Evented Irc Client/lib on NodeJS

irc.js

function Irc(host, port, nick){
    this._host = host;
    this._port = port;
    this._nick = nick;
}

Irc.prototype.setChannels = function(channels) {
    this._chans = channels;
}

Irc.prototype.log = function(msg){
    if (this._debug) console.log(msg);
}

Irc.prototype.connect = function(handlers){
    var _sock = new net.Socket();
    var _chans = this._chans;
    var _nick = this._nick;

    _sock.setEncoding('utf-8');

    /* Regex */
    _rx_privmsg = /:([\w\d\-\_]+).*@([\d\.\w]+)\s+PRIVMSG\s+([\#\w\-\_]+)\s+:(.*)/;
    _rx_ping = /PING\s+:(.*)/;
    _rx_notice = /:([\d\.\w]+)+\s+NOTICE\s+\*\s+:(.*)/;

    _sock.connect(this._port, this._host, function() {
        //Irc.log("Connected to " + this._host + ":"+ this._port);
        console.log("Connected");
        
        // Send identify data;
        _sock.write("NICK " + _nick + "\n\r");
        _sock.write("USER " + _nick + " nodejs nodejsbot :" + _nick + "\n\r")
        
        // Connect to channels if exists;
        if (_chans.length > 0){
            _chans.forEach( function(chan){
                _sock.write("JOIN " + chan + "\n\r");
            });
        }

        // Init eventloop;
        this.on('data', function(data){
            var matches = null
            if (matches = data.match(_rx_ping)){
                this.write("PONG " + matches[1] + "\n\r");
            }
            else if (matches = data.match(_rx_privmsg)){
                if (handlers.on_privmsg){
                    // args: nick, chan, msg
                    handlers.on_privmsg(matches[1], matches[3], matches[4]);
                }
            }
            else if (matches = data.match(_rx_notice)){
                if (handlers.on_notice){
                    // args: server, msg
                    handlers.on_notice(matches[1], matches[2]);
                }
            }
        });
    });

    // Error handling;
    if (handlers.on_error){
        _sock.on('error', handlers.on_error);
    }
    else {
        _sock.on('error', function(exception) {
            console.log("Internal error: " + exception);
        });
    }
}

var handlers = {
    on_error: function(exception){
        console.log("Error: " + exception);
    },
    on_privmsg: function(nick, chan, msg){
        console.log("Nick:" + nick + " Chan:" + chan + " Msg:" + msg);
    },
    on_notice: function(server, msg){
        console.log("Notice [" + server + "]: " + msg);
    }
}

var irc = new Irc('irc.freenode.net', 6667, 'niwibot');
irc.setChannels(['#archlinux-co']);
irc.connect(handlers);