simple irc bot in F#

ircbot.fs

#light

open System
open System.IO
open System.Net
open System.Net.Sockets
open System.Text.RegularExpressions

let server = "irc.enigmagroup.org"
let port  = 6667
let channel = "#enigmagroup"
let nick = "ishbot"

// establish a connection to the server
let irc_client = new TcpClient();
irc_client.Connect( server, port )

// get the input and output streams
let irc_reader = new StreamReader( irc_client.GetStream() )
let irc_writer = new StreamWriter( irc_client.GetStream() )

// identify with the server and join a room
irc_writer.WriteLine( sprintf "USER %s %s %s %s" nick nick nick nick )
irc_writer.AutoFlush <- true
irc_writer.WriteLine( sprintf "NICK %s" nick )
irc_writer.WriteLine( sprintf "JOIN %s\n" channel )

// some flow control stuff
let irc_ping ( writer : StreamWriter ) =
  writer.WriteLine( sprintf "PONG %s\n" server)

let irc_privmsg ( writer : StreamWriter ) ( phrase : string ) =
  writer.WriteLine( sprintf "PRIVMSG %s %s" channel phrase )
  
let irc_get_msg ( line : string )=
  line.Substring( line.Substring(1).IndexOf(":") + 2)

// main loop operation; homeostasis
while( irc_reader.EndOfStream = false ) do
  let line = irc_reader.ReadLine()
  // Console.WriteLine( line )
  if (line.Contains("PING")) then
    irc_ping irc_writer
  // active pattern for matching commands
  let (|Prefix|_|) (p:string) (s:string) =
    if s.StartsWith( p ) then
      Some( s.Substring(p.Length))
     else
      None
  let (msg:string) = irc_get_msg line

  // really maintainable list of patterns to match against
  match msg with
  | Prefix "!version" rest -> irc_privmsg irc_writer (sprintf "%s on %A" nick Environment.Version)
  | Prefix "!date" rest -> irc_privmsg irc_writer (sprintf "%A" System.DateTime.Now)
  | Prefix "!help" rest -> irc_privmsg irc_writer "Google it for now.."
  | _ -> Console.WriteLine( msg )