X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2FhsSyn%2FHsTypes.lhs;h=a0e899940aec7f7e99e26df884ae992f1562b808;hb=0bffc410964e1688ad80d277d53400659e697ab5;hp=884ee9f8bef644e0663343f8b4647760886eae95;hpb=a77abe6a30ea2763cfa1c0ca83cdce9b7200ced2;p=ghc-hetmet.git diff --git a/ghc/compiler/hsSyn/HsTypes.lhs b/ghc/compiler/hsSyn/HsTypes.lhs index 884ee9f..a0e8999 100644 --- a/ghc/compiler/hsSyn/HsTypes.lhs +++ b/ghc/compiler/hsSyn/HsTypes.lhs @@ -1,271 +1,570 @@ % -% (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, + , hsUsOnce, hsUsMany + + , 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 -import 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, + usOnceTyConKey, usManyTyConKey, hasKey, unboundKey, + usOnceTyConName, usManyTyConName ) +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 -import Outputable ( interppSP, ifnotPprForUser ) -import Pretty -import Type ( Kind ) -import Util ( thenCmp, cmpList, isIn, panic# ) +placeHolderType :: PostTcType -- Used before typechecking +placeHolderType = panic "Evaluated the place holder for a PostTcType" -#endif {- COMPILING_GHC -} + +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} -data PolyType name - = HsPreForAllTy (Context name) - (MonoType name) +type HsContext name = [HsPred name] + +data HsPred name = HsClassP name [HsType name] + | HsIParam (IPName name) (HsType name) + +data HsType name + = HsForAllTy (Maybe [HsTyVarBndr name]) -- Nothing for implicitly quantified signatures + (HsContext name) + (HsType name) + + | HsTyVar name -- Type variable or type constructor + + | HsAppTy (HsType name) + (HsType name) + + | HsFunTy (HsType name) -- function type + (HsType name) + + | HsListTy (HsType name) -- Element type - -- 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. + | HsPArrTy (HsType name) -- Elem. type of parallel array: [:t:] - | HsForAllTy [name] - (Context name) - (MonoType name) + | HsTupleTy HsTupCon + [HsType name] -- Element types (length gives arity) -type Context name = [ClassAssertion name] + | HsOpTy (HsType name) (HsTyOp name) (HsType name) -type ClassAssertion name = (name, 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. -data MonoType name - = MonoTyVar name -- Type variable + | HsNumTy Integer -- Generics only - | MonoTyApp name -- Type constructor or variable - [MonoType name] + -- these next two are only used in interfaces + | HsPredTy (HsPred name) - -- We *could* have a "MonoTyCon name" equiv to "MonoTyApp name []" - -- (for efficiency, what?) WDP 96/02/18 + | HsKindSig (HsType name) -- (ty :: kind) + Kind -- A type with a kind signature - | MonoFunTy (MonoType name) -- function type - (MonoType name) - | MonoListTy (MonoType name) -- list type - | MonoTupleTy [MonoType name] -- tuple type (length gives arity) +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 -#ifdef COMPILING_GHC - -- these next two are only used in unfoldings in interfaces - | MonoDictTy name -- Class - (MonoType name) +----------------------- +hsUsOnce, hsUsMany :: HsType RdrName +hsUsOnce = HsTyVar (mkUnqual tvName FSLIT(".")) -- deep magic +hsUsMany = HsTyVar (mkUnqual tvName FSLIT("!")) -- deep magic - | MonoForAllTy [(name, Kind)] - (MonoType name) +hsUsOnce_Name, hsUsMany_Name :: HsType Name +hsUsOnce_Name = HsTyVar usOnceTyConName +hsUsMany_Name = HsTyVar usManyTyConName + +----------------------- +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') + | tc `hasKey` usOnceTyConKey = hsUsOnce_Name -- must print !, . unqualified + | tc `hasKey` usManyTyConKey = hsUsMany_Name -- must print !, . unqualified + | 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} -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! + +%************************************************************************ +%* * +\subsection{Comparison} +%* * +%************************************************************************ + \begin{code} -#ifdef COMPILING_GHC +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} -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} +type EqHsEnv n = FiniteMap n n +-- Tracks the mapping from L-variables to R-variables --- 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_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 -cmpPolyType cmp (HsForAllTy tvs1 c1 t1) (HsForAllTy tvs2 c2 t2) - = thenCmp (cmp_tvs tvs1 tvs2) - (thenCmp (cmpContext cmp c1 c2) (cmpMonoType cmp t1 t2)) - where - cmp_tvs [] [] = EQ_ - cmp_tvs [] _ = LT_ - cmp_tvs _ [] = GT_ - cmp_tvs (a:as) (b:bs) - = thenCmp (cmp a b) (cmp_tvs as bs) - cmp_tvs _ _ = panic# "cmp_tvs" - ------------ -cmpMonoType 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 - -cmpMonoType cmp (MonoTyApp tc1 tys1) (MonoTyApp tc2 tys2) - = thenCmp (cmp tc1 tc2) (cmpList (cmpMonoType cmp) tys1 tys2) - -cmpMonoType cmp (MonoFunTy a1 b1) (MonoFunTy a2 b2) - = thenCmp (cmpMonoType cmp a1 a2) (cmpMonoType cmp b1 b2) - -cmpMonoType cmp (MonoDictTy c1 ty1) (MonoDictTy c2 ty2) - = thenCmp (cmp c1 c2) (cmpMonoType cmp ty1 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) +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. +\begin{code} ------------------- -cmpContext cmp a b - = cmpList cmp_ctxt a b +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} + +\begin{code} +------------------- +eq_hsTypes env = eqListBy (eq_hsType env) + +------------------- +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 - cmp_ctxt (c1, tv1) (c2, tv2) - = thenCmp (cmp c1 c2) (cmp tv1 tv2) + 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 + +eq_hsType env (HsTyVar n1) (HsTyVar n2) + = eq_hsVar env n1 n2 + +eq_hsType env (HsTupleTy c1 tys1) (HsTupleTy c2 tys2) + = (c1 == c2) && eq_hsTypes env tys1 tys2 + +eq_hsType env (HsListTy ty1) (HsListTy ty2) + = eq_hsType env ty1 ty2 + +eq_hsType env (HsKindSig ty1 k1) (HsKindSig ty2 k2) + = eq_hsType env ty1 ty2 && k1 `eqKind` k2 + +eq_hsType env (HsPArrTy ty1) (HsPArrTy ty2) + = eq_hsType env ty1 ty2 -#endif {- COMPILING_GHC -} +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 + +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 + +------------------- +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}