X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2FhsSyn%2FHsTypes.lhs;h=a795a2f1ae1ad91e88285e2de91f56cd076563e3;hb=e7f04a0da2a711266b58274a1a935d93bb034620;hp=2536e8d07ca8f2f694c30880a22e64476aa7d21f;hpb=a61b7e6edcf2fa8e1a882b6c786126560ec6090d;p=ghc-hetmet.git diff --git a/ghc/compiler/hsSyn/HsTypes.lhs b/ghc/compiler/hsSyn/HsTypes.lhs index 2536e8d..a795a2f 100644 --- a/ghc/compiler/hsSyn/HsTypes.lhs +++ b/ghc/compiler/hsSyn/HsTypes.lhs @@ -5,71 +5,101 @@ \begin{code} module HsTypes ( - HsType(..), MonoUsageAnn(..), HsTyVar(..), - HsContext, HsClassAssertion, HsPred(..) + HsType(..), HsUsageAnn(..), HsTyVarBndr(..), + , HsContext, HsPred(..) + , HsTupCon(..), hsTupParens, mkHsTupCon, - , mkHsForAllTy, mkHsUsForAllTy + , mkHsForAllTy, mkHsUsForAllTy, mkHsDictTy, mkHsIParamTy , getTyVarName, replaceTyVarName - , pprParendHsType - , pprForAll, pprHsContext, pprHsClassAssertion, pprHsPred - , cmpHsType, cmpHsTypes, cmpHsContext, cmpHsPred + + -- Printing + , pprParendHsType, pprHsForAll, pprHsContext, pprHsTyVarBndr + + -- Equality over Hs things + , EqHsEnv, emptyEqHsEnv, extendEqHsEnv, + , eqWithHsTyVars, eq_hsVar, eq_hsVars, eq_hsType, eq_hsContext, eqListBy + + -- Converting from Type to HsType + , toHsType, toHsTyVar, toHsTyVars, toHsContext, toHsFDs ) where #include "HsVersions.h" -import Type ( Kind, UsageAnn(..) ) -import PprType ( {- instance Outputable Kind -} ) +import Class ( FunDep ) +import Type ( Type, Kind, PredType(..), UsageAnn(..), ClassContext, + getTyVar_maybe, splitFunTy_maybe, splitAppTy_maybe, + splitTyConApp_maybe, splitPredTy_maybe, + splitUsgTy, splitSigmaTy, unUsgTy, boxedTypeKind + ) +import TypeRep ( Type(..), TyNote(..) ) -- toHsType sees the representation +import TyCon ( isTupleTyCon, tupleTyConBoxity, tyConArity, tyConClass_maybe ) +import PrelInfo ( mkTupConRdrName ) +import RdrName ( RdrName ) +import Name ( toRdrName ) +import OccName ( NameSpace ) +import Var ( TyVar, tyVarKind ) +import PprType ( {- instance Outputable Kind -}, pprParendKind ) +import BasicTypes ( Arity, Boxity(..), tupleParens ) +import Unique ( hasKey, listTyConKey, Uniquable(..) ) +import Maybes ( maybeToBool ) +import FiniteMap import Outputable -import Util ( thenCmp, cmpList ) \end{code} This is the syntax for types as seen in type signatures. \begin{code} 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 HsPred name = HsPClass name [HsType name] + | HsPIParam name (HsType name) data HsType name - = HsForAllTy (Maybe [HsTyVar name]) -- Nothing for implicitly quantified signatures - (HsContext name) - (HsType name) + = HsForAllTy (Maybe [HsTyVarBndr name]) -- Nothing for implicitly quantified signatures + (HsContext name) + (HsType name) - | MonoTyVar name -- Type variable + | HsTyVar name -- Type variable - | MonoTyApp (HsType name) + | HsAppTy (HsType name) (HsType name) - | MonoFunTy (HsType name) -- function type + | HsFunTy (HsType name) -- function type (HsType name) - | MonoListTy (HsType name) -- Element type - - | MonoTupleTy [HsType name] -- Element types (length gives arity) - Bool -- boxed? + | HsListTy (HsType name) -- Element type - | MonoIParamTy name (HsType name) + | HsTupleTy (HsTupCon name) + [HsType name] -- Element types (length gives arity) -- these next two are only used in interfaces - | MonoDictTy name -- Class - [HsType name] + | HsPredTy (HsPred name) - | MonoUsgTy (MonoUsageAnn name) + | HsUsgTy (HsUsageAnn name) (HsType name) - | MonoUsgForAllTy name + | HsUsgForAllTy name (HsType name) -data MonoUsageAnn name - = MonoUsOnce - | MonoUsMany - | MonoUsVar name +data HsUsageAnn name + = HsUsOnce + | HsUsMany + | HsUsVar name +----------------------- +data HsTupCon name = HsTupCon name Boxity + +instance Eq name => Eq (HsTupCon name) where + (HsTupCon _ b1) == (HsTupCon _ b2) = b1==b2 + +mkHsTupCon :: NameSpace -> Boxity -> [a] -> HsTupCon RdrName +mkHsTupCon space boxity args = HsTupCon (mkTupConRdrName space boxity (length args)) boxity + +hsTupParens :: HsTupCon name -> SDoc -> SDoc +hsTupParens (HsTupCon _ b) p = tupleParens b p + +----------------------- -- Combine adjacent for-alls. -- The following awkward situation can happen otherwise: -- f :: forall a. ((Num a) => Int) @@ -87,10 +117,13 @@ mkHsForAllTy mtvs1 [] (HsForAllTy mtvs2 ctxt ty) = mkHsForAllTy (mtvs1 `plus (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) +mkHsUsForAllTy uvs ty = foldr (\ uv ty -> HsUsgForAllTy uv ty) ty uvs -data HsTyVar name +mkHsDictTy cls tys = HsPredTy (HsPClass cls tys) +mkHsIParamTy v ty = HsPredTy (HsPIParam v ty) + +data HsTyVarBndr name = UserTyVar name | IfaceTyVar name Kind -- *** NOTA BENE *** A "monotype" in a pragma can have @@ -100,7 +133,7 @@ data HsTyVar name getTyVarName (UserTyVar n) = n getTyVarName (IfaceTyVar n _) = n -replaceTyVarName :: HsTyVar name1 -> name2 -> HsTyVar name2 +replaceTyVarName :: HsTyVarBndr name1 -> name2 -> HsTyVarBndr name2 replaceTyVarName (UserTyVar n) n' = UserTyVar n' replaceTyVarName (IfaceTyVar n k) n' = IfaceTyVar n' k \end{code} @@ -113,31 +146,30 @@ replaceTyVarName (IfaceTyVar n k) n' = IfaceTyVar n' k %************************************************************************ \begin{code} - instance (Outputable name) => Outputable (HsType name) where ppr ty = pprHsType ty -instance (Outputable name) => Outputable (HsTyVar name) where +instance (Outputable name) => Outputable (HsTyVarBndr name) where ppr (UserTyVar name) = ppr name - ppr (IfaceTyVar name kind) = hsep [ppr name, dcolon, ppr kind] + ppr (IfaceTyVar name kind) = pprHsTyVarBndr name kind + +instance Outputable name => Outputable (HsPred name) where + ppr (HsPClass clas tys) = ppr clas <+> hsep (map pprParendHsType tys) + ppr (HsPIParam n ty) = hsep [{- char '?' <> -} ppr n, text "::", ppr ty] --- Better to see those for-alls --- pprForAll [] = empty -pprForAll tvs = ptext SLIT("forall") <+> interppSP tvs <> ptext SLIT(".") +pprHsTyVarBndr :: Outputable name => name -> Kind -> SDoc +pprHsTyVarBndr name kind | kind == boxedTypeKind = ppr name + | otherwise = hsep [ppr name, dcolon, pprParendKind kind] + +pprHsForAll [] [] = empty +pprHsForAll tvs cxt = ptext SLIT("__forall") <+> interppSP tvs <+> ppr_context cxt <+> 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] +pprHsContext [] = empty +pprHsContext cxt = ppr_context cxt <+> ptext SLIT("=>") + +ppr_context [] = empty +ppr_context cxt = parens (interpp'SP cxt) \end{code} \begin{code} @@ -158,42 +190,35 @@ pprParendHsType ty = ppr_mono_ty pREC_CON ty ppr_mono_ty ctxt_prec (HsForAllTy maybe_tvs ctxt ty) = maybeParen (ctxt_prec >= pREC_FUN) $ - sep [pp_tvs, pprHsContext ctxt, pprHsType ty] + sep [pp_header, pprHsType ty] where - pp_tvs = case maybe_tvs of - Just tvs -> pprForAll tvs - Nothing -> text "{- implicit forall -}" + pp_header = case maybe_tvs of + Just tvs -> pprHsForAll tvs ctxt + Nothing -> pprHsContext ctxt -ppr_mono_ty ctxt_prec (MonoTyVar name) +ppr_mono_ty ctxt_prec (HsTyVar name) = ppr name -ppr_mono_ty ctxt_prec (MonoFunTy ty1 ty2) +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 (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 ctxt_prec (HsTupleTy con tys) = hsTupParens con (interpp'SP tys) +ppr_mono_ty ctxt_prec (HsListTy ty) = brackets (ppr_mono_ty pREC_TOP ty) -ppr_mono_ty ctxt_prec (MonoListTy ty) - = brackets (ppr_mono_ty pREC_TOP ty) - -ppr_mono_ty ctxt_prec (MonoTyApp fun_ty arg_ty) +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]) -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 _ _) +ppr_mono_ty ctxt_prec (HsPredTy pred) = maybeParen (ctxt_prec >= pREC_FUN) $ + braces (ppr pred) + +ppr_mono_ty ctxt_prec ty@(HsUsgForAllTy _ _) + = sep [ ptext SLIT("__fuall") <+> brackets pp_uvars <+> ptext SLIT("=>"), ppr_mono_ty pREC_TOP sigma ] @@ -201,17 +226,83 @@ ppr_mono_ty ctxt_prec ty@(MonoUsgForAllTy _ _) (uvars,sigma) = split [] ty pp_uvars = interppSP uvars - split uvs (MonoUsgForAllTy uv ty') = split (uv:uvs) ty' + split uvs (HsUsgForAllTy uv ty') = split (uv:uvs) ty' split uvs ty' = (reverse uvs,ty') -ppr_mono_ty ctxt_prec (MonoUsgTy u ty) +ppr_mono_ty ctxt_prec (HsUsgTy 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 + HsUsOnce -> ptext SLIT("-") + HsUsMany -> ptext SLIT("!") + HsUsVar uv -> ppr uv +\end{code} + + +%************************************************************************ +%* * +\subsection{Converting from Type to HsType} +%* * +%************************************************************************ + +@toHsType@ converts from a Type to a HsType, making the latter look as +user-friendly as possible. Notably, it uses synonyms where possible, and +expresses overloaded functions using the '=>' context part of a HsForAllTy. + +\begin{code} +toHsTyVar :: TyVar -> HsTyVarBndr RdrName +toHsTyVar tv = IfaceTyVar (toRdrName tv) (tyVarKind tv) + +toHsTyVars tvs = map toHsTyVar tvs + +toHsType :: Type -> HsType RdrName +toHsType ty = toHsType' (unUsgTy ty) + -- For now we just discard the usage +-- = case splitUsgTy ty of +-- (usg, tau) -> HsUsgTy (toHsUsg usg) (toHsType' tau) + +toHsType' :: Type -> HsType RdrName +-- Called after the usage is stripped off +-- This function knows the representation of types +toHsType' (TyVarTy tv) = HsTyVar (toRdrName tv) +toHsType' (FunTy arg res) = HsFunTy (toHsType arg) (toHsType res) +toHsType' (AppTy fun arg) = HsAppTy (toHsType fun) (toHsType arg) + +toHsType' (NoteTy (SynNote ty) _) = toHsType ty -- Use synonyms if possible!! +toHsType' (NoteTy _ ty) = toHsType ty + +toHsType' ty@(TyConApp tc tys) -- Must be saturated because toHsType's arg is of kind * + | not saturated = generic_case + | isTupleTyCon tc = HsTupleTy (HsTupCon (toRdrName tc) (tupleTyConBoxity tc)) tys' + | tc `hasKey` listTyConKey = HsListTy (head tys') + | maybeToBool maybe_class = HsPredTy (HsPClass (toRdrName clas) tys') + | otherwise = generic_case + where + generic_case = foldl HsAppTy (HsTyVar (toRdrName tc)) tys' + maybe_class = tyConClass_maybe tc + Just clas = maybe_class + tys' = map toHsType tys + saturated = length tys == tyConArity tc + +toHsType' ty@(ForAllTy _ _) = case splitSigmaTy ty of + (tvs, preds, tau) -> HsForAllTy (Just (map toHsTyVar tvs)) + (map toHsPred preds) + (toHsType tau) + + +toHsPred (Class cls tys) = HsPClass (toRdrName cls) (map toHsType tys) +toHsPred (IParam n ty) = HsPIParam (toRdrName n) (toHsType ty) + +toHsContext :: ClassContext -> HsContext RdrName +toHsContext cxt = [HsPClass (toRdrName cls) (map toHsType tys) | (cls,tys) <- cxt] + +toHsUsg UsOnce = HsUsOnce +toHsUsg UsMany = HsUsMany +toHsUsg (UsVar v) = HsUsVar (toRdrName v) + +toHsFDs :: [FunDep TyVar] -> [FunDep RdrName] +toHsFDs fds = [(map toRdrName ns, map toRdrName ms) | (ns,ms) <- fds] \end{code} @@ -221,97 +312,115 @@ ppr_mono_ty ctxt_prec (MonoUsgTy u ty) %* * %************************************************************************ +\begin{code} +instance Ord a => Eq (HsType a) where + -- The Ord is needed because we keep a + -- finite map of variables to variables + (==) a b = eq_hsType emptyEqHsEnv a b + +instance Ord a => Eq (HsPred a) where + (==) a b = eq_hsPred emptyEqHsEnv a b + +eqWithHsTyVars :: Ord name => + [HsTyVarBndr name] -> [HsTyVarBndr name] + -> (EqHsEnv name -> Bool) -> Bool +eqWithHsTyVars = eq_hsTyVars emptyEqHsEnv +\end{code} + +\begin{code} +type EqHsEnv n = FiniteMap n n +-- Tracks the mapping from L-variables to R-variables + +eq_hsVar :: Ord n => EqHsEnv n -> n -> n -> Bool +eq_hsVar env n1 n2 = case lookupFM env n1 of + Just n1 -> n1 == n2 + Nothing -> n1 == n2 + +extendEqHsEnv env n1 n2 + | n1 == n2 = env + | otherwise = addToFM env n1 n2 + +emptyEqHsEnv :: EqHsEnv n +emptyEqHsEnv = emptyFM +\end{code} + 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! +in checking interfaces. \begin{code} -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 +------------------- +eq_hsTyVars env [] [] k = k env +eq_hsTyVars env (tv1:tvs1) (tv2:tvs2) k = eq_hsTyVar env tv1 tv2 $ \ env -> + eq_hsTyVars env tvs1 tvs2 k +eq_hsTyVars env _ _ _ = False + +eq_hsTyVar env (UserTyVar v1) (UserTyVar v2) k = k (extendEqHsEnv env v1 v2) +eq_hsTyVar env (IfaceTyVar v1 k1) (IfaceTyVar v2 k2) k = k1 == k2 && k (extendEqHsEnv env v1 v2) +eq_hsTyVar env _ _ _ = False + +eq_hsVars env [] [] k = k env +eq_hsVars env (v1:bs1) (v2:bs2) k = eq_hsVars (extendEqHsEnv env v1 v2) bs1 bs2 k +eq_hsVars env _ _ _ = False +\end{code} -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 +\begin{code} +------------------- +eq_hsTypes env = eqListBy (eq_hsType env) -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 +------------------- +eq_hsType env (HsForAllTy tvs1 c1 t1) (HsForAllTy tvs2 c2 t2) + = eq_tvs tvs1 tvs2 $ \env -> + eq_hsContext env c1 c2 && + eq_hsType env t1 t2 + where + eq_tvs Nothing (Just _) k = False + eq_tvs Nothing Nothing k = k env + eq_tvs (Just _) Nothing k = False + eq_tvs (Just tvs1) (Just tvs2) k = eq_hsTyVars env tvs1 tvs2 k -cmpHsType cmp (HsForAllTy tvs1 c1 t1) (HsForAllTy tvs2 c2 t2) - = cmpMaybe (cmpList (cmpHsTyVar cmp)) tvs1 tvs2 `thenCmp` - cmpHsContext cmp c1 c2 `thenCmp` - cmpHsType cmp t1 t2 +eq_hsType env (HsTyVar n1) (HsTyVar n2) + = eq_hsVar env n1 n2 -cmpHsType cmp (MonoTyVar n1) (MonoTyVar n2) - = cmp n1 n2 +eq_hsType env (HsTupleTy c1 tys1) (HsTupleTy c2 tys2) + = (c1 == c2) && eq_hsTypes env tys1 tys2 -cmpHsType cmp (MonoTupleTy tys1 b1) (MonoTupleTy tys2 b2) - = (b1 `compare` b2) `thenCmp` cmpHsTypes cmp tys1 tys2 +eq_hsType env (HsListTy ty1) (HsListTy ty2) + = eq_hsType env ty1 ty2 -cmpHsType cmp (MonoListTy ty1) (MonoListTy ty2) - = cmpHsType cmp 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 -cmpHsType cmp (MonoTyApp fun_ty1 arg_ty1) (MonoTyApp fun_ty2 arg_ty2) - = cmpHsType cmp fun_ty1 fun_ty2 `thenCmp` cmpHsType cmp arg_ty1 arg_ty2 +eq_hsType env (HsFunTy a1 b1) (HsFunTy a2 b2) + = eq_hsType env a1 a2 && eq_hsType env b1 b2 -cmpHsType cmp (MonoFunTy a1 b1) (MonoFunTy a2 b2) - = cmpHsType cmp a1 a2 `thenCmp` cmpHsType cmp b1 b2 +eq_hsType env (HsPredTy p1) (HsPredTy p2) + = eq_hsPred env p1 p2 -cmpHsType cmp (MonoDictTy c1 tys1) (MonoDictTy c2 tys2) - = cmp c1 c2 `thenCmp` cmpHsTypes cmp tys1 tys2 +eq_hsType env (HsUsgTy u1 ty1) (HsUsgTy u2 ty2) + = eqUsg u1 u2 && eq_hsType env ty1 ty2 -cmpHsType cmp (MonoUsgTy u1 ty1) (MonoUsgTy u2 ty2) - = cmpUsg cmp u1 u2 `thenCmp` cmpHsType cmp ty1 ty2 +eq_hsType env ty1 ty2 = False -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 (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) ------------------- -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 - 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 +eq_hsContext env a b = eqListBy (eq_hsPred env) a b + +------------------- +eq_hsPred env (HsPClass c1 tys1) (HsPClass c2 tys2) + = c1 == c2 && eq_hsTypes env tys1 tys2 +eq_hsPred env (HsPIParam n1 ty1) (HsPIParam n2 ty2) + = n1 == n2 && eq_hsType env ty1 ty2 +eq_hsPred env _ _ = False + +------------------- +eqUsg HsUsOnce HsUsOnce = True +eqUsg HsUsMany HsUsMany = True +eqUsg (HsUsVar u1) (HsUsVar u2) = u1 == u2 +eqUsg _ _ = False + +------------------- +eqListBy :: (a->a->Bool) -> [a] -> [a] -> Bool +eqListBy eq [] [] = True +eqListBy eq (x:xs) (y:ys) = eq x y && eqListBy eq xs ys +eqListBy eq xs ys = False \end{code}