gistfile1.diff

diff --git a/src/Syntax.hs b/src/Syntax.hs
index 1905488..475a02a 100644
--- a/src/Syntax.hs
+++ b/src/Syntax.hs
@@ -2,6 +2,7 @@
 module Syntax where
 
 import Labels
+import Control.Monad.State
 import Data.Generics
 import Text.PrettyPrint
 
@@ -55,40 +56,9 @@ data LCmd = CSkip
            deriving (Eq,Show,Data,Typeable)
 
 
-relabel c = snd $ aux 1 c
-  where aux n CSkip          = (n, CSkip)
-        aux n (CAsn _ lhs e) = (n+1, CAsn (Posn n) lhs e)
-        aux n (CNew _ lhs)   = (n+1, CNew (Posn n) lhs)
-
-        aux n (CBlock cs)     = let (n', cs') = f n cs  in (n', CBlock cs')
-          where f n []     = (n, [])
-                f n (c:cs) = let (n' ,c')  = aux n c 
-                                 (n'',cs') = f n' cs in
-                             (n'', c' : cs')
-
-        aux n (CIf _ e c1 c2) = 
-            let (n' ,c1') = aux (n+1) c1
-                (n'',c2') = aux n' c2 in 
-            (n'', CIf (Posn n) e c1' c2')
-
-        aux n (CWhile _ e c) = 
-            let (n' ,c') = aux (n+1) c in
-            (n', CWhile (Posn n) e c')
-
-        aux n (CThrow _)   = (n+1, CThrow (Posn n))
-
-        aux n (CTry _ c1 c2) = 
-            let (n' ,c1') = aux (n+1) c1
-                (n'',c2') = aux n' c2 in 
-            (n'', CTry (Posn n) c1' c2')
-        
-        aux n (CUp _ lhs l)       = (n+1, CUp (Posn n) lhs l)
-        aux n (CUpError _ l)      = (n+1, CUpError (Posn n) l)
-        aux n (CUpStruct _ lhs l) = (n+1, CUpStruct (Posn n) lhs l)
-        aux n (CUpExist _ lhs l)  = (n+1, CUpExist (Posn n) lhs l)
-
-        aux _ _ = error "relabel: CEnd, CTryEnd, COr only for internal use"
-
+reposition :: Posn -> State Int Posn
+reposition x = modify (+1) >> get >>= return . Posn
 
+relabel c = evalState (everywhereM (mkM reposition) c) 0