Listing 3. pl-server.rb

#!/usr/bin/ruby

require 'rubygems'
require 'net/http'
require 'rexml/document'
require 'xmlrpc/server'

# ------------------------------------------------------------
# Load the translation cache
# ------------------------------------------------------------

dictionary = { }

puts "Loading cached translations"
translation_file = 'translations.txt'

if FileTest.exists?(translation_file)
  File.open(translation_file, "r").each do |line|
    (english, piglatin) = line.chomp.split('=')
    dictionary[english] = piglatin
    puts "'#{english}' => '#{piglatin}'"
  end
else
  File.open(translation_file, 'w') do |line|
  end
end

# ------------------------------------------------------------
# XML-RPC
# ------------------------------------------------------------

# Start an HTTP server on port 9000, to listen for clients
server = XMLRPC::Server.new(port=9000, host='127.0.0.1')

server.add_handler(name="atf.pl_sentence",
                   signature=['array', 'array']) do |words|

  output = [ ]

  words.map {|word| word.to_s}.each do |word|

    # Have we already seen this word? Don't bother to translate it
    if dictionary.has_key?(word)
      puts "Grabbing translation of '#{word}' from the dictionary"
      output << dictionary[word]
      next
    end

    # If it's not in the cache, then go for it.
    piglatin = ''
    if word =~ /^[aeiou]/
      piglatin << word
      piglatin << 'way'
    else
      piglatin = word[1..-1]
      piglatin << word[0]
      piglatin << 'ay'
    end

    puts "Translated '#{word}' => '#{piglatin}'"

    # Cache it
    puts "Trying to cache..."
    dictionary[word] = piglatin
    File.open(translation_file, 'a') {|f| f.puts "#{word}=#{piglatin}"}
    output << piglatin
  end

  output

end

server.serve