This module converts Template Haskell syntax into HsSyn
\begin{code}
-{-# OPTIONS_GHC -w #-}
+{-# 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/WorkingConventions#Warnings
+-- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
-- for details
-module Convert( convertToHsExpr, convertToHsDecls,
- convertToHsType, thRdrName ) where
-
-#include "HsVersions.h"
+module Convert( convertToHsExpr, convertToPat, convertToHsDecls,
+ convertToHsType, thRdrNameGuesses ) where
import HsSyn as Hs
import qualified Class
import Module
import RdrHsSyn
import qualified OccName
-import PackageConfig
import OccName
import SrcLoc
import Type
convertToHsExpr :: SrcSpan -> TH.Exp -> Either Message (LHsExpr RdrName)
convertToHsExpr loc e
= case initCvt loc (cvtl e) of
- Left msg -> Left (msg $$ (ptext SLIT("When converting TH expression")
+ Left msg -> Left (msg $$ (ptext (sLit "When splicing TH expression:")
<+> text (show e)))
Right res -> Right res
+convertToPat :: SrcSpan -> TH.Pat -> Either Message (LPat RdrName)
+convertToPat loc e
+ = case initCvt loc (cvtPat e) of
+ Left msg -> Left (msg $$ (ptext (sLit "When splicing TH pattern:")
+ <+> text (show e)))
+ Right res -> Right res
+
convertToHsType :: SrcSpan -> TH.Type -> Either Message (LHsType RdrName)
convertToHsType loc t = initCvt loc (cvtType t)
-- the spliced-in declarations get a location that at least relates to the splice point
instance Monad CvtM where
- return x = CvtM $ \loc -> Right x
+ return x = CvtM $ \_ -> Right x
(CvtM m) >>= k = CvtM $ \loc -> case m loc of
Left err -> Left err
Right v -> unCvtM (k v) loc
force a = a `seq` return a
failWith :: Message -> CvtM a
-failWith m = CvtM (\loc -> Left full_msg)
+failWith m = CvtM (\_ -> Left full_msg)
where
- full_msg = m $$ ptext SLIT("When splicing generated code into the program")
+ full_msg = m $$ ptext (sLit "When splicing generated code into the program")
returnL :: a -> CvtM (Located a)
returnL x = CvtM (\loc -> Right (L loc x))
; 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
+ -- no ATs in TH ^^
}
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])
cvt_tycl_hdr cxt tc tvs
= do { cxt' <- cvtContext cxt
; tc' <- tconNameL tc
-- Can't handle GADTs yet
---------------------------------------------------
+cvtConstr :: TH.Con -> CvtM (LConDecl RdrName)
+
cvtConstr (NormalC c strtys)
= do { c' <- cNameL c
; cxt' <- returnL []
; case con' of
ConDecl l _ [] (L _ []) x ResTyH98 _
-> returnL $ ConDecl l Explicit tvs' ctxt' x ResTyH98 Nothing
- c -> panic "ForallC: Can't happen" }
+ _ -> panic "ForallC: Can't happen" }
+cvt_arg :: (TH.Strict, TH.Type) -> CvtM (LHsType RdrName)
cvt_arg (IsStrict, ty) = do { ty' <- cvtType ty; returnL $ HsBangTy HsStrict ty' }
cvt_arg (NotStrict, ty) = cvtType ty
+cvt_id_arg :: (TH.Name, TH.Strict, TH.Type) -> CvtM (ConDeclField RdrName)
cvt_id_arg (i, str, ty)
= do { i' <- vNameL i
; ty' <- cvt_arg (str,ty)
; return (ConDeclField { cd_fld_name = i', cd_fld_type = ty', cd_fld_doc = Nothing}) }
+cvtDerivs :: [TH.Name] -> CvtM (Maybe [LHsType RdrName])
cvtDerivs [] = return Nothing
cvtDerivs cs = do { cs' <- mapM cvt_one cs
; return (Just cs') }
cvt_fundep :: FunDep -> CvtM (Located (Class.FunDep RdrName))
cvt_fundep (FunDep xs ys) = do { xs' <- mapM tName xs; ys' <- mapM tName ys; returnL (xs', ys') }
+noExistentials :: [LHsTyVarBndr RdrName]
noExistentials = []
------------------------------------------
; return $ ForeignImport nm' ty' i }
| otherwise
- = failWith $ text (show from)<+> ptext SLIT("is not a valid ccall impent")
+ = failWith $ text (show from)<+> ptext (sLit "is not a valid ccall impent")
where
safety' = case safety of
Unsafe -> PlayRisky
; let e = CExport (CExportStatic (mkFastString as) (cvt_conv callconv))
; return $ ForeignExport nm' ty' e }
+cvt_conv :: TH.Callconv -> CCallConv
cvt_conv TH.CCall = CCallConv
cvt_conv TH.StdCall = StdCallConv
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') }
(sigs, binds) = partition is_sig ds
is_sig (TH.SigD _ _) = True
- is_sig other = False
+ 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') }
; 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"))
+ | otherwise
= do { nm' <- vNameL nm
; cls' <- mapM cvtClause cls
; returnL $ mkFunBind nm' cls' }
pat_rhs_ty = void, bind_fvs = placeHolderNames } }
cvtBind d
- = failWith (sep [ptext SLIT("Illegal kind of declaration in where clause"),
+ = failWith (sep [ptext (sLit "Illegal kind of declaration in where clause"),
nest 2 (text (TH.pprint d))])
cvtClause :: TH.Clause -> CvtM (Hs.LMatch RdrName)
cvt (AppE x y) = do { x' <- cvtl x; y' <- cvtl y; return $ HsApp x' y' }
cvt (LamE ps e) = do { ps' <- cvtPats ps; e' <- cvtl e
; return $ HsLam (mkMatchGroup [mkSimpleMatch ps' e']) }
- cvt (TupE [e]) = cvt 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 (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 (CaseE e ms) = do { e' <- cvtl e; ms' <- mapM cvtMatch ms
+ cvt (CaseE e ms)
+ | null ms = failWith (ptext (sLit "Case expression with no alternatives"))
+ | otherwise = do { e' <- cvtl e; ms' <- mapM cvtMatch ms
; return $ HsCase e' (mkMatchGroup ms') }
cvt (DoE ss) = cvtHsDo DoExpr ss
cvt (CompE ss) = cvtHsDo ListComp ss
; 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
; flds' <- mapM cvtFld flds
; return $ RecordUpd e' (HsRecFields flds' Nothing) [] [] [] }
+cvtFld :: (TH.Name, TH.Exp) -> CvtM (HsRecField RdrName (LHsExpr RdrName))
cvtFld (v,e)
= do { v' <- vNameL v; e' <- cvtl e
; return (HsRecField { hsRecFieldId = v', hsRecFieldArg = e', hsRecPun = False}) }
-- Do notation and statements
-------------------------------------
+cvtHsDo :: HsStmtContext Name.Name -> [TH.Stmt] -> CvtM (HsExpr RdrName)
cvtHsDo do_or_lc stmts
+ | 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
; return $ HsDo do_or_lc (init stmts') body void }
+cvtStmts :: [TH.Stmt] -> CvtM [Hs.LStmt RdrName]
cvtStmts = mapM cvtStmt
cvtStmt :: TH.Stmt -> CvtM (Hs.LStmt RdrName)
cvtpair :: (TH.Guard, TH.Exp) -> CvtM (LGRHS RdrName)
cvtpair (NormalG ge,rhs) = do { ge' <- cvtl ge; rhs' <- cvtl rhs
- ; g' <- returnL $ mkBindStmt truePat ge'
+ ; g' <- returnL $ mkExprStmt ge'
; returnL $ GRHS [g'] rhs' }
cvtpair (PatG gs,rhs) = do { gs' <- cvtStmts gs; rhs' <- cvtl rhs
; returnL $ GRHS gs' rhs' }
cvtOverLit :: Lit -> CvtM (HsOverLit RdrName)
-cvtOverLit (IntegerL i) = do { force i; return $ mkHsIntegral i }
-cvtOverLit (RationalL r) = do { force r; return $ mkHsFractional r }
-cvtOverLit (StringL s) = do { let { s' = mkFastString s }; force s'; return $ mkHsIsString s' }
+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
-- Similarly 3.5 for fractionals
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 }
cvtp (ListP ps) = do { ps' <- cvtPats ps; return $ ListPat ps' void }
cvtp (SigP p t) = do { p' <- cvtPat p; t' <- cvtType t; return $ SigPatIn p' t' }
+cvtPatFld :: (TH.Name, TH.Pat) -> CvtM (HsRecField RdrName (LPat RdrName))
cvtPatFld (s,p)
= do { s' <- vNameL s; p' <- cvtPat p
; return (HsRecField { hsRecFieldId = s', hsRecFieldArg = p', hsRecPun = False}) }
cvtTvs :: [TH.Name] -> 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)
; case head of
ConT tc -> do { tc' <- tconName tc; returnL $ HsClassP tc' tys' }
VarT tv -> do { tv' <- tName tv; returnL $ HsClassP tv' tys' }
- other -> 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, tys') <- split_ty_app ty
- ; case head of
- TupleT n | length tys' == n -> returnL (HsTupleTy Boxed tys')
- | n == 0 -> mk_apps (HsTyVar (getRdrName unitTyCon)) tys'
+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' }
; cxt' <- cvtContext cxt
; ty' <- cvtType ty
; returnL $ mkExplicitHsForAllTy tvs' cxt' ty' }
- otherwise -> failWith (ptext SLIT("Malformed type") <+> text (show ty))
+ _ -> failWith (ptext (sLit "Malformed type") <+> text (show ty))
}
where
- mk_apps head [] = returnL head
- mk_apps head (ty:tys) = do { head' <- returnL head; mk_apps (HsAppTy head' ty) tys }
+ mk_apps head_ty [] = returnL head_ty
+ mk_apps head_ty (ty:tys) = do { head_ty' <- returnL head_ty
+ ; mk_apps (HsAppTy head_ty' ty) tys }
split_ty_app :: TH.Type -> CvtM (TH.Type, [LHsType RdrName])
split_ty_app ty = go ty []
-----------------------------------------------------------
-- some useful things
-truePat = nlConPat (getRdrName trueDataCon) []
-
overloadedLit :: Lit -> Bool
-- True for literals that Haskell treats as overloaded
-overloadedLit (IntegerL l) = True
-overloadedLit (RationalL l) = True
-overloadedLit l = False
+overloadedLit (IntegerL _) = True
+overloadedLit (RationalL _) = True
+overloadedLit _ = False
void :: Type.Type
void = placeHolderType
okOcc :: OccName.NameSpace -> String -> Bool
okOcc _ [] = False
okOcc ns str@(c:_)
- | OccName.isVarName ns = startsVarId c || startsVarSym c
- | otherwise = startsConId c || startsConSym c || str == "[]"
+ | OccName.isVarNameSpace ns = startsVarId c || startsVarSym c
+ | otherwise = startsConId c || startsConSym c || str == "[]"
badOcc :: OccName.NameSpace -> String -> SDoc
badOcc ctxt_ns occ
- = ptext SLIT("Illegal") <+> pprNameSpace ctxt_ns
- <+> ptext SLIT("name:") <+> quotes (text occ)
+ = ptext (sLit "Illegal") <+> pprNameSpace ctxt_ns
+ <+> ptext (sLit "name:") <+> quotes (text occ)
thRdrName :: OccName.NameSpace -> String -> TH.NameFlavour -> RdrName
-- This turns a Name into a RdrName
-- which will give confusing error messages later
--
-- The strict applications ensure that any buried exceptions get forced
-thRdrName ctxt_ns 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
"[]" -> Just (Name.getName nilDataCon)
"()" -> Just (tup_name 0)
'(' : ',' : rest -> go_tuple 2 rest
- other -> Nothing
+ _ -> Nothing
where
go_tuple n ")" = Just (tup_name n)
go_tuple n (',' : rest) = go_tuple (n+1) rest
- go_tuple n other = Nothing
+ go_tuple _ _ = Nothing
tup_name n
- | OccName.isTcClsName ctxt_ns = Name.getName (tupleTyCon Boxed n)
- | otherwise = Name.getName (tupleCon Boxed n)
+ | OccName.isTcClsNameSpace ctxt_ns = Name.getName (tupleTyCon Boxed n)
+ | otherwise = Name.getName (tupleCon Boxed n)
mk_uniq_occ :: OccName.NameSpace -> String -> Int# -> OccName.OccName
mk_uniq_occ ns occ uniq