http://github.com/sandal/rbp-book/blob/master/manuscript/unmerged/api.txt#L980

server.rb

require 'socket'

class Server

  def initialize(options={:host=>'localhost', :port=>'3000'})
    @server = TCPServer.new(options[:host], options[:port])
    @rules = []
  end

  def handle(regexp, &block)
    @rules << {:regexp => regexp, :block => block}
  end

  def run
    loop do
      Thread.start(@server.accept) do |socket|
        while message = socket.gets
          @rules.each do |rule|
            m = message.match(rule[:regexp])
            if(m)
              socket.write(rule[:block].call(m) + "\n")
              break
            end
          end
        end
        socket.close
      end
    end
  end

end

server = Server.new
   
server.handle(/hello/i) { "Hello from server at #{Time.now}" }
server.handle(/goodbye/i) { "Goodbye from server at #{Time.now}" }
server.handle(/name is (\w+)/) { |m| "Nice to meet you #{m[1]}!" }

server.run