-]%
+%
% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
%
\section[HsTypes]{Abstract syntax: user-defined types}
HsExplicitForAll(..),
HsContext, LHsContext,
HsPred(..), LHsPred,
+
+ LBangType, BangType, HsBang(..),
+ getBangType, getBangStrictness,
mkExplicitHsForAllTy, mkImplicitHsForAllTy,
hsTyVarName, hsTyVarNames, replaceTyVarName,
hsLTyVarName, hsLTyVarNames, hsLTyVarLocName, hsLTyVarLocNames,
- splitHsInstDeclTy,
+ splitHsInstDeclTy, splitHsFunType,
-- Type place holder
PostTcType, placeHolderType,
- -- Name place holder
- SyntaxName, placeHolderName,
-
-- Printing
pprParendHsType, pprHsForAll, pprHsContext, ppr_hs_context, pprHsTyVarBndr
) where
import Type ( Type )
import Kind ( {- instance Outputable Kind -}, Kind,
pprParendKind, pprKind, isLiftedTypeKind )
-import Name ( Name, mkInternalName )
-import OccName ( mkVarOcc )
import BasicTypes ( IPName, Boxity, tupleParens )
-import PrelNames ( unboundKey )
-import SrcLoc ( noSrcLoc, Located(..), unLoc, noSrcSpan )
-import CmdLineOpts ( opt_PprStyle_Debug )
+import SrcLoc ( Located(..), unLoc, noSrcSpan )
+import StaticFlags ( opt_PprStyle_Debug )
import Outputable
\end{code}
placeHolderType :: PostTcType -- Used before typechecking
placeHolderType = panic "Evaluated the place holder for a PostTcType"
+\end{code}
+%************************************************************************
+%* *
+\subsection{Bang annotations}
+%* *
+%************************************************************************
-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
+\begin{code}
+type LBangType name = Located (BangType name)
+type BangType name = HsType name -- Bangs are in the HsType data type
+
+data HsBang = HsNoBang -- Only used as a return value for getBangStrictness,
+ -- never appears on a HsBangTy
+ | HsStrict -- !
+ | HsUnbox -- {-# UNPACK #-} ! (GHC extension, meaning "unbox")
+
+instance Outputable HsBang where
+ ppr (HsNoBang) = empty
+ ppr (HsStrict) = char '!'
+ ppr (HsUnbox) = ptext SLIT("!!")
+
+getBangType :: LHsType a -> LHsType a
+getBangType (L _ (HsBangTy _ ty)) = ty
+getBangType ty = ty
+
+getBangStrictness :: LHsType a -> HsBang
+getBangStrictness (L _ (HsBangTy s _)) = s
+getBangStrictness _ = HsNoBang
\end{code}
| HsTyVar name -- Type variable or type constructor
+ | HsBangTy HsBang (LHsType name) -- Bang-style type annotations
+
| HsAppTy (LHsType name)
(LHsType name)
| HsNumTy Integer -- Generics only
- | HsPredTy (LHsPred name) -- Only used in the type of an instance
+ | HsPredTy (HsPred name) -- Only used in the type of an instance
-- declaration, eg. Eq [a] -> Eq a
-- ^^^^
-- HsPredTy
+ -- Note no need for location info on the
+ -- enclosed HsPred; the one on the type will do
| HsKindSig (LHsType name) -- (ty :: kind)
Kind -- A type with a kind signature
data HsTyVarBndr name
= UserTyVar name
| KindedTyVar name Kind
- -- *** NOTA BENE *** A "monotype" in a pragma can have
+ -- *** NOTA BENE *** A "monotype" in a pragma can have
-- for-alls in it, (mostly to do with dictionaries). These
-- must be explicitly Kinded.
-> ([LHsTyVarBndr name], HsContext name, name, [LHsType 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 _ tvs cxt1 tau -- The type vars should have been
- -- computed by now, even if they were implicit
- -> (tvs, unLoc cxt1 ++ cxt2, cls, tys)
- where
- (cxt2, cls, tys) = split_tau (unLoc tau)
-
- other -> ([], cxt2, cls, tys)
- where
- (cxt2, cls, tys) = split_tau inst_ty
-
+ HsParTy (L _ ty) -> splitHsInstDeclTy ty
+ HsForAllTy _ tvs cxt (L _ ty) -> split_tau tvs (unLoc cxt) ty
+ other -> split_tau [] [] other
+ -- The type vars should have been computed by now, even if they were implicit
+ where
+ split_tau tvs cxt (HsPredTy (HsClassP cls tys)) = (tvs, cxt, cls, tys)
+ split_tau tvs cxt (HsParTy (L _ ty)) = split_tau tvs cxt ty
+
+-- Splits HsType into the (init, last) parts
+-- Breaks up any parens in the result type:
+-- splitHsFunType (a -> (b -> c)) = ([a,b], c)
+splitHsFunType :: LHsType name -> ([LHsType name], LHsType name)
+splitHsFunType (L l (HsFunTy x y)) = (x:args, res)
where
- split_tau (HsFunTy (L _ (HsPredTy p)) ty) = (p:ps, cls, tys)
- where
- (ps, cls, tys) = split_tau (unLoc ty)
- split_tau (HsPredTy (L _ (HsClassP cls tys))) = ([], cls, tys)
- split_tau other = pprPanic "splitHsInstDeclTy" (ppr inst_ty)
+ (args, res) = splitHsFunType y
+splitHsFunType (L _ (HsParTy ty)) = splitHsFunType ty
+splitHsFunType other = ([], other)
\end{code}
= maybeParen ctxt_prec pREC_FUN $
sep [pprHsForAll exp tvs ctxt, ppr_mono_lty pREC_TOP ty]
+-- gaw 2004
+ppr_mono_ty ctxt_prec (HsBangTy b ty) = ppr b <> ppr ty
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) = tupleParens con (interpp'SP tys)
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