Added support for cf and ebnf formats

src/GF/Infra/Comments.hs

@@ -0,0 +1,29 @@
+module Comments where
+
+-- comment removal : line tails prefixed by -- as well as chunks in {- ... -}
+
+remComments :: String -> String
+remComments s = 
+  case s of
+    '"':s2 -> '"':pass remComments s2 -- comment marks in quotes not removed!
+    '{':'-':cs -> readNested cs
+    '-':'-':cs -> readTail cs
+    c:cs -> c : remComments cs
+    [] -> []
+   where
+     readNested t = 
+       case t of
+         '"':s2 -> '"':pass readNested s2
+         '-':'}':cs -> remComments cs
+         _:cs -> readNested cs
+         [] -> []
+     readTail t = 
+       case t of
+         '\n':cs -> '\n':remComments cs
+         _:cs -> readTail cs
+         [] -> []
+     pass f t = 
+       case t of
+         '"':s2 -> '"': f s2
+         c:s2 -> c:pass f s2
+         _ -> t