%
-% (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 (
- PolyType(..), MonoType(..),
- Context(..), ClassAssertion(..)
-
-#ifdef COMPILING_GHC
- , pprParendPolyType
- , pprParendMonoType, pprContext
- , extractMonoTyNames, extractCtxtTyNames
- , cmpPolyType, cmpMonoType, cmpContext
-#endif
+ 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
-#ifdef COMPILING_GHC
-IMP_Ubiq()
+#include "HsVersions.h"
+
+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
+\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"
+
-import Outputable ( interppSP, ifnotPprForUser )
-import Pretty
-import Type ( Kind )
-import Util ( thenCmp, cmpList, isIn, panic# )
+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
-#endif {- COMPILING_GHC -}
+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}
-data PolyType name
- = HsPreForAllTy (Context name)
- (MonoType name)
+type HsContext name = [HsPred 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.
+data HsPred name = HsClassP name [HsType name]
+ | HsIParam (IPName name) (HsType name)
- | HsForAllTy [name]
- (Context name)
- (MonoType name)
+data HsType name
+ = HsForAllTy (Maybe [HsTyVarBndr name]) -- Nothing for implicitly quantified signatures
+ (HsContext name)
+ (HsType name)
-type Context name = [ClassAssertion name]
+ | HsTyVar name -- Type variable or type constructor
-type ClassAssertion name = (name, name)
+ | HsAppTy (HsType name)
+ (HsType name)
-data MonoType name
- = MonoTyVar name -- Type variable
+ | HsFunTy (HsType name) -- function type
+ (HsType name)
- | MonoTyApp name -- Type constructor or variable
- [MonoType name]
+ | HsListTy (HsType name) -- Element type
- -- We *could* have a "MonoTyCon name" equiv to "MonoTyApp name []"
- -- (for efficiency, what?) WDP 96/02/18
+ | HsPArrTy (HsType name) -- Elem. type of parallel array: [:t:]
- | MonoFunTy (MonoType name) -- function type
- (MonoType name)
+ | HsTupleTy HsTupCon
+ [HsType name] -- Element types (length gives arity)
- | MonoListTy (MonoType name) -- list type
- | MonoTupleTy [MonoType name] -- tuple type (length gives arity)
+ | HsOpTy (HsType name) (HsTyOp name) (HsType name)
-#ifdef COMPILING_GHC
- -- these next two are only used in unfoldings in interfaces
- | MonoDictTy name -- Class
- (MonoType 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.
- | MonoForAllTy [(name, Kind)]
- (MonoType name)
+ | HsNumTy Integer -- Generics only
+
+ -- these next two are only used in interfaces
+ | HsPredTy (HsPred name)
+
+ | HsKindSig (HsType name) -- (ty :: kind)
+ Kind -- A type with a kind signature
+
+
+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
+
+-----------------------
+data HsTupCon = HsTupCon Boxity Arity
+
+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)
+-- 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 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)
+
+mkHsDictTy cls tys = HsPredTy (HsClassP cls tys)
+mkHsIParamTy v ty = HsPredTy (HsIParam v ty)
+
+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.
-#endif {- COMPILING_GHC -}
+hsTyVarName (UserTyVar n) = n
+hsTyVarName (IfaceTyVar n _) = n
+
+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}
-This is used in various places:
+
\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 "=>"]
-pprContext sty context
- = ppBesides [ppLparen,
- ppInterleave ppComma (map pp_assert context),
- ppRparen, ppStr " =>"]
+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
- pp_assert (clas, ty)
- = ppCat [ppr sty clas, ppr sty ty]
+ 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}
+%* *
+%************************************************************************
+
+NB: these types get printed into interface files, so
+ don't change the printing format lightly
+
\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)
+instance (Outputable name) => Outputable (HsType name) where
+ ppr ty = pprHsType ty
+
+instance (Outputable name) => Outputable (HsTyOp name) where
+ ppr HsArrow = ftext FSLIT("->")
+ ppr (HsTyOp n) = ppr n
+
+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 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) -- 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
-pprMonoType, pprParendMonoType :: (Outputable name) => PprStyle -> MonoType name -> Pretty
+pprHsType, pprParendHsType :: (Outputable name) => HsType name -> SDoc
-pprMonoType sty ty = ppr_mono_ty sty pREC_TOP ty
-pprParendMonoType sty ty = ppr_mono_ty sty pREC_CON ty
+pprHsType ty = ppr_mono_ty pREC_TOP (de_paren ty)
+pprParendHsType ty = ppr_mono_ty pREC_CON ty
-ppr_mono_ty sty ctxt_prec (MonoTyVar name) = ppr sty name
+-- Remove outermost HsParTy parens before printing a type
+de_paren (HsParTy ty) = de_paren ty
+de_paren ty = ty
-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 (HsForAllTy maybe_tvs ctxt ty)
+ = maybeParen ctxt_prec pREC_FUN $
+ sep [pp_header, pprHsType ty]
+ where
+ 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
- if ctxt_prec < pREC_FUN then -- no parens needed
- ppSep [p1, ppBeside (ppStr "-> ") p2]
- else
- ppSep [ppBeside ppLparen p1, ppBesides [ppStr "-> ", p2, ppRparen]]
-
-ppr_mono_ty sty ctxt_prec (MonoTupleTy tys)
- = ppBesides [ppLparen, ppInterleave ppComma (map (ppr sty) tys), ppRparen]
-
-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 ]
-
--- 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 -}
+ maybeParen ctxt_prec pREC_FUN $
+ sep [p1, ptext SLIT("->") <+> p2]
+
+--------------------------
+pabrackets p = ptext SLIT("[:") <> p <> ptext SLIT(":]")
\end{code}
-\begin{code}
-#ifdef COMPILING_GHC
-extractCtxtTyNames :: Eq name => Context name -> [name]
-extractMonoTyNames :: Eq name => (name -> Bool) -> MonoType name -> [name]
+%************************************************************************
+%* *
+\subsection{Converting from Type to HsType}
+%* *
+%************************************************************************
-extractCtxtTyNames ctxt
- = foldr get [] ctxt
+@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 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
- get (clas, tv) acc
- | tv `is_elem` acc = acc
- | otherwise = tv : acc
+ 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
+ generic_case = foldl HsAppTy (HsTyVar (getName tc)) tys'
+ tys' = map toHsType tys
+ saturated = tys `lengthIs` tyConArity tc
- is_elem = isIn "extractCtxtTyNames"
+toHsType ty@(ForAllTy _ _) = case tcSplitSigmaTy ty of
+ (tvs, preds, tau) -> HsForAllTy (Just (map toHsTyVar tvs))
+ (map toHsPred preds)
+ (toHsType tau)
-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 -}
+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}
+
+
+%************************************************************************
+%* *
+\subsection{Comparison}
+%* *
+%************************************************************************
+
+\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}
-#ifdef COMPILING_GHC
+-------------------
+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}
-cmpPolyType :: (a -> a -> TAG_) -> PolyType a -> PolyType a -> TAG_
-cmpMonoType :: (a -> a -> TAG_) -> MonoType a -> MonoType a -> TAG_
-cmpContext :: (a -> a -> TAG_) -> Context a -> Context a -> TAG_
+\begin{code}
+-------------------
+eq_hsTypes env = eqListBy (eq_hsType env)
--- 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"
-# endif
+-------------------
+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
-cmpPolyType cmp (HsForAllTy tvs1 c1 t1) (HsForAllTy tvs2 c2 t2)
- = cmpList cmp tvs1 tvs2 `thenCmp`
- cmpContext cmp c1 c2 `thenCmp`
- cmpMonoType cmp t1 t2
+eq_hsType env (HsTyVar n1) (HsTyVar n2)
+ = eq_hsVar env n1 n2
------------
-cmpMonoType cmp (MonoTyVar n1) (MonoTyVar n2)
- = cmp n1 n2
+eq_hsType env (HsTupleTy c1 tys1) (HsTupleTy c2 tys2)
+ = (c1 == c2) && eq_hsTypes env tys1 tys2
-cmpMonoType cmp (MonoTupleTy tys1) (MonoTupleTy tys2)
- = cmpList (cmpMonoType cmp) tys1 tys2
-cmpMonoType cmp (MonoListTy ty1) (MonoListTy ty2)
- = cmpMonoType cmp ty1 ty2
+eq_hsType env (HsListTy ty1) (HsListTy ty2)
+ = eq_hsType env ty1 ty2
-cmpMonoType cmp (MonoTyApp tc1 tys1) (MonoTyApp tc2 tys2)
- = cmp tc1 tc2 `thenCmp`
- cmpList (cmpMonoType cmp) tys1 tys2
+eq_hsType env (HsKindSig ty1 k1) (HsKindSig ty2 k2)
+ = eq_hsType env ty1 ty2 && k1 `eqKind` k2
-cmpMonoType cmp (MonoFunTy a1 b1) (MonoFunTy a2 b2)
- = cmpMonoType cmp a1 a2 `thenCmp` cmpMonoType cmp b1 b2
+eq_hsType env (HsPArrTy ty1) (HsPArrTy ty2)
+ = eq_hsType env ty1 ty2
-cmpMonoType cmp (MonoDictTy c1 ty1) (MonoDictTy c2 ty2)
- = cmp c1 c2 `thenCmp` cmpMonoType 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
-cmpMonoType 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 ty1) = ILIT(7)
+eq_hsType env (HsFunTy a1 b1) (HsFunTy a2 b2)
+ = eq_hsType env a1 a2 && eq_hsType env b1 b2
+
+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
+
+
+eq_hsOp env (HsTyOp n1) (HsTyOp n2) = eq_hsVar env n1 n2
+eq_hsOp env HsArrow HsArrow = True
+eq_hsOp env op1 op2 = False
-------------------
-cmpContext cmp a b
- = cmpList cmp_ctxt a b
- where
- cmp_ctxt (c1, tv1) (c2, tv2)
- = cmp c1 c2 `thenCmp` cmp tv1 tv2
+eq_hsContext env a b = eqListBy (eq_hsPred env) a b
-#endif {- COMPILING_GHC -}
+-------------------
+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