DeprecDecl(..), LDeprecDecl,
HsGroup(..), emptyRdrGroup, emptyRnGroup, appendGroups,
tcdName, tyClDeclNames, tyClDeclTyVars,
- isClassDecl, isSynDecl, isDataDecl,
+ isClassDecl, isTFunDecl, isSynDecl, isTEqnDecl, isDataDecl,
countTyClDecls,
conDetailsTys,
instDeclATs,
-- are non-empty for the newtype-deriving case
}
+ | TyFunction {tcdLName :: Located name, -- type constructor
+ tcdTyVars :: [LHsTyVarBndr name], -- type variables
+ tcdIso :: Bool, -- injective type?
+ tcdKindSig:: Maybe Kind -- result kind
+ }
+
| TySynonym { tcdLName :: Located name, -- type constructor
tcdTyVars :: [LHsTyVarBndr name], -- type variables
+ tcdTyPats :: Maybe [LHsType name], -- Type patterns
tcdSynRhs :: LHsType name -- synonym expansion
}
Simple classifiers
\begin{code}
-isDataDecl, isSynDecl, isClassDecl :: TyClDecl name -> Bool
+isTFunDecl, isDataDecl, isSynDecl, isTEqnDecl, isClassDecl ::
+ TyClDecl name -> Bool
+
+-- type function kind signature
+isTFunDecl (TyFunction {}) = True
+isTFunDecl other = False
+
+-- vanilla Haskell type synonym
+isSynDecl (TySynonym {tcdTyPats = Nothing}) = True
+isSynDecl other = False
-isSynDecl (TySynonym {}) = True
-isSynDecl other = False
+-- type equation (of a type function)
+isTEqnDecl (TySynonym {tcdTyPats = Just _}) = True
+isTEqnDecl other = False
isDataDecl (TyData {}) = True
isDataDecl other = False
-- For record fields, the first one counts as the SrcLoc
-- We use the equality to filter out duplicate field names
-tyClDeclNames (TySynonym {tcdLName = name}) = [name]
-tyClDeclNames (ForeignType {tcdLName = name}) = [name]
+tyClDeclNames (TyFunction {tcdLName = name}) = [name]
+tyClDeclNames (TySynonym {tcdLName = name,
+ tcdTyPats= Nothing}) = [name]
+tyClDeclNames (TySynonym {} ) = [] -- type equation
+tyClDeclNames (ForeignType {tcdLName = name}) = [name]
tyClDeclNames (ClassDecl {tcdLName = cls_name, tcdSigs = sigs, tcdATs = ats})
= cls_name :
tyClDeclNames (TyData {tcdLName = tc_name, tcdCons = cons})
= tc_name : conDeclsNames (map unLoc cons)
-tyClDeclTyVars (TySynonym {tcdTyVars = tvs}) = tvs
-tyClDeclTyVars (TyData {tcdTyVars = tvs}) = tvs
-tyClDeclTyVars (ClassDecl {tcdTyVars = tvs}) = tvs
-tyClDeclTyVars (ForeignType {}) = []
+tyClDeclTyVars (TyFunction {tcdTyVars = tvs}) = tvs
+tyClDeclTyVars (TySynonym {tcdTyVars = tvs}) = tvs
+tyClDeclTyVars (TyData {tcdTyVars = tvs}) = tvs
+tyClDeclTyVars (ClassDecl {tcdTyVars = tvs}) = tvs
+tyClDeclTyVars (ForeignType {}) = []
\end{code}
\begin{code}
-countTyClDecls :: [TyClDecl name] -> (Int, Int, Int, Int)
- -- class, data, newtype, synonym decls
+countTyClDecls :: [TyClDecl name] -> (Int, Int, Int, Int, Int, Int)
+ -- class, synonym decls, type function signatures,
+ -- type function equations, data, newtype
countTyClDecls decls
= (count isClassDecl decls,
count isSynDecl decls,
+ count isTFunDecl decls,
+ count isTEqnDecl decls,
count isDataTy decls,
count isNewTy decls)
where
ppr (ForeignType {tcdLName = ltycon})
= hsep [ptext SLIT("foreign import type dotnet"), ppr ltycon]
- ppr (TySynonym {tcdLName = ltycon, tcdTyVars = tyvars, tcdSynRhs = mono_ty})
- = hang (ptext SLIT("type") <+> pp_decl_head [] ltycon tyvars Nothing <+> equals)
+ ppr (TyFunction {tcdLName = ltycon, tcdTyVars = tyvars, tcdIso = iso,
+ tcdKindSig = mb_sig})
+ = typeMaybeIso <+> pp_decl_head [] ltycon tyvars Nothing <+>
+ ppr_sig mb_sig
+ where
+ typeMaybeIso = if iso
+ then ptext SLIT("type iso")
+ else ptext SLIT("type")
+
+ ppr_sig Nothing = empty
+ ppr_sig (Just kind) = dcolon <+> pprKind kind
+
+ ppr (TySynonym {tcdLName = ltycon, tcdTyVars = tyvars, tcdTyPats = typats,
+ tcdSynRhs = mono_ty})
+ = hang (ptext SLIT("type") <+> pp_decl_head [] ltycon tyvars typats <+>
+ equals)
4 (ppr mono_ty)
ppr (TyData {tcdND = new_or_data, tcdCtxt = context, tcdLName = ltycon,
("FixityDecls ", fixity_sigs),
("DefaultDecls ", default_ds),
("TypeDecls ", type_ds),
+ ("TypeFunDecls ", type_fun_ds),
+ ("TypeEquations ", type_equs),
("DataDecls ", data_ds),
("NewTypeDecls ", newt_ds),
("DataConstrs ", data_constrs),
-- in class decls. ToDo
tycl_decls = [d | TyClD d <- decls]
- (class_ds, type_ds, data_ds, newt_ds) = countTyClDecls tycl_decls
+ (class_ds, type_ds, type_fun_ds, type_equs, data_ds, newt_ds) =
+ countTyClDecls tycl_decls
inst_decls = [d | InstD d <- decls]
inst_ds = length inst_decls
| ITccallconv
| ITdotnet
| ITmdo
+ | ITiso
-- Pragmas
| ITinline_prag Bool -- True <=> INLINE, False <=> NOINLINE
isSpecial ITccallconv = True
isSpecial ITstdcallconv = True
isSpecial ITmdo = True
+isSpecial ITiso = True
isSpecial _ = False
-- the bitmap provided as the third component indicates whether the
( "forall", ITforall, bit tvBit),
( "mdo", ITmdo, bit glaExtsBit),
+ ( "iso", ITiso, bit glaExtsBit),
( "foreign", ITforeign, bit ffiBit),
( "export", ITexport, bit ffiBit),
They each add a SrcSpan to their argument.
L0 adds 'noSrcSpan', used for empty productions
+ -- This doesn't seem to work anymore -=chak
L1 for a production with a single token on the lhs. Grabs the SrcSpan
from that token.
'where' { L _ ITwhere }
'_scc_' { L _ ITscc } -- ToDo: remove
- 'forall' { L _ ITforall } -- GHC extension keywords
+ 'forall' { L _ ITforall } -- GHC extension keywords
'foreign' { L _ ITforeign }
'export' { L _ ITexport }
'label' { L _ ITlabel }
'threadsafe' { L _ ITthreadsafe }
'unsafe' { L _ ITunsafe }
'mdo' { L _ ITmdo }
+ 'iso' { L _ ITiso }
'stdcall' { L _ ITstdcallconv }
'ccall' { L _ ITccallconv }
'dotnet' { L _ ITdotnet }
{% do { let { (binds, sigs, ats) =
cvBindsAndSigs (unLoc $4)
; (ctxt, tc, tvs, Just tparms) = unLoc $2}
- ; checkTyVars tparms
+ ; checkTyVars tparms False -- only type vars allowed
; return $ L (comb4 $1 $2 $3 $4)
(mkClassDecl (ctxt, tc, tvs)
(unLoc $3) sigs binds ats) } }
-- Type declarations
--
ty_decl :: { LTyClDecl RdrName }
- : 'type' type '=' ctype
- -- Note type on the left of the '='; this allows
- -- infix type constructors to be declared
+ -- type function signature and equations (w/ type synonyms as special
+ -- case); we need to handle all this in one rule to avoid a large
+ -- number of shift/reduce conflicts (due to the generality of `type')
+ : 'type' opt_iso type kind_or_ctype
+ --
+ -- Note the use of type for the head; this allows
+ -- infix type constructors to be declared and type
+ -- patterns for type function equations
--
- -- Note ctype, not sigtype, on the right
- -- We allow an explicit for-all but we don't insert one
- -- in type Foo a = (b,b)
- -- Instead we just say b is out of scope
- {% do { (tc,tvs) <- checkSynHdr $2
- ; return (LL (TySynonym tc tvs $4)) } }
-
+ -- We have that `typats :: Maybe [LHsType name]' is `Nothing'
+ -- (in the second case alternative) when all arguments are
+ -- variables (and we thus have a vanilla type synonym
+ -- declaration); otherwise, it contains all arguments as type
+ -- patterns.
+ --
+ {% case $4 of
+ Left kind ->
+ do { (tc, tvs, _) <- checkSynHdr $3 False
+ ; return (L (comb3 $1 $3 kind)
+ (TyFunction tc tvs $2 (unLoc kind)))
+ }
+ Right ty ->
+ do { (tc, tvs, typats) <- checkSynHdr $3 True
+ ; return (L (comb2 $1 ty)
+ (TySynonym tc tvs typats ty)) }
+ }
+
+ -- data type or newtype declaration
| data_or_newtype tycl_hdr constrs deriving
{ L (comb4 $1 $2 $3 $4) -- We need the location on tycl_hdr
- -- in case constrs and deriving are both empty
- (mkTyData (unLoc $1) (unLoc $2) Nothing (reverse (unLoc $3)) (unLoc $4)) }
+ -- in case constrs and deriving are
+ -- both empty
+ (mkTyData (unLoc $1) (unLoc $2) Nothing
+ (reverse (unLoc $3)) (unLoc $4)) }
+ -- GADT declaration
| data_or_newtype tycl_hdr opt_kind_sig
'where' gadt_constrlist
deriving
{ L (comb4 $1 $2 $4 $5)
- (mkTyData (unLoc $1) (unLoc $2) $3 (reverse (unLoc $5)) (unLoc $6)) }
+ (mkTyData (unLoc $1) (unLoc $2) $3
+ (reverse (unLoc $5)) (unLoc $6)) }
+
+opt_iso :: { Bool }
+ : { False }
+ | 'iso' { True }
+
+kind_or_ctype :: { Either (Located (Maybe Kind)) (LHsType RdrName) }
+ : { Left (noLoc Nothing) }
+ | '::' kind { Left (LL (Just (unLoc $2))) }
+ | '=' ctype { Right (LL (unLoc $2)) }
+ -- Note ctype, not sigtype, on the right of '='
+ -- We allow an explicit for-all but we don't insert one
+ -- in type Foo a = (b,b)
+ -- Instead we just say b is out of scope
data_or_newtype :: { Located NewOrData }
: 'data' { L1 DataType }
opt_kind_sig :: { Maybe Kind }
: { Nothing }
- | '::' kind { Just $2 }
+ | '::' kind { Just (unLoc $2) }
-- tycl_hdr parses the header of a type decl,
-- which takes the form
| '[' ctype ']' { LL $ HsListTy $2 }
| '[:' ctype ':]' { LL $ HsPArrTy $2 }
| '(' ctype ')' { LL $ HsParTy $2 }
- | '(' ctype '::' kind ')' { LL $ HsKindSig $2 $4 }
+ | '(' ctype '::' kind ')' { LL $ HsKindSig $2 (unLoc $4) }
-- Generics
| INTEGER { L1 (HsNumTy (getINTEGER $1)) }
tv_bndr :: { LHsTyVarBndr RdrName }
: tyvar { L1 (UserTyVar (unLoc $1)) }
- | '(' tyvar '::' kind ')' { LL (KindedTyVar (unLoc $2) $4) }
+ | '(' tyvar '::' kind ')' { LL (KindedTyVar (unLoc $2)
+ (unLoc $4)) }
fds :: { Located [Located ([RdrName], [RdrName])] }
: {- empty -} { noLoc [] }
-----------------------------------------------------------------------------
-- Kinds
-kind :: { Kind }
+kind :: { Located Kind }
: akind { $1 }
- | akind '->' kind { mkArrowKind $1 $3 }
+ | akind '->' kind { LL (mkArrowKind (unLoc $1) (unLoc $3)) }
-akind :: { Kind }
- : '*' { liftedTypeKind }
- | '!' { unliftedTypeKind }
- | '(' kind ')' { $2 }
+akind :: { Located Kind }
+ : '*' { L1 liftedTypeKind }
+ | '!' { L1 unliftedTypeKind }
+ | '(' kind ')' { LL (unLoc $2) }
-----------------------------------------------------------------------------
checkContext, -- HsType -> P HsContext
checkPred, -- HsType -> P HsPred
checkTyClHdr, -- LHsContext RdrName -> LHsType RdrName -> P (LHsContext RdrName, Located RdrName, [LHsTyVarBndr RdrName])
- checkTyVars, -- [LHsType RdrName] -> P ()
- checkSynHdr, -- LHsType RdrName -> P (Located RdrName, [LHsTyVarBndr RdrName])
+ checkTyVars, -- [LHsType RdrName] -> Bool -> P ()
+ checkSynHdr, -- LHsType RdrName -> P (Located RdrName, [LHsTyVarBndr RdrName], Maybe [LHsType RdrName])
checkTopTyClD, -- LTyClDecl RdrName -> P (HsDecl RdrName)
checkInstType, -- HsType -> P HsType
checkPattern, -- HsExp -> P HsPat
ty -> do dict_ty <- checkDictTy (L l ty)
return (L l (HsForAllTy Implicit [] (noLoc []) dict_ty))
--- Check that the given list of type parameters are all type variables
--- (possibly with a kind signature).
+-- Check whether the given list of type parameters are all type variables
+-- (possibly with a kind signature). If the second argument is `False', we
+-- only type variables are allowed and we raise an error on encountering a
+-- non-variable; otherwise, we return the entire list parameters iff at least
+-- one is not a variable.
--
-checkTyVars :: [LHsType RdrName] -> P ()
-checkTyVars tvs = mapM_ chk tvs
+checkTyVars :: [LHsType RdrName] -> Bool -> P (Maybe [LHsType RdrName])
+checkTyVars tparms nonVarsOk =
+ do
+ areVars <- mapM chk tparms
+ return $ if and areVars then Nothing else Just tparms
where
-- Check that the name space is correct!
chk (L l (HsKindSig (L _ (HsTyVar tv)) k))
- | isRdrTyVar tv = return ()
+ | isRdrTyVar tv = return True
chk (L l (HsTyVar tv))
- | isRdrTyVar tv = return ()
+ | isRdrTyVar tv = return True
chk (L l other)
- = parseError l "Type found where type variable expected"
-
-checkSynHdr :: LHsType RdrName -> P (Located RdrName, [LHsTyVarBndr RdrName])
-checkSynHdr ty = do { (_, tc, tvs, Just tparms) <- checkTyClHdr (noLoc []) ty
- ; checkTyVars tparms
- ; return (tc, tvs) }
+ | nonVarsOk = return False
+ | otherwise =
+ parseError l "Type found where type variable expected"
+-- Check whether the type arguments in a type synonym head are simply
+-- variables. If not, we have a type equation of a type function and return
+-- all patterns.
+--
+checkSynHdr :: LHsType RdrName
+ -> Bool -- non-variables admitted?
+ -> P (Located RdrName, -- head symbol
+ [LHsTyVarBndr RdrName], -- parameters
+ Maybe [LHsType RdrName]) -- type patterns
+checkSynHdr ty nonVarsOk =
+ do { (_, tc, tvs, Just tparms) <- checkTyClHdr (noLoc []) ty
+ ; typats <- checkTyVars tparms nonVarsOk
+ ; return (tc, tvs, typats) }
+
+
+-- Well-formedness check and decomposition of type and class heads.
+--
checkTyClHdr :: LHsContext RdrName -> LHsType RdrName
-> P (LHsContext RdrName, -- the type context
Located RdrName, -- the head symbol (type or class name)
checkTopTyClD :: LTyClDecl RdrName -> P (HsDecl RdrName)
checkTopTyClD (L _ d@TyData {tcdTyPats = Just typats}) =
do
- checkTyVars typats
+ checkTyVars typats False
return $ TyClD d {tcdTyPats = Nothing}
checkTopTyClD (L _ d) = return $ TyClD d
projects / ghc-hetmet.git / commitdiff