X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2FhsSyn%2FHsTypes.lhs;h=a0e899940aec7f7e99e26df884ae992f1562b808;hb=e26dd9a959b7b7810c2e2089940422092a95f2e3;hp=738ab167eab0da86db32ce4b2ad2ef064e0c68b2;hpb=ef2b170c6298b4826d3b56465a3c1438b5be7307;p=ghc-hetmet.git diff --git a/ghc/compiler/hsSyn/HsTypes.lhs b/ghc/compiler/hsSyn/HsTypes.lhs index 738ab16..a0e8999 100644 --- a/ghc/compiler/hsSyn/HsTypes.lhs +++ b/ghc/compiler/hsSyn/HsTypes.lhs @@ -12,11 +12,14 @@ module HsTypes ( , mkHsForAllTy, mkHsDictTy, mkHsIParamTy , hsTyVarName, hsTyVarNames, replaceTyVarName - , getHsInstHead + , splitHsInstDeclTy -- Type place holder , PostTcType, placeHolderType, + -- Name place holder + , SyntaxName, placeHolderName, + -- Printing , pprParendHsType, pprHsForAll, pprHsContext, ppr_hs_context, pprHsTyVarBndr @@ -37,17 +40,18 @@ import TcType ( Type, Kind, ThetaType, SourceType(..), 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, pprKind ) import BasicTypes ( Boxity(..), Arity, IPName, tupleParens ) -import PrelNames ( mkTupConRdrName, listTyConKey, parrTyConKey, - usOnceTyConKey, usManyTyConKey, hasKey, +import PrelNames ( listTyConKey, parrTyConKey, + usOnceTyConKey, usManyTyConKey, hasKey, unboundKey, usOnceTyConName, usManyTyConName ) -import FiniteMap +import SrcLoc ( noSrcLoc ) import Util ( eqListBy, lengthIs ) +import FiniteMap import Outputable \end{code} @@ -66,6 +70,18 @@ type PostTcType = Type -- Used for slots in the abstract syntax 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} @@ -93,17 +109,26 @@ data HsType name | HsAppTy (HsType name) (HsType name) - | HsFunTy (HsType name) -- function type + | HsFunTy (HsType name) -- function type (HsType name) | HsListTy (HsType name) -- Element type | HsPArrTy (HsType name) -- Elem. type of parallel array: [:t:] - | HsTupleTy (HsTupCon name) + | HsTupleTy HsTupCon [HsType name] -- Element types (length gives arity) | 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 @@ -128,18 +153,16 @@ hsUsOnce_Name = HsTyVar usOnceTyConName hsUsMany_Name = HsTyVar usManyTyConName ----------------------- -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. @@ -151,13 +174,18 @@ hsTupParens (HsTupCon _ b _) p = tupleParens b p -- -- 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) @@ -181,23 +209,41 @@ replaceTyVarName (IfaceTyVar n k) n' = IfaceTyVar n' k \begin{code} -getHsInstHead :: HsType name -> ([HsTyVarBndr name], (name, [HsType name])) - -- Split up an instance decl type, returning the 'head' part - --- In interface fiels, the type of the decl is held like this: --- forall a. Foo a -> Baz (T a) --- so we have to strip off function argument types, --- as well as the bit before the '=>' (which is always --- empty in interface files) --- --- The parser ensures the type will have the right shape. +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) -getHsInstHead (HsForAllTy (Just tvs) _ tau) = (tvs, get_head1 tau) -getHsInstHead tau = ([], get_head1 tau) +splitHsInstDeclTy inst_ty + = case inst_ty of + HsForAllTy (Just tvs) cxt1 tau + -> (tvs, cxt1++cxt2, cls, tys) + where + (cxt2, cls, tys) = split_tau tau -get_head1 (HsFunTy _ ty) = get_head1 ty -get_head1 (HsPredTy (HsClassP cls tys)) = (cls,tys) + 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} @@ -256,54 +302,73 @@ ppr_hs_context cxt = parens (interpp'SP cxt) \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) - where - pabrackets p = ptext SLIT("[:") <> p <> ptext SLIT(":]") +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 (HsPredTy pred) - = braces (ppr pred) +ppr_mono_ty ctxt_prec (HsOpTy ty1 HsArrow ty2) + = ppr_fun_ty ctxt_prec ty1 ty2 + +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 (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 + +-------------------------- +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] --- 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 +-------------------------- +pabrackets p = ptext SLIT("[:") <> p <> ptext SLIT(":]") \end{code} @@ -360,7 +425,7 @@ toHsType (SourceTy pred) = HsPredTy (toHsPred pred) 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` parrTyConKey = HsPArrTy (head tys') | tc `hasKey` usOnceTyConKey = hsUsOnce_Name -- must print !, . unqualified