This module converts Template Haskell syntax into HsSyn
\begin{code}
-{-# OPTIONS -fno-warn-incomplete-patterns #-}
--- The above warning supression flag is a temporary kludge.
--- While working on this module you are encouraged to remove it and fix
--- any warnings in the module. See
--- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
--- for details
-
module Convert( convertToHsExpr, convertToPat, convertToHsDecls,
- convertToHsType, thRdrName ) where
+ convertToHsType, thRdrNameGuesses ) where
import HsSyn as Hs
import qualified Class
import SrcLoc
import Type
import TysWiredIn
-import BasicTypes
+import BasicTypes as Hs
import ForeignCall
import Char
import List
import Unique
+import MonadUtils
import ErrUtils
import Bag
import FastString
-------------------------------------------------------------------
cvtTop :: TH.Dec -> CvtM (LHsDecl RdrName)
-cvtTop d@(TH.ValD _ _ _) = do { L loc d' <- cvtBind d; return (L loc $ Hs.ValD d') }
-cvtTop d@(TH.FunD _ _) = do { L loc d' <- cvtBind d; return (L loc $ Hs.ValD d') }
-cvtTop (TH.SigD nm typ) = do { nm' <- vNameL nm
- ; ty' <- cvtType typ
- ; returnL $ Hs.SigD (TypeSig nm' ty') }
+cvtTop d@(TH.ValD _ _ _)
+ = do { L loc d' <- cvtBind d
+ ; return (L loc $ Hs.ValD d') }
+
+cvtTop d@(TH.FunD _ _)
+ = do { L loc d' <- cvtBind d
+ ; return (L loc $ Hs.ValD d') }
+
+cvtTop (TH.SigD nm typ)
+ = do { nm' <- vNameL nm
+ ; ty' <- cvtType typ
+ ; returnL $ Hs.SigD (TypeSig nm' ty') }
cvtTop (TySynD tc tvs rhs)
- = do { tc' <- tconNameL tc
- ; tvs' <- cvtTvs tvs
+ = do { (_, tc', tvs', _) <- cvt_tycl_hdr [] tc tvs
; rhs' <- cvtType rhs
; returnL $ TyClD (TySynonym tc' tvs' Nothing rhs') }
; derivs' <- cvtDerivs derivs
; returnL $ TyClD (mkTyData DataType stuff Nothing cons' derivs') }
-
cvtTop (NewtypeD ctxt tc tvs constr derivs)
= do { stuff <- cvt_tycl_hdr ctxt tc tvs
; con' <- cvtConstr constr
cvtTop (ClassD ctxt cl tvs fds decs)
= do { (cxt', tc', tvs', _) <- cvt_tycl_hdr ctxt cl tvs
; fds' <- mapM cvt_fundep fds
- ; (binds', sigs') <- cvtBindsAndSigs decs
- ; returnL $ TyClD $ mkClassDecl (cxt', tc', tvs') fds' sigs' binds' [] []
- -- no ATs or docs in TH ^^ ^^
+ ; let (ats, bind_sig_decs) = partition isFamilyD decs
+ ; (binds', sigs') <- cvtBindsAndSigs bind_sig_decs
+ ; ats' <- mapM cvtTop ats
+ ; let ats'' = map unTyClD ats'
+ ; returnL $
+ TyClD $ mkClassDecl (cxt', tc', tvs') fds' sigs' binds' ats'' []
+ -- no docs in TH ^^
}
-
-cvtTop (InstanceD tys ty decs)
- = do { (binds', sigs') <- cvtBindsAndSigs decs
- ; ctxt' <- cvtContext tys
- ; L loc pred' <- cvtPred ty
- ; inst_ty' <- returnL $ mkImplicitHsForAllTy ctxt' (L loc (HsPredTy pred'))
- ; returnL $ InstD (InstDecl inst_ty' binds' sigs' [])
- -- no ATs in TH ^^
+ where
+ isFamilyD (FamilyD _ _ _ _) = True
+ isFamilyD _ = False
+
+cvtTop (InstanceD ctxt ty decs)
+ = do { let (ats, bind_sig_decs) = partition isFamInstD decs
+ ; (binds', sigs') <- cvtBindsAndSigs bind_sig_decs
+ ; ats' <- mapM cvtTop ats
+ ; let ats'' = map unTyClD ats'
+ ; ctxt' <- cvtContext ctxt
+ ; L loc pred' <- cvtPredTy ty
+ ; inst_ty' <- returnL $
+ mkImplicitHsForAllTy ctxt' (L loc (HsPredTy pred'))
+ ; returnL $ InstD (InstDecl inst_ty' binds' sigs' ats'')
}
-
-cvtTop (ForeignD ford) = do { ford' <- cvtForD ford; returnL $ ForD ford' }
-
-cvt_tycl_hdr :: TH.Cxt -> TH.Name -> [TH.Name]
- -> CvtM (LHsContext RdrName
- ,Located RdrName
- ,[LHsTyVarBndr RdrName]
- ,Maybe [LHsType RdrName])
+ where
+ isFamInstD (DataInstD _ _ _ _ _) = True
+ isFamInstD (NewtypeInstD _ _ _ _ _) = True
+ isFamInstD (TySynInstD _ _ _) = True
+ isFamInstD _ = False
+
+cvtTop (ForeignD ford)
+ = do { ford' <- cvtForD ford
+ ; returnL $ ForD ford'
+ }
+
+cvtTop (PragmaD prag)
+ = do { prag' <- cvtPragmaD prag
+ ; returnL $ Hs.SigD prag'
+ }
+
+cvtTop (FamilyD flav tc tvs kind)
+ = do { (_, tc', tvs', _) <- cvt_tycl_hdr [] tc tvs
+ ; let kind' = fmap cvtKind kind
+ ; returnL $ TyClD (TyFamily (cvtFamFlavour flav) tc' tvs' kind')
+ }
+ where
+ cvtFamFlavour TypeFam = TypeFamily
+ cvtFamFlavour DataFam = DataFamily
+
+cvtTop (DataInstD ctxt tc tys constrs derivs)
+ = do { stuff <- cvt_tyinst_hdr ctxt tc tys
+ ; cons' <- mapM cvtConstr constrs
+ ; derivs' <- cvtDerivs derivs
+ ; returnL $ TyClD (mkTyData DataType stuff Nothing cons' derivs')
+ }
+
+cvtTop (NewtypeInstD ctxt tc tys constr derivs)
+ = do { stuff <- cvt_tyinst_hdr ctxt tc tys
+ ; con' <- cvtConstr constr
+ ; derivs' <- cvtDerivs derivs
+ ; returnL $ TyClD (mkTyData NewType stuff Nothing [con'] derivs')
+ }
+
+cvtTop (TySynInstD tc tys rhs)
+ = do { (_, tc', tvs', tys') <- cvt_tyinst_hdr [] tc tys
+ ; rhs' <- cvtType rhs
+ ; returnL $ TyClD (TySynonym tc' tvs' tys' rhs') }
+
+-- FIXME: This projection is not nice, but to remove it, cvtTop should be
+-- refactored.
+unTyClD :: LHsDecl a -> LTyClDecl a
+unTyClD (L l (TyClD d)) = L l d
+unTyClD _ = panic "Convert.unTyClD: internal error"
+
+cvt_tycl_hdr :: TH.Cxt -> TH.Name -> [TH.TyVarBndr]
+ -> CvtM ( LHsContext RdrName
+ , Located RdrName
+ , [LHsTyVarBndr RdrName]
+ , Maybe [LHsType RdrName])
cvt_tycl_hdr cxt tc tvs
- = do { cxt' <- cvtContext cxt
- ; tc' <- tconNameL tc
- ; tvs' <- cvtTvs tvs
- ; return (cxt', tc', tvs', Nothing) }
+ = do { cxt' <- cvtContext cxt
+ ; tc' <- tconNameL tc
+ ; tvs' <- cvtTvs tvs
+ ; return (cxt', tc', tvs', Nothing)
+ }
+
+cvt_tyinst_hdr :: TH.Cxt -> TH.Name -> [TH.Type]
+ -> CvtM ( LHsContext RdrName
+ , Located RdrName
+ , [LHsTyVarBndr RdrName]
+ , Maybe [LHsType RdrName])
+cvt_tyinst_hdr cxt tc tys
+ = do { cxt' <- cvtContext cxt
+ ; tc' <- tconNameL tc
+ ; tvs <- concatMapM collect tys
+ ; tvs' <- cvtTvs tvs
+ ; tys' <- mapM cvtType tys
+ ; return (cxt', tc', tvs', Just tys')
+ }
+ where
+ collect (ForallT _ _ _)
+ = failWith $ text "Forall type not allowed as type parameter"
+ collect (VarT tv) = return [PlainTV tv]
+ collect (ConT _) = return []
+ collect (TupleT _) = return []
+ collect ArrowT = return []
+ collect ListT = return []
+ collect (AppT t1 t2)
+ = do { tvs1 <- collect t1
+ ; tvs2 <- collect t2
+ ; return $ tvs1 ++ tvs2
+ }
+ collect (SigT (VarT tv) ki) = return [KindedTV tv ki]
+ collect (SigT ty _) = collect ty
---------------------------------------------------
-- Data types
where is_valid :: Char -> Bool
is_valid c = isAscii c && (isAlphaNum c || c `elem` "._")
+------------------------------------------
+-- Pragmas
+------------------------------------------
+
+cvtPragmaD :: Pragma -> CvtM (Sig RdrName)
+cvtPragmaD (InlineP nm ispec)
+ = do { nm' <- vNameL nm
+ ; return $ InlineSig nm' (cvtInlineSpec (Just ispec))
+ }
+cvtPragmaD (SpecialiseP nm ty opt_ispec)
+ = do { nm' <- vNameL nm
+ ; ty' <- cvtType ty
+ ; return $ SpecSig nm' ty' (cvtInlineSpec opt_ispec)
+ }
+
+cvtInlineSpec :: Maybe TH.InlineSpec -> Hs.InlineSpec
+cvtInlineSpec Nothing
+ = defaultInlineSpec
+cvtInlineSpec (Just (TH.InlineSpec inline conlike opt_activation))
+ = mkInlineSpec opt_activation' matchinfo inline
+ where
+ matchinfo = cvtRuleMatchInfo conlike
+ opt_activation' = fmap cvtActivation opt_activation
+
+ cvtRuleMatchInfo False = FunLike
+ cvtRuleMatchInfo True = ConLike
+
+ cvtActivation (False, phase) = ActiveBefore phase
+ cvtActivation (True , phase) = ActiveAfter phase
---------------------------------------------------
-- Declarations
cvtDecs :: [TH.Dec] -> CvtM (HsLocalBinds RdrName)
cvtDecs [] = return EmptyLocalBinds
-cvtDecs ds = do { (binds,sigs) <- cvtBindsAndSigs ds
+cvtDecs ds = do { (binds, sigs) <- cvtBindsAndSigs ds
; return (HsValBinds (ValBindsIn binds sigs)) }
cvtBindsAndSigs :: [TH.Dec] -> CvtM (Bag (LHsBind RdrName), [LSig RdrName])
cvtBindsAndSigs ds
- = do { binds' <- mapM cvtBind binds; sigs' <- mapM cvtSig sigs
+ = do { binds' <- mapM cvtBind binds
+ ; sigs' <- mapM cvtSig sigs
; return (listToBag binds', sigs') }
where
(sigs, binds) = partition is_sig ds
- is_sig (TH.SigD _ _) = True
- is_sig _ = False
+ is_sig (TH.SigD _ _) = True
+ is_sig (TH.PragmaD _) = True
+ is_sig _ = False
cvtSig :: TH.Dec -> CvtM (LSig RdrName)
cvtSig (TH.SigD nm ty)
- = do { nm' <- vNameL nm; ty' <- cvtType ty; returnL (Hs.TypeSig nm' ty') }
+ = do { nm' <- vNameL nm
+ ; ty' <- cvtType ty
+ ; returnL (Hs.TypeSig nm' ty')
+ }
+cvtSig (TH.PragmaD prag)
+ = do { prag' <- cvtPragmaD prag
+ ; returnL prag'
+ }
+cvtSig _ = panic "Convert.cvtSig: Signature expected"
cvtBind :: TH.Dec -> CvtM (LHsBind RdrName)
-- Used only for declarations in a 'let/where' clause,
; e' <- returnL $ OpApp x' s' undefined y'
; return $ HsPar e' }
cvt (InfixE Nothing s (Just y)) = do { s' <- cvtl s; y' <- cvtl y
- ; return $ SectionR s' y' }
+ ; sec <- returnL $ SectionR s' y'
+ ; return $ HsPar sec }
cvt (InfixE (Just x) s Nothing ) = do { x' <- cvtl x; s' <- cvtl s
- ; return $ SectionL x' s' }
+ ; sec <- returnL $ SectionL x' s'
+ ; return $ HsPar sec }
cvt (InfixE Nothing s Nothing ) = cvt s -- Can I indicate this is an infix thing?
cvt (SigE e t) = do { e' <- cvtl e; t' <- cvtType t
= do { stmts' <- cvtStmts stmts
; let body = case last stmts' of
L _ (ExprStmt body _ _) -> body
+ _ -> panic "Malformed body"
; return $ HsDo do_or_lc (init stmts') body void }
cvtStmts :: [TH.Stmt] -> CvtM [Hs.LStmt RdrName]
; returnL $ GRHS gs' rhs' }
cvtOverLit :: Lit -> CvtM (HsOverLit RdrName)
-cvtOverLit (IntegerL i) = do { force i; return $ mkHsIntegral i placeHolderType}
-cvtOverLit (RationalL r) = do { force r; return $ mkHsFractional r placeHolderType}
-cvtOverLit (StringL s) = do { let { s' = mkFastString s }; force s'; return $ mkHsIsString s' placeHolderType }
--- An Integer is like an an (overloaded) '3' in a Haskell source program
+cvtOverLit (IntegerL i)
+ = do { force i; return $ mkHsIntegral i placeHolderType}
+cvtOverLit (RationalL r)
+ = do { force r; return $ mkHsFractional r placeHolderType}
+cvtOverLit (StringL s)
+ = do { let { s' = mkFastString s }
+ ; force s'
+ ; return $ mkHsIsString s' placeHolderType
+ }
+cvtOverLit _ = panic "Convert.cvtOverLit: Unexpected overloaded literal"
+-- An Integer is like an (overloaded) '3' in a Haskell source program
-- Similarly 3.5 for fractionals
cvtLit :: Lit -> CvtM HsLit
cvtLit (FloatPrimL f) = do { force f; return $ HsFloatPrim f }
cvtLit (DoublePrimL f) = do { force f; return $ HsDoublePrim f }
cvtLit (CharL c) = do { force c; return $ HsChar c }
-cvtLit (StringL s) = do { let { s' = mkFastString s }; force s'; return $ HsString s' }
+cvtLit (StringL s)
+ = do { let { s' = mkFastString s }
+ ; force s'
+ ; return $ HsString s'
+ }
+cvtLit _ = panic "Convert.cvtLit: Unexpected literal"
cvtPats :: [TH.Pat] -> CvtM [Hs.LPat RdrName]
cvtPats pats = mapM cvtPat pats
cvtp (InfixP p1 s p2) = do { s' <- cNameL s; p1' <- cvtPat p1; p2' <- cvtPat p2
; return $ ConPatIn s' (InfixCon p1' p2') }
cvtp (TildeP p) = do { p' <- cvtPat p; return $ LazyPat p' }
+cvtp (BangP p) = do { p' <- cvtPat p; return $ BangPat p' }
cvtp (TH.AsP s p) = do { s' <- vNameL s; p' <- cvtPat p; return $ AsPat s' p' }
cvtp TH.WildP = return $ WildPat void
cvtp (RecP c fs) = do { c' <- cNameL c; fs' <- mapM cvtPatFld fs
-----------------------------------------------------------
-- Types and type variables
-cvtTvs :: [TH.Name] -> CvtM [LHsTyVarBndr RdrName]
+cvtTvs :: [TH.TyVarBndr] -> CvtM [LHsTyVarBndr RdrName]
cvtTvs tvs = mapM cvt_tv tvs
-cvt_tv :: TH.Name -> CvtM (LHsTyVarBndr RdrName)
-cvt_tv tv = do { tv' <- tName tv; returnL $ UserTyVar tv' }
-
-cvtContext :: Cxt -> CvtM (LHsContext RdrName)
+cvt_tv :: TH.TyVarBndr -> CvtM (LHsTyVarBndr RdrName)
+cvt_tv (TH.PlainTV nm)
+ = do { nm' <- tName nm
+ ; returnL $ UserTyVar nm'
+ }
+cvt_tv (TH.KindedTV nm ki)
+ = do { nm' <- tName nm
+ ; returnL $ KindedTyVar nm' (cvtKind ki)
+ }
+
+cvtContext :: TH.Cxt -> CvtM (LHsContext RdrName)
cvtContext tys = do { preds' <- mapM cvtPred tys; returnL preds' }
-cvtPred :: TH.Type -> CvtM (LHsPred RdrName)
-cvtPred ty
+cvtPred :: TH.Pred -> CvtM (LHsPred RdrName)
+cvtPred (TH.ClassP cla tys)
+ = do { cla' <- if isVarName cla then tName cla else tconName cla
+ ; tys' <- mapM cvtType tys
+ ; returnL $ HsClassP cla' tys'
+ }
+cvtPred (TH.EqualP ty1 ty2)
+ = do { ty1' <- cvtType ty1
+ ; ty2' <- cvtType ty2
+ ; returnL $ HsEqualP ty1' ty2'
+ }
+
+cvtPredTy :: TH.Type -> CvtM (LHsPred RdrName)
+cvtPredTy ty
= do { (head, tys') <- split_ty_app ty
; case head of
ConT tc -> do { tc' <- tconName tc; returnL $ HsClassP tc' tys' }
VarT tv -> do { tv' <- tName tv; returnL $ HsClassP tv' tys' }
- _ -> failWith (ptext (sLit "Malformed predicate") <+> text (TH.pprint ty)) }
+ _ -> failWith (ptext (sLit "Malformed predicate") <+>
+ text (TH.pprint ty)) }
cvtType :: TH.Type -> CvtM (LHsType RdrName)
-cvtType ty = do { (head_ty, tys') <- split_ty_app ty
- ; case head_ty of
- TupleT n | length tys' == n -- Saturated
- -> if n==1 then return (head tys') -- Singleton tuples treated
- -- like nothing (ie just parens)
- else returnL (HsTupleTy Boxed tys')
- | n == 1 -> failWith (ptext (sLit "Illegal 1-tuple type constructor"))
- | otherwise -> mk_apps (HsTyVar (getRdrName (tupleTyCon Boxed n))) tys'
- ArrowT | [x',y'] <- tys' -> returnL (HsFunTy x' y')
- ListT | [x'] <- tys' -> returnL (HsListTy x')
- VarT nm -> do { nm' <- tName nm; mk_apps (HsTyVar nm') tys' }
- ConT nm -> do { nm' <- tconName nm; mk_apps (HsTyVar nm') tys' }
-
- ForallT tvs cxt ty | null tys' -> do { tvs' <- cvtTvs tvs
- ; cxt' <- cvtContext cxt
- ; ty' <- cvtType ty
- ; returnL $ mkExplicitHsForAllTy tvs' cxt' ty' }
- _ -> failWith (ptext (sLit "Malformed type") <+> text (show ty))
- }
+cvtType ty
+ = do { (head_ty, tys') <- split_ty_app ty
+ ; case head_ty of
+ TupleT n
+ | length tys' == n -- Saturated
+ -> if n==1 then return (head tys') -- Singleton tuples treated
+ -- like nothing (ie just parens)
+ else returnL (HsTupleTy Boxed tys')
+ | n == 1
+ -> failWith (ptext (sLit "Illegal 1-tuple type constructor"))
+ | otherwise
+ -> mk_apps (HsTyVar (getRdrName (tupleTyCon Boxed n))) tys'
+ ArrowT
+ | [x',y'] <- tys' -> returnL (HsFunTy x' y')
+ | otherwise -> mk_apps (HsTyVar (getRdrName funTyCon)) tys'
+ ListT
+ | [x'] <- tys' -> returnL (HsListTy x')
+ | otherwise -> mk_apps (HsTyVar (getRdrName listTyCon)) tys'
+ VarT nm -> do { nm' <- tName nm; mk_apps (HsTyVar nm') tys' }
+ ConT nm -> do { nm' <- tconName nm; mk_apps (HsTyVar nm') tys' }
+
+ ForallT tvs cxt ty
+ | null tys'
+ -> do { tvs' <- cvtTvs tvs
+ ; cxt' <- cvtContext cxt
+ ; ty' <- cvtType ty
+ ; returnL $ mkExplicitHsForAllTy tvs' cxt' ty'
+ }
+
+ SigT ty ki
+ -> do { ty' <- cvtType ty
+ ; mk_apps (HsKindSig ty' (cvtKind ki)) tys'
+ }
+
+ _ -> failWith (ptext (sLit "Malformed type") <+> text (show ty))
+ }
where
mk_apps head_ty [] = returnL head_ty
mk_apps head_ty (ty:tys) = do { head_ty' <- returnL head_ty
go (AppT f a) as' = do { a' <- cvtType a; go f (a':as') }
go f as = return (f,as)
+cvtKind :: TH.Kind -> Type.Kind
+cvtKind StarK = liftedTypeKind
+cvtKind (ArrowK k1 k2) = mkArrowKind (cvtKind k1) (cvtKind k2)
+
-----------------------------------------------------------
| OccName.isVarNameSpace ns = startsVarId c || startsVarSym c
| otherwise = startsConId c || startsConSym c || str == "[]"
+-- Determine the name space of a name in a type
+--
+isVarName :: TH.Name -> Bool
+isVarName (TH.Name occ _)
+ = case TH.occString occ of
+ "" -> False
+ (c:_) -> startsVarId c || startsVarSym c
+
badOcc :: OccName.NameSpace -> String -> SDoc
badOcc ctxt_ns occ
= ptext (sLit "Illegal") <+> pprNameSpace ctxt_ns
-- which will give confusing error messages later
--
-- The strict applications ensure that any buried exceptions get forced
-thRdrName _ occ (TH.NameG th_ns pkg mod) = (mkOrig $! (mkModule (mk_pkg pkg) (mk_mod mod))) $! (mk_occ (mk_ghc_ns th_ns) occ)
+thRdrName _ occ (TH.NameG th_ns pkg mod) = thOrigRdrName occ th_ns pkg mod
thRdrName ctxt_ns occ (TH.NameL uniq) = nameRdrName $! (((Name.mkInternalName $! (mk_uniq uniq)) $! (mk_occ ctxt_ns occ)) noSrcSpan)
thRdrName ctxt_ns occ (TH.NameQ mod) = (mkRdrQual $! (mk_mod mod)) $! (mk_occ ctxt_ns occ)
thRdrName ctxt_ns occ (TH.NameU uniq) = mkRdrUnqual $! (mk_uniq_occ ctxt_ns occ uniq)
| Just name <- isBuiltInOcc ctxt_ns occ = nameRdrName $! name
| otherwise = mkRdrUnqual $! (mk_occ ctxt_ns occ)
+thOrigRdrName :: String -> TH.NameSpace -> PkgName -> ModName -> RdrName
+thOrigRdrName occ th_ns pkg mod = (mkOrig $! (mkModule (mk_pkg pkg) (mk_mod mod))) $! (mk_occ (mk_ghc_ns th_ns) occ)
+
+thRdrNameGuesses :: TH.Name -> [RdrName]
+thRdrNameGuesses (TH.Name occ flavour)
+ -- This special case for NameG ensures that we don't generate duplicates in the output list
+ | TH.NameG th_ns pkg mod <- flavour = [thOrigRdrName occ_str th_ns pkg mod]
+ | otherwise = [ thRdrName gns occ_str flavour
+ | gns <- guessed_nss]
+ where
+ -- guessed_ns are the name spaces guessed from looking at the TH name
+ guessed_nss | isLexCon (mkFastString occ_str) = [OccName.tcName, OccName.dataName]
+ | otherwise = [OccName.varName, OccName.tvName]
+ occ_str = TH.occString occ
+
isBuiltInOcc :: OccName.NameSpace -> String -> Maybe Name.Name
-- Built in syntax isn't "in scope" so an Unqual RdrName won't do
-- We must generate an Exact name, just as the parser does