X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2FhsSyn%2FHsDecls.lhs;h=54f993da7fc264931d5f99b89b79215354269cac;hb=47eef4b5780f0a5b5a37847097842daebd0f9285;hp=6952ef0c8bd8850137ea46da69c6ad05de90983b;hpb=f9120c200bcf613b58d742802172fb4c08171f0d;p=ghc-hetmet.git diff --git a/ghc/compiler/hsSyn/HsDecls.lhs b/ghc/compiler/hsSyn/HsDecls.lhs index 6952ef0..54f993d 100644 --- a/ghc/compiler/hsSyn/HsDecls.lhs +++ b/ghc/compiler/hsSyn/HsDecls.lhs @@ -1,143 +1,371 @@ % -% (c) The GRASP/AQUA Project, Glasgow University, 1992-1996 +% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998 % \section[HsDecls]{Abstract syntax: global declarations} -Definitions for: @FixityDecl@, @TyDecl@ and @ConDecl@, @ClassDecl@, -@InstDecl@, @DefaultDecl@. +Definitions for: @TyDecl@ and @ConDecl@, @ClassDecl@, +@InstDecl@, @DefaultDecl@ and @ForeignDecl@. \begin{code} -#include "HsVersions.h" - -module HsDecls where +module HsDecls ( + HsDecl(..), TyClDecl(..), InstDecl(..), RuleDecl(..), RuleBndr(..), + DefaultDecl(..), ForeignDecl(..), ForKind(..), + ExtName(..), isDynamicExtName, extNameStatic, + ConDecl(..), ConDetails(..), + BangType(..), getBangType, + DeprecDecl(..), DeprecTxt, + hsDeclName, instDeclName, tyClDeclName, tyClDeclNames, + isClassDecl, isSynDecl, isDataDecl, isIfaceSigDecl, countTyClDecls, + mkClassDeclSysNames, isIfaceRuleDecl, + getClassDeclSysNames + ) where -import Ubiq +#include "HsVersions.h" -- friends: -import HsLoop ( nullMonoBinds, MonoBinds, Sig ) -import HsPragmas ( DataPragmas, ClassPragmas, - InstancePragmas, ClassOpPragmas ) +import HsBinds ( HsBinds, MonoBinds, Sig(..), FixitySig(..) ) +import HsExpr ( HsExpr ) import HsTypes +import PprCore ( pprCoreRule ) +import HsCore ( UfExpr, UfBinder, HsIdInfo, pprHsIdInfo, + eq_ufBinders, eq_ufExpr, pprUfExpr + ) +import CoreSyn ( CoreRule(..) ) +import BasicTypes ( NewOrData(..) ) +import CallConv ( CallConv, pprCallConv ) -- others: -import Outputable -import Pretty +import FunDeps ( pprFundeps ) +import Class ( FunDep ) +import CStrings ( CLabelString, pprCLabelString ) +import Outputable import SrcLoc ( SrcLoc ) -import Util ( cmpList, panic#{-ToDo:rm eventually-} ) \end{code} + %************************************************************************ %* * -\subsection[FixityDecl]{A fixity declaration} +\subsection[HsDecl]{Declarations} %* * %************************************************************************ \begin{code} -data FixityDecl name - = InfixL name Int - | InfixR name Int - | InfixN name Int +data HsDecl name pat + = TyClD (TyClDecl name pat) + | InstD (InstDecl name pat) + | DefD (DefaultDecl name) + | ValD (HsBinds name pat) + | ForD (ForeignDecl name) + | FixD (FixitySig name) + | DeprecD (DeprecDecl name) + | RuleD (RuleDecl name pat) + +-- NB: all top-level fixity decls are contained EITHER +-- EITHER FixDs +-- OR in the ClassDecls in TyClDs +-- +-- The former covers +-- a) data constructors +-- b) class methods (but they can be also done in the +-- signatures of class decls) +-- c) imported functions (that have an IfacSig) +-- d) top level decls +-- +-- The latter is for class methods only +\end{code} + +\begin{code} +#ifdef DEBUG +hsDeclName :: (Outputable name, Outputable pat) + => HsDecl name pat -> name +#endif +hsDeclName (TyClD decl) = tyClDeclName decl +hsDeclName (InstD decl) = instDeclName decl +hsDeclName (ForD (ForeignDecl name _ _ _ _ _)) = name +hsDeclName (FixD (FixitySig name _ _)) = name +-- Others don't make sense +#ifdef DEBUG +hsDeclName x = pprPanic "HsDecls.hsDeclName" (ppr x) +#endif + + +instDeclName :: InstDecl name pat -> name +instDeclName (InstDecl _ _ _ (Just name) _) = name + \end{code} \begin{code} -instance (NamedThing name, Outputable name) - => Outputable (FixityDecl name) where - ppr sty (InfixL var prec) = print_it sty "l" prec var - ppr sty (InfixR var prec) = print_it sty "r" prec var - ppr sty (InfixN var prec) = print_it sty "" prec var - -print_it sty suff prec var - = ppBesides [ppStr "infix", ppStr suff, ppSP, ppInt prec, ppSP, pprOp sty var] +instance (Outputable name, Outputable pat) + => Outputable (HsDecl name pat) where + + ppr (TyClD dcl) = ppr dcl + ppr (ValD binds) = ppr binds + ppr (DefD def) = ppr def + ppr (InstD inst) = ppr inst + ppr (ForD fd) = ppr fd + ppr (FixD fd) = ppr fd + ppr (RuleD rd) = ppr rd + ppr (DeprecD dd) = ppr dd \end{code} +\begin{code} +instance Ord name => Eq (HsDecl name pat) where + -- Used only when comparing interfaces, + -- at which time only signature and type/class decls + (TyClD d1) == (TyClD d2) = d1 == d2 + _ == _ = False +\end{code} + + %************************************************************************ %* * \subsection[TyDecl]{@data@, @newtype@ or @type@ (synonym) type declaration} %* * %************************************************************************ +Type and class declarations carry 'implicit names'. In particular: + +Type A. +~~~~~~~ + Each data type decl defines + a worker name for each constructor + to-T and from-T convertors + Each class decl defines + a tycon for the class + a data constructor for that tycon + the worker for that constructor + a selector for each superclass + +All have occurrence names that are derived uniquely from their parent declaration. + +None of these get separate definitions in an interface file; they are +fully defined by the data or class decl. But they may *occur* in +interface files, of course. Any such occurrence must haul in the +relevant type or class decl. + +Plan of attack: + - Make up their occurrence names immediately + + - Ensure they "point to" the parent data/class decl + when loading that decl from an interface file + + - When renaming the decl look them up in the name cache, + ensure correct module and provenance is set + +Type B: Default methods and dictionary functions +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +Have their own binding in an interface file. + +Default methods : occurrence name is derived uniquely from the class decl. +Dict functions : occurrence name is derived from the instance decl, plus a unique number. + +Plan of attack: + - Do *not* make them point to the parent class decl + - Interface-file decls: treat just like Type A + - Source-file decls: the names aren't in the decl at all; + instead the typechecker makes them up + \begin{code} -data TyDecl name - = TyData (Context name) -- context - name -- type constructor - [name] -- type variables - [ConDecl name] -- data constructors (empty if abstract) - (Maybe [name]) -- derivings; Nothing => not specified - -- (i.e., derive default); Just [] => derive - -- *nothing*; Just => as you would - -- expect... - (DataPragmas name) +data TyClDecl name pat + = IfaceSig name -- It may seem odd to classify an interface-file signature + (HsType name) -- as a 'TyClDecl', but it's very convenient. These three + [HsIdInfo name] -- are the kind that appear in interface files. SrcLoc - | TyNew (Context name) -- context - name -- type constructor - [name] -- type variables - [ConDecl name] -- data constructor (empty if abstract) - (Maybe [name]) -- derivings; as above - (DataPragmas name) + | TyData NewOrData + (HsContext name) -- context + name -- type constructor + [HsTyVarBndr name] -- type variables + [ConDecl name] -- data constructors (empty if abstract) + Int -- Number of data constructors (valid even if type is abstract) + (Maybe [name]) -- derivings; Nothing => not specified + -- (i.e., derive default); Just [] => derive + -- *nothing*; Just => as you would + -- expect... SrcLoc + name -- generic converter functions + name -- generic converter functions - | TySynonym name -- type constructor - [name] -- type variables - (MonoType name) -- synonym expansion + | TySynonym name -- type constructor + [HsTyVarBndr name] -- type variables + (HsType name) -- synonym expansion SrcLoc + | ClassDecl (HsContext name) -- context... + name -- name of the class + [HsTyVarBndr name] -- the class type variables + [FunDep name] -- functional dependencies + [Sig name] -- methods' signatures + (MonoBinds name pat) -- default methods + (ClassDeclSysNames name) + SrcLoc \end{code} +Simple classifiers + \begin{code} -instance (NamedThing name, Outputable name) - => Outputable (TyDecl name) where +isIfaceSigDecl, isDataDecl, isSynDecl, isClassDecl :: TyClDecl name pat -> Bool - ppr sty (TySynonym tycon tyvars mono_ty src_loc) - = ppHang (pp_decl_head sty SLIT("type") ppNil tycon tyvars) - 4 (ppCat [ppEquals, ppr sty mono_ty]) +isIfaceSigDecl (IfaceSig _ _ _ _) = True +isIfaceSigDecl other = False - ppr sty (TyData context tycon tyvars condecls derivings pragmas src_loc) - = pp_tydecl sty - (pp_decl_head sty SLIT("data") (pprContext sty context) tycon tyvars) - (pp_condecls sty condecls) - derivings +isSynDecl (TySynonym _ _ _ _) = True +isSynDecl other = False - ppr sty (TyNew context tycon tyvars condecl derivings pragmas src_loc) - = pp_tydecl sty - (pp_decl_head sty SLIT("newtype") (pprContext sty context) tycon tyvars) - (pp_condecls sty condecl) - derivings +isDataDecl (TyData _ _ _ _ _ _ _ _ _ _) = True +isDataDecl other = False -pp_decl_head sty str pp_context tycon tyvars - = ppCat [ppPStr str, pp_context, ppr sty tycon, interppSP sty tyvars] +isClassDecl (ClassDecl _ _ _ _ _ _ _ _ ) = True +isClassDecl other = False +\end{code} -pp_condecls sty [] = ppNil -- abstract datatype -pp_condecls sty (c:cs) - = ppSep (ppBeside (ppStr "= ") (ppr sty c) - : map (\ x -> ppBeside (ppStr "| ") (ppr sty x)) cs) +Dealing with names -pp_tydecl sty pp_head pp_decl_rhs derivings - = ppHang pp_head 4 (ppSep [ - pp_decl_rhs, - case derivings of - Nothing -> ppNil - Just ds -> ppBeside (ppPStr SLIT("deriving ")) - (ppParens (ppInterleave ppComma (map (ppr sty) ds)))]) +\begin{code} +tyClDeclName :: TyClDecl name pat -> name +tyClDeclName (IfaceSig name _ _ _) = name +tyClDeclName (TyData _ _ name _ _ _ _ _ _ _) = name +tyClDeclName (TySynonym name _ _ _) = name +tyClDeclName (ClassDecl _ name _ _ _ _ _ _) = name + + +tyClDeclNames :: Eq name => TyClDecl name pat -> [(name, SrcLoc)] +-- Returns all the binding names of the decl, along with their SrcLocs +-- The first one is guaranteed to be the name of the decl +-- For record fields, the first one counts as the SrcLoc +-- We use the equality to filter out duplicate field names + +tyClDeclNames (TySynonym name _ _ loc) + = [(name,loc)] + +tyClDeclNames (ClassDecl _ cls_name _ _ sigs _ _ loc) + = (cls_name,loc) : [(n,loc) | ClassOpSig n _ _ loc <- sigs] + +tyClDeclNames (TyData _ _ tc_name _ cons _ _ loc _ _) + = (tc_name,loc) : conDeclsNames cons + +tyClDeclNames (IfaceSig name _ _ loc) = [(name,loc)] + +type ClassDeclSysNames name = [name] + -- [tycon, datacon wrapper, datacon worker, + -- superclass selector 1, ..., superclass selector n] + -- They are kept in a list rather than a tuple to make the + -- renamer easier. + +mkClassDeclSysNames :: (name, name, name, [name]) -> [name] +getClassDeclSysNames :: [name] -> (name, name, name, [name]) +mkClassDeclSysNames (a,b,c,ds) = a:b:c:ds +getClassDeclSysNames (a:b:c:ds) = (a,b,c,ds) \end{code} -A type for recording what types a datatype should be specialised to. -It's called a ``Sig'' because it's sort of like a ``type signature'' -for an datatype declaration. +\begin{code} +instance Ord name => Eq (TyClDecl name pat) where + -- Used only when building interface files + (==) (IfaceSig n1 t1 i1 _) + (IfaceSig n2 t2 i2 _) = n1==n2 && t1==t2 && i1==i2 + + (==) (TyData nd1 cxt1 n1 tvs1 cons1 _ _ _ _ _) + (TyData nd2 cxt2 n2 tvs2 cons2 _ _ _ _ _) + = n1 == n2 && + nd1 == nd2 && + eqWithHsTyVars tvs1 tvs2 (\ env -> + eq_hsContext env cxt1 cxt2 && + eqListBy (eq_ConDecl env) cons1 cons2 + ) + + (==) (TySynonym n1 tvs1 ty1 _) + (TySynonym n2 tvs2 ty2 _) + = n1 == n2 && + eqWithHsTyVars tvs1 tvs2 (\ env -> eq_hsType env ty1 ty2) + + (==) (ClassDecl cxt1 n1 tvs1 fds1 sigs1 _ _ _ ) + (ClassDecl cxt2 n2 tvs2 fds2 sigs2 _ _ _ ) + = n1 == n2 && + eqWithHsTyVars tvs1 tvs2 (\ env -> + eq_hsContext env cxt1 cxt2 && + eqListBy (eq_hsFD env) fds1 fds2 && + eqListBy (eq_cls_sig env) sigs1 sigs2 + ) + + (==) _ _ = False -- default case + + +eq_hsFD env (ns1,ms1) (ns2,ms2) + = eqListBy (eq_hsVar env) ns1 ns2 && eqListBy (eq_hsVar env) ms1 ms2 + +eq_cls_sig env (ClassOpSig n1 dm1 ty1 _) (ClassOpSig n2 dm2 ty2 _) + = n1==n2 && dm1 `eq_dm` dm2 && eq_hsType env ty1 ty2 + where + -- Ignore the name of the default method. + -- This is used for comparing declarations before putting + -- them into interface files, and the name of the default + -- method isn't relevant + (Just (explicit_dm1)) `eq_dm` (Just (explicit_dm2)) = explicit_dm1 == explicit_dm2 + Nothing `eq_dm` Nothing = True + dm1 `eq_dm` dm2 = False +\end{code} \begin{code} -data SpecDataSig name - = SpecDataSig name -- tycon to specialise - (MonoType name) - SrcLoc +countTyClDecls :: [TyClDecl name pat] -> (Int, Int, Int, Int, Int) + -- class, data, newtype, synonym decls +countTyClDecls decls + = (length [() | ClassDecl _ _ _ _ _ _ _ _ <- decls], + length [() | TyData DataType _ _ _ _ _ _ _ _ _ <- decls], + length [() | TyData NewType _ _ _ _ _ _ _ _ _ <- decls], + length [() | TySynonym _ _ _ _ <- decls], + length [() | IfaceSig _ _ _ _ <- decls]) +\end{code} + +\begin{code} +instance (Outputable name, Outputable pat) + => Outputable (TyClDecl name pat) where -instance (NamedThing name, Outputable name) - => Outputable (SpecDataSig name) where + ppr (IfaceSig var ty info _) = hsep [ppr var, dcolon, ppr ty, pprHsIdInfo info] - ppr sty (SpecDataSig tycon ty _) - = ppCat [ppStr "{-# SPECIALIZE data", ppr sty ty, ppStr "#-}"] + ppr (TySynonym tycon tyvars mono_ty src_loc) + = hang (ptext SLIT("type") <+> pp_decl_head [] tycon tyvars <+> equals) + 4 (ppr mono_ty) + + ppr (TyData new_or_data context tycon tyvars condecls ncons + derivings src_loc gen_conv1 gen_conv2) -- The generic names are not printed out ATM + = pp_tydecl + (ptext keyword <+> pp_decl_head context tycon tyvars <+> equals) + (pp_condecls condecls ncons) + derivings + where + keyword = case new_or_data of + NewType -> SLIT("newtype") + DataType -> SLIT("data") + + ppr (ClassDecl context clas tyvars fds sigs methods _ src_loc) + | null sigs -- No "where" part + = top_matter + + | otherwise -- Laid out + = sep [hsep [top_matter, ptext SLIT("where {")], + nest 4 (sep [sep (map ppr_sig sigs), pp_methods, char '}'])] + where + top_matter = ptext SLIT("class") <+> pp_decl_head context clas tyvars <+> pprFundeps fds + ppr_sig sig = ppr sig <> semi + pp_methods = getPprStyle $ \ sty -> + if ifaceStyle sty then empty else ppr methods + +pp_decl_head :: Outputable name => HsContext name -> name -> [HsTyVarBndr name] -> SDoc +pp_decl_head context thing tyvars = hsep [pprHsContext context, ppr thing, interppSP tyvars] + +pp_condecls [] ncons = ptext SLIT("{- abstract with") <+> int ncons <+> ptext SLIT("constructors -}") +pp_condecls (c:cs) ncons = sep (ppr c : map (\ c -> ptext SLIT("|") <+> ppr c) cs) + +pp_tydecl pp_head pp_decl_rhs derivings + = hang pp_head 4 (sep [ + pp_decl_rhs, + case derivings of + Nothing -> empty + Just ds -> hsep [ptext SLIT("deriving"), parens (interpp'SP ds)] + ]) \end{code} + %************************************************************************ %* * \subsection[ConDecl]{A data-constructor declaration} @@ -146,151 +374,162 @@ instance (NamedThing name, Outputable name) \begin{code} data ConDecl name - = ConDecl name -- prefix-style con decl - [BangType name] + = ConDecl name -- Constructor name; this is used for the + -- DataCon itself, and for the user-callable wrapper Id + + name -- Name of the constructor's 'worker Id' + -- Filled in as the ConDecl is built + + [HsTyVarBndr name] -- Existentially quantified type variables + (HsContext name) -- ...and context + -- If both are empty then there are no existentials + + (ConDetails name) SrcLoc - | ConOpDecl (BangType name) -- infix-style con decl - name +data ConDetails name + = VanillaCon -- prefix-style con decl + [BangType name] + + | InfixCon -- infix-style con decl + (BangType name) (BangType name) - SrcLoc - | RecConDecl name + | RecCon -- record-style con decl [([name], BangType name)] -- list of "fields" - SrcLoc +\end{code} - | NewConDecl name -- newtype con decl - (MonoType name) - SrcLoc +\begin{code} +conDeclsNames :: Eq name => [ConDecl name] -> [(name,SrcLoc)] + -- See tyClDeclNames for what this does + -- The function is boringly complicated because of the records + -- And since we only have equality, we have to be a little careful +conDeclsNames cons + = snd (foldl do_one ([], []) cons) + where + do_one (flds_seen, acc) (ConDecl name _ _ _ details loc) + = do_details ((name,loc):acc) details + where + do_details acc (RecCon flds) = foldl do_fld (flds_seen, acc) flds + do_details acc other = (flds_seen, acc) + + do_fld acc (flds, _) = foldl do_fld1 acc flds + + do_fld1 (flds_seen, acc) fld + | fld `elem` flds_seen = (flds_seen,acc) + | otherwise = (fld:flds_seen, (fld,loc):acc) +\end{code} +\begin{code} +eq_ConDecl env (ConDecl n1 _ tvs1 cxt1 cds1 _) + (ConDecl n2 _ tvs2 cxt2 cds2 _) + = n1 == n2 && + (eqWithHsTyVars tvs1 tvs2 $ \ env -> + eq_hsContext env cxt1 cxt2 && + eq_ConDetails env cds1 cds2) + +eq_ConDetails env (VanillaCon bts1) (VanillaCon bts2) + = eqListBy (eq_btype env) bts1 bts2 +eq_ConDetails env (InfixCon bta1 btb1) (InfixCon bta2 btb2) + = eq_btype env bta1 bta2 && eq_btype env btb1 btb2 +eq_ConDetails env (RecCon fs1) (RecCon fs2) + = eqListBy (eq_fld env) fs1 fs2 +eq_ConDetails env _ _ = False + +eq_fld env (ns1,bt1) (ns2, bt2) = ns1==ns2 && eq_btype env bt1 bt2 +\end{code} + +\begin{code} data BangType name - = Banged (MonoType name) - | Unbanged (MonoType name) + = Banged (HsType name) -- HsType: to allow Haskell extensions + | Unbanged (HsType name) -- (MonoType only needed for straight Haskell) + | Unpacked (HsType name) -- Field is strict and to be unpacked if poss. + +getBangType (Banged ty) = ty +getBangType (Unbanged ty) = ty +getBangType (Unpacked ty) = ty + +eq_btype env (Banged t1) (Banged t2) = eq_hsType env t1 t2 +eq_btype env (Unbanged t1) (Unbanged t2) = eq_hsType env t1 t2 +eq_btype env (Unpacked t1) (Unpacked t2) = eq_hsType env t1 t2 +eq_btype env _ _ = False \end{code} \begin{code} -instance (NamedThing name, Outputable name) => Outputable (ConDecl name) where - - ppr sty (ConDecl con tys _) - = ppCat [pprNonOp sty con, ppInterleave ppNil (map (ppr_bang sty) tys)] - ppr sty (ConOpDecl ty1 op ty2 _) - = ppCat [ppr_bang sty ty1, pprOp sty op, ppr_bang sty ty2] - ppr sty (NewConDecl con ty _) - = ppCat [pprNonOp sty con, pprParendMonoType sty ty] - ppr sty (RecConDecl con fields _) - = ppCat [pprNonOp sty con, ppChar '{', - ppInterleave pp'SP (map pp_field fields), ppChar '}'] - where - pp_field (n, ty) = ppCat [ppr sty n, ppPStr SLIT("::"), ppr_bang sty ty] +instance (Outputable name) => Outputable (ConDecl name) where + ppr (ConDecl con _ tvs cxt con_details loc) + = sep [pprHsForAll tvs cxt, ppr_con_details con con_details] -ppr_bang sty (Banged ty) = ppBeside (ppChar '!') (pprParendMonoType sty ty) -ppr_bang sty (Unbanged ty) = pprParendMonoType sty ty -\end{code} +ppr_con_details con (InfixCon ty1 ty2) + = hsep [ppr_bang ty1, ppr con, ppr_bang ty2] -%************************************************************************ -%* * -\subsection[ClassDecl]{A class declaration} -%* * -%************************************************************************ +ppr_con_details con (VanillaCon tys) + = ppr con <+> hsep (map (ppr_bang) tys) -\begin{code} -data ClassDecl tyvar uvar name pat - = ClassDecl (Context name) -- context... - name -- name of the class - name -- the class type variable - [Sig name] -- methods' signatures - (MonoBinds tyvar uvar name pat) -- default methods - (ClassPragmas name) - SrcLoc -\end{code} +ppr_con_details con (RecCon fields) + = ppr con <+> braces (hsep (punctuate comma (map ppr_field fields))) + where + ppr_field (ns, ty) = hsep (map (ppr) ns) <+> + dcolon <+> + ppr_bang ty -\begin{code} -instance (NamedThing name, Outputable name, Outputable pat, - Eq tyvar, Outputable tyvar, Eq uvar, Outputable uvar) - => Outputable (ClassDecl tyvar uvar name pat) where - - ppr sty (ClassDecl context clas tyvar sigs methods pragmas src_loc) - = let - top_matter = ppCat [ppStr "class", pprContext sty context, - ppr sty clas, ppr sty tyvar] - in - if null sigs && nullMonoBinds methods then - ppAbove top_matter (ppNest 4 (ppr sty pragmas)) - else - ppAboves [ppCat [top_matter, ppStr "where"], - ppNest 4 (ppAboves (map (ppr sty) sigs)), - ppNest 4 (ppr sty methods), - ppNest 4 (ppr sty pragmas) ] +instance Outputable name => Outputable (BangType name) where + ppr = ppr_bang + +ppr_bang (Banged ty) = ptext SLIT("!") <> pprParendHsType ty +ppr_bang (Unbanged ty) = pprParendHsType ty +ppr_bang (Unpacked ty) = ptext SLIT("! !") <> pprParendHsType ty \end{code} + %************************************************************************ %* * -\subsection[InstDecl]{An instance declaration (also, @SpecInstSig@)} +\subsection[InstDecl]{An instance declaration %* * %************************************************************************ \begin{code} -data InstDecl tyvar uvar name pat - = InstDecl name -- Class - - (PolyType name) -- Context => Instance-type +data InstDecl name pat + = InstDecl (HsType name) -- Context => Class Instance-type -- Using a polytype means that the renamer conveniently -- figures out the quantified type variables for us. - (MonoBinds tyvar uvar name pat) + (MonoBinds name pat) - Bool -- True <=> This instance decl is from the - -- module being compiled; False <=> It is from - -- an imported interface. + [Sig name] -- User-supplied pragmatic info - (Maybe Module) -- The name of the module where the instance decl - -- originally came from; Nothing => Prelude + (Maybe name) -- Name for the dictionary function + -- Nothing for source-file instance decls - [Sig name] -- actually user-supplied pragmatic info - (InstancePragmas name) -- interface-supplied pragmatic info SrcLoc \end{code} \begin{code} -instance (NamedThing name, Outputable name, Outputable pat, - Eq tyvar, Outputable tyvar, Eq uvar, Outputable uvar) - => Outputable (InstDecl tyvar uvar name pat) where - - ppr sty (InstDecl clas ty binds local modname uprags pragmas src_loc) - = let - (context, inst_ty) - = case ty of - HsPreForAllTy c t -> (c, t) - HsForAllTy _ c t -> (c, t) - - top_matter = ppCat [ppStr "instance", pprContext sty context, - ppr sty clas, pprParendMonoType sty inst_ty] - in - if nullMonoBinds binds && null uprags then - ppAbove top_matter (ppNest 4 (ppr sty pragmas)) +instance (Outputable name, Outputable pat) + => Outputable (InstDecl name pat) where + + ppr (InstDecl inst_ty binds uprags maybe_dfun_name src_loc) + = getPprStyle $ \ sty -> + if ifaceStyle sty then + hsep [ptext SLIT("instance"), ppr inst_ty, equals, pp_dfun] else - ppAboves [ppCat [top_matter, ppStr "where"], - if null uprags then ppNil else ppNest 4 (ppr sty uprags), - ppNest 4 (ppr sty binds), - ppNest 4 (ppr sty pragmas) ] + vcat [hsep [ptext SLIT("instance"), ppr inst_ty, ptext SLIT("where")], + nest 4 (ppr uprags), + nest 4 (ppr binds) ] + where + pp_dfun = case maybe_dfun_name of + Just df -> ppr df + Nothing -> empty \end{code} -A type for recording what instances the user wants to specialise; -called a ``Sig'' because it's sort of like a ``type signature'' for an -instance. \begin{code} -data SpecInstSig name - = SpecInstSig name -- class - (MonoType name) -- type to specialise to - SrcLoc - -instance (NamedThing name, Outputable name) - => Outputable (SpecInstSig name) where - - ppr sty (SpecInstSig clas ty _) - = ppCat [ppStr "{-# SPECIALIZE instance", ppr sty clas, ppr sty ty, ppStr "#-}"] +instance Ord name => Eq (InstDecl name pat) where + -- Used for interface comparison only, so don't compare bindings + (==) (InstDecl inst_ty1 _ _ dfun1 _) (InstDecl inst_ty2 _ _ dfun2 _) + = inst_ty1 == inst_ty2 && dfun1 == dfun2 \end{code} + %************************************************************************ %* * \subsection[DefaultDecl]{A @default@ declaration} @@ -303,12 +542,158 @@ syntax, and that restriction must be checked in the front end. \begin{code} data DefaultDecl name - = DefaultDecl [MonoType name] + = DefaultDecl [HsType name] SrcLoc -instance (NamedThing name, Outputable name) +instance (Outputable name) => Outputable (DefaultDecl name) where - ppr sty (DefaultDecl tys src_loc) - = ppBeside (ppPStr SLIT("default ")) (ppParens (interpp'SP sty tys)) + ppr (DefaultDecl tys src_loc) + = ptext SLIT("default") <+> parens (interpp'SP tys) +\end{code} + +%************************************************************************ +%* * +\subsection{Foreign function interface declaration} +%* * +%************************************************************************ + +\begin{code} +data ForeignDecl name = + ForeignDecl + name + ForKind + (HsType name) + ExtName + CallConv + SrcLoc + +instance (Outputable name) + => Outputable (ForeignDecl name) where + + ppr (ForeignDecl nm imp_exp ty ext_name cconv src_loc) + = ptext SLIT("foreign") <+> ppr_imp_exp <+> pprCallConv cconv <+> + ppr ext_name <+> ppr_unsafe <+> ppr nm <+> dcolon <+> ppr ty + where + (ppr_imp_exp, ppr_unsafe) = + case imp_exp of + FoLabel -> (ptext SLIT("label"), empty) + FoExport -> (ptext SLIT("export"), empty) + FoImport us + | us -> (ptext SLIT("import"), ptext SLIT("unsafe")) + | otherwise -> (ptext SLIT("import"), empty) + +data ForKind + = FoLabel + | FoExport + | FoImport Bool -- True => unsafe call. + +data ExtName + = Dynamic + | ExtName CLabelString -- The external name of the foreign thing, + (Maybe CLabelString) -- and optionally its DLL or module name + -- Both of these are completely unencoded; + -- we just print them as they are + +isDynamicExtName :: ExtName -> Bool +isDynamicExtName Dynamic = True +isDynamicExtName _ = False + +extNameStatic :: ExtName -> CLabelString +extNameStatic (ExtName f _) = f +extNameStatic Dynamic = panic "staticExtName: Dynamic - shouldn't ever happen." + +instance Outputable ExtName where + ppr Dynamic = ptext SLIT("dynamic") + ppr (ExtName nm mb_mod) = + case mb_mod of { Nothing -> empty; Just m -> doubleQuotes (ptext m) } <+> + doubleQuotes (pprCLabelString nm) +\end{code} + +%************************************************************************ +%* * +\subsection{Transformation rules} +%* * +%************************************************************************ + +\begin{code} +data RuleDecl name pat + = HsRule -- Source rule + FAST_STRING -- Rule name + [name] -- Forall'd tyvars, filled in by the renamer with + -- tyvars mentioned in sigs; then filled out by typechecker + [RuleBndr name] -- Forall'd term vars + (HsExpr name pat) -- LHS + (HsExpr name pat) -- RHS + SrcLoc + + | IfaceRule -- One that's come in from an interface file; pre-typecheck + FAST_STRING + [UfBinder name] -- Tyvars and term vars + name -- Head of lhs + [UfExpr name] -- Args of LHS + (UfExpr name) -- Pre typecheck + SrcLoc + + | IfaceRuleOut -- Post typecheck + name -- Head of LHS + CoreRule + +isIfaceRuleDecl (HsRule _ _ _ _ _ _) = False +isIfaceRuleDecl other = True + +data RuleBndr name + = RuleBndr name + | RuleBndrSig name (HsType name) + +instance Ord name => Eq (RuleDecl name pat) where + -- Works for IfaceRules only; used when comparing interface file versions + (IfaceRule n1 bs1 f1 es1 rhs1 _) == (IfaceRule n2 bs2 f2 es2 rhs2 _) + = n1==n2 && f1 == f2 && + eq_ufBinders emptyEqHsEnv bs1 bs2 (\env -> + eqListBy (eq_ufExpr env) (rhs1:es1) (rhs2:es2)) + +instance (Outputable name, Outputable pat) + => Outputable (RuleDecl name pat) where + ppr (HsRule name tvs ns lhs rhs loc) + = sep [text "{-# RULES" <+> doubleQuotes (ptext name), + pp_forall, ppr lhs, equals <+> ppr rhs, + text "#-}" ] + where + pp_forall | null tvs && null ns = empty + | otherwise = text "forall" <+> + fsep (map ppr tvs ++ map ppr ns) + <> dot + + ppr (IfaceRule name tpl_vars fn tpl_args rhs loc) + = hsep [ doubleQuotes (ptext name), + ptext SLIT("__forall") <+> braces (interppSP tpl_vars), + ppr fn <+> sep (map (pprUfExpr parens) tpl_args), + ptext SLIT("=") <+> ppr rhs + ] <+> semi + + ppr (IfaceRuleOut fn rule) = pprCoreRule (ppr fn) rule + +instance Outputable name => Outputable (RuleBndr name) where + ppr (RuleBndr name) = ppr name + ppr (RuleBndrSig name ty) = ppr name <> dcolon <> ppr ty +\end{code} + + +%************************************************************************ +%* * +\subsection[DeprecDecl]{Deprecations} +%* * +%************************************************************************ + +We use exported entities for things to deprecate. + +\begin{code} +data DeprecDecl name = Deprecation name DeprecTxt SrcLoc + +type DeprecTxt = FAST_STRING -- reason/explanation for deprecation + +instance Outputable name => Outputable (DeprecDecl name) where + ppr (Deprecation thing txt _) + = hsep [text "{-# DEPRECATED", ppr thing, doubleQuotes (ppr txt), text "#-}"] \end{code}