def eval
      results = []

      @statements.each do |s|
        st_res = eval_statement(s)
        results << st_res if st_res
      end
      results
    end
def eval
      results = []

      @statements.each do |s|
        st_res = eval_statement(s)
        results << st_res if st_res
      end
      results
    end
:nodoc:
 Evaluate every statement given to the initializer.
 Returns:
 +result+:: An array containing the result of each statement