recursively upload files by ftp using a Y combinator

  ftp = Net::FTP::new(site)
  ftp.login(user, password)

  y_combinator {|callback|
    lambda {|entry|
      if FileTest.directory?(entry)
        entries = ftp.nlst
        ftp.mkdir(File.basename(entry)) unless entries.include?(File.basename(entry))
        ftp.chdir(File.basename(entry))
        puts 'cd ' + File.basename(entry)
        Dir[entry + '/*'].each {|e| callback.call(e)}
        ftp.chdir('..')
        puts 'cd ..'
      else
        puts entry + ' --> ' + File.basename(entry)
        ftp.putbinaryfile(entry, File.basename(entry))
      end
    }
  }.call('public_html')
  ftp.close