#include "HsVersions.h"
module HsTypes (
- PolyType(..), MonoType(..),
+ HsType(..), HsTyVar(..),
SYN_IE(Context), SYN_IE(ClassAssertion)
-#ifdef COMPILING_GHC
- , pprParendPolyType
- , pprParendMonoType, pprContext
- , extractMonoTyNames, extractCtxtTyNames
- , cmpPolyType, cmpMonoType, cmpContext
-#endif
+ , mkHsForAllTy
+ , getTyVarName, replaceTyVarName
+ , pprParendHsType
+ , pprContext
+ , cmpHsType, cmpContext
) where
-#ifdef COMPILING_GHC
IMP_Ubiq()
import Outputable ( interppSP, ifnotPprForUser )
+import Kind ( Kind {- instance Outputable -} )
import Pretty
import Util ( thenCmp, cmpList, isIn, panic# )
-
-#endif {- COMPILING_GHC -}
\end{code}
This is the syntax for types as seen in type signatures.
\begin{code}
-data PolyType name
+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
+
+data HsType name
= HsPreForAllTy (Context name)
- (MonoType name)
+ (HsType name)
-- The renamer turns HsPreForAllTys into HsForAllTys when they
-- occur in signatures, to make the binding of variables
-- non-COMPILING_GHC code, because you probably want to do the
-- same thing.
- | HsForAllTy [name]
+ | HsForAllTy [HsTyVar name]
(Context name)
- (MonoType name)
+ (HsType name)
-type Context name = [ClassAssertion name]
-
-type ClassAssertion name = (name, name)
-
-data MonoType name
- = MonoTyVar name -- Type variable
+ | MonoTyVar name -- Type variable
| MonoTyApp name -- Type constructor or variable
- [MonoType name]
+ [HsType name]
-- We *could* have a "MonoTyCon name" equiv to "MonoTyApp name []"
-- (for efficiency, what?) WDP 96/02/18
- | MonoFunTy (MonoType name) -- function type
- (MonoType name)
+ | MonoFunTy (HsType name) -- function type
+ (HsType name)
- | MonoListTy (MonoType name) -- list type
- | MonoTupleTy [MonoType name] -- tuple type (length gives arity)
+ | MonoListTy name -- The list TyCon name
+ (HsType name) -- Element type
+
+ | MonoTupleTy name -- The tuple TyCon name
+ [HsType name] -- Element types (length gives arity)
-#ifdef COMPILING_GHC
-- these next two are only used in unfoldings in interfaces
| MonoDictTy name -- Class
- (MonoType name)
+ (HsType name)
+
+mkHsForAllTy [] [] ty = ty
+mkHsForAllTy tvs ctxt ty = HsForAllTy tvs ctxt ty
- | MonoForAllTy [(name, Kind)]
- (MonoType name)
+data HsTyVar name
+ = UserTyVar name
+ | IfaceTyVar name Kind
-- *** NOTA BENE *** A "monotype" in a pragma can have
-- for-alls in it, (mostly to do with dictionaries). These
-- must be explicitly Kinded.
-#endif {- COMPILING_GHC -}
+getTyVarName (UserTyVar n) = n
+getTyVarName (IfaceTyVar n _) = n
+
+replaceTyVarName :: HsTyVar name1 -> name2 -> HsTyVar name2
+replaceTyVarName (UserTyVar n) n' = UserTyVar n'
+replaceTyVarName (IfaceTyVar n k) n' = IfaceTyVar n' k
\end{code}
-This is used in various places:
+
+%************************************************************************
+%* *
+\subsection{Pretty printing}
+%* *
+%************************************************************************
+
\begin{code}
-#ifdef COMPILING_GHC
-pprContext :: (Outputable name) => PprStyle -> (Context name) -> Pretty
-pprContext sty [] = ppNil
-pprContext sty [(clas, ty)] = ppCat [ppr sty clas, ppr sty ty, ppStr "=>"]
+instance (Outputable name) => Outputable (HsType name) where
+ ppr = pprHsType
+
+instance (Outputable name) => Outputable (HsTyVar name) where
+ ppr sty (UserTyVar name) = ppr sty name
+ ppr sty (IfaceTyVar name kind) = ppCat [ppr sty name, ppStr "::", ppr sty kind]
+
+
+ppr_forall sty ctxt_prec [] [] ty
+ = ppr_mono_ty sty ctxt_prec ty
+ppr_forall sty ctxt_prec tvs ctxt ty
+ = ppSep [ppStr "_forall_", ppBracket (interppSP sty tvs),
+ pprContext sty ctxt, ppStr "=>",
+ pprHsType sty ty]
+
+pprContext :: (Outputable name) => PprStyle -> (Context name) -> Pretty
+pprContext sty [] = ppNil
pprContext sty context
- = ppBesides [ppLparen,
- ppInterleave ppComma (map pp_assert context),
- ppRparen, ppStr " =>"]
+ = ppCat [ppCurlies (ppIntersperse pp'SP (map ppr_assert context))]
where
- pp_assert (clas, ty)
- = ppCat [ppr sty clas, ppr sty ty]
+ ppr_assert (clas, ty) = ppCat [ppr sty clas, ppr sty ty]
\end{code}
\begin{code}
-instance (Outputable name) => Outputable (PolyType name) where
- ppr sty (HsPreForAllTy ctxt ty)
- = print_it sty ppNil ctxt ty
- ppr sty (HsForAllTy [] ctxt ty)
- = print_it sty ppNil ctxt ty
- ppr sty (HsForAllTy tvs ctxt ty)
- = print_it sty
- (ppBesides [ppStr "_forall_ ", interppSP sty tvs, ppStr " => "])
- ctxt ty
-
-print_it sty pp_forall ctxt ty
- = ppCat [ifnotPprForUser sty pp_forall, -- print foralls unless PprForUser
- pprContext sty ctxt, ppr sty ty]
-
-pprParendPolyType :: Outputable name => PprStyle -> PolyType name -> Pretty
-pprParendPolyType sty ty = ppr sty ty -- ToDo: more later
-
-instance (Outputable name) => Outputable (MonoType name) where
- ppr = pprMonoType
-
pREC_TOP = (0 :: Int)
pREC_FUN = (1 :: Int)
pREC_CON = (2 :: Int)
+maybeParen :: Bool -> Pretty -> Pretty
+maybeParen True p = ppParens p
+maybeParen False p = p
+
-- printing works more-or-less as for Types
-pprMonoType, pprParendMonoType :: (Outputable name) => PprStyle -> MonoType name -> Pretty
+pprHsType, pprParendHsType :: (Outputable name) => PprStyle -> HsType name -> Pretty
-pprMonoType sty ty = ppr_mono_ty sty pREC_TOP ty
-pprParendMonoType sty ty = ppr_mono_ty sty pREC_CON ty
+pprHsType sty ty = ppr_mono_ty sty pREC_TOP ty
+pprParendHsType sty ty = ppr_mono_ty sty 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 sty ctxt_prec (MonoTyVar name) = ppr sty name
= let p1 = ppr_mono_ty sty pREC_FUN ty1
p2 = ppr_mono_ty sty pREC_TOP ty2
in
- if ctxt_prec < pREC_FUN then -- no parens needed
- ppSep [p1, ppBeside (ppStr "-> ") p2]
- else
- ppSep [ppBeside ppLparen p1, ppBesides [ppStr "-> ", p2, ppRparen]]
+ maybeParen (ctxt_prec >= pREC_FUN)
+ (ppSep [p1, ppBeside (ppStr "-> ") p2])
-ppr_mono_ty sty ctxt_prec (MonoTupleTy tys)
- = ppBesides [ppLparen, ppInterleave ppComma (map (ppr sty) tys), ppRparen]
+ppr_mono_ty sty ctxt_prec (MonoTupleTy _ tys)
+ = ppParens (ppInterleave ppComma (map (ppr sty) tys))
-ppr_mono_ty sty ctxt_prec (MonoListTy ty)
+ppr_mono_ty sty ctxt_prec (MonoListTy _ ty)
= ppBesides [ppLbrack, ppr_mono_ty sty pREC_TOP ty, ppRbrack]
ppr_mono_ty sty ctxt_prec (MonoTyApp tycon tys)
= let pp_tycon = ppr sty tycon in
if null tys then
pp_tycon
- else if ctxt_prec < pREC_CON then -- no parens needed
- ppCat [pp_tycon, ppInterleave ppNil (map (ppr_mono_ty sty pREC_CON) tys)]
- else
- ppBesides [ ppLparen, pp_tycon, ppSP,
- ppInterleave ppNil (map (ppr_mono_ty sty pREC_CON) tys), ppRparen ]
+ else
+ maybeParen (ctxt_prec >= pREC_CON)
+ (ppCat [pp_tycon, ppInterleave ppNil (map (ppr_mono_ty sty pREC_CON) tys)])
--- unfoldings only
ppr_mono_ty sty ctxt_prec (MonoDictTy clas ty)
- = ppBesides [ppStr "{{", ppr sty clas, ppSP, ppr_mono_ty sty ctxt_prec ty, ppStr "}}"]
-
-#endif {- COMPILING_GHC -}
+ = ppCurlies (ppCat [ppr sty clas, ppr_mono_ty sty pREC_CON ty])
+ -- Curlies are temporary
\end{code}
-\begin{code}
-#ifdef COMPILING_GHC
-
-extractCtxtTyNames :: Eq name => Context name -> [name]
-extractMonoTyNames :: Eq name => (name -> Bool) -> MonoType name -> [name]
-
-extractCtxtTyNames ctxt
- = foldr get [] ctxt
- where
- get (clas, tv) acc
- | tv `is_elem` acc = acc
- | otherwise = tv : acc
-
- is_elem = isIn "extractCtxtTyNames"
-extractMonoTyNames is_tyvar_name ty
- = get ty []
- where
- get (MonoTyApp con tys) acc = let
- rest = foldr get acc tys
- in
- if is_tyvar_name con && not (con `is_elem` rest)
- then con : rest
- else rest
- get (MonoListTy ty) acc = get ty acc
- get (MonoFunTy ty1 ty2) acc = get ty1 (get ty2 acc)
- get (MonoDictTy _ ty) acc = get ty acc
- get (MonoTupleTy tys) acc = foldr get acc tys
- get (MonoTyVar tv) acc
- | tv `is_elem` acc = acc
- | otherwise = tv : acc
-
- is_elem = isIn "extractMonoTyNames"
-
-#endif {- COMPILING_GHC -}
-\end{code}
+%************************************************************************
+%* *
+\subsection{Comparison}
+%* *
+%************************************************************************
We do define a specialised equality for these \tr{*Type} types; used
in checking interfaces. Most any other use is likely to be {\em
wrong}, so be careful!
-\begin{code}
-#ifdef COMPILING_GHC
-cmpPolyType :: (a -> a -> TAG_) -> PolyType a -> PolyType a -> TAG_
-cmpMonoType :: (a -> a -> TAG_) -> MonoType a -> MonoType a -> TAG_
+\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 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_
+
+
-- We assume that HsPreForAllTys have been smashed by now.
# ifdef DEBUG
-cmpPolyType _ (HsPreForAllTy _ _) _ = panic# "cmpPolyType:HsPreForAllTy:1st arg"
-cmpPolyType _ _ (HsPreForAllTy _ _) = panic# "cmpPolyType:HsPreForAllTy:2nd arg"
+cmpHsType _ (HsPreForAllTy _ _) _ = panic# "cmpHsType:HsPreForAllTy:1st arg"
+cmpHsType _ _ (HsPreForAllTy _ _) = panic# "cmpHsType:HsPreForAllTy:2nd arg"
# endif
-cmpPolyType cmp (HsForAllTy tvs1 c1 t1) (HsForAllTy tvs2 c2 t2)
- = cmpList cmp tvs1 tvs2 `thenCmp`
- cmpContext cmp c1 c2 `thenCmp`
- cmpMonoType cmp t1 t2
+cmpHsType cmp (HsForAllTy tvs1 c1 t1) (HsForAllTy tvs2 c2 t2)
+ = cmpList (cmpHsTyVar cmp) tvs1 tvs2 `thenCmp`
+ cmpContext cmp c1 c2 `thenCmp`
+ cmpHsType cmp t1 t2
------------
-cmpMonoType cmp (MonoTyVar n1) (MonoTyVar n2)
+cmpHsType cmp (MonoTyVar n1) (MonoTyVar n2)
= cmp n1 n2
-cmpMonoType cmp (MonoTupleTy tys1) (MonoTupleTy tys2)
- = cmpList (cmpMonoType cmp) tys1 tys2
-cmpMonoType cmp (MonoListTy ty1) (MonoListTy ty2)
- = cmpMonoType cmp ty1 ty2
+cmpHsType cmp (MonoTupleTy _ tys1) (MonoTupleTy _ tys2)
+ = cmpList (cmpHsType cmp) tys1 tys2
+cmpHsType cmp (MonoListTy _ ty1) (MonoListTy _ ty2)
+ = cmpHsType cmp ty1 ty2
-cmpMonoType cmp (MonoTyApp tc1 tys1) (MonoTyApp tc2 tys2)
+cmpHsType cmp (MonoTyApp tc1 tys1) (MonoTyApp tc2 tys2)
= cmp tc1 tc2 `thenCmp`
- cmpList (cmpMonoType cmp) tys1 tys2
+ cmpList (cmpHsType cmp) tys1 tys2
-cmpMonoType cmp (MonoFunTy a1 b1) (MonoFunTy a2 b2)
- = cmpMonoType cmp a1 a2 `thenCmp` cmpMonoType cmp b1 b2
+cmpHsType cmp (MonoFunTy a1 b1) (MonoFunTy a2 b2)
+ = cmpHsType cmp a1 a2 `thenCmp` cmpHsType cmp b1 b2
-cmpMonoType cmp (MonoDictTy c1 ty1) (MonoDictTy c2 ty2)
- = cmp c1 c2 `thenCmp` cmpMonoType cmp ty1 ty2
+cmpHsType cmp (MonoDictTy c1 ty1) (MonoDictTy c2 ty2)
+ = cmp c1 c2 `thenCmp` cmpHsType cmp ty1 ty2
-cmpMonoType cmp ty1 ty2 -- tags must be different
+cmpHsType cmp ty1 ty2 -- tags must be different
= let tag1 = tag ty1
tag2 = tag ty2
in
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 (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)
-------------------
cmpContext cmp a b
= cmpList cmp_ctxt a b
where
- cmp_ctxt (c1, tv1) (c2, tv2)
- = cmp c1 c2 `thenCmp` cmp tv1 tv2
-
-#endif {- COMPILING_GHC -}
+ cmp_ctxt (c1, ty1) (c2, ty2)
+ = cmp c1 c2 `thenCmp` cmpHsType cmp ty1 ty2
\end{code}