%
-% (c) The GRASP/AQUA Project, Glasgow University, 1992-1996
+% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
%
\section[HsTypes]{Abstract syntax: user-defined types}
-If compiled without \tr{#define COMPILING_GHC}, you get
-(part of) a Haskell-abstract-syntax library. With it,
-you get part of GHC.
-
\begin{code}
-#include "HsVersions.h"
-
module HsTypes (
- HsType(..), HsTyVar(..),
- SYN_IE(Context), SYN_IE(ClassAssertion)
+ HsType(..), MonoUsageAnn(..), HsTyVar(..),
+ HsContext, HsClassAssertion, HsPred(..)
- , mkHsForAllTy
+ , mkHsForAllTy, mkHsUsForAllTy
, getTyVarName, replaceTyVarName
, pprParendHsType
- , pprContext
- , cmpHsType, cmpContext
+ , pprForAll, pprHsContext, pprHsClassAssertion, pprHsPred
+ , cmpHsType, cmpHsTypes, cmpHsContext, cmpHsPred
) where
-IMP_Ubiq()
+#include "HsVersions.h"
-import CmdLineOpts ( opt_PprUserLength )
-import Outputable ( Outputable(..), PprStyle(..), pprQuote, interppSP )
-import Kind ( Kind {- instance Outputable -} )
-import Name ( nameOccName )
-import Pretty
-import Util ( thenCmp, cmpList, isIn, panic# )
+import Type ( Kind, UsageAnn(..) )
+import PprType ( {- instance Outputable Kind -} )
+import Outputable
+import Util ( thenCmp, cmpList )
\end{code}
This is the syntax for types as seen in type signatures.
\begin{code}
-type Context name = [ClassAssertion name]
-
-type ClassAssertion name = (name, HsType name)
- -- The type is usually a type variable, but it
- -- doesn't have to be when reading interface files
+type HsContext name = [HsPred name]
+type HsClassAssertion name = (name, [HsType name])
+-- The type is usually a type variable, but it
+-- doesn't have to be when reading interface files
+data HsPred name =
+ HsPClass name [HsType name]
+ | HsPIParam name (HsType name)
data HsType name
- = HsPreForAllTy (Context name)
- (HsType name)
-
- -- The renamer turns HsPreForAllTys into HsForAllTys when they
- -- occur in signatures, to make the binding of variables
- -- explicit. This distinction is made visible for
- -- non-COMPILING_GHC code, because you probably want to do the
- -- same thing.
-
- | HsForAllTy [HsTyVar name]
- (Context name)
+ = HsForAllTy (Maybe [HsTyVar name]) -- Nothing for implicitly quantified signatures
+ (HsContext name)
(HsType name)
| MonoTyVar name -- Type variable
| MonoFunTy (HsType name) -- function type
(HsType name)
- | MonoListTy name -- The list TyCon name
- (HsType name) -- Element type
+ | MonoListTy (HsType name) -- Element type
- | MonoTupleTy name -- The tuple TyCon name
- [HsType name] -- Element types (length gives arity)
+ | MonoTupleTy [HsType name] -- Element types (length gives arity)
+ Bool -- boxed?
- -- these next two are only used in unfoldings in interfaces
- | MonoDictTy name -- Class
- (HsType name)
+ | MonoIParamTy name (HsType name)
-mkHsForAllTy [] [] ty = ty
+ -- these next two are only used in interfaces
+ | MonoDictTy name -- Class
+ [HsType name]
+
+ | MonoUsgTy (MonoUsageAnn name)
+ (HsType name)
+
+ | MonoUsgForAllTy name
+ (HsType name)
+
+data MonoUsageAnn name
+ = MonoUsOnce
+ | MonoUsMany
+ | MonoUsVar name
+
+
+-- Combine adjacent for-alls.
+-- The following awkward situation can happen otherwise:
+-- f :: forall a. ((Num a) => Int)
+-- might generate HsForAll (Just [a]) [] (HsForAll Nothing [Num a] t)
+-- Then a isn't discovered as ambiguous, and we abstract the AbsBinds wrt []
+-- but the export list abstracts f wrt [a]. Disaster.
+--
+-- 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
+mkHsUsForAllTy uvs ty = foldr (\ uv ty -> MonoUsgForAllTy uv ty)
+ ty uvs
+
data HsTyVar name
= UserTyVar name
| IfaceTyVar name Kind
\begin{code}
instance (Outputable name) => Outputable (HsType name) where
- ppr sty ty = pprQuote sty $ \ sty -> pprHsType sty ty
+ ppr ty = pprHsType ty
instance (Outputable name) => Outputable (HsTyVar name) where
- ppr sty (UserTyVar name) = ppr sty name
- ppr sty (IfaceTyVar name kind) = pprQuote sty $ \ sty ->
- hsep [ppr sty name, ptext SLIT("::"), ppr sty kind]
-
-ppr_forall sty ctxt_prec [] [] ty
- = ppr_mono_ty sty ctxt_prec ty
-ppr_forall sty ctxt_prec tvs ctxt ty
- = maybeParen (ctxt_prec >= pREC_FUN) $
- sep [ptext SLIT("_forall_"), brackets (interppSP sty tvs),
- pprContext sty ctxt, ptext SLIT("=>"),
- pprHsType sty ty]
-
-pprContext :: (Outputable name) => PprStyle -> (Context name) -> Doc
-pprContext sty [] = empty
-pprContext sty context
- = hsep [braces (hsep (punctuate comma (map ppr_assert context)))]
- where
- ppr_assert (clas, ty) = hsep [ppr sty clas, ppr sty ty]
+ ppr (UserTyVar name) = ppr name
+ ppr (IfaceTyVar name kind) = hsep [ppr name, dcolon, ppr kind]
+
+-- Better to see those for-alls
+-- pprForAll [] = empty
+pprForAll tvs = ptext SLIT("forall") <+> interppSP tvs <> ptext SLIT(".")
+
+pprHsContext :: (Outputable name) => HsContext name -> SDoc
+pprHsContext [] = empty
+pprHsContext context = parens (hsep (punctuate comma (map pprHsPred context))) <+> ptext SLIT("=>")
+
+pprHsClassAssertion :: (Outputable name) => HsClassAssertion name -> SDoc
+pprHsClassAssertion (clas, tys)
+ = ppr clas <+> hsep (map pprParendHsType tys)
+
+pprHsPred :: (Outputable name) => HsPred name -> SDoc
+pprHsPred (HsPClass clas tys)
+ = ppr clas <+> hsep (map pprParendHsType tys)
+pprHsPred (HsPIParam n ty)
+ = hsep [{- char '?' <> -} ppr n, text "::", ppr ty]
\end{code}
\begin{code}
pREC_FUN = (1 :: Int)
pREC_CON = (2 :: Int)
-maybeParen :: Bool -> Doc -> Doc
+maybeParen :: Bool -> SDoc -> SDoc
maybeParen True p = parens p
maybeParen False p = p
-- printing works more-or-less as for Types
-pprHsType, pprParendHsType :: (Outputable name) => PprStyle -> HsType name -> Doc
+pprHsType, pprParendHsType :: (Outputable name) => HsType name -> SDoc
-pprHsType sty ty = ppr_mono_ty sty pREC_TOP ty
-pprParendHsType sty ty = ppr_mono_ty sty pREC_CON ty
+pprHsType ty = ppr_mono_ty pREC_TOP ty
+pprParendHsType ty = ppr_mono_ty pREC_CON ty
-ppr_mono_ty sty ctxt_prec (HsPreForAllTy ctxt ty) = ppr_forall sty ctxt_prec [] ctxt ty
-ppr_mono_ty sty ctxt_prec (HsForAllTy tvs ctxt ty) = ppr_forall sty ctxt_prec tvs ctxt ty
+ppr_mono_ty ctxt_prec (HsForAllTy maybe_tvs ctxt ty)
+ = maybeParen (ctxt_prec >= pREC_FUN) $
+ sep [pp_tvs, pprHsContext ctxt, pprHsType ty]
+ where
+ pp_tvs = case maybe_tvs of
+ Just tvs -> pprForAll tvs
+ Nothing -> text "{- implicit forall -}"
-ppr_mono_ty sty ctxt_prec (MonoTyVar name) = ppr sty name
+ppr_mono_ty ctxt_prec (MonoTyVar name)
+ = ppr name
-ppr_mono_ty sty ctxt_prec (MonoFunTy ty1 ty2)
- = let p1 = ppr_mono_ty sty pREC_FUN ty1
- p2 = ppr_mono_ty sty pREC_TOP ty2
+ppr_mono_ty ctxt_prec (MonoFunTy 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 sty ctxt_prec (MonoTupleTy _ tys)
- = parens (sep (punctuate comma (map (ppr sty) tys)))
+ppr_mono_ty ctxt_prec (MonoTupleTy tys True)
+ = parens (sep (punctuate comma (map ppr tys)))
+ppr_mono_ty ctxt_prec (MonoTupleTy tys False)
+ = ptext SLIT("(#") <> sep (punctuate comma (map ppr tys)) <> ptext SLIT("#)")
-ppr_mono_ty sty ctxt_prec (MonoListTy _ ty)
- = brackets (ppr_mono_ty sty pREC_TOP ty)
+ppr_mono_ty ctxt_prec (MonoListTy ty)
+ = brackets (ppr_mono_ty pREC_TOP ty)
-ppr_mono_ty sty ctxt_prec (MonoTyApp fun_ty arg_ty)
+ppr_mono_ty ctxt_prec (MonoTyApp fun_ty arg_ty)
= maybeParen (ctxt_prec >= pREC_CON)
- (hsep [ppr_mono_ty sty pREC_FUN fun_ty, ppr_mono_ty sty pREC_CON arg_ty])
+ (hsep [ppr_mono_ty pREC_FUN fun_ty, ppr_mono_ty pREC_CON arg_ty])
+
+ppr_mono_ty ctxt_prec (MonoIParamTy n ty)
+ = hsep [{- char '?' <> -} ppr n, text "::", ppr_mono_ty pREC_TOP ty]
+
+ppr_mono_ty ctxt_prec (MonoDictTy clas tys)
+ = ppr clas <+> hsep (map (ppr_mono_ty pREC_CON) tys)
+
+ppr_mono_ty ctxt_prec ty@(MonoUsgForAllTy _ _)
+ = maybeParen (ctxt_prec >= pREC_FUN) $
+ sep [ ptext SLIT("__fuall") <+> brackets pp_uvars <+> ptext SLIT("=>"),
+ ppr_mono_ty pREC_TOP sigma
+ ]
+ where
+ (uvars,sigma) = split [] ty
+ pp_uvars = interppSP uvars
-ppr_mono_ty sty ctxt_prec (MonoDictTy clas ty)
- = hsep [ppr sty clas, ppr_mono_ty sty pREC_CON ty]
+ split uvs (MonoUsgForAllTy uv ty') = split (uv:uvs) ty'
+ split uvs ty' = (reverse uvs,ty')
+
+ppr_mono_ty ctxt_prec (MonoUsgTy u ty)
+ = maybeParen (ctxt_prec >= pREC_CON) $
+ ptext SLIT("__u") <+> pp_ua <+> ppr_mono_ty pREC_CON ty
+ where
+ pp_ua = case u of
+ MonoUsOnce -> ptext SLIT("-")
+ MonoUsMany -> ptext SLIT("!")
+ MonoUsVar uv -> ppr uv
\end{code}
wrong}, so be careful!
\begin{code}
-cmpHsTyVar :: (a -> a -> TAG_) -> HsTyVar a -> HsTyVar a -> TAG_
---cmpHsType :: (a -> a -> TAG_) -> HsType a -> HsType a -> TAG_
---cmpContext :: (a -> a -> TAG_) -> Context a -> Context a -> TAG_
+cmpHsTyVar :: (a -> a -> Ordering) -> HsTyVar a -> HsTyVar a -> Ordering
+cmpHsType :: (a -> a -> Ordering) -> HsType a -> HsType a -> Ordering
+cmpHsTypes :: (a -> a -> Ordering) -> [HsType a] -> [HsType a] -> Ordering
+cmpHsContext :: (a -> a -> Ordering) -> HsContext a -> HsContext a -> Ordering
+cmpHsPred :: (a -> a -> Ordering) -> HsPred a -> HsPred a -> Ordering
cmpHsTyVar cmp (UserTyVar v1) (UserTyVar v2) = v1 `cmp` v2
cmpHsTyVar cmp (IfaceTyVar v1 _) (IfaceTyVar v2 _) = v1 `cmp` v2
-cmpHsTyVar cmp (UserTyVar _) other = LT_
-cmpHsTyVar cmp other1 other2 = GT_
-
+cmpHsTyVar cmp (UserTyVar _) other = LT
+cmpHsTyVar cmp other1 other2 = GT
--- We assume that HsPreForAllTys have been smashed by now.
-# ifdef DEBUG
-cmpHsType _ (HsPreForAllTy _ _) _ = panic# "cmpHsType:HsPreForAllTy:1st arg"
-cmpHsType _ _ (HsPreForAllTy _ _) = panic# "cmpHsType:HsPreForAllTy:2nd arg"
-# endif
+cmpHsTypes cmp [] [] = EQ
+cmpHsTypes cmp [] tys2 = LT
+cmpHsTypes cmp tys1 [] = GT
+cmpHsTypes cmp (ty1:tys1) (ty2:tys2) = cmpHsType cmp ty1 ty2 `thenCmp` cmpHsTypes cmp tys1 tys2
cmpHsType cmp (HsForAllTy tvs1 c1 t1) (HsForAllTy tvs2 c2 t2)
- = cmpList (cmpHsTyVar cmp) tvs1 tvs2 `thenCmp`
- cmpContext cmp c1 c2 `thenCmp`
+ = cmpMaybe (cmpList (cmpHsTyVar cmp)) tvs1 tvs2 `thenCmp`
+ cmpHsContext cmp c1 c2 `thenCmp`
cmpHsType cmp t1 t2
cmpHsType cmp (MonoTyVar n1) (MonoTyVar n2)
= cmp n1 n2
-cmpHsType cmp (MonoTupleTy _ tys1) (MonoTupleTy _ tys2)
- = cmpList (cmpHsType cmp) tys1 tys2
-cmpHsType cmp (MonoListTy _ ty1) (MonoListTy _ ty2)
+cmpHsType cmp (MonoTupleTy tys1 b1) (MonoTupleTy tys2 b2)
+ = (b1 `compare` b2) `thenCmp` cmpHsTypes cmp tys1 tys2
+
+cmpHsType cmp (MonoListTy ty1) (MonoListTy ty2)
= cmpHsType cmp ty1 ty2
cmpHsType cmp (MonoTyApp fun_ty1 arg_ty1) (MonoTyApp fun_ty2 arg_ty2)
cmpHsType cmp (MonoFunTy a1 b1) (MonoFunTy a2 b2)
= cmpHsType cmp a1 a2 `thenCmp` cmpHsType cmp b1 b2
-cmpHsType cmp (MonoDictTy c1 ty1) (MonoDictTy c2 ty2)
- = cmp c1 c2 `thenCmp` cmpHsType cmp ty1 ty2
+cmpHsType cmp (MonoDictTy c1 tys1) (MonoDictTy c2 tys2)
+ = cmp c1 c2 `thenCmp` cmpHsTypes cmp tys1 tys2
+
+cmpHsType cmp (MonoUsgTy u1 ty1) (MonoUsgTy u2 ty2)
+ = cmpUsg cmp u1 u2 `thenCmp` cmpHsType cmp ty1 ty2
cmpHsType cmp ty1 ty2 -- tags must be different
= let tag1 = tag ty1
tag2 = tag ty2
in
- if tag1 _LT_ tag2 then LT_ else GT_
+ if tag1 _LT_ tag2 then LT else GT
where
- tag (MonoTyVar n1) = (ILIT(1) :: FAST_INT)
- tag (MonoTupleTy _ tys1) = ILIT(2)
- tag (MonoListTy _ ty1) = ILIT(3)
- tag (MonoTyApp tc1 tys1) = ILIT(4)
- tag (MonoFunTy a1 b1) = ILIT(5)
- tag (MonoDictTy c1 ty1) = ILIT(7)
- tag (HsForAllTy _ _ _) = ILIT(8)
- tag (HsPreForAllTy _ _) = ILIT(9)
+ tag (MonoTyVar n1) = (ILIT(1) :: FAST_INT)
+ tag (MonoTupleTy tys1 _) = ILIT(2)
+ tag (MonoListTy ty1) = ILIT(3)
+ tag (MonoTyApp tc1 tys1) = ILIT(4)
+ tag (MonoFunTy a1 b1) = ILIT(5)
+ tag (MonoDictTy c1 tys1) = ILIT(6)
+ tag (MonoUsgTy c1 ty1) = ILIT(7)
+ tag (MonoUsgForAllTy uv1 ty1) = ILIT(8)
+ tag (HsForAllTy _ _ _) = ILIT(9)
-------------------
-cmpContext cmp a b
- = cmpList cmp_ctxt a b
+cmpHsContext cmp a b
+ = cmpList (cmpHsPred cmp) a b
+
+cmpHsPred cmp (HsPClass c1 tys1) (HsPClass c2 tys2)
+ = cmp c1 c2 `thenCmp` cmpHsTypes cmp tys1 tys2
+cmpHsPred cmp (HsPIParam n1 ty1) (HsPIParam n2 ty2)
+ = cmp n1 n2 `thenCmp` cmpHsType cmp ty1 ty2
+cmpHsPred cmp (HsPClass _ _) (HsPIParam _ _) = LT
+cmpHsPred cmp _ _ = GT
+
+cmpUsg cmp MonoUsOnce MonoUsOnce = EQ
+cmpUsg cmp MonoUsMany MonoUsMany = EQ
+cmpUsg cmp (MonoUsVar u1) (MonoUsVar u2) = cmp u1 u2
+
+cmpUsg cmp ua1 ua2 -- tags must be different
+ = let tag1 = tag ua1
+ tag2 = tag ua2
+ in
+ if tag1 _LT_ tag2 then LT else GT
where
- cmp_ctxt (c1, ty1) (c2, ty2)
- = cmp c1 c2 `thenCmp` cmpHsType cmp ty1 ty2
+ tag MonoUsOnce = (ILIT(1) :: FAST_INT)
+ tag MonoUsMany = ILIT(2)
+ tag (MonoUsVar _) = ILIT(3)
+
+-- Should be in Maybes, I guess
+cmpMaybe cmp Nothing Nothing = EQ
+cmpMaybe cmp Nothing (Just x) = LT
+cmpMaybe cmp (Just x) Nothing = GT
+cmpMaybe cmp (Just x) (Just y) = x `cmp` y
\end{code}
projects / ghc-hetmet.git / blobdiff