# File lib/facet/lisp-format.rb, line 1645
        def execute(state)
          n = param(0, state, nil)
          return if not n.nil? and n == 0
          if colon_mod? and at_mod?
            execute_sets(n, state, false)
          elsif at_mod?
            execute_args(n, nil, state, false)
          elsif colon_mod?
            execute_sets(n, state, true)
          else
            execute_args(n, state.next_arg, state, true)
          end
        end