aesuceahu

W2/calculator/Lexer.fsl

@@ -35,7 +35,7 @@ rule Token = parse
   | '-' { Parser.MINUS }
   | '*' { Parser.TIMES }
 
-  | ['a'-'z' 'A'-'Z'] (['a'-'z' 'A'-'Z' '_']|'_'['0'-'9'])*
+  | ['a'-'z' 'A'-'Z']* ('_' ['a'-'z' 'A'-'Z' '_' '0'-'9']* )?
     { keyword (Encoding.UTF8.GetString lexbuf.Lexeme) }
 
     (* FIXME: You should implement lexing for: