net-irc

• cho45
• http://www.lowreal.net/
• google 「ちんこ演算子の人」
• Chemr (きめぇwww)
• JSDeferred
• $X

Agenda

1. Introducing to net-irc
2. Applications using net-irc
3. Citrus IRC BOT framework
4. About the DSL (or something DSL-ish)
5. DSL in the language

My IRC status

• irssi user
• window number -> 54 (not channel num)
• IRC addict

...

I want to watch all information by IRC.

• twitter...
• lingr...
• server log...

...

• Posting to mixi...
• Recent hatena stars...
• Posting to Hatena Haiku...
• etc.. etc..

...

But there were no library to write IRC server easily...

And I made it.

What is net-irc?

• http://lowreal.rubyforge.org/net-irc/

• Is IRC library
• Parser from RICE by akira yamada
• Has both Client and Server

Changes from RICE

• Violate RFC for practical issue
• Don't use observer design pattern
• Wrote prettily

Violate RFC

• no restriction on nick length
• RFC restrict nick length to 9 chars
• allow utf-8 nick
• allow multibyte string
• (extendable MODE parser)
• (working)

Don't use observer

• Observer pattern
• in the end, must write event dispatcher
• on_event is popular
• no more charms

Wrote prettily

Write to server socket:

post PRIVMSG, '#foo', 'msg'
post NOTICE,  '#foo', 'msg'

All commands are defined as constant.

Use RFC as reference instead of net-irc reference.

Sample Client

class SimpleClient < Net::IRC::Client
  def on_privmsg(m)
    super
    post NOTICE, m[0], m[1] # echo
  end
end

SimpleClient.new("host", 6667, {
  :nick => "foobartest",
  :user => "foobartest",
  :real => "foobartest",
}).start

Sample Server

class Sample < Net::IRC::Server::Session
  def on_privmsg(m)
    super
    post "foo!foo@host", NOTICE, m[0], m[1] # echo
  end
end

Net::IRC::Server.new(opts[:host], opts[:port], Sample, opts).start

mini-blog IRC gateways

• Twitter (tig.rb) like TIG
• Wassr (wig.rb)
• Nowa (nig.rb) すいませんまだ使ってません

Suitable for practical use!

Distributed with net-irc. (examples/)

Lingr IRC gateway

• Using Linger API

Suitable for practical use!

Distributed with net-irc. (examples/)

でもたまに切れる。

...

examples なのはテスト書くのがめんどうだから……

昨日書いたもの

demo

Citrus IRC BOT framework

http://coderepos.org/share/wiki/Citrus

• Has testing framework (using rspec)
• Supports gettext
• Has dynamic re-loading plugins

coderepos++

Citrus

• Sample: chokan @freenode (registered)

Citrus plugin

• Plugin tests are in same file!
• Use RSpec
• DummyCore class for test

• http://lab.lowreal.net/test/citrus/

Citrus plugin

class SimpleReply < Citrus::Plugin
  def on_privmsg(prefix, channel, message)
    # do...
  end
end

test do
  # run when test
  describe SimpleReply do
    before :all do
      @core   = DummyCore.new({})
      @socket = @core.socket

      @plugin = SimpleReply.new(@core, {
        "SimpleReply" => { config }
      })
    end

    it "should ..." do
    end
  end
end

It's DSL

# client
post PRIVMSG, "#foo", "bar"

# server
post prefix, PRIVMSG, "#foo", "bar

Effective utilzation of Constant

PRIVMSG     = 'PRIVMSG'
NOTICE      = 'NOTICE'
...
RPL_WELCOME = '001'

I don't want to use String.

• It mades typo.
• It is not pretty.

...

post PRIVMSG, "#foo", "bar"

DSL...?

Maybe not.

Often, I try to make DSL.

But I assessed that DSL is irrelevance for this library..

DSL bad example

• scrAPI

ebay_auction = Scraper.define do
  process "h3.ens>a",             :description=>:text, :url=>"@href"
  process "td.ebcPr>span",        :price=>:text
  process "div.ebPicture>a>img",  :image=>"@src"
  result :description, :url, :price, :image
end

Can't understand the purpose at first view.

某所で scrAPI なコードをメンテしたとき発狂しそうだった

DSL bad example - scrAPI

• what is second argument of process
• need to look the reference
• lerning cost > convenience
• mechanize and hpricot is better

DSL good examples

• Rake
• RSpec

DSL good examples - Rake

desc "Publish to RubyForge"
task :rubyforge => [:rdoc, :package] do
  require 'rubyforge'
  Rake::RubyForgePublisher.new(RUBYFORGE_PROJECT, 'fobar').upload
end

Good example of hash arrow to represent dependency.

DSL good examples - RSpec

obj.should == "foo"
foo.should be_true

Easy to read, easy to write.

DSL good examples

• Rake
• RSpec

Can understand the purpose at first view!

So, DSL requires...

• Readable!
• not requires precedent
• Writable!
• not relying on reference

DSL's problems

• hard to trace process
• hard to know Class defining the method
• IT IS A LANGUAGE.
• It is difficult to design a language.

Any sufficiently designed DSL is indistinguishable from NEW language.

高度に発達した DSL は新言語と見分けがつかない

Think before using DSL!

End

Thank you