X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Fiface%2FBuildTyCl.lhs;h=864cb1950f0ed7e19b82fb4892374dbed8727faa;hb=c8bee21ecc0952200e43ce353e6a660334a6f756;hp=bf71ca843ce8fa5158f27b326197aa2aa42341cb;hpb=bb106f283663e9c16a4c72ec9ca57109ae57a0ed;p=ghc-hetmet.git diff --git a/compiler/iface/BuildTyCl.lhs b/compiler/iface/BuildTyCl.lhs index bf71ca8..864cb19 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 % @@ -12,38 +13,24 @@ module BuildTyCl ( #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(..), - SynTyConRhs(..), newTyConRhs ) -import Type ( mkArrowKinds, liftedTypeKind, typeKind, - tyVarsOfType, tyVarsOfTypes, tyVarsOfPred, - splitTyConApp_maybe, splitAppTy_maybe, - getTyVar_maybe, - mkPredTys, mkTyVarTys, ThetaType, Type, Kind, - TyThing(..), - substTyWith, zipTopTvSubst, substTheta, mkForAllTys, - mkTyConApp, mkTyVarTy ) -import Coercion ( mkNewTypeCoercion ) +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 Outputable -import List ( nub ) +import Data.List \end{code} @@ -67,15 +54,46 @@ 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 <- parentInfo mb_family 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 + } + 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 + } + ------------------------------------------------------ mkAbstractTyConRhs :: AlgTyConRhs @@ -97,21 +115,20 @@ 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 - cocon_maybe - | all_coercions || isRecursiveTyCon tycon - = Just co_tycon - | otherwise - = Nothing - ; return (NewTyCon { data_con = con, - nt_co = cocon_maybe, + ; 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 + -- 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 @@ -120,18 +137,22 @@ mkNewTyConRhs tycon_name tycon con -- 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 @@ -195,7 +216,8 @@ 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 } @@ -280,7 +302,7 @@ buildClass class_name tvs sc_theta fds ats 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 }