[project @ 2006-01-10 14:39:01 by simonmar]

[ghc-hetmet.git] / ghc / compiler / parser / Lexer.x

diff --git a/ghc/compiler/parser/Lexer.x b/ghc/compiler/parser/Lexer.x
index 38908a0..84e5a1a 100644 (file)
--- a/ghc/compiler/parser/Lexer.x
+++ b/ghc/compiler/parser/Lexer.x
@@ -1181,7 +1181,7 @@ alexGetChar (AI loc ofs s)
 #if __GLASGOW_HASKELL__ < 605
          = c  -- no Unicode support
 #else
-         | c <= '\x04' = non_graphic
+         | c <= '\x06' = non_graphic
          | c <= '\xff' = c
          | otherwise = 
                case generalCategory c of
@@ -1348,7 +1348,7 @@ lexError :: String -> P a
 lexError str = do
   loc <- getSrcLoc
   i@(AI end _ buf) <- getInput
-  reportLexError loc end buf False str
+  reportLexError loc end buf str
 
 -- -----------------------------------------------------------------------------
 -- This is the top-level function: called from the parser each time a
@@ -1370,7 +1370,7 @@ lexToken = do
                  setLastToken span 0
                  return (L span ITeof)
     AlexError (AI loc2 _ buf) -> do 
-       reportLexError loc1 loc2 buf True "lexical error"
+       reportLexError loc1 loc2 buf "lexical error"
     AlexSkip inp2 _ -> do
        setInput inp2
        lexToken
@@ -1381,10 +1381,13 @@ lexToken = do
        span `seq` setLastToken span bytes
        t span buf bytes
 
-reportLexError loc1 loc2 buf is_prev str = 
+-- 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 = 
   let 
-       c | is_prev   = prevChar buf '\0'
-         | otherwise = fst (nextChar buf)
+       c = fst (nextChar buf)
   in
   if c == '\0' -- decoding errors are mapped to '\0', see utf8DecodeChar#
     then failLocMsgP loc2 loc2 "UTF-8 decoding error"