\begin{code}
module HsTypes (
- HsType(..), HsTyVarBndr(..),
+ HsType(..), HsTyVarBndr(..), HsTyOp(..),
, HsContext, HsPred(..)
, HsTupCon(..), hsTupParens, mkHsTupCon,
- , hsUsOnce, hsUsMany
, mkHsForAllTy, mkHsDictTy, mkHsIParamTy
- , hsTyVarName, hsTyVarNames, replaceTyVarName,
+ , hsTyVarName, hsTyVarNames, replaceTyVarName
+ , splitHsInstDeclTy
-- Type place holder
- PostTcType, placeHolderType,
+ , PostTcType, placeHolderType,
+
+ -- Name place holder
+ , SyntaxName, placeHolderName,
-- Printing
- , pprParendHsType, pprHsForAll, pprHsContext, pprHsTyVarBndr
+ , pprParendHsType, pprHsForAll, pprHsContext, ppr_hs_context, pprHsTyVarBndr
-- Equality over Hs things
, EqHsEnv, emptyEqHsEnv, extendEqHsEnv,
import TypeRep ( Type(..), TyNote(..) ) -- toHsType sees the representation
import TyCon ( isTupleTyCon, tupleTyConBoxity, tyConArity, isNewTyCon, getSynTyConDefn )
import RdrName ( RdrName, mkUnqual )
-import Name ( Name, getName )
-import OccName ( NameSpace, tvName )
+import Name ( Name, getName, mkInternalName )
+import OccName ( NameSpace, mkVarOcc, tvName )
import Var ( TyVar, tyVarKind )
import Subst ( substTyWith )
-import PprType ( {- instance Outputable Kind -}, pprParendKind )
-import BasicTypes ( Boxity(..), Arity, tupleParens )
-import PrelNames ( mkTupConRdrName, listTyConKey, usOnceTyConKey, usManyTyConKey, hasKey,
- usOnceTyConName, usManyTyConName
- )
+import PprType ( {- instance Outputable Kind -}, pprParendKind, pprKind )
+import BasicTypes ( Boxity(..), Arity, IPName, tupleParens )
+import PrelNames ( listTyConKey, parrTyConKey,
+ hasKey, unboundKey )
+import SrcLoc ( noSrcLoc )
+import Util ( eqListBy, lengthIs )
import FiniteMap
-import Util ( eqListBy )
import Outputable
\end{code}
placeHolderType :: PostTcType -- Used before typechecking
placeHolderType = panic "Evaluated the place holder for a PostTcType"
+
+
+type SyntaxName = Name -- These names are filled in by the renamer
+ -- Before then they are a placeHolderName (so that
+ -- we can still print the HsSyn)
+ -- They correspond to "rebindable syntax";
+ -- See RnEnv.lookupSyntaxName
+
+placeHolderName :: SyntaxName
+placeHolderName = mkInternalName unboundKey
+ (mkVarOcc FSLIT("syntaxPlaceHolder"))
+ noSrcLoc
\end{code}
type HsContext name = [HsPred name]
data HsPred name = HsClassP name [HsType name]
- | HsIParam name (HsType name)
+ | HsIParam (IPName name) (HsType name)
data HsType name
= HsForAllTy (Maybe [HsTyVarBndr name]) -- Nothing for implicitly quantified signatures
| HsAppTy (HsType name)
(HsType name)
- | HsFunTy (HsType name) -- function type
+ | HsFunTy (HsType name) -- function type
(HsType name)
| HsListTy (HsType name) -- Element type
- | HsTupleTy (HsTupCon name)
+ | HsPArrTy (HsType name) -- Elem. type of parallel array: [:t:]
+
+ | HsTupleTy HsTupCon
[HsType name] -- Element types (length gives arity)
- -- Generics
- | HsOpTy (HsType name) name (HsType name)
- | HsNumTy Integer
+
+ | HsOpTy (HsType name) (HsTyOp name) (HsType name)
+
+ | HsParTy (HsType name)
+ -- Parenthesis preserved for the precedence re-arrangement in RnTypes
+ -- It's important that a * (b + c) doesn't get rearranged to (a*b) + c!
+ --
+ -- However, NB that toHsType doesn't add HsParTys (in an effort to keep
+ -- interface files smaller), so when printing a HsType we may need to
+ -- add parens.
+
+ | HsNumTy Integer -- Generics only
-- these next two are only used in interfaces
| HsPredTy (HsPred name)
-
- | HsUsageTy (HsType name) -- Usage annotation
- (HsType name) -- Annotated type
+ | HsKindSig (HsType name) -- (ty :: kind)
+ Kind -- A type with a kind signature
------------------------
-hsUsOnce, hsUsMany :: HsType RdrName
-hsUsOnce = HsTyVar (mkUnqual tvName SLIT(".")) -- deep magic
-hsUsMany = HsTyVar (mkUnqual tvName SLIT("!")) -- deep magic
-hsUsOnce_Name, hsUsMany_Name :: HsType Name
-hsUsOnce_Name = HsTyVar usOnceTyConName
-hsUsMany_Name = HsTyVar usManyTyConName
+data HsTyOp name = HsArrow | HsTyOp name
+ -- Function arrows from *source* get read in as HsOpTy t1 HsArrow t2
+ -- But when we generate or parse interface files, we use HsFunTy.
+ -- This keeps interfaces a bit smaller, because there are a lot of arrows
-----------------------
-data HsTupCon name = HsTupCon name Boxity Arity
+data HsTupCon = HsTupCon Boxity Arity
-instance Eq name => Eq (HsTupCon name) where
- (HsTupCon _ b1 a1) == (HsTupCon _ b2 a2) = b1==b2 && a1==a2
+instance Eq HsTupCon where
+ (HsTupCon b1 a1) == (HsTupCon b2 a2) = b1==b2 && a1==a2
-mkHsTupCon :: NameSpace -> Boxity -> [a] -> HsTupCon RdrName
-mkHsTupCon space boxity args = HsTupCon (mkTupConRdrName space boxity arity) boxity arity
- where
- arity = length args
+mkHsTupCon :: NameSpace -> Boxity -> [a] -> HsTupCon
+mkHsTupCon space boxity args = HsTupCon boxity (length args)
-hsTupParens :: HsTupCon name -> SDoc -> SDoc
-hsTupParens (HsTupCon _ b _) p = tupleParens b p
+hsTupParens :: HsTupCon -> SDoc -> SDoc
+hsTupParens (HsTupCon b _) p = tupleParens b p
-----------------------
-- Combine adjacent for-alls.
--
-- A valid type must have one for-all at the top of the type, or of the fn arg types
-mkHsForAllTy (Just []) [] ty = ty -- Explicit for-all with no tyvars
-mkHsForAllTy mtvs1 [] (HsForAllTy mtvs2 ctxt ty) = mkHsForAllTy (mtvs1 `plus` mtvs2) ctxt ty
- where
- mtvs1 `plus` Nothing = mtvs1
- Nothing `plus` mtvs2 = mtvs2
- (Just tvs1) `plus` (Just tvs2) = Just (tvs1 ++ tvs2)
-mkHsForAllTy tvs ctxt ty = HsForAllTy tvs ctxt ty
+mkHsForAllTy mtvs [] ty = mk_forall_ty mtvs ty
+mkHsForAllTy mtvs ctxt ty = HsForAllTy mtvs ctxt ty
+
+-- mk_forall_ty makes a pure for-all type (no context)
+mk_forall_ty (Just []) ty = ty -- Explicit for-all with no tyvars
+mk_forall_ty mtvs1 (HsParTy ty) = mk_forall_ty mtvs1 ty
+mk_forall_ty mtvs1 (HsForAllTy mtvs2 ctxt ty) = mkHsForAllTy (mtvs1 `plus` mtvs2) ctxt ty
+mk_forall_ty mtvs1 ty = HsForAllTy mtvs1 [] ty
+
+mtvs1 `plus` Nothing = mtvs1
+Nothing `plus` mtvs2 = mtvs2
+(Just tvs1) `plus` (Just tvs2) = Just (tvs1 ++ tvs2)
mkHsDictTy cls tys = HsPredTy (HsClassP cls tys)
mkHsIParamTy v ty = HsPredTy (HsIParam v ty)
\end{code}
+\begin{code}
+splitHsInstDeclTy
+ :: Outputable name
+ => HsType name
+ -> ([HsTyVarBndr name], HsContext name, name, [HsType name])
+ -- Split up an instance decl type, returning the pieces
+
+-- In interface files, the instance declaration head is created
+-- by HsTypes.toHsType, which does not guarantee to produce a
+-- HsForAllTy. For example, if we had the weird decl
+-- instance Foo T => Foo [T]
+-- then we'd get the instance type
+-- Foo T -> Foo [T]
+-- So when colleting the instance context, to be on the safe side
+-- we gather predicate arguments
+--
+-- For source code, the parser ensures the type will have the right shape.
+-- (e.g. see ParseUtil.checkInstType)
+
+splitHsInstDeclTy inst_ty
+ = case inst_ty of
+ HsForAllTy (Just tvs) cxt1 tau
+ -> (tvs, cxt1++cxt2, cls, tys)
+ where
+ (cxt2, cls, tys) = split_tau tau
+
+ other -> ([], cxt2, cls, tys)
+ where
+ (cxt2, cls, tys) = split_tau inst_ty
+
+ where
+ split_tau (HsFunTy (HsPredTy p) ty) = (p:ps, cls, tys)
+ where
+ (ps, cls, tys) = split_tau ty
+ split_tau (HsPredTy (HsClassP cls tys)) = ([], cls,tys)
+ split_tau other = pprPanic "splitHsInstDeclTy" (ppr inst_ty)
+\end{code}
+
+
%************************************************************************
%* *
\subsection{Pretty printing}
instance (Outputable name) => Outputable (HsType name) where
ppr ty = pprHsType ty
+instance (Outputable name) => Outputable (HsTyOp name) where
+ ppr HsArrow = ftext FSLIT("->")
+ ppr (HsTyOp n) = ppr n
+
instance (Outputable name) => Outputable (HsTyVarBndr name) where
ppr (UserTyVar name) = ppr name
ppr (IfaceTyVar name kind) = pprHsTyVarBndr name kind
instance Outputable name => Outputable (HsPred name) where
ppr (HsClassP clas tys) = ppr clas <+> hsep (map pprParendHsType tys)
- ppr (HsIParam n ty) = hsep [char '?' <> ppr n, text "::", ppr ty]
+ ppr (HsIParam n ty) = hsep [ppr n, dcolon, ppr ty]
pprHsTyVarBndr :: Outputable name => name -> Kind -> SDoc
pprHsTyVarBndr name kind | kind `eqKind` liftedTypeKind = ppr name
ptext SLIT("forall") <+> interppSP tvs <> dot <+>
-- **! ToDo: want to hide uvars from user, but not enough info
-- in a HsTyVarBndr name (see PprType). KSW 2000-10.
- (if null cxt then
- empty
- else
- ppr_context cxt <+> ptext SLIT("=>")
- )
+ pprHsContext cxt
else -- Used in interfaces
ptext SLIT("__forall") <+> interppSP tvs <+>
- ppr_context cxt <+> ptext SLIT("=>")
+ ppr_hs_context cxt <+> ptext SLIT("=>")
pprHsContext :: (Outputable name) => HsContext name -> SDoc
pprHsContext [] = empty
-pprHsContext cxt = ppr_context cxt <+> ptext SLIT("=>")
+pprHsContext cxt = ppr_hs_context cxt <+> ptext SLIT("=>")
-ppr_context [] = empty
-ppr_context cxt = parens (interpp'SP cxt)
+ppr_hs_context [] = empty
+ppr_hs_context cxt = parens (interpp'SP cxt)
\end{code}
\begin{code}
pREC_TOP = (0 :: Int) -- type in ParseIface.y
pREC_FUN = (1 :: Int) -- btype in ParseIface.y
-pREC_CON = (2 :: Int) -- atype in ParseIface.y
-
-maybeParen :: Bool -> SDoc -> SDoc
-maybeParen True p = parens p
-maybeParen False p = p
+ -- Used for LH arg of (->)
+pREC_OP = (2 :: Int) -- Used for arg of any infix operator
+ -- (we don't keep their fixities around)
+pREC_CON = (3 :: Int) -- Used for arg of type applicn:
+ -- always parenthesise unless atomic
+
+maybeParen :: Int -- Precedence of context
+ -> Int -- Precedence of top-level operator
+ -> SDoc -> SDoc -- Wrap in parens if (ctxt >= op)
+maybeParen ctxt_prec op_prec p | ctxt_prec >= op_prec = parens p
+ | otherwise = p
-- printing works more-or-less as for Types
pprHsType, pprParendHsType :: (Outputable name) => HsType name -> SDoc
-pprHsType ty = ppr_mono_ty pREC_TOP ty
+pprHsType ty = ppr_mono_ty pREC_TOP (de_paren ty)
pprParendHsType ty = ppr_mono_ty pREC_CON ty
+-- Remove outermost HsParTy parens before printing a type
+de_paren (HsParTy ty) = de_paren ty
+de_paren ty = ty
+
ppr_mono_ty ctxt_prec (HsForAllTy maybe_tvs ctxt ty)
- = maybeParen (ctxt_prec >= pREC_FUN) $
+ = maybeParen ctxt_prec pREC_FUN $
sep [pp_header, pprHsType ty]
where
pp_header = case maybe_tvs of
Just tvs -> pprHsForAll tvs ctxt
Nothing -> pprHsContext ctxt
-ppr_mono_ty ctxt_prec (HsTyVar name)
- = ppr name
-
-ppr_mono_ty ctxt_prec (HsFunTy ty1 ty2)
- = let p1 = ppr_mono_ty pREC_FUN ty1
- p2 = ppr_mono_ty pREC_TOP ty2
- in
- maybeParen (ctxt_prec >= pREC_FUN)
- (sep [p1, (<>) (ptext SLIT("-> ")) p2])
-
+ppr_mono_ty ctxt_prec (HsTyVar name) = ppr name
+ppr_mono_ty ctxt_prec (HsFunTy ty1 ty2) = ppr_fun_ty ctxt_prec ty1 ty2
ppr_mono_ty ctxt_prec (HsTupleTy con tys) = hsTupParens con (interpp'SP tys)
+ppr_mono_ty ctxt_prec (HsKindSig ty kind) = parens (ppr_mono_ty pREC_TOP ty <+> dcolon <+> pprKind kind)
ppr_mono_ty ctxt_prec (HsListTy ty) = brackets (ppr_mono_ty pREC_TOP ty)
+ppr_mono_ty ctxt_prec (HsPArrTy ty) = pabrackets (ppr_mono_ty pREC_TOP ty)
+ppr_mono_ty ctxt_prec (HsPredTy pred) = braces (ppr pred)
+ppr_mono_ty ctxt_prec (HsNumTy n) = integer n -- generics only
ppr_mono_ty ctxt_prec (HsAppTy fun_ty arg_ty)
- = maybeParen (ctxt_prec >= pREC_CON)
- (hsep [ppr_mono_ty pREC_FUN fun_ty, ppr_mono_ty pREC_CON arg_ty])
+ = maybeParen ctxt_prec pREC_CON $
+ hsep [ppr_mono_ty pREC_FUN fun_ty, ppr_mono_ty pREC_CON arg_ty]
+
+ppr_mono_ty ctxt_prec (HsOpTy ty1 HsArrow ty2)
+ = ppr_fun_ty ctxt_prec ty1 ty2
-ppr_mono_ty ctxt_prec (HsPredTy pred)
- = braces (ppr pred)
+ppr_mono_ty ctxt_prec (HsOpTy ty1 op ty2)
+ = maybeParen ctxt_prec pREC_OP $
+ ppr_mono_ty pREC_OP ty1 <+> ppr op <+> ppr_mono_ty pREC_OP ty2
-ppr_mono_ty ctxt_prec (HsUsageTy u ty)
- = maybeParen (ctxt_prec >= pREC_CON)
- (sep [ptext SLIT("__u") <+> ppr_mono_ty pREC_CON u,
- ppr_mono_ty pREC_CON ty])
- -- pREC_FUN would be logical for u, but it yields a reduce/reduce conflict with AppTy
+ppr_mono_ty ctxt_prec (HsParTy ty)
+ = parens (ppr_mono_ty pREC_TOP ty)
+ -- Put the parens in where the user did
+ -- But we still use the precedence stuff to add parens because
+ -- toHsType doesn't put in any HsParTys, so we may still need them
--- Generics
-ppr_mono_ty ctxt_prec (HsNumTy n) = integer n
-ppr_mono_ty ctxt_prec (HsOpTy ty1 op ty2) = ppr ty1 <+> ppr op <+> ppr ty2
+--------------------------
+ppr_fun_ty ctxt_prec ty1 ty2
+ = let p1 = ppr_mono_ty pREC_FUN ty1
+ p2 = ppr_mono_ty pREC_TOP ty2
+ in
+ maybeParen ctxt_prec pREC_FUN $
+ sep [p1, ptext SLIT("->") <+> p2]
+
+--------------------------
+pabrackets p = ptext SLIT("[:") <> p <> ptext SLIT(":]")
\end{code}
toHsType ty@(TyConApp tc tys) -- Must be saturated because toHsType's arg is of kind *
| not saturated = generic_case
- | isTupleTyCon tc = HsTupleTy (HsTupCon (getName tc) (tupleTyConBoxity tc) (tyConArity tc)) tys'
+ | isTupleTyCon tc = HsTupleTy (HsTupCon (tupleTyConBoxity tc) (tyConArity tc)) tys'
| tc `hasKey` listTyConKey = HsListTy (head tys')
- | tc `hasKey` usOnceTyConKey = hsUsOnce_Name -- must print !, . unqualified
- | tc `hasKey` usManyTyConKey = hsUsMany_Name -- must print !, . unqualified
+ | tc `hasKey` parrTyConKey = HsPArrTy (head tys')
| otherwise = generic_case
where
generic_case = foldl HsAppTy (HsTyVar (getName tc)) tys'
tys' = map toHsType tys
- saturated = length tys == tyConArity tc
+ saturated = tys `lengthIs` tyConArity tc
toHsType ty@(ForAllTy _ _) = case tcSplitSigmaTy ty of
(tvs, preds, tau) -> HsForAllTy (Just (map toHsTyVar tvs))
(map toHsPred preds)
(toHsType tau)
-toHsType (UsageTy u ty) = HsUsageTy (toHsType u) (toHsType ty)
- -- **! consider dropping usMany annotations ToDo KSW 2000-10
-
-
toHsPred (ClassP cls tys) = HsClassP (getName cls) (map toHsType tys)
-toHsPred (IParam n ty) = HsIParam (getName n) (toHsType ty)
+toHsPred (IParam n ty) = HsIParam n (toHsType ty)
toHsContext :: ThetaType -> HsContext Name
toHsContext theta = map toHsPred theta
eq_hsType env (HsListTy ty1) (HsListTy ty2)
= eq_hsType env ty1 ty2
+eq_hsType env (HsKindSig ty1 k1) (HsKindSig ty2 k2)
+ = eq_hsType env ty1 ty2 && k1 `eqKind` k2
+
+eq_hsType env (HsPArrTy ty1) (HsPArrTy ty2)
+ = eq_hsType env ty1 ty2
+
eq_hsType env (HsAppTy fun_ty1 arg_ty1) (HsAppTy fun_ty2 arg_ty2)
= eq_hsType env fun_ty1 fun_ty2 && eq_hsType env arg_ty1 arg_ty2
eq_hsType env (HsPredTy p1) (HsPredTy p2)
= eq_hsPred env p1 p2
-eq_hsType env (HsUsageTy u1 ty1) (HsUsageTy u2 ty2)
- = eq_hsType env u1 u2 && eq_hsType env ty1 ty2
-
eq_hsType env (HsOpTy lty1 op1 rty1) (HsOpTy lty2 op2 rty2)
- = eq_hsVar env op1 op2 && eq_hsType env lty1 lty2 && eq_hsType env rty1 rty2
+ = eq_hsOp env op1 op2 && eq_hsType env lty1 lty2 && eq_hsType env rty1 rty2
eq_hsType env ty1 ty2 = False
+eq_hsOp env (HsTyOp n1) (HsTyOp n2) = eq_hsVar env n1 n2
+eq_hsOp env HsArrow HsArrow = True
+eq_hsOp env op1 op2 = False
+
-------------------
eq_hsContext env a b = eqListBy (eq_hsPred env) a b
projects / ghc-hetmet.git / blobdiff