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Diffstat (limited to 'compiler/hsSyn/HsDecls.lhs')
| -rw-r--r-- | compiler/hsSyn/HsDecls.lhs | 796 |
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diff --git a/compiler/hsSyn/HsDecls.lhs b/compiler/hsSyn/HsDecls.lhs new file mode 100644 index 0000000000..8ff39857c6 --- /dev/null +++ b/compiler/hsSyn/HsDecls.lhs @@ -0,0 +1,796 @@ +% +% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998 +% +\section[HsDecls]{Abstract syntax: global declarations} + +Definitions for: @TyDecl@ and @oCnDecl@, @ClassDecl@, +@InstDecl@, @DefaultDecl@ and @ForeignDecl@. + +\begin{code} +module HsDecls ( + HsDecl(..), LHsDecl, TyClDecl(..), LTyClDecl, + InstDecl(..), LInstDecl, NewOrData(..), + RuleDecl(..), LRuleDecl, RuleBndr(..), + DefaultDecl(..), LDefaultDecl, SpliceDecl(..), + ForeignDecl(..), LForeignDecl, ForeignImport(..), ForeignExport(..), + CImportSpec(..), FoType(..), + ConDecl(..), ResType(..), LConDecl, + DeprecDecl(..), LDeprecDecl, + HsGroup(..), emptyRdrGroup, emptyRnGroup, appendGroups, + tcdName, tyClDeclNames, tyClDeclTyVars, + isClassDecl, isSynDecl, isDataDecl, + countTyClDecls, + conDetailsTys, + collectRuleBndrSigTys, + ) where + +#include "HsVersions.h" + +-- friends: +import {-# SOURCE #-} HsExpr( HsExpr, pprExpr ) + -- Because Expr imports Decls via HsBracket + +import HsBinds ( HsValBinds(..), HsBind, LHsBinds, plusHsValBinds, + Sig(..), LSig, LFixitySig, pprLHsBinds, + emptyValBindsIn, emptyValBindsOut ) +import HsPat ( HsConDetails(..), hsConArgs ) +import HsImpExp ( pprHsVar ) +import HsTypes +import NameSet ( NameSet ) +import HscTypes ( DeprecTxt ) +import CoreSyn ( RuleName ) +import Kind ( Kind, pprKind ) +import BasicTypes ( Activation(..) ) +import ForeignCall ( CCallTarget(..), DNCallSpec, CCallConv, Safety, + CExportSpec(..), CLabelString ) + +-- others: +import FunDeps ( pprFundeps ) +import Class ( FunDep ) +import Outputable +import Util ( count ) +import SrcLoc ( Located(..), unLoc, noLoc ) +import FastString +\end{code} + + +%************************************************************************ +%* * +\subsection[HsDecl]{Declarations} +%* * +%************************************************************************ + +\begin{code} +type LHsDecl id = Located (HsDecl id) + +data HsDecl id + = TyClD (TyClDecl id) + | InstD (InstDecl id) + | ValD (HsBind id) + | SigD (Sig id) + | DefD (DefaultDecl id) + | ForD (ForeignDecl id) + | DeprecD (DeprecDecl id) + | RuleD (RuleDecl id) + | SpliceD (SpliceDecl id) + +-- NB: all top-level fixity decls are contained EITHER +-- EITHER SigDs +-- 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 + +-- A [HsDecl] is categorised into a HsGroup before being +-- fed to the renamer. +data HsGroup id + = HsGroup { + hs_valds :: HsValBinds id, + hs_tyclds :: [LTyClDecl id], + hs_instds :: [LInstDecl id], + + hs_fixds :: [LFixitySig id], + -- Snaffled out of both top-level fixity signatures, + -- and those in class declarations + + hs_defds :: [LDefaultDecl id], + hs_fords :: [LForeignDecl id], + hs_depds :: [LDeprecDecl id], + hs_ruleds :: [LRuleDecl id] + } + +emptyGroup, emptyRdrGroup, emptyRnGroup :: HsGroup a +emptyRdrGroup = emptyGroup { hs_valds = emptyValBindsIn } +emptyRnGroup = emptyGroup { hs_valds = emptyValBindsOut } + +emptyGroup = HsGroup { hs_tyclds = [], hs_instds = [], + hs_fixds = [], hs_defds = [], hs_fords = [], + hs_depds = [], hs_ruleds = [], + hs_valds = error "emptyGroup hs_valds: Can't happen" } + +appendGroups :: HsGroup a -> HsGroup a -> HsGroup a +appendGroups + HsGroup { + hs_valds = val_groups1, + hs_tyclds = tyclds1, + hs_instds = instds1, + hs_fixds = fixds1, + hs_defds = defds1, + hs_fords = fords1, + hs_depds = depds1, + hs_ruleds = rulds1 } + HsGroup { + hs_valds = val_groups2, + hs_tyclds = tyclds2, + hs_instds = instds2, + hs_fixds = fixds2, + hs_defds = defds2, + hs_fords = fords2, + hs_depds = depds2, + hs_ruleds = rulds2 } + = + HsGroup { + hs_valds = val_groups1 `plusHsValBinds` val_groups2, + hs_tyclds = tyclds1 ++ tyclds2, + hs_instds = instds1 ++ instds2, + hs_fixds = fixds1 ++ fixds2, + hs_defds = defds1 ++ defds2, + hs_fords = fords1 ++ fords2, + hs_depds = depds1 ++ depds2, + hs_ruleds = rulds1 ++ rulds2 } +\end{code} + +\begin{code} +instance OutputableBndr name => Outputable (HsDecl name) 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 (SigD sd) = ppr sd + ppr (RuleD rd) = ppr rd + ppr (DeprecD dd) = ppr dd + ppr (SpliceD dd) = ppr dd + +instance OutputableBndr name => Outputable (HsGroup name) where + ppr (HsGroup { hs_valds = val_decls, + hs_tyclds = tycl_decls, + hs_instds = inst_decls, + hs_fixds = fix_decls, + hs_depds = deprec_decls, + hs_fords = foreign_decls, + hs_defds = default_decls, + hs_ruleds = rule_decls }) + = vcat [ppr_ds fix_decls, ppr_ds default_decls, + ppr_ds deprec_decls, ppr_ds rule_decls, + ppr val_decls, + ppr_ds tycl_decls, ppr_ds inst_decls, + ppr_ds foreign_decls] + where + ppr_ds [] = empty + ppr_ds ds = text "" $$ vcat (map ppr ds) + +data SpliceDecl id = SpliceDecl (Located (HsExpr id)) -- Top level splice + +instance OutputableBndr name => Outputable (SpliceDecl name) where + ppr (SpliceDecl e) = ptext SLIT("$") <> parens (pprExpr (unLoc e)) +\end{code} + + +%************************************************************************ +%* * +\subsection[TyDecl]{@data@, @newtype@ or @type@ (synonym) type declaration} +%* * +%************************************************************************ + + -------------------------------- + THE NAMING STORY + -------------------------------- + +Here is the story about the implicit names that go with type, class, +and instance decls. It's a bit tricky, so pay attention! + +"Implicit" (or "system") binders +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + 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: + - Ensure they "point to" the parent data/class decl + when loading that decl from an interface file + (See RnHiFiles.getSysBinders) + + - When typechecking the decl, we build the implicit TyCons and Ids. + When doing so we look them up in the name cache (RnEnv.lookupSysName), + to ensure correct module and provenance is set + +These are the two places that we have to conjure up the magic derived +names. (The actual magic is in OccName.mkWorkerOcc, etc.) + +Default methods +~~~~~~~~~~~~~~~ + - Occurrence name is derived uniquely from the method name + E.g. $dmmax + + - If there is a default method name at all, it's recorded in + the ClassOpSig (in HsBinds), in the DefMeth field. + (DefMeth is defined in Class.lhs) + +Source-code class decls and interface-code class decls are treated subtly +differently, which has given me a great deal of confusion over the years. +Here's the deal. (We distinguish the two cases because source-code decls +have (Just binds) in the tcdMeths field, whereas interface decls have Nothing. + +In *source-code* class declarations: + + - When parsing, every ClassOpSig gets a DefMeth with a suitable RdrName + This is done by RdrHsSyn.mkClassOpSigDM + + - The renamer renames it to a Name + + - During typechecking, we generate a binding for each $dm for + which there's a programmer-supplied default method: + class Foo a where + op1 :: <type> + op2 :: <type> + op1 = ... + We generate a binding for $dmop1 but not for $dmop2. + The Class for Foo has a NoDefMeth for op2 and a DefMeth for op1. + The Name for $dmop2 is simply discarded. + +In *interface-file* class declarations: + - When parsing, we see if there's an explicit programmer-supplied default method + because there's an '=' sign to indicate it: + class Foo a where + op1 = :: <type> -- NB the '=' + op2 :: <type> + We use this info to generate a DefMeth with a suitable RdrName for op1, + and a NoDefMeth for op2 + - The interface file has a separate definition for $dmop1, with unfolding etc. + - The renamer renames it to a Name. + - The renamer treats $dmop1 as a free variable of the declaration, so that + the binding for $dmop1 will be sucked in. (See RnHsSyn.tyClDeclFVs) + This doesn't happen for source code class decls, because they *bind* the default method. + +Dictionary functions +~~~~~~~~~~~~~~~~~~~~ +Each instance declaration gives rise to one dictionary function binding. + +The type checker makes up new source-code instance declarations +(e.g. from 'deriving' or generic default methods --- see +TcInstDcls.tcInstDecls1). So we can't generate the names for +dictionary functions in advance (we don't know how many we need). + +On the other hand for interface-file instance declarations, the decl +specifies the name of the dictionary function, and it has a binding elsewhere +in the interface file: + instance {Eq Int} = dEqInt + dEqInt :: {Eq Int} <pragma info> + +So again we treat source code and interface file code slightly differently. + +Source code: + - Source code instance decls have a Nothing in the (Maybe name) field + (see data InstDecl below) + + - The typechecker makes up a Local name for the dict fun for any source-code + instance decl, whether it comes from a source-code instance decl, or whether + the instance decl is derived from some other construct (e.g. 'deriving'). + + - The occurrence name it chooses is derived from the instance decl (just for + documentation really) --- e.g. dNumInt. Two dict funs may share a common + occurrence name, but will have different uniques. E.g. + instance Foo [Int] where ... + instance Foo [Bool] where ... + These might both be dFooList + + - The CoreTidy phase externalises the name, and ensures the occurrence name is + unique (this isn't special to dict funs). So we'd get dFooList and dFooList1. + + - We can take this relaxed approach (changing the occurrence name later) + because dict fun Ids are not captured in a TyCon or Class (unlike default + methods, say). Instead, they are kept separately in the InstEnv. This + makes it easy to adjust them after compiling a module. (Once we've finished + compiling that module, they don't change any more.) + + +Interface file code: + - The instance decl gives the dict fun name, so the InstDecl has a (Just name) + in the (Maybe name) field. + + - RnHsSyn.instDeclFVs treats the dict fun name as free in the decl, so that we + suck in the dfun binding + + +\begin{code} +-- TyClDecls are precisely the kind of declarations that can +-- appear in interface files; or (internally) in GHC's interface +-- for a module. That's why (despite the misnomer) IfaceSig and ForeignType +-- are both in TyClDecl + +type LTyClDecl name = Located (TyClDecl name) + +data TyClDecl name + = ForeignType { + tcdLName :: Located name, + tcdExtName :: Maybe FastString, + tcdFoType :: FoType + } + + | TyData { tcdND :: NewOrData, + tcdCtxt :: LHsContext name, -- Context + tcdLName :: Located name, -- Type constructor + tcdTyVars :: [LHsTyVarBndr name], -- Type variables + tcdKindSig :: Maybe Kind, -- Optional kind sig; + -- (only for the 'where' form) + + tcdCons :: [LConDecl name], -- Data constructors + -- For data T a = T1 | T2 a the LConDecls all have ResTyH98 + -- For data T a where { T1 :: T a } the LConDecls all have ResTyGADT + + tcdDerivs :: Maybe [LHsType name] + -- Derivings; Nothing => not specified + -- Just [] => derive exactly what is asked + -- These "types" must be of form + -- forall ab. C ty1 ty2 + -- Typically the foralls and ty args are empty, but they + -- are non-empty for the newtype-deriving case + } + + | TySynonym { tcdLName :: Located name, -- type constructor + tcdTyVars :: [LHsTyVarBndr name], -- type variables + tcdSynRhs :: LHsType name -- synonym expansion + } + + | ClassDecl { tcdCtxt :: LHsContext name, -- Context... + tcdLName :: Located name, -- Name of the class + tcdTyVars :: [LHsTyVarBndr name], -- Class type variables + tcdFDs :: [Located (FunDep name)], -- Functional deps + tcdSigs :: [LSig name], -- Methods' signatures + tcdMeths :: LHsBinds name -- Default methods + } + +data NewOrData + = NewType -- "newtype Blah ..." + | DataType -- "data Blah ..." + deriving( Eq ) -- Needed because Demand derives Eq +\end{code} + +Simple classifiers + +\begin{code} +isDataDecl, isSynDecl, isClassDecl :: TyClDecl name -> Bool + +isSynDecl (TySynonym {}) = True +isSynDecl other = False + +isDataDecl (TyData {}) = True +isDataDecl other = False + +isClassDecl (ClassDecl {}) = True +isClassDecl other = False +\end{code} + +Dealing with names + +\begin{code} +tcdName :: TyClDecl name -> name +tcdName decl = unLoc (tcdLName decl) + +tyClDeclNames :: Eq name => TyClDecl name -> [Located name] +-- 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 {tcdLName = name}) = [name] +tyClDeclNames (ForeignType {tcdLName = name}) = [name] + +tyClDeclNames (ClassDecl {tcdLName = cls_name, tcdSigs = sigs}) + = cls_name : [n | L _ (TypeSig n _) <- sigs] + +tyClDeclNames (TyData {tcdLName = tc_name, tcdCons = cons}) + = tc_name : conDeclsNames (map unLoc cons) + +tyClDeclTyVars (TySynonym {tcdTyVars = tvs}) = tvs +tyClDeclTyVars (TyData {tcdTyVars = tvs}) = tvs +tyClDeclTyVars (ClassDecl {tcdTyVars = tvs}) = tvs +tyClDeclTyVars (ForeignType {}) = [] +\end{code} + +\begin{code} +countTyClDecls :: [TyClDecl name] -> (Int, Int, Int, Int) + -- class, data, newtype, synonym decls +countTyClDecls decls + = (count isClassDecl decls, + count isSynDecl decls, + count isDataTy decls, + count isNewTy decls) + where + isDataTy TyData{tcdND=DataType} = True + isDataTy _ = False + + isNewTy TyData{tcdND=NewType} = True + isNewTy _ = False +\end{code} + +\begin{code} +instance OutputableBndr name + => Outputable (TyClDecl name) where + + ppr (ForeignType {tcdLName = ltycon}) + = hsep [ptext SLIT("foreign import type dotnet"), ppr ltycon] + + ppr (TySynonym {tcdLName = ltycon, tcdTyVars = tyvars, tcdSynRhs = mono_ty}) + = hang (ptext SLIT("type") <+> pp_decl_head [] ltycon tyvars <+> equals) + 4 (ppr mono_ty) + + ppr (TyData {tcdND = new_or_data, tcdCtxt = context, tcdLName = ltycon, + tcdTyVars = tyvars, tcdKindSig = mb_sig, tcdCons = condecls, + tcdDerivs = derivings}) + = pp_tydecl (ppr new_or_data <+> pp_decl_head (unLoc context) ltycon tyvars <+> ppr_sig mb_sig) + (pp_condecls condecls) + derivings + where + ppr_sig Nothing = empty + ppr_sig (Just kind) = dcolon <+> pprKind kind + + ppr (ClassDecl {tcdCtxt = context, tcdLName = lclas, tcdTyVars = tyvars, tcdFDs = fds, + tcdSigs = sigs, tcdMeths = methods}) + | 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), ppr methods, char '}'])] + where + top_matter = ptext SLIT("class") <+> pp_decl_head (unLoc context) lclas tyvars <+> pprFundeps (map unLoc fds) + ppr_sig sig = ppr sig <> semi + +pp_decl_head :: OutputableBndr name + => HsContext name + -> Located name + -> [LHsTyVarBndr name] + -> SDoc +pp_decl_head context thing tyvars + = hsep [pprHsContext context, ppr thing, interppSP tyvars] +pp_condecls cs@(L _ ConDecl{ con_res = ResTyGADT _ } : _) -- In GADT syntax + = hang (ptext SLIT("where")) 2 (vcat (map ppr cs)) +pp_condecls cs -- In H98 syntax + = equals <+> sep (punctuate (ptext SLIT(" |")) (map ppr 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)] + ]) + +instance Outputable NewOrData where + ppr NewType = ptext SLIT("newtype") + ppr DataType = ptext SLIT("data") +\end{code} + + +%************************************************************************ +%* * +\subsection[ConDecl]{A data-constructor declaration} +%* * +%************************************************************************ + +\begin{code} +type LConDecl name = Located (ConDecl name) + +-- data T b = forall a. Eq a => MkT a b +-- MkT :: forall b a. Eq a => MkT a b + +-- data T b where +-- MkT1 :: Int -> T Int + +-- data T = Int `MkT` Int +-- | MkT2 + +-- data T a where +-- Int `MkT` Int :: T Int + +data ConDecl name + = ConDecl + { con_name :: Located name -- Constructor name; this is used for the + -- DataCon itself, and for the user-callable wrapper Id + + , con_explicit :: HsExplicitForAll -- Is there an user-written forall? (cf. HStypes.HsForAllTy) + + , con_qvars :: [LHsTyVarBndr name] -- ResTyH98: the constructor's existential type variables + -- ResTyGADT: all the constructor's quantified type variables + + , con_cxt :: LHsContext name -- The context. This *does not* include the + -- "stupid theta" which lives only in the TyData decl + + , con_details :: HsConDetails name (LBangType name) -- The main payload + + , con_res :: ResType name -- Result type of the constructor + } + +data ResType name + = ResTyH98 -- Constructor was declared using Haskell 98 syntax + | ResTyGADT (LHsType name) -- Constructor was declared using GADT-style syntax, + -- and here is its result type +\end{code} + +\begin{code} +conDeclsNames :: Eq name => [ConDecl name] -> [Located name] + -- 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 { con_name = lname, con_details = RecCon flds }) + = (map unLoc new_flds ++ flds_seen, lname : [f | f <- new_flds] ++ acc) + where + new_flds = [ f | (f,_) <- flds, not (unLoc f `elem` flds_seen) ] + + do_one (flds_seen, acc) c + = (flds_seen, (con_name c):acc) + +conDetailsTys details = map getBangType (hsConArgs details) +\end{code} + + +\begin{code} +instance (OutputableBndr name) => Outputable (ConDecl name) where + ppr = pprConDecl + +pprConDecl (ConDecl con expl tvs cxt details ResTyH98) + = sep [pprHsForAll expl tvs cxt, ppr_details con details] + where + ppr_details con (InfixCon t1 t2) = hsep [ppr t1, pprHsVar con, ppr t2] + ppr_details con (PrefixCon tys) = hsep (pprHsVar con : map ppr tys) + ppr_details con (RecCon fields) = ppr con <+> ppr_fields fields + +pprConDecl (ConDecl con expl tvs cxt details (ResTyGADT res_ty)) + = sep [pprHsForAll expl tvs cxt, ppr con <+> ppr_details details] + where + ppr_details (PrefixCon arg_tys) = dcolon <+> ppr (foldr mk_fun_ty res_ty arg_tys) + ppr_details (RecCon fields) = ppr fields <+> dcolon <+> ppr res_ty + + mk_fun_ty a b = noLoc (HsFunTy a b) + +ppr_fields fields = braces (sep (punctuate comma (map ppr_field fields))) +ppr_field (n, ty) = ppr n <+> dcolon <+> ppr ty +\end{code} + +%************************************************************************ +%* * +\subsection[InstDecl]{An instance declaration +%* * +%************************************************************************ + +\begin{code} +type LInstDecl name = Located (InstDecl name) + +data InstDecl name + = InstDecl (LHsType name) -- Context => Class Instance-type + -- Using a polytype means that the renamer conveniently + -- figures out the quantified type variables for us. + (LHsBinds name) + [LSig name] -- User-supplied pragmatic info + +instance (OutputableBndr name) => Outputable (InstDecl name) where + + ppr (InstDecl inst_ty binds uprags) + = vcat [hsep [ptext SLIT("instance"), ppr inst_ty, ptext SLIT("where")], + nest 4 (ppr uprags), + nest 4 (pprLHsBinds binds) ] +\end{code} + +%************************************************************************ +%* * +\subsection[DefaultDecl]{A @default@ declaration} +%* * +%************************************************************************ + +There can only be one default declaration per module, but it is hard +for the parser to check that; we pass them all through in the abstract +syntax, and that restriction must be checked in the front end. + +\begin{code} +type LDefaultDecl name = Located (DefaultDecl name) + +data DefaultDecl name + = DefaultDecl [LHsType name] + +instance (OutputableBndr name) + => Outputable (DefaultDecl name) where + + ppr (DefaultDecl tys) + = ptext SLIT("default") <+> parens (interpp'SP tys) +\end{code} + +%************************************************************************ +%* * +\subsection{Foreign function interface declaration} +%* * +%************************************************************************ + +\begin{code} + +-- foreign declarations are distinguished as to whether they define or use a +-- Haskell name +-- +-- * the Boolean value indicates whether the pre-standard deprecated syntax +-- has been used +-- +type LForeignDecl name = Located (ForeignDecl name) + +data ForeignDecl name + = ForeignImport (Located name) (LHsType name) ForeignImport Bool -- defines name + | ForeignExport (Located name) (LHsType name) ForeignExport Bool -- uses name + +-- specification of an imported external entity in dependence on the calling +-- convention +-- +data ForeignImport = -- import of a C entity + -- + -- * the two strings specifying a header file or library + -- may be empty, which indicates the absence of a + -- header or object specification (both are not used + -- in the case of `CWrapper' and when `CFunction' + -- has a dynamic target) + -- + -- * the calling convention is irrelevant for code + -- generation in the case of `CLabel', but is needed + -- for pretty printing + -- + -- * `Safety' is irrelevant for `CLabel' and `CWrapper' + -- + CImport CCallConv -- ccall or stdcall + Safety -- safe or unsafe + FastString -- name of C header + FastString -- name of library object + CImportSpec -- details of the C entity + + -- import of a .NET function + -- + | DNImport DNCallSpec + +-- details of an external C entity +-- +data CImportSpec = CLabel CLabelString -- import address of a C label + | CFunction CCallTarget -- static or dynamic function + | CWrapper -- wrapper to expose closures + -- (former f.e.d.) + +-- specification of an externally exported entity in dependence on the calling +-- convention +-- +data ForeignExport = CExport CExportSpec -- contains the calling convention + | DNExport -- presently unused + +-- abstract type imported from .NET +-- +data FoType = DNType -- In due course we'll add subtype stuff + deriving (Eq) -- Used for equality instance for TyClDecl + + +-- pretty printing of foreign declarations +-- + +instance OutputableBndr name => Outputable (ForeignDecl name) where + ppr (ForeignImport n ty fimport _) = + ptext SLIT("foreign import") <+> ppr fimport <+> + ppr n <+> dcolon <+> ppr ty + ppr (ForeignExport n ty fexport _) = + ptext SLIT("foreign export") <+> ppr fexport <+> + ppr n <+> dcolon <+> ppr ty + +instance Outputable ForeignImport where + ppr (DNImport spec) = + ptext SLIT("dotnet") <+> ppr spec + ppr (CImport cconv safety header lib spec) = + ppr cconv <+> ppr safety <+> + char '"' <> pprCEntity header lib spec <> char '"' + where + pprCEntity header lib (CLabel lbl) = + ptext SLIT("static") <+> ftext header <+> char '&' <> + pprLib lib <> ppr lbl + pprCEntity header lib (CFunction (StaticTarget lbl)) = + ptext SLIT("static") <+> ftext header <+> char '&' <> + pprLib lib <> ppr lbl + pprCEntity header lib (CFunction (DynamicTarget)) = + ptext SLIT("dynamic") + pprCEntity _ _ (CWrapper) = ptext SLIT("wrapper") + -- + pprLib lib | nullFS lib = empty + | otherwise = char '[' <> ppr lib <> char ']' + +instance Outputable ForeignExport where + ppr (CExport (CExportStatic lbl cconv)) = + ppr cconv <+> char '"' <> ppr lbl <> char '"' + ppr (DNExport ) = + ptext SLIT("dotnet") <+> ptext SLIT("\"<unused>\"") + +instance Outputable FoType where + ppr DNType = ptext SLIT("type dotnet") +\end{code} + + +%************************************************************************ +%* * +\subsection{Transformation rules} +%* * +%************************************************************************ + +\begin{code} +type LRuleDecl name = Located (RuleDecl name) + +data RuleDecl name + = HsRule -- Source rule + RuleName -- Rule name + Activation + [RuleBndr name] -- Forall'd vars; after typechecking this includes tyvars + (Located (HsExpr name)) -- LHS + NameSet -- Free-vars from the LHS + (Located (HsExpr name)) -- RHS + NameSet -- Free-vars from the RHS + +data RuleBndr name + = RuleBndr (Located name) + | RuleBndrSig (Located name) (LHsType name) + +collectRuleBndrSigTys :: [RuleBndr name] -> [LHsType name] +collectRuleBndrSigTys bndrs = [ty | RuleBndrSig _ ty <- bndrs] + +instance OutputableBndr name => Outputable (RuleDecl name) where + ppr (HsRule name act ns lhs fv_lhs rhs fv_rhs) + = sep [text "{-# RULES" <+> doubleQuotes (ftext name) <+> ppr act, + nest 4 (pp_forall <+> pprExpr (unLoc lhs)), + nest 4 (equals <+> pprExpr (unLoc rhs) <+> text "#-}") ] + where + pp_forall | null ns = empty + | otherwise = text "forall" <+> fsep (map ppr ns) <> dot + +instance OutputableBndr 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} +type LDeprecDecl name = Located (DeprecDecl name) + +data DeprecDecl name = Deprecation name DeprecTxt + +instance OutputableBndr name => Outputable (DeprecDecl name) where + ppr (Deprecation thing txt) + = hsep [text "{-# DEPRECATED", ppr thing, doubleQuotes (ppr txt), text "#-}"] +\end{code} |