Add (a) CoreM monad, (b) new Annotations feature

[ghc-hetmet.git] / compiler / hsSyn / Convert.lhs

diff --git a/compiler/hsSyn/Convert.lhs b/compiler/hsSyn/Convert.lhs
index 5a5bb1b..f3401f2 100644 (file)
--- a/compiler/hsSyn/Convert.lhs
+++ b/compiler/hsSyn/Convert.lhs
@@ -14,7 +14,7 @@ This module converts Template Haskell syntax into HsSyn
 -- for details
 
 module Convert( convertToHsExpr, convertToPat, convertToHsDecls,
-                convertToHsType, thRdrName ) where
+                convertToHsType, thRdrNameGuesses ) where
 
 import HsSyn as Hs
 import qualified Class
@@ -51,14 +51,14 @@ convertToHsDecls loc ds = initCvt loc (mapM cvtTop ds)
 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
 
@@ -327,6 +327,11 @@ cvtBind (TH.ValD (TH.VarP s) 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"))
+  | otherwise
   = do { nm' <- vNameL nm
        ; cls' <- mapM cvtClause cls
        ; returnL $ mkFunBind nm' cls' }
@@ -371,7 +376,9 @@ cvtl e = wrapL (cvt e)
     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
@@ -412,6 +419,8 @@ cvtDD (FromThenToR x y z) = do { x' <- cvtl x; y' <- cvtl y; z' <- cvtl z; retur
 
 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
@@ -591,8 +600,8 @@ cvtName ctxt_ns (TH.Name occ flavour)
 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 
@@ -610,7 +619,7 @@ thRdrName :: OccName.NameSpace -> String -> TH.NameFlavour -> RdrName
 --      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)
@@ -618,6 +627,21 @@ thRdrName ctxt_ns occ TH.NameS
   | 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
@@ -634,8 +658,8 @@ isBuiltInOcc ctxt_ns occ
     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