-- for details
module Convert( convertToHsExpr, convertToPat, convertToHsDecls,
- convertToHsType, thRdrName ) where
+ convertToHsType, thRdrNameGuesses ) where
import HsSyn as Hs
import qualified Class
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 $$ (ptext (sLit "When converting TH pattern")
+ Left msg -> Left (msg $$ (ptext (sLit "When splicing TH pattern:")
<+> text (show e)))
Right res -> Right res
; 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' }
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
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
| 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' }
-- 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