\begin{code}
module Convert( convertToHsExpr, convertToPat, convertToHsDecls,
- convertToHsType, thRdrNameGuesses ) where
+ convertToHsType, convertToHsPred,
+ thRdrNameGuesses ) where
import HsSyn as Hs
import qualified Class
import OccName
import SrcLoc
import Type
+import Coercion
import TysWiredIn
import BasicTypes as Hs
import ForeignCall
-import Char
-import List
import Unique
import MonadUtils
import ErrUtils
import Bag
+import Util
import FastString
import Outputable
+import Control.Monad( unless )
+
import Language.Haskell.TH as TH hiding (sigP)
import Language.Haskell.TH.Syntax as TH
-- The external interface
convertToHsDecls :: SrcSpan -> [TH.Dec] -> Either Message [LHsDecl RdrName]
-convertToHsDecls loc ds = initCvt loc (mapM cvtTop ds)
+convertToHsDecls loc ds = initCvt loc (mapM cvt_dec ds)
+ where
+ cvt_dec d = wrapMsg "declaration" d (cvtDec d)
convertToHsExpr :: SrcSpan -> TH.Exp -> Either Message (LHsExpr RdrName)
convertToHsExpr loc e
- = case initCvt loc (cvtl e) of
- Left msg -> Left (msg $$ (ptext (sLit "When splicing TH expression:")
- <+> text (show e)))
- Right res -> Right res
+ = initCvt loc $ wrapMsg "expression" e $ cvtl e
convertToPat :: SrcSpan -> TH.Pat -> Either Message (LPat RdrName)
-convertToPat loc e
- = case initCvt loc (cvtPat e) of
- Left msg -> Left (msg $$ (ptext (sLit "When splicing TH pattern:")
- <+> text (show e)))
- Right res -> Right res
+convertToPat loc p
+ = initCvt loc $ wrapMsg "pattern" p $ cvtPat p
convertToHsType :: SrcSpan -> TH.Type -> Either Message (LHsType RdrName)
-convertToHsType loc t = initCvt loc (cvtType t)
+convertToHsType loc t
+ = initCvt loc $ wrapMsg "type" t $ cvtType t
+convertToHsPred :: SrcSpan -> TH.Pred -> Either Message (LHsPred RdrName)
+convertToHsPred loc t
+ = initCvt loc $ wrapMsg "type" t $ cvtPred t
-------------------------------------------------------------------
newtype CvtM a = CvtM { unCvtM :: SrcSpan -> Either Message a }
initCvt :: SrcSpan -> CvtM a -> Either Message a
initCvt loc (CvtM m) = m loc
-force :: a -> CvtM a
-force a = a `seq` return a
+force :: a -> CvtM ()
+force a = a `seq` return ()
failWith :: Message -> CvtM a
-failWith m = CvtM (\_ -> Left full_msg)
- where
- full_msg = m $$ ptext (sLit "When splicing generated code into the program")
+failWith m = CvtM (\_ -> Left m)
returnL :: a -> CvtM (Located a)
returnL x = CvtM (\loc -> Right (L loc x))
+wrapMsg :: (Show a, TH.Ppr a) => String -> a -> CvtM b -> CvtM b
+-- E.g wrapMsg "declaration" dec thing
+wrapMsg what item (CvtM m)
+ = CvtM (\loc -> case m loc of
+ Left err -> Left (err $$ getPprStyle msg)
+ Right v -> Right v)
+ where
+ -- Show the item in pretty syntax normally,
+ -- but with all its constructors if you say -dppr-debug
+ msg sty = hang (ptext (sLit "When splicing a TH") <+> text what <> colon)
+ 2 (if debugStyle sty
+ then text (show item)
+ else text (pprint item))
+
wrapL :: CvtM a -> CvtM (Located a)
wrapL (CvtM m) = CvtM (\loc -> case m loc of
Left err -> Left err
Right v -> Right (L loc v))
-------------------------------------------------------------------
-cvtTop :: TH.Dec -> CvtM (LHsDecl RdrName)
-cvtTop d@(TH.ValD _ _ _)
- = do { L loc d' <- cvtBind d
- ; return (L loc $ Hs.ValD d') }
+cvtDec :: TH.Dec -> CvtM (LHsDecl RdrName)
+cvtDec (TH.ValD pat body ds)
+ | TH.VarP s <- pat
+ = do { s' <- vNameL s
+ ; cl' <- cvtClause (Clause [] body ds)
+ ; returnL $ Hs.ValD $ mkFunBind s' [cl'] }
-cvtTop d@(TH.FunD _ _)
- = do { L loc d' <- cvtBind d
- ; return (L loc $ Hs.ValD d') }
+ | otherwise
+ = do { pat' <- cvtPat pat
+ ; body' <- cvtGuard body
+ ; ds' <- cvtLocalDecs (ptext (sLit "a where clause")) ds
+ ; returnL $ Hs.ValD $
+ PatBind { pat_lhs = pat', pat_rhs = GRHSs body' ds'
+ , pat_rhs_ty = void, bind_fvs = placeHolderNames } }
+
+cvtDec (TH.FunD nm cls)
+ | null cls
+ = failWith (ptext (sLit "Function binding for")
+ <+> quotes (text (TH.pprint nm))
+ <+> ptext (sLit "has no equations"))
+ | otherwise
+ = do { nm' <- vNameL nm
+ ; cls' <- mapM cvtClause cls
+ ; returnL $ Hs.ValD $ mkFunBind nm' cls' }
-cvtTop (TH.SigD nm typ)
+cvtDec (TH.SigD nm typ)
= do { nm' <- vNameL nm
; ty' <- cvtType typ
; returnL $ Hs.SigD (TypeSig nm' ty') }
-cvtTop (TySynD tc tvs rhs)
- = do { (_, tc', tvs', _) <- cvt_tycl_hdr [] tc tvs
+cvtDec (PragmaD prag)
+ = do { prag' <- cvtPragmaD prag
+ ; returnL $ Hs.SigD prag' }
+
+cvtDec (TySynD tc tvs rhs)
+ = do { (_, tc', tvs') <- cvt_tycl_hdr [] tc tvs
; rhs' <- cvtType rhs
; returnL $ TyClD (TySynonym tc' tvs' Nothing rhs') }
-cvtTop (DataD ctxt tc tvs constrs derivs)
- = do { stuff <- cvt_tycl_hdr ctxt tc tvs
+cvtDec (DataD ctxt tc tvs constrs derivs)
+ = do { (ctxt', tc', tvs') <- cvt_tycl_hdr ctxt tc tvs
; cons' <- mapM cvtConstr constrs
; derivs' <- cvtDerivs derivs
- ; returnL $ TyClD (mkTyData DataType stuff Nothing cons' derivs') }
+ ; returnL $ TyClD (TyData { tcdND = DataType, tcdLName = tc', tcdCtxt = ctxt'
+ , tcdTyVars = tvs', tcdTyPats = Nothing, tcdKindSig = Nothing
+ , tcdCons = cons', tcdDerivs = derivs' }) }
-cvtTop (NewtypeD ctxt tc tvs constr derivs)
- = do { stuff <- cvt_tycl_hdr ctxt tc tvs
+cvtDec (NewtypeD ctxt tc tvs constr derivs)
+ = do { (ctxt', tc', tvs') <- cvt_tycl_hdr ctxt tc tvs
; con' <- cvtConstr constr
; derivs' <- cvtDerivs derivs
- ; returnL $ TyClD (mkTyData NewType stuff Nothing [con'] derivs') }
+ ; returnL $ TyClD (TyData { tcdND = NewType, tcdLName = tc', tcdCtxt = ctxt'
+ , tcdTyVars = tvs', tcdTyPats = Nothing, tcdKindSig = Nothing
+ , tcdCons = [con'], tcdDerivs = derivs'}) }
-cvtTop (ClassD ctxt cl tvs fds decs)
- = do { (cxt', tc', tvs', _) <- cvt_tycl_hdr ctxt cl tvs
+cvtDec (ClassD ctxt cl tvs fds decs)
+ = do { (cxt', tc', tvs') <- cvt_tycl_hdr ctxt cl tvs
; fds' <- mapM cvt_fundep fds
- ; let (ats, bind_sig_decs) = partition isFamilyD decs
- ; (binds', sigs') <- cvtBindsAndSigs bind_sig_decs
- ; ats' <- mapM cvtTop ats
- ; let ats'' = map unTyClD ats'
+ ; (binds', sigs', ats') <- cvt_ci_decs (ptext (sLit "a class declaration")) decs
; returnL $
- TyClD $ mkClassDecl (cxt', tc', tvs') fds' sigs' binds' ats'' []
- -- no docs in TH ^^
+ TyClD $ ClassDecl { tcdCtxt = cxt', tcdLName = tc', tcdTyVars = tvs'
+ , tcdFDs = fds', tcdSigs = sigs', tcdMeths = binds'
+ , tcdATs = ats', tcdDocs = [] }
+ -- no docs 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'
+
+cvtDec (InstanceD ctxt ty decs)
+ = do { (binds', sigs', ats') <- cvt_ci_decs (ptext (sLit "an instance declaration")) decs
; 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'')
- }
- where
- isFamInstD (DataInstD _ _ _ _ _) = True
- isFamInstD (NewtypeInstD _ _ _ _ _) = True
- isFamInstD (TySynInstD _ _ _) = True
- isFamInstD _ = False
+ ; let inst_ty' = L loc $ mkImplicitHsForAllTy ctxt' $ L loc $ HsPredTy pred'
+ ; returnL $ InstD (InstDecl inst_ty' binds' sigs' ats') }
-cvtTop (ForeignD ford)
+cvtDec (ForeignD ford)
= do { ford' <- cvtForD ford
- ; returnL $ ForD 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
+cvtDec (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')
- }
+ ; 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
+cvtDec (DataInstD ctxt tc tys constrs derivs)
+ = do { (ctxt', tc', tvs', typats') <- cvt_tyinst_hdr ctxt tc tys
; cons' <- mapM cvtConstr constrs
; derivs' <- cvtDerivs derivs
- ; returnL $ TyClD (mkTyData DataType stuff Nothing cons' derivs')
- }
+ ; returnL $ TyClD (TyData { tcdND = DataType, tcdLName = tc', tcdCtxt = ctxt'
+ , tcdTyVars = tvs', tcdTyPats = typats', tcdKindSig = Nothing
+ , tcdCons = cons', tcdDerivs = derivs' }) }
-cvtTop (NewtypeInstD ctxt tc tys constr derivs)
- = do { stuff <- cvt_tyinst_hdr ctxt tc tys
+cvtDec (NewtypeInstD ctxt tc tys constr derivs)
+ = do { (ctxt', tc', tvs', typats') <- cvt_tyinst_hdr ctxt tc tys
; con' <- cvtConstr constr
; derivs' <- cvtDerivs derivs
- ; returnL $ TyClD (mkTyData NewType stuff Nothing [con'] derivs')
+ ; returnL $ TyClD (TyData { tcdND = NewType, tcdLName = tc', tcdCtxt = ctxt'
+ , tcdTyVars = tvs', tcdTyPats = typats', tcdKindSig = Nothing
+ , tcdCons = [con'], tcdDerivs = derivs' })
}
-cvtTop (TySynInstD tc tys rhs)
+cvtDec (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_ci_decs :: Message -> [TH.Dec]
+ -> CvtM (LHsBinds RdrName,
+ [LSig RdrName],
+ [LTyClDecl RdrName])
+-- Convert the declarations inside a class or instance decl
+-- ie signatures, bindings, and associated types
+cvt_ci_decs doc decs
+ = do { decs' <- mapM cvtDec decs
+ ; let (ats', bind_sig_decs') = partitionWith is_tycl decs'
+ ; let (sigs', prob_binds') = partitionWith is_sig bind_sig_decs'
+ ; let (binds', bads) = partitionWith is_bind prob_binds'
+ ; unless (null bads) (failWith (mkBadDecMsg doc bads))
+ ; return (listToBag binds', sigs', ats') }
+
+----------------
cvt_tycl_hdr :: TH.Cxt -> TH.Name -> [TH.TyVarBndr]
-> CvtM ( LHsContext RdrName
, Located RdrName
- , [LHsTyVarBndr RdrName]
- , Maybe [LHsType RdrName])
+ , [LHsTyVarBndr RdrName])
cvt_tycl_hdr cxt tc tvs
= do { cxt' <- cvtContext cxt
; tc' <- tconNameL tc
; tvs' <- cvtTvs tvs
- ; return (cxt', tc', tvs', Nothing)
+ ; return (cxt', tc', tvs')
}
cvt_tyinst_hdr :: TH.Cxt -> TH.Name -> [TH.Type]
collect (SigT (VarT tv) ki) = return [KindedTV tv ki]
collect (SigT ty _) = collect ty
+-------------------------------------------------------------------
+-- Partitioning declarations
+-------------------------------------------------------------------
+
+is_tycl :: LHsDecl RdrName -> Either (LTyClDecl RdrName) (LHsDecl RdrName)
+is_tycl (L loc (Hs.TyClD tcd)) = Left (L loc tcd)
+is_tycl decl = Right decl
+
+is_sig :: LHsDecl RdrName -> Either (LSig RdrName) (LHsDecl RdrName)
+is_sig (L loc (Hs.SigD sig)) = Left (L loc sig)
+is_sig decl = Right decl
+
+is_bind :: LHsDecl RdrName -> Either (LHsBind RdrName) (LHsDecl RdrName)
+is_bind (L loc (Hs.ValD bind)) = Left (L loc bind)
+is_bind decl = Right decl
+
+mkBadDecMsg :: Message -> [LHsDecl RdrName] -> Message
+mkBadDecMsg doc bads
+ = sep [ ptext (sLit "Illegal declaration(s) in") <+> doc <> colon
+ , nest 2 (vcat (map Outputable.ppr bads)) ]
+
---------------------------------------------------
-- Data types
-- Can't handle GADTs yet
= do { c' <- cNameL c
; cxt' <- returnL []
; tys' <- mapM cvt_arg strtys
- ; returnL $ ConDecl c' Explicit noExistentials cxt' (PrefixCon tys') ResTyH98 Nothing }
+ ; returnL $ mkSimpleConDecl c' noExistentials cxt' (PrefixCon tys') }
cvtConstr (RecC c varstrtys)
= do { c' <- cNameL c
; cxt' <- returnL []
; args' <- mapM cvt_id_arg varstrtys
- ; returnL $ ConDecl c' Explicit noExistentials cxt' (RecCon args') ResTyH98 Nothing }
+ ; returnL $ mkSimpleConDecl c' noExistentials cxt' (RecCon args') }
cvtConstr (InfixC st1 c st2)
= do { c' <- cNameL c
; cxt' <- returnL []
; st1' <- cvt_arg st1
; st2' <- cvt_arg st2
- ; returnL $ ConDecl c' Explicit noExistentials cxt' (InfixCon st1' st2') ResTyH98 Nothing }
-
-cvtConstr (ForallC tvs ctxt (ForallC tvs' ctxt' con'))
- = cvtConstr (ForallC (tvs ++ tvs') (ctxt ++ ctxt') con')
+ ; returnL $ mkSimpleConDecl c' noExistentials cxt' (InfixCon st1' st2') }
cvtConstr (ForallC tvs ctxt con)
- = do { L _ con' <- cvtConstr con
- ; tvs' <- cvtTvs tvs
- ; ctxt' <- cvtContext ctxt
- ; case con' of
- ConDecl l _ [] (L _ []) x ResTyH98 _
- -> returnL $ ConDecl l Explicit tvs' ctxt' x ResTyH98 Nothing
- _ -> panic "ForallC: Can't happen" }
+ = do { tvs' <- cvtTvs tvs
+ ; L loc ctxt' <- cvtContext ctxt
+ ; L _ con' <- cvtConstr con
+ ; returnL $ con' { con_qvars = tvs' ++ con_qvars con'
+ , con_cxt = L loc (ctxt' ++ (unLoc $ con_cxt con')) } }
cvt_arg :: (TH.Strict, TH.Type) -> CvtM (LHsType RdrName)
cvt_arg (IsStrict, ty) = do { ty' <- cvtType ty; returnL $ HsBangTy HsStrict ty' }
cvtForD :: Foreign -> CvtM (ForeignDecl RdrName)
cvtForD (ImportF callconv safety from nm ty)
- | Just (c_header, cis) <- parse_ccall_impent (TH.nameBase nm) from
- = do { nm' <- vNameL nm
- ; ty' <- cvtType ty
- ; let i = CImport (cvt_conv callconv) safety' c_header nilFS cis
- ; return $ ForeignImport nm' ty' i }
-
+ | Just impspec <- parseCImport (cvt_conv callconv) safety'
+ (mkFastString (TH.nameBase nm)) from
+ = do { nm' <- vNameL nm
+ ; ty' <- cvtType ty
+ ; return (ForeignImport nm' ty' impspec)
+ }
| otherwise
- = failWith $ text (show from)<+> ptext (sLit "is not a valid ccall impent")
- where
+ = failWith $ text (show from) <+> ptext (sLit "is not a valid ccall impent")
+ where
safety' = case safety of
Unsafe -> PlayRisky
Safe -> PlaySafe False
Threadsafe -> PlaySafe True
+ Interruptible -> PlayInterruptible
cvtForD (ExportF callconv as nm ty)
= do { nm' <- vNameL nm
cvt_conv TH.CCall = CCallConv
cvt_conv TH.StdCall = StdCallConv
-parse_ccall_impent :: String -> String -> Maybe (FastString, CImportSpec)
-parse_ccall_impent nm s
- = case lex_ccall_impent s of
- Just ["dynamic"] -> Just (nilFS, CFunction DynamicTarget)
- Just ["wrapper"] -> Just (nilFS, CWrapper)
- Just ("static":ts) -> parse_ccall_impent_static nm ts
- Just ts -> parse_ccall_impent_static nm ts
- Nothing -> Nothing
-
-parse_ccall_impent_static :: String
- -> [String]
- -> Maybe (FastString, CImportSpec)
-parse_ccall_impent_static nm ts
- = let ts' = case ts of
- [ "&", cid] -> [ cid]
- [fname, "&" ] -> [fname ]
- [fname, "&", cid] -> [fname, cid]
- _ -> ts
- in case ts' of
- [ cid] | is_cid cid -> Just (nilFS, mk_cid cid)
- [fname, cid] | is_cid cid -> Just (mkFastString fname, mk_cid cid)
- [ ] -> Just (nilFS, mk_cid nm)
- [fname ] -> Just (mkFastString fname, mk_cid nm)
- _ -> Nothing
- where is_cid :: String -> Bool
- is_cid x = all (/= '.') x && (isAlpha (head x) || head x == '_')
- mk_cid :: String -> CImportSpec
- mk_cid = CFunction . StaticTarget . mkFastString
-
-lex_ccall_impent :: String -> Maybe [String]
-lex_ccall_impent "" = Just []
-lex_ccall_impent ('&':xs) = fmap ("&":) $ lex_ccall_impent xs
-lex_ccall_impent (' ':xs) = lex_ccall_impent xs
-lex_ccall_impent ('\t':xs) = lex_ccall_impent xs
-lex_ccall_impent xs = case span is_valid xs of
- ("", _) -> Nothing
- (t, xs') -> fmap (t:) $ lex_ccall_impent xs'
- 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))
- }
+ ; 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)
- }
+ = do { nm' <- vNameL nm
+ ; ty' <- cvtType ty
+ ; return $ SpecSig nm' ty' (cvtInlineSpec opt_ispec) }
-cvtInlineSpec :: Maybe TH.InlineSpec -> Hs.InlineSpec
+cvtInlineSpec :: Maybe TH.InlineSpec -> Hs.InlinePragma
cvtInlineSpec Nothing
- = defaultInlineSpec
+ = defaultInlinePragma
cvtInlineSpec (Just (TH.InlineSpec inline conlike opt_activation))
- = mkInlineSpec opt_activation' matchinfo inline
+ = InlinePragma { inl_act = opt_activation', inl_rule = matchinfo
+ , inl_inline = inl_spec, inl_sat = Nothing }
where
matchinfo = cvtRuleMatchInfo conlike
- opt_activation' = fmap cvtActivation opt_activation
+ opt_activation' = cvtActivation opt_activation
cvtRuleMatchInfo False = FunLike
cvtRuleMatchInfo True = ConLike
- cvtActivation (False, phase) = ActiveBefore phase
- cvtActivation (True , phase) = ActiveAfter phase
+ inl_spec | inline = Inline
+ | otherwise = NoInline
+ -- Currently we have no way to say Inlinable
+
+ cvtActivation Nothing | inline = AlwaysActive
+ | otherwise = NeverActive
+ cvtActivation (Just (False, phase)) = ActiveBefore phase
+ cvtActivation (Just (True , phase)) = ActiveAfter phase
---------------------------------------------------
-- Declarations
---------------------------------------------------
-cvtDecs :: [TH.Dec] -> CvtM (HsLocalBinds RdrName)
-cvtDecs [] = return EmptyLocalBinds
-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
- ; return (listToBag binds', sigs') }
- where
- (sigs, binds) = partition is_sig ds
-
- 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')
- }
-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,
--- not for top level decls
-cvtBind (TH.ValD (TH.VarP s) body ds)
- = do { s' <- vNameL s
- ; cl' <- cvtClause (Clause [] body ds)
- ; returnL $ mkFunBind s' [cl'] }
-
-cvtBind (TH.FunD nm cls)
- | null cls
- = failWith (ptext (sLit "Function binding for")
- <+> quotes (text (TH.pprint nm))
- <+> ptext (sLit "has no equations"))
+cvtLocalDecs :: Message -> [TH.Dec] -> CvtM (HsLocalBinds RdrName)
+cvtLocalDecs doc ds
+ | null ds
+ = return EmptyLocalBinds
| otherwise
- = do { nm' <- vNameL nm
- ; cls' <- mapM cvtClause cls
- ; returnL $ mkFunBind nm' cls' }
-
-cvtBind (TH.ValD p body ds)
- = do { p' <- cvtPat p
- ; g' <- cvtGuard body
- ; ds' <- cvtDecs ds
- ; returnL $ PatBind { pat_lhs = p', pat_rhs = GRHSs g' ds',
- pat_rhs_ty = void, bind_fvs = placeHolderNames } }
-
-cvtBind d
- = failWith (sep [ptext (sLit "Illegal kind of declaration in where clause"),
- nest 2 (text (TH.pprint d))])
+ = do { ds' <- mapM cvtDec ds
+ ; let (binds, prob_sigs) = partitionWith is_bind ds'
+ ; let (sigs, bads) = partitionWith is_sig prob_sigs
+ ; unless (null bads) (failWith (mkBadDecMsg doc bads))
+ ; return (HsValBinds (ValBindsIn (listToBag binds) sigs)) }
cvtClause :: TH.Clause -> CvtM (Hs.LMatch RdrName)
cvtClause (Clause ps body wheres)
= do { ps' <- cvtPats ps
; g' <- cvtGuard body
- ; ds' <- cvtDecs wheres
+ ; ds' <- cvtLocalDecs (ptext (sLit "a where clause")) wheres
; returnL $ Hs.Match ps' Nothing (GRHSs g' ds') }
cvt (LamE ps e) = do { ps' <- cvtPats ps; e' <- cvtl e
; return $ HsLam (mkMatchGroup [mkSimpleMatch ps' e']) }
cvt (TupE [e]) = cvt e -- Singleton tuples treated like nothing (just parens)
- cvt (TupE es) = do { es' <- mapM cvtl es; return $ ExplicitTuple es' Boxed }
+ cvt (TupE es) = do { es' <- mapM cvtl es; return $ ExplicitTuple (map Present es') Boxed }
cvt (CondE x y z) = do { x' <- cvtl x; y' <- cvtl y; z' <- cvtl z
; return $ HsIf x' y' z' }
- cvt (LetE ds e) = do { ds' <- cvtDecs ds; e' <- cvtl e; return $ HsLet ds' e' }
+ cvt (LetE ds e) = do { ds' <- cvtLocalDecs (ptext (sLit "a let expression")) ds
+ ; e' <- cvtl e; return $ HsLet ds' e' }
cvt (CaseE e ms)
| null ms = failWith (ptext (sLit "Case expression with no alternatives"))
| otherwise = do { e' <- cvtl e; ms' <- mapM cvtMatch ms
cvt (DoE ss) = cvtHsDo DoExpr ss
cvt (CompE ss) = cvtHsDo ListComp ss
cvt (ArithSeqE dd) = do { dd' <- cvtDD dd; return $ ArithSeq noPostTcExpr dd' }
- cvt (ListE xs) = do { xs' <- mapM cvtl xs; return $ ExplicitList void xs' }
+ cvt (ListE xs)
+ | Just s <- allCharLs xs = do { l' <- cvtLit (StringL s); return (HsLit l') }
+ -- Note [Converting strings]
+ | otherwise = do { xs' <- mapM cvtl xs; return $ ExplicitList void xs' }
cvt (InfixE (Just x) s (Just y)) = do { x' <- cvtl x; s' <- cvtl s; y' <- cvtl y
; e' <- returnL $ OpApp x' s' undefined y'
; return $ HsPar e' }
| null stmts = failWith (ptext (sLit "Empty stmt list in do-block"))
| otherwise
= do { stmts' <- cvtStmts stmts
- ; let body = case last stmts' of
- L _ (ExprStmt body _ _) -> body
- _ -> panic "Malformed body"
+ ; body <- case last stmts' of
+ L _ (ExprStmt body _ _) -> return body
+ stmt' -> failWith (bad_last stmt')
; return $ HsDo do_or_lc (init stmts') body void }
-
+ where
+ bad_last stmt = vcat [ ptext (sLit "Illegal last statement of") <+> pprStmtContext do_or_lc <> colon
+ , nest 2 $ Outputable.ppr stmt
+ , ptext (sLit "(It should be an expression.)") ]
+
cvtStmts :: [TH.Stmt] -> CvtM [Hs.LStmt RdrName]
cvtStmts = mapM cvtStmt
cvtStmt :: TH.Stmt -> CvtM (Hs.LStmt RdrName)
cvtStmt (NoBindS e) = do { e' <- cvtl e; returnL $ mkExprStmt e' }
cvtStmt (TH.BindS p e) = do { p' <- cvtPat p; e' <- cvtl e; returnL $ mkBindStmt p' e' }
-cvtStmt (TH.LetS ds) = do { ds' <- cvtDecs ds; returnL $ LetStmt ds' }
+cvtStmt (TH.LetS ds) = do { ds' <- cvtLocalDecs (ptext (sLit "a let binding")) ds
+ ; returnL $ LetStmt ds' }
cvtStmt (TH.ParS dss) = do { dss' <- mapM cvt_one dss; returnL $ ParStmt dss' }
where
cvt_one ds = do { ds' <- cvtStmts ds; return (ds', undefined) }
cvtMatch (TH.Match p body decs)
= do { p' <- cvtPat p
; g' <- cvtGuard body
- ; decs' <- cvtDecs decs
+ ; decs' <- cvtLocalDecs (ptext (sLit "a where clause")) decs
; returnL $ Hs.Match [p'] Nothing (GRHSs g' decs') }
cvtGuard :: TH.Body -> CvtM [LGRHS RdrName]
-- An Integer is like an (overloaded) '3' in a Haskell source program
-- Similarly 3.5 for fractionals
+{- Note [Converting strings]
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+If we get (ListE [CharL 'x', CharL 'y']) we'd like to convert to
+a string literal for "xy". Of course, we might hope to get
+(LitE (StringL "xy")), but not always, and allCharLs fails quickly
+if it isn't a literal string
+-}
+
+allCharLs :: [TH.Exp] -> Maybe String
+-- Note [Converting strings]
+-- NB: only fire up this setup for a non-empty list, else
+-- there's a danger of returning "" for [] :: [Int]!
+allCharLs xs
+ = case xs of
+ LitE (CharL c) : ys -> go [c] ys
+ _ -> Nothing
+ where
+ go cs [] = Just (reverse cs)
+ go cs (LitE (CharL c) : ys) = go (c:cs) ys
+ go _ _ = Nothing
+
cvtLit :: Lit -> CvtM HsLit
cvtLit (IntPrimL i) = do { force i; return $ HsIntPrim i }
cvtLit (WordPrimL w) = do { force w; return $ HsWordPrim w }
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 (StringPrimL s) = do { let { s' = mkFastString s }
+ ; force s'
+ ; return $ HsStringPrim s' }
cvtLit _ = panic "Convert.cvtLit: Unexpected literal"
+ -- cvtLit should not be called on IntegerL, RationalL
+ -- That precondition is established right here in
+ -- Convert.lhs, hence panic
cvtPats :: [TH.Pat] -> CvtM [Hs.LPat RdrName]
cvtPats pats = mapM cvtPat pats
cvt_tv :: TH.TyVarBndr -> CvtM (LHsTyVarBndr RdrName)
cvt_tv (TH.PlainTV nm)
= do { nm' <- tName nm
- ; returnL $ UserTyVar nm'
+ ; returnL $ UserTyVar nm' placeHolderKind
}
cvt_tv (TH.KindedTV nm ki)
= do { nm' <- tName nm
cvtName :: OccName.NameSpace -> TH.Name -> CvtM RdrName
cvtName ctxt_ns (TH.Name occ flavour)
| not (okOcc ctxt_ns occ_str) = failWith (badOcc ctxt_ns occ_str)
- | otherwise = force (thRdrName ctxt_ns occ_str flavour)
+ | otherwise = force rdr_name >> return rdr_name
where
occ_str = TH.occString occ
+ rdr_name = thRdrName ctxt_ns occ_str flavour
okOcc :: OccName.NameSpace -> String -> Bool
okOcc _ [] = False
mk_uniq_occ :: OccName.NameSpace -> String -> Int# -> OccName.OccName
mk_uniq_occ ns occ uniq
= OccName.mkOccName ns (occ ++ '[' : shows (mk_uniq uniq) "]")
- -- The idea here is to make a name that
- -- a) the user could not possibly write, and
- -- b) cannot clash with another NameU
- -- Previously I generated an Exact RdrName with mkInternalName.
- -- This works fine for local binders, but does not work at all for
- -- top-level binders, which must have External Names, since they are
- -- rapidly baked into data constructors and the like. Baling out
- -- and generating an unqualified RdrName here is the simple solution
+ -- See Note [Unique OccNames from Template Haskell]
-- The packing and unpacking is rather turgid :-(
mk_occ :: OccName.NameSpace -> String -> OccName.OccName
mk_mod :: TH.ModName -> ModuleName
mk_mod mod = mkModuleName (TH.modString mod)
-mk_pkg :: TH.ModName -> PackageId
+mk_pkg :: TH.PkgName -> PackageId
mk_pkg pkg = stringToPackageId (TH.pkgString pkg)
mk_uniq :: Int# -> Unique
mk_uniq u = mkUniqueGrimily (I# u)
\end{code}
+Note [Unique OccNames from Template Haskell]
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+The idea here is to make a name that
+ a) the user could not possibly write (it has a "["
+ and letters or digits from the unique)
+ b) cannot clash with another NameU
+Previously I generated an Exact RdrName with mkInternalName. This
+works fine for local binders, but does not work at all for top-level
+binders, which must have External Names, since they are rapidly baked
+into data constructors and the like. Baling out and generating an
+unqualified RdrName here is the simple solution
+
+See also Note [Suppressing uniques in OccNames] in OccName, which
+suppresses the unique when opt_SuppressUniques is on.
projects / ghc-hetmet.git / blobdiff