Erlectricity sample (Erlang <-> Ruby)

README

This sample is strongly based on Erlectricity, avaliable from:

http://github.com/mojombo/erlectricity

The echo.rb is the same, but the echo.erl is really a little bit better. It's because I refactored it to
extract functions to send and receive messages and also (and more important) introduce some patterns on
receive statement to matching other messages (specially to receive exit_status messages from "dead" ports).

More sugar is always good. At least for me. ;)

echo.erl

-module(echo).
-export([say/0]).

say() ->
  Command = "ruby echo.rb",
  Port = open_port({spawn, Command}, [{packet, 4}, nouse_stdio, exit_status, binary]),
  Message = term_to_binary({echo, <<"A message from Erlang to Ruby">>}),

  send_to(Port, Message),
  receive_from(Port).

send_to(Port, Message) ->
  port_command(Port, Message).  

receive_from(Port) ->
  receive
    {Port, {data, Data}} ->
      {response, Text} = binary_to_term(Data),
      io:format("echoed message >> ~p~n", [Text]);
    {DeadPort, {exit_status, Number}} ->
      io:format("exit message >> dead port: ~p | status: ~p~n", [DeadPort, Number]),
      receive_from(Port);
    Unrecognized ->
      io:format("unrecognized message >> ~p~n", [Unrecognized])
  end.

echo.rb

require 'rubygems'
require 'erlectricity'

receive do |f|
  f.when([:echo, String]) do |text|
    f.send!([:response, "Received message: #{text}"])
    f.receive_loop
  end
end