-- f :: Num a => a -> a
TypeSig (Located name) (LHsType name)
+ -- A type signature for a generic function inside a class
+ -- generic eq :: (Representable0 a, GEq (Rep0 a)) => a -> a -> Bool
+ | GenericSig (Located name) (LHsType name)
+
-- A type signature in generated code, notably the code
-- generated for record selectors. We simply record
-- the desired Id itself, replete with its name, type
okBindSig _ = True
okHsBootSig :: Sig a -> Bool
-okHsBootSig (TypeSig _ _) = True
-okHsBootSig (FixSig _) = True
-okHsBootSig _ = False
+okHsBootSig (TypeSig _ _) = True
+okHsBootSig (GenericSig _ _) = True -- JPM: Is this true?
+okHsBootSig (FixSig _) = True
+okHsBootSig _ = False
okClsDclSig :: Sig a -> Bool
okClsDclSig (SpecInstSig _) = False
okClsDclSig _ = True -- All others OK
okInstDclSig :: Sig a -> Bool
-okInstDclSig (TypeSig _ _) = False
-okInstDclSig (FixSig _) = False
-okInstDclSig _ = True
+okInstDclSig (TypeSig _ _) = False
+okInstDclSig (GenericSig _ _) = False
+okInstDclSig (FixSig _) = False
+okInstDclSig _ = True
- sigForThisGroup :: NameSet -> LSig Name -> Bool
- sigForThisGroup ns sig
- = case sigName sig of
- Nothing -> False
- Just n -> n `elemNameSet` ns
-
sigName :: LSig name -> Maybe name
+ -- Used only in Haddock
sigName (L _ sig) = sigNameNoLoc sig
sigNameNoLoc :: Sig name -> Maybe name
+ -- Used only in Haddock
sigNameNoLoc (TypeSig n _) = Just (unLoc n)
sigNameNoLoc (SpecSig n _ _) = Just (unLoc n)
sigNameNoLoc (InlineSig n _) = Just (unLoc n)
isVanillaLSig _ = False
isTypeLSig :: LSig name -> Bool -- Type signatures
-isTypeLSig (L _(TypeSig {})) = True
-isTypeLSig (L _(IdSig {})) = True
-isTypeLSig _ = False
+isTypeLSig (L _(TypeSig {})) = True
+isTypeLSig (L _(GenericSig {})) = True
+isTypeLSig (L _(IdSig {})) = True
+isTypeLSig _ = False
isSpecLSig :: LSig name -> Bool
isSpecLSig (L _(SpecSig {})) = True
hsSigDoc :: Sig name -> SDoc
hsSigDoc (TypeSig {}) = ptext (sLit "type signature")
+hsSigDoc (GenericSig {}) = ptext (sLit "generic default type signature")
hsSigDoc (IdSig {}) = ptext (sLit "id signature")
hsSigDoc (SpecSig {}) = ptext (sLit "SPECIALISE pragma")
hsSigDoc (InlineSig {}) = ptext (sLit "INLINE pragma")
eqHsSig (L _ (FixSig (FixitySig n1 _))) (L _ (FixSig (FixitySig n2 _))) = unLoc n1 == unLoc n2
eqHsSig (L _ (IdSig n1)) (L _ (IdSig n2)) = n1 == n2
eqHsSig (L _ (TypeSig n1 _)) (L _ (TypeSig n2 _)) = unLoc n1 == unLoc n2
+eqHsSig (L _ (GenericSig n1 _)) (L _ (GenericSig n2 _)) = unLoc n1 == unLoc n2
eqHsSig (L _ (InlineSig n1 _)) (L _ (InlineSig n2 _)) = unLoc n1 == unLoc n2
-- For specialisations, we don't have equality over
-- HsType, so it's not convenient to spot duplicate
ppr_sig :: OutputableBndr name => Sig name -> SDoc
ppr_sig (TypeSig var ty) = pprVarSig (unLoc var) (ppr ty)
+ppr_sig (GenericSig var ty) = ptext (sLit "generic") <+> pprVarSig (unLoc var) (ppr ty)
ppr_sig (IdSig id) = pprVarSig id (ppr (varType id))
ppr_sig (FixSig fix_sig) = ppr fix_sig
ppr_sig (SpecSig var ty inl) = pragBrackets (pprSpec var (ppr ty) inl)
-> RnM (LHsBinds Name, FreeVars)
rnMethodBinds cls sig_fn gen_tyvars binds
- = foldlM do_one (emptyBag,emptyFVs) (bagToList binds)
+ = do { checkDupRdrNames meth_names
+ -- Check that the same method is not given twice in the
+ -- same instance decl instance C T where
+ -- f x = ...
+ -- g y = ...
+ -- f x = ...
+ -- We must use checkDupRdrNames because the Name of the
+ -- method is the Name of the class selector, whose SrcSpan
+ -- points to the class declaration; and we use rnMethodBinds
+ -- for instance decls too
+
+ ; foldlM do_one (emptyBag, emptyFVs) (bagToList binds) }
where
+ meth_names = collectMethodBinders binds
do_one (binds,fvs) bind
= do { (bind', fvs_bind) <- rnMethodBind cls sig_fn gen_tyvars bind
; return (binds `unionBags` bind', fvs_bind `plusFV` fvs) }
-- Check for duplicates on RdrName version,
-- because renamed version has unboundName for
-- not-in-scope binders, which gives bogus dup-sig errors
-
+ -- NB: in a class decl, a 'generic' sig is not considered
+ -- equal to an ordinary sig, so we allow, say
+ -- class C a where
+ -- op :: a -> a
+ -- generic op :: Eq a => a -> a
+
; sigs' <- mapM (wrapLocM (renameSig mb_names)) sigs
; let (good_sigs, bad_sigs) = partition (ok_sig . unLoc) sigs'
; new_ty <- rnHsSigType (quotes (ppr v)) ty
; return (TypeSig new_v new_ty) }
+renameSig mb_names sig@(GenericSig v ty)
+ = do { new_v <- lookupSigOccRn mb_names sig v
+ ; new_ty <- rnHsSigType (quotes (ppr v)) ty
+ ; return (GenericSig new_v new_ty) } -- JPM: ?
+
renameSig _ (SpecInstSig ty)
= do { new_ty <- rnLHsType (text "A SPECIALISE instance pragma") ty
; return (SpecInstSig new_ty) }
-- {-# SPECIALISE #-} pragmas can refer to imported Ids
-- so, in the top-level case (when mb_names is Nothing)
-- we use lookupOccRn. If there's both an imported and a local 'f'
- -- then the SPECIALISE pragma is ambiguous, unlike alll other signatures
+ -- then the SPECIALISE pragma is ambiguous, unlike all other signatures
renameSig mb_names sig@(SpecSig v ty inl)
= do { new_v <- case mb_names of
Just {} -> lookupSigOccRn mb_names sig v
import NameSet
import TyCon
import TcType
+import BuildTyCl
+import BasicTypes
import Var
import VarSet
import PrelNames
import SrcLoc
+import UniqSupply
import Util
import ListSetOps
import Outputable
tcDeriving :: [LTyClDecl Name] -- All type constructors
-> [LInstDecl Name] -- All instance declarations
-> [LDerivDecl Name] -- All stand-alone deriving declarations
- -> TcM ([InstInfo Name], -- The generated "instance decls"
- HsValBinds Name, -- Extra generated top-level bindings
- DefUses)
+ -> TcM ([InstInfo Name] -- The generated "instance decls"
+ ,HsValBinds Name -- Extra generated top-level bindings
+ ,DefUses
+ ,[TyCon] -- Extra generated top-level types
+ ,[TyCon]) -- Extra generated type family instances
tcDeriving tycl_decls inst_decls deriv_decls
- = recoverM (return ([], emptyValBindsOut, emptyDUs)) $
+ = recoverM (return ([], emptyValBindsOut, emptyDUs, [], [])) $
do { -- Fish the "deriving"-related information out of the TcEnv
-- And make the necessary "equations".
is_boot <- tcIsHsBoot
; insts2 <- mapM (genInst False overlap_flag) final_specs
- -- Generate the generic to/from functions from each type declaration
- ; gen_binds <- mkGenericBinds is_boot tycl_decls
- ; (inst_info, rn_binds, rn_dus) <- renameDeriv is_boot gen_binds (insts1 ++ insts2)
+ -- Generate the (old) generic to/from functions from each type declaration
+ ; gen_binds <- return emptyBag -- mkGenericBinds is_boot tycl_decls
+
+ -- Generate the generic Representable0/1 instances from each type declaration
+ ; repInstsMeta <- genGenericRepBinds is_boot tycl_decls
+
+ ; let repInsts = concat (map (\(a,_,_) -> a) repInstsMeta)
+ repMetaTys = map (\(_,b,_) -> b) repInstsMeta
+ repTyCons = map (\(_,_,c) -> c) repInstsMeta
+ -- Should we extendLocalInstEnv with repInsts?
+
+ ; (inst_info, rn_binds, rn_dus) <- renameDeriv is_boot gen_binds (insts1 ++ insts2 ++ repInsts)
+
+ ; dflags <- getDOpts
+ ; liftIO (dumpIfSet_dyn dflags Opt_D_dump_deriv "Derived instances"
+ (ddump_deriving inst_info rn_binds))
; when (not (null inst_info)) $
dumpDerivingInfo (ddump_deriving inst_info rn_binds)
-
- ; return (inst_info, rn_binds, rn_dus) }
+ ; return ( inst_info, rn_binds, rn_dus
+ , concat (map metaTyCons2TyCons repMetaTys), repTyCons) }
where
ddump_deriving :: [InstInfo Name] -> HsValBinds Name -> SDoc
ddump_deriving inst_infos extra_binds
clas_nm = className clas
-----------------------------------------
+{- Now unused
mkGenericBinds :: Bool -> [LTyClDecl Name] -> TcM (LHsBinds RdrName)
mkGenericBinds is_boot tycl_decls
| is_boot
-- We are only interested in the data type declarations,
-- and then only in the ones whose 'has-generics' flag is on
-- The predicate tyConHasGenerics finds both of these
+-}
\end{code}
Note [Newtype deriving and unused constructors]
gen_soln (DS { ds_loc = loc, ds_orig = orig, ds_tvs = tyvars
, ds_cls = clas, ds_tys = inst_tys, ds_theta = deriv_rhs })
= setSrcSpan loc $
- addErrCtxt (derivInstCtxt clas inst_tys) $
+ addErrCtxt (derivInstCtxt the_pred) $
do { -- Check for a bizarre corner case, when the derived instance decl should
-- have form instance C a b => D (T a) where ...
-- Note that 'b' isn't a parameter of T. This gives rise to all sorts
, not (tyVarsOfPred pred `subVarSet` tv_set)]
; mapM_ (addErrTc . badDerivedPred) weird_preds
- ; theta <- simplifyDeriv orig tyvars deriv_rhs
+ ; theta <- simplifyDeriv orig the_pred tyvars deriv_rhs
-- checkValidInstance tyvars theta clas inst_tys
-- Not necessary; see Note [Exotic derived instance contexts]
-- in TcSimplify
-- Hence no need to call:
-- checkValidInstance tyvars theta clas inst_tys
; return (sortLe (<=) theta) } -- Canonicalise before returning the solution
+ where
+ the_pred = mkClassPred clas inst_tys
------------------------------------------------------------------
mkInstance :: OverlapFlag -> ThetaType -> DerivSpec -> Instance
,(foldableClassKey, gen_Foldable_binds)
,(traversableClassKey, gen_Traversable_binds)
]
+
+-- Generate the binds for the generic representation
+genGenericRepBinds :: Bool -> [LTyClDecl Name]
+ -> TcM [([(InstInfo RdrName, DerivAuxBinds)]
+ , MetaTyCons, TyCon)]
+genGenericRepBinds isBoot tyclDecls
+ | isBoot = return []
+ | otherwise = do
+ allTyDecls <- mapM tcLookupTyCon [ tcdName d | L _ d <- tyclDecls
+ , isDataDecl d ]
+ let tyDecls = filter tyConHasGenerics allTyDecls
+ inst1 <- mapM genGenericRepBind tyDecls
+ let (_repInsts, metaTyCons, _repTys) = unzip3 inst1
+ metaInsts <- ASSERT (length tyDecls == length metaTyCons)
+ mapM genDtMeta (zip tyDecls metaTyCons)
+ return (ASSERT (length inst1 == length metaInsts)
+ [ (ri : mi, ms, rt)
+ | ((ri, ms, rt), mi) <- zip inst1 metaInsts ])
+
+genGenericRepBind :: TyCon -> TcM ((InstInfo RdrName, DerivAuxBinds)
+ , MetaTyCons, TyCon)
+genGenericRepBind tc =
+ do clas <- tcLookupClass rep0ClassName
+ uniqS <- newUniqueSupply
+ dfun_name <- new_dfun_name clas tc
+ let
+ -- Uniques for everyone
+ (uniqD:uniqs) = uniqsFromSupply uniqS
+ (uniqsC,us) = splitAt (length tc_cons) uniqs
+ uniqsS :: [[Unique]] -- Unique supply for the S datatypes
+ uniqsS = mkUniqsS tc_arits us
+ mkUniqsS [] _ = []
+ mkUniqsS (n:t) us = case splitAt n us of
+ (us1,us2) -> us1 : mkUniqsS t us2
+
+ tc_name = tyConName tc
+ tc_cons = tyConDataCons tc
+ tc_arits = map dataConSourceArity tc_cons
+
+ tc_occ = nameOccName tc_name
+ d_occ = mkGenD tc_occ
+ c_occ m = mkGenC tc_occ m
+ s_occ m n = mkGenS tc_occ m n
+ mod_name = nameModule (tyConName tc)
+ d_name = mkExternalName uniqD mod_name d_occ wiredInSrcSpan
+ c_names = [ mkExternalName u mod_name (c_occ m) wiredInSrcSpan
+ | (u,m) <- zip uniqsC [0..] ]
+ s_names = [ [ mkExternalName u mod_name (s_occ m n) wiredInSrcSpan
+ | (u,n) <- zip us [0..] ] | (us,m) <- zip uniqsS [0..] ]
+ tvs = tyConTyVars tc
+ tc_ty = mkTyConApp tc (mkTyVarTys tvs)
+
+ mkTyCon name = ASSERT( isExternalName name )
+ buildAlgTyCon name [] [] mkAbstractTyConRhs
+ NonRecursive False False NoParentTyCon Nothing
+
+ metaDTyCon <- mkTyCon d_name
+ metaCTyCons <- sequence [ mkTyCon c_name | c_name <- c_names ]
+ metaSTyCons <- mapM sequence
+ [ [ mkTyCon s_name
+ | s_name <- s_namesC ] | s_namesC <- s_names ]
+
+ let metaDts = MetaTyCons metaDTyCon metaCTyCons metaSTyCons
+
+ rep0_tycon <- tc_mkRep0TyCon tc metaDts
+
+ let
+ mkInstRep0 = (InstInfo { iSpec = inst, iBinds = binds }
+ , [ {- No DerivAuxBinds -} ])
+ inst = mkLocalInstance dfun NoOverlap
+ binds = VanillaInst (mkBindsRep0 tc) [] False
+
+ dfun = mkDictFunId dfun_name (tyConTyVars tc) [] clas [tc_ty]
+ return (mkInstRep0, metaDts, rep0_tycon)
+
+genDtMeta :: (TyCon, MetaTyCons) -> TcM [(InstInfo RdrName, DerivAuxBinds)]
+genDtMeta (tc,metaDts) =
+ do dClas <- tcLookupClass datatypeClassName
+ d_dfun_name <- new_dfun_name dClas tc
+ cClas <- tcLookupClass constructorClassName
+ c_dfun_names <- sequence [ new_dfun_name cClas tc | _ <- metaC metaDts ]
+ sClas <- tcLookupClass selectorClassName
+ s_dfun_names <- sequence (map sequence [ [ new_dfun_name sClas tc
+ | _ <- x ]
+ | x <- metaS metaDts ])
+ fix_env <- getFixityEnv
+
+ let
+ (dBinds,cBinds,sBinds) = mkBindsMetaD fix_env tc
+
+ -- Datatype
+ d_metaTycon = metaD metaDts
+ d_inst = mkLocalInstance d_dfun NoOverlap
+ d_binds = VanillaInst dBinds [] False
+ d_dfun = mkDictFunId d_dfun_name (tyConTyVars tc) [] dClas
+ [ mkTyConTy d_metaTycon ]
+ d_mkInst = (InstInfo { iSpec = d_inst, iBinds = d_binds }, [])
+
+ -- Constructor
+ c_metaTycons = metaC metaDts
+ c_insts = [ mkLocalInstance (c_dfun c ds) NoOverlap
+ | (c, ds) <- myZip1 c_metaTycons c_dfun_names ]
+ c_binds = [ VanillaInst c [] False | c <- cBinds ]
+ c_dfun c dfun_name = mkDictFunId dfun_name (tyConTyVars tc) [] cClas
+ [ mkTyConTy c ]
+ c_mkInst = [ (InstInfo { iSpec = is, iBinds = bs }, [])
+ | (is,bs) <- myZip1 c_insts c_binds ]
+
+ -- Selector
+ s_metaTycons = metaS metaDts
+ s_insts = map (map (\(s,ds) -> mkLocalInstance (s_dfun s ds) NoOverlap))
+ (myZip2 s_metaTycons s_dfun_names)
+ s_binds = [ [ VanillaInst s [] False | s <- ss ] | ss <- sBinds ]
+ s_dfun s dfun_name = mkDictFunId dfun_name (tyConTyVars tc) [] sClas
+ [ mkTyConTy s ]
+ s_mkInst = map (map (\(is,bs) -> (InstInfo {iSpec=is, iBinds=bs}, [])))
+ (myZip2 s_insts s_binds)
+
+ myZip1 :: [a] -> [b] -> [(a,b)]
+ myZip1 l1 l2 = ASSERT (length l1 == length l2) zip l1 l2
+
+ myZip2 :: [[a]] -> [[b]] -> [[(a,b)]]
+ myZip2 l1 l2 =
+ ASSERT (and (zipWith (>=) (map length l1) (map length l2)))
+ [ zip x1 x2 | (x1,x2) <- zip l1 l2 ]
+
+ return (d_mkInst : c_mkInst ++ concat s_mkInst)
\end{code}
standaloneCtxt ty = hang (ptext (sLit "In the stand-alone deriving instance for"))
2 (quotes (ppr ty))
- derivInstCtxt :: Class -> [Type] -> Message
- derivInstCtxt clas inst_tys
- = ptext (sLit "When deriving the instance for") <+> parens (pprClassPred clas inst_tys)
+ derivInstCtxt :: PredType -> Message
+ derivInstCtxt pred
+ = ptext (sLit "When deriving the instance for") <+> parens (ppr pred)
badDerivedPred :: PredType -> Message
badDerivedPred pred
import HscTypes
import PrelInfo
import MkCore ( eRROR_ID )
-import PrelNames
+import PrelNames hiding (error_RDR)
import PrimOp
import SrcLoc
import TyCon
read_nullary_cons
= case nullary_cons of
[] -> []
- [con] -> [nlHsDo DoExpr [bindLex (match_con con)] (result_expr con [])]
+ [con] -> [nlHsDo DoExpr (match_con con) (result_expr con [])]
_ -> [nlHsApp (nlHsVar choose_RDR)
(nlList (map mk_pair nullary_cons))]
-- NB For operators the parens around (:=:) are matched by the
-- enclosing "parens" call, so here we must match the naked
-- data_con_str con
- match_con con | isSym con_str = symbol_pat con_str
- | otherwise = ident_pat con_str
+ match_con con | isSym con_str = [symbol_pat con_str]
+ | otherwise = ident_h_pat con_str
where
con_str = data_con_str con
-- For nullary constructors we must match Ident s for normal constrs
prefix_parser = mk_parser prefix_prec prefix_stmts body
read_prefix_con
- | isSym con_str = [read_punc "(", bindLex (symbol_pat con_str), read_punc ")"]
- | otherwise = [bindLex (ident_pat con_str)]
+ | isSym con_str = [read_punc "(", symbol_pat con_str, read_punc ")"]
+ | otherwise = ident_h_pat con_str
read_infix_con
- | isSym con_str = [bindLex (symbol_pat con_str)]
- | otherwise = [read_punc "`", bindLex (ident_pat con_str), read_punc "`"]
+ | isSym con_str = [symbol_pat con_str]
+ | otherwise = [read_punc "`"] ++ ident_h_pat con_str ++ [read_punc "`"]
prefix_stmts -- T a b c
= read_prefix_con ++ read_args
result_expr con as = nlHsApp (nlHsVar returnM_RDR) (con_app con as) -- return (con as)
punc_pat s = nlConPat punc_RDR [nlLitPat (mkHsString s)] -- Punc 'c'
- ident_pat s = nlConPat ident_RDR [nlLitPat (mkHsString s)] -- Ident "foo"
- symbol_pat s = nlConPat symbol_RDR [nlLitPat (mkHsString s)] -- Symbol ">>"
+
+ -- For constructors and field labels ending in '#', we hackily
+ -- let the lexer generate two tokens, and look for both in sequence
+ -- Thus [Ident "I"; Symbol "#"]. See Trac #5041
+ ident_h_pat s | Just (ss, '#') <- snocView s = [ ident_pat ss, symbol_pat "#" ]
+ | otherwise = [ ident_pat s ]
+
+ ident_pat s = bindLex $ nlConPat ident_RDR [nlLitPat (mkHsString s)] -- Ident "foo" <- lexP
+ symbol_pat s = bindLex $ nlConPat symbol_RDR [nlLitPat (mkHsString s)] -- Symbol ">>" <- lexP
data_con_str con = occNameString (getOccName con)
-- or (#) = 4
-- Note the parens!
read_lbl lbl | isSym lbl_str
- = [read_punc "(",
- bindLex (symbol_pat lbl_str),
- read_punc ")"]
+ = [read_punc "(", symbol_pat lbl_str, read_punc ")"]
| otherwise
- = [bindLex (ident_pat lbl_str)]
+ = ident_h_pat lbl_str
where
lbl_str = occNameString (getOccName lbl)
\end{code}