# File lib/rdoc/parsers/parse_rb.rb, line 270
  def RubyToken.def_token(token_n, super_token = Token, reading = nil, *opts)
    token_n = token_n.id2name unless token_n.kind_of?(String)
    if RubyToken.const_defined?(token_n)
      IRB.fail AlreadyDefinedToken, token_n
    end

    token_c =  Class.new super_token
    RubyToken.const_set token_n, token_c
#    token_c.inspect
 
    if reading
      if TkReading2Token[reading]
        IRB.fail TkReading2TokenDuplicateError, token_n, reading
      end
      if opts.empty?
        TkReading2Token[reading] = [token_c]
      else
        TkReading2Token[reading] = [token_c].concat(opts)
      end
    end
    TkSymbol2Token[token_n.intern] = token_c

    if token_c <= TkOp
      token_c.class_eval %{
        def self.op_name; "#{reading}"; end
      }
    end
  end