# File lib/facet/lisp-format.rb, line 940
        def execute(state)
          arg = state.next_arg
          arg_error 'argument not a Fixnum' unless arg.is_a? Fixnum
          ch = arg & 0xff
          if colon_mod?
            state.output('Control-') if (ch & 0x7f) < 0x1f
            state.output('Meta-')    if ch >= 0x7f
            state.output(ch & 0x7f | 0x60)
          elsif at_mod?
            state.output('?' + convert_char(ch))
          else
            state.output ch
          end
        end