\begin{code}
-module Generics ( mkTyConGenInfo, mkGenericRhs,
+module Generics ( canDoGenerics, mkGenericBinds,
+ mkGenericRhs,
validGenericInstanceType, validGenericMethodType
) where
-import RnHsSyn ( RenamedHsExpr )
-import HsSyn ( HsExpr(..), Pat(..), mkSimpleMatch, placeHolderType )
-
+import HsSyn
import Type ( Type, isUnLiftedType, tyVarsOfType, tyVarsOfTypes,
- mkTyVarTys, mkForAllTys, mkTyConApp,
- mkFunTy, isTyVarTy, getTyVar_maybe,
- funTyCon
+ isTyVarTy, getTyVar_maybe, funTyCon
)
-import TcType ( tcSplitTyConApp_maybe, tcSplitSigmaTy, tcSplitSigmaTy )
-import DataCon ( DataCon, dataConOrigArgTys, dataConWrapId, isExistentialDataCon )
+import TcType ( tcSplitTyConApp_maybe, tcSplitSigmaTy, tcSplitSigmaTy, isTauTy )
+import DataCon ( DataCon, dataConOrigArgTys, isExistentialDataCon,
+ dataConSourceArity )
-import TyCon ( TyCon, tyConTyVars, tyConDataCons_maybe,
- tyConGenInfo, isNewTyCon, isBoxedTupleTyCon
+import TyCon ( TyCon, tyConName, tyConDataCons,
+ tyConHasGenerics, isBoxedTupleTyCon
)
-import Name ( Name, mkSystemName )
-import CoreSyn ( mkLams, Expr(..), CoreExpr, AltCon(..),
- mkConApp, Alt, mkTyApps, mkVarApps )
-import CoreUtils ( exprArity )
+import Name ( nameModuleName, nameOccName, getSrcLoc )
+import OccName ( mkGenOcc1, mkGenOcc2 )
+import RdrName ( RdrName, getRdrName, mkVarUnqual, mkOrig )
import BasicTypes ( EP(..), Boxity(..) )
import Var ( TyVar )
import VarSet ( varSetElems )
-import Id ( Id, mkGlobalId, idType, idName, mkSysLocal )
-import MkId ( mkReboxingAlt, mkNewTypeBody )
-import TysWiredIn ( genericTyCons,
- genUnitTyCon, genUnitDataCon, plusTyCon, inrDataCon,
- inlDataCon, crossTyCon, crossDataCon
- )
-import IdInfo ( GlobalIdDetails(..), noCafIdInfo, setUnfoldingInfo, setArityInfo )
-import CoreUnfold ( mkTopUnfolding )
-
-import Maybe ( isNothing )
-import SrcLoc ( noSrcLoc )
-import Unique ( Unique, builtinUniques, mkBuiltinUnique )
-import Util ( takeList, dropList )
+import Id ( Id, idType )
+import PrelNames
+
+import SrcLoc ( generatedSrcLoc )
+import Util ( takeList )
import Outputable
import FastString
validGenericInstanceType inst_ty
= case tcSplitTyConApp_maybe inst_ty of
- Just (tycon, tys) -> all isTyVarTy tys && tycon `elem` genericTyCons
+ Just (tycon, tys) -> all isTyVarTy tys && tyConName tycon `elem` genericTyConNames
Nothing -> False
validGenericMethodType :: Type -> Bool
%************************************************************************
\begin{code}
-mkTyConGenInfo :: TyCon -> [Name] -> Maybe (EP Id)
--- mkTyConGenInfo is called twice
--- once from TysWiredIn for Tuples
--- once the typechecker TcTyDecls
--- to generate generic types and conversion functions for all datatypes.
---
--- Must only be called with an algebraic type.
---
--- The two names are the names constructed by the renamer
--- for the fromT and toT conversion functions.
-
-mkTyConGenInfo tycon []
- = Nothing -- This happens when we deal with the interface-file type
- -- decl for a module compiled without -fgenerics
-
-mkTyConGenInfo tycon [from_name, to_name]
- | isNothing maybe_datacons -- Abstractly imported types don't have
- = Nothing -- to/from operations, (and should not need them)
-
- -- If any of the constructor has an unboxed type as argument,
+canDoGenerics :: [DataCon] -> Bool
+-- Called on source-code data types, to see if we should generate
+-- generic functions for them. (This info is recorded in the interface file for
+-- imported data types.)
+
+canDoGenerics data_cons
+ = not (any bad_con data_cons) -- See comment below
+ && not (null data_cons) -- No values of the type
+ where
+ bad_con dc = any bad_arg_type (dataConOrigArgTys dc) || isExistentialDataCon dc
+ -- If any of the constructor has an unboxed type as argument,
-- then we can't build the embedding-projection pair, because
-- it relies on instantiating *polymorphic* sum and product types
-- at the argument types of the constructors
+
-- Nor can we do the job if it's an existential data constructor,
- | or [ any isUnLiftedType (dataConOrigArgTys dc) || isExistentialDataCon dc
- | dc <- datacons ]
- = Nothing
- | null datacons -- There are no constructors;
- = Nothing -- there are no values of this type
+ -- Nor if the args are polymorphic types (I don't think)
+ bad_arg_type ty = isUnLiftedType ty || not (isTauTy ty)
+\end{code}
- | otherwise
- = ASSERT( not (null datacons) ) -- mk_sum_stuff loops if no datacons
- Just (EP { fromEP = mk_id from_name from_ty from_id_info,
- toEP = mk_id to_name to_ty to_id_info })
+%************************************************************************
+%* *
+\subsection{Generating the RHS of a generic default method}
+%* *
+%************************************************************************
+
+\begin{code}
+type US = Int -- Local unique supply, just a plain Int
+type FromAlt = (Pat RdrName, HsExpr RdrName)
+
+mkGenericBinds :: [TyCon] -> MonoBinds RdrName
+mkGenericBinds tcs = andMonoBindList [ mkTyConGenBinds tc
+ | tc <- tcs, tyConHasGenerics tc]
+
+mkTyConGenBinds :: TyCon -> MonoBinds RdrName
+mkTyConGenBinds tycon
+ = FunMonoBind to_RDR False {- Not infix -}
+ [mkSimpleHsAlt pat rhs | (pat,rhs) <- from_alts]
+ loc
+ `AndMonoBinds`
+ FunMonoBind from_RDR False
+ [mkSimpleHsAlt (VarPat to_arg) to_body] loc
where
- mk_id = mkGlobalId (GenericOpId tycon)
-
- maybe_datacons = tyConDataCons_maybe tycon
- Just datacons = maybe_datacons -- [C, D]
-
- tyvars = tyConTyVars tycon -- [a, b, c]
- tycon_ty = mkTyConApp tycon tyvar_tys -- T a b c
- tyvar_tys = mkTyVarTys tyvars
-
- from_id_info = noCafIdInfo `setUnfoldingInfo` mkTopUnfolding from_fn
- `setArityInfo` exprArity from_fn
- to_id_info = noCafIdInfo `setUnfoldingInfo` mkTopUnfolding to_fn
- `setArityInfo` exprArity to_fn
- -- It's important to set the arity info, so that
- -- the calling convention (gotten from arity)
- -- matches reality.
-
- from_ty = mkForAllTys tyvars (mkFunTy tycon_ty rep_ty)
- to_ty = mkForAllTys tyvars (mkFunTy rep_ty tycon_ty)
-
- (from_fn, to_fn, rep_ty)
- | isNewTyCon tycon
- = ( mkLams tyvars $ Lam x $ mkNewTypeBody tycon the_arg_ty (Var x),
- Var (dataConWrapId the_datacon),
- the_arg_ty )
-
- | otherwise
- = ( mkLams tyvars $ Lam x $ Case (Var x) x from_alts,
- mkLams tyvars $ Lam rep_var to_inner,
- idType rep_var )
-
- -- x :: T a b c
- x = mkGenericLocal u1 tycon_ty
- (u1 : uniqs) = builtinUniques
-
- ----------------------
- -- Newtypes only
- [the_datacon] = datacons
- the_arg_ty = head (dataConOrigArgTys the_datacon)
- -- NB: we use the arg type of the data constructor, rather than
- -- the representation type of the newtype; in degnerate (recursive)
- -- cases the rep type might be (), but the arg type is still T:
- -- newtype T = MkT T
-
- ----------------------
- -- Non-newtypes only
+ loc = getSrcLoc tycon
+ datacons = tyConDataCons tycon
+ (from_RDR, to_RDR) = mkGenericNames tycon
+
-- Recurse over the sum first
- -- The "2" is the first free unique
- (from_alts, to_inner, rep_var) = mk_sum_stuff uniqs tyvars datacons
-
-mkTyConGenInfo tycon names = pprPanic "mkTyConGenInfo" (ppr tycon <+> ppr names)
-
+ from_alts :: [FromAlt]
+ (from_alts, to_arg, to_body) = mk_sum_stuff init_us datacons
+ init_us = 1::Int -- Unique supply
----------------------------------------------------
-- Dealing with sums
----------------------------------------------------
-mk_sum_stuff :: [Unique] -- Base for generating unique names
- -> [TyVar] -- Type variables over which the tycon is abstracted
- -> [DataCon] -- The data constructors
- -> ([Alt Id], CoreExpr, Id)
+
+mk_sum_stuff :: US -- Base for generating unique names
+ -> [DataCon] -- The data constructors
+ -> ([FromAlt], -- Alternatives for the T->Trep "from" function
+ RdrName, HsExpr RdrName) -- Arg and body of the Trep->T "to" function
-- For example, given
-- data T = C | D Int Int Int
-- D a b c }} },
-- cd)
-mk_sum_stuff us tyvars [datacon]
- = ([from_alt], to_body_fn app_exp, rep_var)
+mk_sum_stuff us [datacon]
+ = ([from_alt], to_arg, to_body_fn app_exp)
where
- types = dataConOrigArgTys datacon -- Existentials already excluded
- datacon_vars = zipWith mkGenericLocal us types
- us' = dropList types us
-
- app_exp = mkVarApps (Var (dataConWrapId datacon)) (tyvars ++ datacon_vars)
- from_alt = mkReboxingAlt us' datacon datacon_vars from_alt_rhs
- -- We are talking about *user* datacons here; hence
- -- dataConWrapId
- -- mkReboxingAlt
-
- (_,args',_) = from_alt
- us'' = dropList args' us' -- Conservative, but safe
-
- (_, from_alt_rhs, to_body_fn, rep_var) = mk_prod_stuff us'' datacon_vars
-
-mk_sum_stuff (u:us) tyvars datacons
- = (wrap inlDataCon l_from_alts ++ wrap inrDataCon r_from_alts,
- Case (Var rep_var) rep_var [(DataAlt inlDataCon, [l_rep_var], l_to_body),
- (DataAlt inrDataCon, [r_rep_var], r_to_body)],
- rep_var)
+ n_args = dataConSourceArity datacon -- Existentials already excluded
+
+ datacon_vars = map mkGenericLocal [us .. us+n_args-1]
+ us' = us + n_args
+
+ datacon_rdr = getRdrName datacon
+ app_exp = mkHsVarApps datacon_rdr datacon_vars
+ from_alt = (mkConPat datacon_rdr datacon_vars, from_alt_rhs)
+
+ (_, from_alt_rhs, to_arg, to_body_fn) = mk_prod_stuff us' datacon_vars
+
+mk_sum_stuff us datacons
+ = (wrap inlDataCon_RDR l_from_alts ++ wrap inrDataCon_RDR r_from_alts,
+ to_arg,
+ HsCase (HsVar to_arg)
+ [mkSimpleHsAlt (mkConPat inlDataCon_RDR [l_to_arg]) l_to_body,
+ mkSimpleHsAlt (mkConPat inrDataCon_RDR [r_to_arg]) r_to_body]
+ generatedSrcLoc)
where
- (l_datacons, r_datacons) = splitInHalf datacons
- (l_from_alts, l_to_body, l_rep_var) = mk_sum_stuff us tyvars l_datacons
- (r_from_alts, r_to_body, r_rep_var) = mk_sum_stuff us tyvars r_datacons
- rep_tys = [idType l_rep_var, idType r_rep_var]
- rep_ty = mkTyConApp plusTyCon rep_tys
- rep_var = mkGenericLocal u rep_ty
-
- wrap :: DataCon -> [Alt Id] -> [Alt Id]
+ (l_datacons, r_datacons) = splitInHalf datacons
+ (l_from_alts, l_to_arg, l_to_body) = mk_sum_stuff us' l_datacons
+ (r_from_alts, r_to_arg, r_to_body) = mk_sum_stuff us' r_datacons
+
+ to_arg = mkGenericLocal us
+ us' = us+1
+
+ wrap :: RdrName -> [FromAlt] -> [FromAlt]
-- Wrap an application of the Inl or Inr constructor round each alternative
- wrap datacon alts
- = [(dc, args, App datacon_app rhs) | (dc,args,rhs) <- alts]
- where
- datacon_app = mkTyApps (Var (dataConWrapId datacon)) rep_tys
+ wrap dc alts = [(pat, HsApp (HsVar dc) rhs) | (pat,rhs) <- alts]
+
----------------------------------------------------
-- Dealing with products
----------------------------------------------------
-mk_prod_stuff :: [Unique] -- Base for unique names
- -> [Id] -- arg-ids; args of the original user-defined constructor
+mk_prod_stuff :: US -- Base for unique names
+ -> [RdrName] -- arg-ids; args of the original user-defined constructor
-- They are bound enclosing from_rhs
-- Please bind these in the to_body_fn
- -> ([Unique], -- Depleted unique-name supply
- CoreExpr, -- from-rhs: puts together the representation from the arg_ids
- CoreExpr -> CoreExpr, -- to_body_fn: takes apart the representation
- Id) -- The rep-id; please bind this to the representation
+ -> (US, -- Depleted unique-name supply
+ HsExpr RdrName, -- from-rhs: puts together the representation from the arg_ids
+ RdrName, -- to_arg:
+ HsExpr RdrName -> HsExpr RdrName) -- to_body_fn: takes apart the representation
-- For example:
--- mk_prod_stuff [a,b,c] = ( a :*: (b :*: c),
--- \x -> case abc of { a :*: bc ->
--- case bc of { b :*: c ->
--- x,
--- abc )
+-- mk_prod_stuff abc [a,b,c] = ( a :*: (b :*: c),
+-- \x -> case abc of { a :*: bc ->
+-- case bc of { b :*: c ->
+-- x)
--- We need to use different uqiques in the branches
+-- We need to use different uniques in the branches
-- because the returned to_body_fns are nested.
-- Hence the returned unqique-name supply
-mk_prod_stuff (u:us) [] -- Unit case
- = (us,
- Var (dataConWrapId genUnitDataCon),
- \x -> x,
- mkGenericLocal u (mkTyConApp genUnitTyCon []))
+mk_prod_stuff us [] -- Unit case
+ = (us+1,
+ HsVar genUnitDataCon_RDR,
+ mkGenericLocal us,
+ \x -> x)
mk_prod_stuff us [arg_var] -- Singleton case
- = (us, Var arg_var, \x -> x, arg_var)
+ = (us, HsVar arg_var, arg_var, \x -> x)
-mk_prod_stuff (u:us) arg_vars -- Two or more
+mk_prod_stuff us arg_vars -- Two or more
= (us'',
- mkConApp crossDataCon (map Type rep_tys ++ [l_alt_rhs, r_alt_rhs]),
- \x -> Case (Var rep_var) rep_var
- [(DataAlt crossDataCon, [l_rep_var, r_rep_var], l_to_body_fn (r_to_body_fn x))],
- rep_var)
+ HsVar crossDataCon_RDR `HsApp` l_alt_rhs `HsApp` r_alt_rhs,
+ to_arg,
+ \x -> HsCase (HsVar to_arg)
+ [mkSimpleHsAlt (mkConPat crossDataCon_RDR [l_to_arg, r_to_arg])
+ (l_to_body_fn (r_to_body_fn x))] generatedSrcLoc)
where
- (l_arg_vars, r_arg_vars) = splitInHalf arg_vars
- (us', l_alt_rhs, l_to_body_fn, l_rep_var) = mk_prod_stuff us l_arg_vars
- (us'', r_alt_rhs, r_to_body_fn, r_rep_var) = mk_prod_stuff us' r_arg_vars
- rep_var = mkGenericLocal u (mkTyConApp crossTyCon rep_tys)
- rep_tys = [idType l_rep_var, idType r_rep_var]
-\end{code}
+ to_arg = mkGenericLocal us
+ (l_arg_vars, r_arg_vars) = splitInHalf arg_vars
+ (us', l_alt_rhs, l_to_arg, l_to_body_fn) = mk_prod_stuff (us+1) l_arg_vars
+ (us'', r_alt_rhs, r_to_arg, r_to_body_fn) = mk_prod_stuff us' r_arg_vars
-A little utility function
-\begin{code}
splitInHalf :: [a] -> ([a],[a])
splitInHalf list = (left, right)
where
left = take half list
right = drop half list
-mkGenericLocal :: Unique -> Type -> Id
-mkGenericLocal uniq ty = mkSysLocal FSLIT("g") uniq ty
+mkGenericLocal :: US -> RdrName
+mkGenericLocal u = mkVarUnqual (mkFastString ("g" ++ show u))
+
+mkGenericNames tycon
+ = (from_RDR, to_RDR)
+ where
+ tc_name = tyConName tycon
+ tc_occ = nameOccName tc_name
+ tc_mod = nameModuleName tc_name
+ from_RDR = mkOrig tc_mod (mkGenOcc1 tc_occ)
+ to_RDR = mkOrig tc_mod (mkGenOcc2 tc_occ)
\end{code}
%************************************************************************
op = \b. \dict::Ord b. toOp b (op Trep b dict)
\begin{code}
-mkGenericRhs :: Id -> TyVar -> TyCon -> RenamedHsExpr
+mkGenericRhs :: Id -> TyVar -> TyCon -> HsExpr RdrName
mkGenericRhs sel_id tyvar tycon
- = HsApp (toEP bimap) (HsVar (idName sel_id))
+ = HsApp (toEP bimap) (HsVar (getRdrName sel_id))
where
-- Initialising the "Environment" with the from/to functions
-- on the datatype (actually tycon) in question
- Just (EP from to) = tyConGenInfo tycon -- Caller checked this will succeed
- ep = EP (HsVar (idName from)) (HsVar (idName to))
+ (from_RDR, to_RDR) = mkGenericNames tycon
-- Takes out the ForAll and the Class restrictions
-- in front of the type of the method.
-- Now we probably have a tycon in front
-- of us, quite probably a FunTyCon.
+ ep = EP (HsVar from_RDR) (HsVar to_RDR)
bimap = generate_bimap (tyvar, ep, local_tvs) final_ty
-type EPEnv = (TyVar, -- The class type variable
- EP RenamedHsExpr, -- The EP it maps to
- [TyVar] -- Other in-scope tyvars; they have an identity EP
+type EPEnv = (TyVar, -- The class type variable
+ EP (HsExpr RdrName), -- The EP it maps to
+ [TyVar] -- Other in-scope tyvars; they have an identity EP
)
-------------------
generate_bimap :: EPEnv
-> Type
- -> EP RenamedHsExpr
+ -> EP (HsExpr RdrName)
-- Top level case - splitting the TyCon.
generate_bimap env@(tv,ep,local_tvs) ty
= case getTyVar_maybe ty of
Nothing -> bimapApp env (tcSplitTyConApp_maybe ty)
-------------------
-bimapApp :: EPEnv -> Maybe (TyCon, [Type]) -> EP RenamedHsExpr
+bimapApp :: EPEnv -> Maybe (TyCon, [Type]) -> EP (HsExpr RdrName)
bimapApp env Nothing = panic "TcClassDecl: Type Application!"
bimapApp env (Just (tycon, ty_args))
| tycon == funTyCon = bimapArrow arg_eps
-------------------
-- bimapArrow :: [EP a a', EP b b'] -> EP (a->b) (a'->b')
bimapArrow [ep1, ep2]
- = EP { fromEP = mk_hs_lam [VarPat g1, VarPat g2] from_body,
- toEP = mk_hs_lam [VarPat g1, VarPat g2] to_body }
+ = EP { fromEP = mk_hs_lam [VarPat a_RDR, VarPat b_RDR] from_body,
+ toEP = mk_hs_lam [VarPat a_RDR, VarPat b_RDR] to_body }
where
- from_body = fromEP ep2 `HsApp` (HsPar $ HsVar g1 `HsApp` (HsPar $ toEP ep1 `HsApp` HsVar g2))
- to_body = toEP ep2 `HsApp` (HsPar $ HsVar g1 `HsApp` (HsPar $ fromEP ep1 `HsApp` HsVar g2))
+ from_body = fromEP ep2 `HsApp` (HsPar $ HsVar a_RDR `HsApp` (HsPar $ toEP ep1 `HsApp` HsVar b_RDR))
+ to_body = toEP ep2 `HsApp` (HsPar $ HsVar a_RDR `HsApp` (HsPar $ fromEP ep1 `HsApp` HsVar b_RDR))
-------------------
bimapTuple eps
= EP { fromEP = mk_hs_lam [tuple_pat] from_body,
toEP = mk_hs_lam [tuple_pat] to_body }
where
- names = takeList eps genericNames
+ names = takeList eps gs_RDR
tuple_pat = TuplePat (map VarPat names) Boxed
eps_w_names = eps `zip` names
to_body = ExplicitTuple [toEP ep `HsApp` HsVar g | (ep,g) <- eps_w_names] Boxed
from_body = ExplicitTuple [fromEP ep `HsApp` HsVar g | (ep,g) <- eps_w_names] Boxed
-------------------
-genericNames :: [Name]
-genericNames = [mkSystemName (mkBuiltinUnique i) (mkFastString ('g' : show i)) | i <- [1..]]
-(g1:g2:g3:_) = genericNames
+a_RDR = mkVarUnqual FSLIT("a")
+b_RDR = mkVarUnqual FSLIT("b")
+gs_RDR = [ mkVarUnqual (mkFastString ("g"++show i)) | i <- [(1::Int) .. ] ]
-mk_hs_lam pats body = HsPar (HsLam (mkSimpleMatch pats body placeHolderType noSrcLoc))
+mk_hs_lam pats body = HsPar (HsLam (mkSimpleMatch pats body placeHolderType generatedSrcLoc))
-idEP :: EP RenamedHsExpr
+idEP :: EP (HsExpr RdrName)
idEP = EP idexpr idexpr
where
- idexpr = mk_hs_lam [VarPat g3] (HsVar g3)
+ idexpr = mk_hs_lam [VarPat a_RDR] (HsVar a_RDR)
\end{code}
projects / ghc-hetmet.git / blobdiff