patch from working tree in git repository

# create patch
$ git diff --no-prefix > topic-name.patch
# confirm
$ patch --dry-run -p0 < topic-name.patch
# exec
$ patch -p0 < topic-name.patch

build tmux from source

Tmux's version in apt is 1.1. (latest is 1.6)
So I built from source. There are some troublesome jobs. (needed libevent etc)
This is memo of at that time.

# install libevent
$wget "http://downloads.sourceforge.net/project/levent/libevent/libevent-2.0/libevent-2.0.19-stable.tar.gz"
$ tar zxvf libevent-2.0.19-stable.tar.gz 
$ cd libevent-2.0.19-stable
$ if [ ! -d /opt/libevent ]; then sudo mkdir -p /opt/libevent; fi
$ ./configure --prefix=/opt/libevent
$ make -j8
$ sudo make install
$ sudo unlink /usr/lib/libevent-2.0.so.5
$ sudo ln -s /opt/libevent/lib/libevent-2.0.so.5.1.7 /usr/lib/libevent-2.0.so.5

# install ncurses
$ apt-get install libncurses5
$ apt-get install libncurses5-deb

# install tmux
$ wget "http://downloads.sourceforge.net/project/tmux/tmux/tmux-1.6/tmux-1.6.tar.gz"
$ tar zxvf tmux-1.6.tar.gz
$ cd tmux-1.6/
$ DIR="/opt/libevent/"
$ if [ ! -d /opt/tmux1.6 ]; then sudo mkdir -p /opt/tmux1.6; fi
$ ./configure CFLAGS="-I$DIR/include" LDFLAGS="-L$DIR/lib" --prefix=/opt/tmux1.6
$ make -j8
$ sudo make install

let vs instance variables in RSpec

merit of "let"

1. When you refactor from local variables into a "let", you should not add @ to variables prefix.
2. "let" is subjective.
3. "let" is lower cost than initialize instance methods by each. e.g. before(:each) { @foo = "foo" }.

Maybe instance variables is useful when you shouldn't save cost.

sample

# let
context 'foo' do
  let(:bar) { :bar }
  it { bar.should eq(:bar) }
end

# instance variables
context 'foo' do
  before do
    @user.role = Role.new(:role => :admin)
  end
  it { @bar.should eq(:bar) }
end

3 things newly learned about tmux

[command] breake-pane

cut off target-pane from window including it, then make target-pane be single pane in new window.

[command] display-panes

show indicator in panes in current window (but, i don't know when needed)

[option] -r option in bind

this option enable to repeat

Presenter in Rails

My first idea.

I feel this is a waste of method_missing.

# app/model/application_model.rb
class ApplicationModel < ActiveRecord::Base
  self.abstract_class = true

  def method_missing(name, *args, &block)
    begin
      klass = eval "#{self.class.to_s}Presenter"
      presenter = klass.new(self)
      method_name = name.to_s
      presenter.send(method_name)
    rescue
      super
    end
  end
end

# app/models/user.rb
class User < ApplicationModel
  # ...
end

# app/presenters/user_presenter.rb
class UserPresenter
  # ...
end

My second idea.

This is more simple than first idea.

# app/models/user.rb
class User < ActiveRecord::Base
  # ...
  include PostPresenter
end

# app/presenters/post_presenter.rb
module PostPresenter
  # instanse methods

  module ClassMethods
    # class methods
  end

  def self.included(mod)
    mod.extend ClassMethods
  end
end

hmm...

I am looking for better idea than these.