\begin{code}
module HsTypes (
- HsType(..), MonoUsageAnn(..), HsTyVar(..),
- HsContext, HsClassAssertion, HsPred(..)
-
- , mkHsForAllTy, mkHsUsForAllTy
- , getTyVarName, replaceTyVarName
- , pprParendHsType
- , pprForAll, pprHsContext, pprHsClassAssertion, pprHsPred
- , cmpHsType, cmpHsTypes, cmpHsContext, cmpHsPred
+ HsType(..), HsTyVarBndr(..), HsTyOp(..),
+ , HsContext, HsPred(..)
+ , HsTupCon(..), hsTupParens, mkHsTupCon,
+
+ , mkHsForAllTy, mkHsDictTy, mkHsIParamTy
+ , hsTyVarName, hsTyVarNames, replaceTyVarName
+ , splitHsInstDeclTy
+
+ -- Type place holder
+ , PostTcType, placeHolderType,
+
+ -- Name place holder
+ , SyntaxName, placeHolderName,
+
+ -- Printing
+ , pprParendHsType, pprHsForAll, pprHsContext, ppr_hs_context, pprHsTyVarBndr
+
+ -- Equality over Hs things
+ , EqHsEnv, emptyEqHsEnv, extendEqHsEnv,
+ , eqWithHsTyVars, eq_hsVar, eq_hsVars, eq_hsTyVars, 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 TcType ( Type, Kind, ThetaType, SourceType(..),
+ tcSplitSigmaTy, liftedTypeKind, eqKind, tcEqType
+ )
+import TypeRep ( Type(..), TyNote(..) ) -- toHsType sees the representation
+import TyCon ( isTupleTyCon, tupleTyConBoxity, tyConArity, isNewTyCon, getSynTyConDefn )
+import RdrName ( RdrName, mkUnqual )
+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 ( listTyConKey, parrTyConKey,
+ hasKey, unboundKey )
+import SrcLoc ( noSrcLoc )
+import Util ( eqListBy, lengthIs )
+import FiniteMap
import Outputable
-import Util ( thenCmp, cmpList )
\end{code}
+
+%************************************************************************
+%* *
+\subsection{Annotating the syntax}
+%* *
+%************************************************************************
+
+\begin{code}
+type PostTcType = Type -- Used for slots in the abstract syntax
+ -- where we want to keep slot for a type
+ -- to be added by the type checker...but
+ -- before typechecking it's just bogus
+
+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}
+
+
+%************************************************************************
+%* *
+\subsection{Data types}
+%* *
+%************************************************************************
+
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 = HsClassP name [HsType name]
+ | HsIParam (IPName 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 or type constructor
- | 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
+ | HsListTy (HsType name) -- Element type
+
+ | HsPArrTy (HsType name) -- Elem. type of parallel array: [:t:]
- | MonoTupleTy [HsType name] -- Element types (length gives arity)
- Bool -- boxed?
+ | 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
- | MonoDictTy name -- Class
- [HsType name]
+ | HsPredTy (HsPred name)
+
+ | HsKindSig (HsType name) -- (ty :: kind)
+ Kind -- A type with a kind signature
+
- | MonoUsgTy (MonoUsageAnn name)
- (HsType name)
+data HsTyOp name = HsArrow | HsTyOp name
+ -- Function arrows from *source* get read in as HsOpTy t1 HsArrow t2
+ -- But when we generate or parse interface files, we use HsFunTy.
+ -- This keeps interfaces a bit smaller, because there are a lot of arrows
- | MonoUsgForAllTy name
- (HsType name)
+-----------------------
+data HsTupCon = HsTupCon Boxity Arity
-data MonoUsageAnn name
- = MonoUsOnce
- | MonoUsMany
- | MonoUsVar name
-
+instance Eq HsTupCon where
+ (HsTupCon b1 a1) == (HsTupCon b2 a2) = b1==b2 && a1==a2
+
+mkHsTupCon :: NameSpace -> Boxity -> [a] -> HsTupCon
+mkHsTupCon space boxity args = HsTupCon boxity (length args)
+hsTupParens :: HsTupCon -> 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)
--
-- 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)
-mkHsUsForAllTy uvs ty = foldr (\ uv ty -> MonoUsgForAllTy uv ty)
- ty uvs
+mkHsDictTy cls tys = HsPredTy (HsClassP cls tys)
+mkHsIParamTy v ty = HsPredTy (HsIParam v ty)
-data HsTyVar name
+data HsTyVarBndr 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.
-getTyVarName (UserTyVar n) = n
-getTyVarName (IfaceTyVar n _) = n
+hsTyVarName (UserTyVar n) = n
+hsTyVarName (IfaceTyVar n _) = n
-replaceTyVarName :: HsTyVar name1 -> name2 -> HsTyVar name2
+hsTyVarNames tvs = map hsTyVarName tvs
+
+replaceTyVarName :: HsTyVarBndr name1 -> name2 -> HsTyVarBndr name2
replaceTyVarName (UserTyVar n) n' = UserTyVar n'
replaceTyVarName (IfaceTyVar n k) n' = IfaceTyVar n' k
\end{code}
+\begin{code}
+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)
+
+splitHsInstDeclTy inst_ty
+ = case inst_ty of
+ HsForAllTy (Just tvs) cxt1 tau
+ -> (tvs, cxt1++cxt2, cls, tys)
+ where
+ (cxt2, cls, tys) = split_tau tau
+
+ 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}
+
+
%************************************************************************
%* *
\subsection{Pretty printing}
%* *
%************************************************************************
-\begin{code}
+NB: these types get printed into interface files, so
+ don't change the printing format lightly
+\begin{code}
instance (Outputable name) => Outputable (HsType name) where
ppr ty = pprHsType ty
-instance (Outputable name) => Outputable (HsTyVar name) where
- ppr (UserTyVar name) = ppr name
- ppr (IfaceTyVar name kind) = hsep [ppr name, dcolon, ppr kind]
+instance (Outputable name) => Outputable (HsTyOp name) where
+ ppr HsArrow = ftext FSLIT("->")
+ ppr (HsTyOp n) = ppr n
--- Better to see those for-alls
--- pprForAll [] = empty
-pprForAll tvs = ptext SLIT("forall") <+> interppSP tvs <> ptext SLIT(".")
+instance (Outputable name) => Outputable (HsTyVarBndr name) where
+ ppr (UserTyVar name) = ppr name
+ ppr (IfaceTyVar name kind) = pprHsTyVarBndr name kind
+
+instance Outputable name => Outputable (HsPred name) where
+ ppr (HsClassP clas tys) = ppr clas <+> hsep (map pprParendHsType tys)
+ ppr (HsIParam n ty) = hsep [ppr n, dcolon, ppr ty]
+
+pprHsTyVarBndr :: Outputable name => name -> Kind -> SDoc
+pprHsTyVarBndr name kind | kind `eqKind` liftedTypeKind = ppr name
+ | otherwise = hsep [ppr name, dcolon, pprParendKind kind]
+
+pprHsForAll [] [] = empty
+pprHsForAll tvs cxt
+ -- This printer is used for both interface files and
+ -- printing user types in error messages; and alas the
+ -- two use slightly different syntax. Ah well.
+ = getPprStyle $ \ sty ->
+ if userStyle sty then
+ ptext SLIT("forall") <+> interppSP tvs <> dot <+>
+ -- **! ToDo: want to hide uvars from user, but not enough info
+ -- in a HsTyVarBndr name (see PprType). KSW 2000-10.
+ pprHsContext cxt
+ else -- Used in interfaces
+ ptext SLIT("__forall") <+> interppSP tvs <+>
+ ppr_hs_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_hs_context cxt <+> ptext SLIT("=>")
+
+ppr_hs_context [] = empty
+ppr_hs_context cxt = parens (interpp'SP cxt)
\end{code}
\begin{code}
-pREC_TOP = (0 :: Int)
-pREC_FUN = (1 :: Int)
-pREC_CON = (2 :: Int)
-
-maybeParen :: Bool -> SDoc -> SDoc
-maybeParen True p = parens p
-maybeParen False p = p
+pREC_TOP = (0 :: Int) -- type in ParseIface.y
+pREC_FUN = (1 :: Int) -- btype in ParseIface.y
+ -- 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) $
- sep [pp_tvs, pprHsContext ctxt, pprHsType ty]
+ = maybeParen ctxt_prec pREC_FUN $
+ sep [pp_header, pprHsType ty]
where
- pp_tvs = case maybe_tvs of
- Just tvs -> pprForAll tvs
- Nothing -> text "{- implicit forall -}"
-
-ppr_mono_ty ctxt_prec (MonoTyVar name)
- = ppr name
-
-ppr_mono_ty ctxt_prec (MonoFunTy ty1 ty2)
+ 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) = 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)
+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]
+
+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])
+ 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("#)")
+--------------------------
+pabrackets p = ptext SLIT("[:") <> p <> ptext SLIT(":]")
+\end{code}
-ppr_mono_ty ctxt_prec (MonoListTy ty)
- = brackets (ppr_mono_ty pREC_TOP ty)
-ppr_mono_ty ctxt_prec (MonoTyApp fun_ty arg_ty)
- = maybeParen (ctxt_prec >= pREC_CON)
- (hsep [ppr_mono_ty pREC_FUN fun_ty, ppr_mono_ty pREC_CON arg_ty])
+%************************************************************************
+%* *
+\subsection{Converting from Type to HsType}
+%* *
+%************************************************************************
-ppr_mono_ty ctxt_prec (MonoDictTy clas tys)
- = ppr clas <+> hsep (map (ppr_mono_ty pREC_CON) tys)
+@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.
-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
- ]
+\begin{code}
+toHsTyVar :: TyVar -> HsTyVarBndr Name
+toHsTyVar tv = IfaceTyVar (getName tv) (tyVarKind tv)
+
+toHsTyVars tvs = map toHsTyVar tvs
+
+toHsType :: Type -> HsType Name
+-- This function knows the representation of types
+toHsType (TyVarTy tv) = HsTyVar (getName tv)
+toHsType (FunTy arg res) = HsFunTy (toHsType arg) (toHsType res)
+toHsType (AppTy fun arg) = HsAppTy (toHsType fun) (toHsType arg)
+
+toHsType (NoteTy (SynNote ty@(TyConApp tycon tyargs)) real_ty)
+ | isNewTyCon tycon = toHsType ty
+ | syn_matches = toHsType ty -- Use synonyms if possible!!
+ | otherwise =
+#ifdef DEBUG
+ pprTrace "WARNING: synonym info lost in .hi file for " (ppr syn_ty) $
+#endif
+ toHsType real_ty -- but drop it if not.
+ where
+ syn_matches = ty_from_syn `tcEqType` real_ty
+ (tyvars,syn_ty) = getSynTyConDefn tycon
+ ty_from_syn = substTyWith tyvars tyargs syn_ty
+
+ -- We only use the type synonym in the file if this doesn't cause
+ -- us to lose important information. This matters for usage
+ -- annotations. It's an issue if some of the args to the synonym
+ -- have arrows in them, or if the synonym's RHS has an arrow; for
+ -- example, with nofib/real/ebnf2ps/ in Parsers.using.
+
+ -- **! It would be nice if when this test fails we could still
+ -- write the synonym in as a Note, so we don't lose the info for
+ -- error messages, but it's too much work for right now.
+ -- KSW 2000-07.
+
+toHsType (NoteTy _ ty) = toHsType ty
+
+toHsType (SourceTy (NType tc tys)) = foldl HsAppTy (HsTyVar (getName tc)) (map toHsType tys)
+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 (tupleTyConBoxity tc) (tyConArity tc)) tys'
+ | tc `hasKey` listTyConKey = HsListTy (head tys')
+ | tc `hasKey` parrTyConKey = HsPArrTy (head tys')
+ | otherwise = generic_case
where
- (uvars,sigma) = split [] ty
- pp_uvars = interppSP uvars
+ generic_case = foldl HsAppTy (HsTyVar (getName tc)) tys'
+ tys' = map toHsType tys
+ saturated = tys `lengthIs` tyConArity tc
- split uvs (MonoUsgForAllTy uv ty') = split (uv:uvs) ty'
- split uvs ty' = (reverse uvs,ty')
+toHsType ty@(ForAllTy _ _) = case tcSplitSigmaTy ty of
+ (tvs, preds, tau) -> HsForAllTy (Just (map toHsTyVar tvs))
+ (map toHsPred preds)
+ (toHsType tau)
-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
+toHsPred (ClassP cls tys) = HsClassP (getName cls) (map toHsType tys)
+toHsPred (IParam n ty) = HsIParam n (toHsType ty)
+
+toHsContext :: ThetaType -> HsContext Name
+toHsContext theta = map toHsPred theta
+
+toHsFDs :: [FunDep TyVar] -> [FunDep Name]
+toHsFDs fds = [(map getName ns, map getName ms) | (ns,ms) <- fds]
\end{code}
%* *
%************************************************************************
+\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 `eqKind` 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 (HsKindSig ty1 k1) (HsKindSig ty2 k2)
+ = eq_hsType env ty1 ty2 && k1 `eqKind` k2
-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 (HsPArrTy ty1) (HsPArrTy ty2)
+ = eq_hsType env ty1 ty2
-cmpHsType cmp (MonoFunTy a1 b1) (MonoFunTy a2 b2)
- = cmpHsType cmp a1 a2 `thenCmp` cmpHsType cmp b1 b2
+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 (MonoDictTy c1 tys1) (MonoDictTy c2 tys2)
- = cmp c1 c2 `thenCmp` cmpHsTypes cmp tys1 tys2
+eq_hsType env (HsFunTy a1 b1) (HsFunTy a2 b2)
+ = eq_hsType env a1 a2 && eq_hsType env b1 b2
-cmpHsType cmp (MonoUsgTy u1 ty1) (MonoUsgTy u2 ty2)
- = cmpUsg cmp u1 u2 `thenCmp` cmpHsType cmp ty1 ty2
+eq_hsType env (HsPredTy p1) (HsPredTy p2)
+ = eq_hsPred env p1 p2
+
+eq_hsType env (HsOpTy lty1 op1 rty1) (HsOpTy lty2 op2 rty2)
+ = eq_hsOp env op1 op2 && eq_hsType env lty1 lty2 && eq_hsType env rty1 rty2
+
+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)
+
+eq_hsOp env (HsTyOp n1) (HsTyOp n2) = eq_hsVar env n1 n2
+eq_hsOp env HsArrow HsArrow = True
+eq_hsOp env op1 op2 = False
-------------------
-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 (HsClassP c1 tys1) (HsClassP c2 tys2)
+ = c1 == c2 && eq_hsTypes env tys1 tys2
+eq_hsPred env (HsIParam n1 ty1) (HsIParam n2 ty2)
+ = n1 == n2 && eq_hsType env ty1 ty2
+eq_hsPred env _ _ = False
\end{code}
projects / ghc-hetmet.git / blobdiff