module Trapper

# File lib/trapper.rb, line 10
def self.trap!(__trapper_obj)
  __trapper_obj.instance_eval {
    Signal.trap("INT") do
      exit 1 if $__trapper_exit # subsequent ^C pressed traps INT again

      print "\n\n"

      while true do
        print "trapper> "
        __trapper_input = $stdin.gets.chomp

        case __trapper_input.downcase
        when "q"
          $__trapper_exit = true
          puts "bye."
          exit 1
        when "c"
          break
        end

        __trapper_output = nil
        begin
          __trapper_output = eval __trapper_input
        rescue SyntaxError => __trapper_se
          puts "#{__trapper_se.class}: #{__trapper_se.message}"
        rescue => __trapper_ex
          puts "#{__trapper_ex.class}: #{__trapper_ex.to_s}"
        end

        puts " => #{__trapper_output}" if __trapper_output
      end
    end
  }

  true
end