X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2Fiface%2FBuildTyCl.lhs;h=333d8084ce4a301144cadb1ddcde85b41ef3c47c;hp=9eda9073dd6e90dde8d9e1f956ec2ffb32ce422f;hb=6777144f7522d8db5935737e12fa451ca3211e6d;hpb=44ba24dc84d271ca9bd5ab5060cb63ed87f585e3 diff --git a/compiler/iface/BuildTyCl.lhs b/compiler/iface/BuildTyCl.lhs index 9eda907..333d808 100644 --- a/compiler/iface/BuildTyCl.lhs +++ b/compiler/iface/BuildTyCl.lhs @@ -1,4 +1,5 @@ % +% (c) The University of Glasgow 2006 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998 % @@ -6,50 +7,57 @@ module BuildTyCl ( buildSynTyCon, buildAlgTyCon, buildDataCon, buildClass, - mkAbstractTyConRhs, mkNewTyConRhs, mkDataTyConRhs + mkAbstractTyConRhs, mkOpenDataTyConRhs, + mkNewTyConRhs, mkDataTyConRhs ) where #include "HsVersions.h" -import IfaceEnv ( newImplicitBinder ) +import IfaceEnv import TcRnMonad -import DataCon ( DataCon, isNullarySrcDataCon, dataConUnivTyVars, - mkDataCon, dataConFieldLabels, dataConInstOrigArgTys, - dataConTyCon ) -import Var ( tyVarKind, TyVar, Id ) -import VarSet ( isEmptyVarSet, intersectVarSet, elemVarSet ) -import TysWiredIn ( unitTy ) -import BasicTypes ( RecFlag, StrictnessMark(..) ) -import Name ( Name ) -import OccName ( mkDataConWrapperOcc, mkDataConWorkerOcc, mkClassTyConOcc, - mkClassDataConOcc, mkSuperDictSelOcc, mkNewTyCoOcc ) -import MkId ( mkDataConIds, mkRecordSelId, mkDictSelId ) -import Class ( mkClass, Class( classTyCon), FunDep, DefMeth(..) ) -import TyCon ( mkSynTyCon, mkAlgTyCon, visibleDataCons, tyConStupidTheta, - tyConDataCons, isNewTyCon, mkClassTyCon, TyCon( tyConTyVars ), - isRecursiveTyCon, tyConArity, - AlgTyConRhs(..), newTyConRhs ) -import Type ( mkArrowKinds, liftedTypeKind, typeKind, - tyVarsOfType, tyVarsOfTypes, tyVarsOfPred, - splitTyConApp_maybe, splitAppTy_maybe, getTyVar_maybe, - mkPredTys, mkTyVarTys, ThetaType, Type, - substTyWith, zipTopTvSubst, substTheta, mkForAllTys, - mkTyConApp, mkTyVarTy ) -import Coercion ( mkNewTypeCoercion ) -import Outputable -import List ( nub ) - +import DataCon +import Var +import VarSet +import TysWiredIn +import BasicTypes +import Name +import OccName +import MkId +import Class +import TyCon +import Type +import Coercion + +import Data.List \end{code} \begin{code} ------------------------------------------------------ -buildSynTyCon name tvs rhs_ty - = mkSynTyCon name kind tvs rhs_ty - 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] @@ -58,20 +66,57 @@ buildAlgTyCon :: Name -> [TyVar] -> RecFlag -> 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 - = do { let { tycon = mkAlgTyCon tc_name kind tvs stupid_theta - rhs fields is_rec want_generics gadt_syn - ; kind = mkArrowKinds (map tyVarKind tvs) liftedTypeKind - ; fields = mkTyConSelIds tycon rhs - } - ; return tycon } - + 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 = mkAlgTyCon tc_name kind tvs stupid_theta rhs + fields parent is_rec want_generics gadt_syn + ; kind = mkArrowKinds (map tyVarKind tvs) liftedTypeKind + ; fields = mkTyConSelIds tycon rhs + } + ; return tycon + }) + ; return 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 = OpenTyCon Nothing + mkDataTyConRhs :: [DataCon] -> AlgTyConRhs mkDataTyConRhs cons = DataTyCon { data_cons = cons, is_enum = all isNullarySrcDataCon cons } @@ -82,32 +127,44 @@ mkNewTyConRhs :: Name -> TyCon -> DataCon -> TcRnIf m n AlgTyConRhs -- 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 tvs rhs_ty - ; return (NewTyCon { data_con = con, - nt_co = Just co_tycon, + ; let co_tycon = mkNewTypeCoercion co_tycon_name tycon etad_tvs etad_rhs + cocon_maybe | all_coercions || isRecursiveTyCon tycon + = Just co_tycon + | otherwise + = Nothing + ; return (NewTyCon { data_con = con, + nt_rhs = rhs_ty, + nt_etad_rhs = (etad_tvs, etad_rhs), + nt_co = cocon_maybe, -- Coreview looks through newtypes with a Nothing -- for nt_co, or uses explicit coercions otherwise - nt_rhs = rhs_ty, - nt_etad_rhs = eta_reduce tvs rhs_ty, nt_rep = mkNewTyConRep tycon rhs_ty }) } where + -- If all_coercions is True then we use coercions for all newtypes + -- otherwise we use coercions for recursive newtypes and look through + -- non-recursive newtypes + all_coercions = True tvs = tyConTyVars tycon rhs_ty = head (dataConInstOrigArgTys con (mkTyVarTys tvs)) -- Instantiate the data con with the -- type variables from the tycon - eta_reduce [] ty = ([], ty) - eta_reduce (a:as) ty | null as', - Just (fun, arg) <- splitAppTy_maybe ty', + etad_tvs :: [TyVar] -- Matched lazily, so that mkNewTypeCoercion can + etad_rhs :: Type -- return a TyCon without pulling on rhs_ty + -- See Note [Tricky iface loop] in LoadIface + (etad_tvs, etad_rhs) = eta_reduce (reverse tvs) rhs_ty + + eta_reduce :: [TyVar] -- Reversed + -> Type -- Rhs type + -> ([TyVar], Type) -- Eta-reduced version (tyvars in normal order) + eta_reduce (a:as) ty | Just (fun, arg) <- splitAppTy_maybe ty, Just tv <- getTyVar_maybe arg, tv == a, not (a `elemVarSet` tyVarsOfType fun) - = ([], fun) -- Successful eta reduction - | otherwise - = (a:as', ty') - where - (as', ty') = eta_reduce as ty + = eta_reduce as fun + eta_reduce tvs ty = (reverse tvs, ty) + mkNewTyConRep :: TyCon -- The original type constructor -> Type -- The arg type of its constructor -> Type -- Chosen representation type @@ -171,7 +228,8 @@ buildDataCon src_name declared_infix arg_stricts field_lbls data_con = mkDataCon src_name declared_infix arg_stricts field_lbls univ_tvs ex_tvs eq_spec ctxt - arg_tys tycon stupid_ctxt dc_ids + arg_tys tycon + stupid_ctxt dc_ids dc_ids = mkDataConIds wrap_name work_name data_con ; returnM data_con } @@ -208,11 +266,12 @@ mkTyConSelIds tycon rhs \begin{code} buildClass :: Name -> [TyVar] -> ThetaType -> [FunDep TyVar] -- Functional dependencies + -> [TyThing] -- Associated types -> [(Name, DefMeth, Type)] -- Method info -> RecFlag -- Info for type constructor -> TcRnIf m n Class -buildClass class_name tvs sc_theta fds sig_stuff tc_isrec +buildClass class_name tvs sc_theta fds ats sig_stuff tc_isrec = do { tycon_name <- newImplicitBinder class_name mkClassTyConOcc ; datacon_name <- newImplicitBinder class_name mkClassDataConOcc -- The class name is the 'parent' for this datacon, not its tycon, @@ -255,17 +314,19 @@ buildClass class_name tvs sc_theta fds sig_stuff tc_isrec ; let { clas_kind = mkArrowKinds (map tyVarKind tvs) liftedTypeKind ; tycon = mkClassTyCon tycon_name clas_kind tvs - rhs rec_clas tc_isrec + rhs rec_clas tc_isrec -- A class can be recursive, and in the case of newtypes -- this matters. For example -- class C a where { op :: C b => a -> b -> Int } -- Because C has only one operation, it is represented by -- a newtype, and it should be a *recursive* newtype. -- [If we don't make it a recursive newtype, we'll expand the - -- newtype like a synonym, but that will lead to an infinite type] + -- newtype like a synonym, but that will lead to an infinite + -- type] + ; atTyCons = [tycon | ATyCon tycon <- ats] } - ; return (mkClass class_name tvs fds - sc_theta sc_sel_ids op_items + ; return (mkClass class_name tvs fds + sc_theta sc_sel_ids atTyCons op_items tycon) })} \end{code}