X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Fparser%2FLexer.x;h=f6863c6286083b64ae1136f9bb08fa95a40c93f5;hb=77452bc2888f3fd071774b1177868e95f85a43dc;hp=1ede5f61c4c292cb8307c73572359c46898fe183;hpb=9e18e7e9673e7839458179db64503d9d31b34bd4;p=ghc-hetmet.git

diff --git a/compiler/parser/Lexer.x b/compiler/parser/Lexer.x
index 1ede5f6..f6863c6 100644
--- a/compiler/parser/Lexer.x
+++ b/compiler/parser/Lexer.x
@@ -1210,6 +1210,7 @@ alexGetChar :: AlexInput -> Maybe (Char,AlexInput)
 alexGetChar (AI loc ofs s) 
   | atEnd s   = Nothing
   | otherwise = adj_c `seq` loc' `seq` ofs' `seq` s' `seq` 
+		--trace (show (ord c)) $
 		Just (adj_c, (AI loc' ofs' s'))
   where (c,s') = nextChar s
         loc'   = advanceSrcLoc loc c
@@ -1259,6 +1260,7 @@ alexGetChar' :: AlexInput -> Maybe (Char,AlexInput)
 alexGetChar' (AI loc ofs s) 
   | atEnd s   = Nothing
   | otherwise = c `seq` loc' `seq` ofs' `seq` s' `seq` 
+		--trace (show (ord c)) $
 		Just (c, (AI loc' ofs' s'))
   where (c,s') = nextChar s
         loc'   = advanceSrcLoc loc c
@@ -1443,15 +1445,13 @@ lexToken = do
 	span `seq` setLastToken span bytes
 	t span buf bytes
 
--- ToDo: Alex reports the buffer at the start of the erroneous lexeme,
--- but it would be more informative to report the location where the
--- error was actually discovered, especially if this is a decoding
--- error.
-reportLexError loc1 loc2 buf str = 
+reportLexError loc1 loc2 buf str
+  | atEnd buf = failLocMsgP loc1 loc2 (str ++ " at end of input")
+  | otherwise =
   let 
 	c = fst (nextChar buf)
   in
   if c == '\0' -- decoding errors are mapped to '\0', see utf8DecodeChar#
-    then failLocMsgP loc2 loc2 "UTF-8 decoding error"
+    then failLocMsgP loc2 loc2 (str ++ " (UTF-8 decoding error)")
     else failLocMsgP loc1 loc2 (str ++ " at character " ++ show c)
 }