anchor.diff:  
   atom
       :   NAME
  +        -> VARIABLENAME[$NAME, newVarString($NAME.text).c_str()]
       |   INT
       |   FLOAT
       |   LBRACKET! expression RBRACKET!
  
positive.code:                 i++;
              }
          }
          return buf;
      }
  }
  
negative.code: }
  
  @parser::members {
      // doesn't work in header, so include it here
      #include <boost/algorithm/string.hpp>
  
      // converts varname into a string formatted as a variable name
      // (lower_case_with_underscores)
      std::string newVarString(pANTLR3_STRING varname) {
  