCon rec_clas - ; op_tys = [ty | (_,_,ty) <- sig_stuff] - ; sc_tys = mkPredTys sc_theta - ; dict_component_tys = sc_tys ++ op_tys - ; sc_sel_ids = [mkDictSelId sc_name rec_clas | sc_name <- sc_sel_names] - ; op_items = [ (mkDictSelId op_name rec_clas, dm_info) - | (op_name, dm_info, _) <- sig_stuff ] } + let { rec_tycon = classTyCon rec_clas + ; op_tys = [ty | (_,_,ty) <- sig_stuff] + ; op_items = [ (mkDictSelId op_name rec_clas, dm_info) + | (op_name, dm_info, _) <- sig_stuff ] } -- Build the selector id and default method id ; dict_con <- buildDataCon datacon_name False -- Not declared infix - (map (const NotMarkedStrict) dict_component_tys) + (map (const NotMarkedStrict) op_tys) [{- No labelled fields -}] tvs [{- no existentials -}] - [{- No equalities -}] [{-No context-}] - dict_component_tys + [{- No GADT equalities -}] sc_theta + op_tys rec_tycon - ; rhs <- case dict_component_tys of - [rep_ty] -> mkNewTyConRhs tycon_name rec_tycon dict_con - other -> return (mkDataTyConRhs [dict_con]) + ; sc_sel_names <- mapM (newImplicitBinder class_name . mkSuperDictSelOcc) + [1..length (dataConDictTheta dict_con)] + -- We number off the Dict superclass selectors, 1, 2, 3 etc so that we + -- can construct names for the selectors. Thus + -- class (C a, C b) => D a b where ... + -- gives superclass selectors + -- D_sc1, D_sc2 + -- (We used to call them D_C, but now we can have two different + -- superclasses both called C!) + ; let sc_sel_ids = [mkDictSelId sc_name rec_clas | sc_name <- sc_sel_names] + + -- Use a newtype if the class constructor has exactly one field: + -- i.e. exactly one operation or superclass taken together + -- Watch out: the sc_theta includes equality predicates, + -- which don't count for this purpose; hence dataConDictTheta + ; rhs <- if ((length $ dataConDictTheta dict_con) + length sig_stuff) == 1 + then mkNewTyConRhs tycon_name rec_tycon dict_con + else return (mkDataTyConRhs [dict_con]) ; let { clas_kind = mkArrowKinds (map tyVarKind tvs) liftedTypeKind @@ -312,10 +343,13 @@ buildClass class_name tvs sc_theta fds ats sig_stuff tc_isrec -- newtype like a synonym, but that will lead to an infinite -- type] ; atTyCons = [tycon | ATyCon tycon <- ats] + + ; result = mkClass class_name tvs fds + sc_theta sc_sel_ids atTyCons + op_items tycon } - ; return (mkClass class_name tvs fds - sc_theta sc_sel_ids atTyCons op_items - tycon) + ; traceIf (text "buildClass" <+> ppr tycon) + ; return result })} \end{code}