An answer to a #ruby irc channel question about `self`

self.rb

# Right inside a class or module, `self` is the module or class itself.
module Same
  def self.same
    self == Same
  end
end

Same.same
#=> true

# You can define a module method like this:
module Foo
  def Foo.foo
    :ok
  end
end

Foo.foo
#=> :ok

# Instead of hardcoding `Foo`, we use `self` for less naming entanglment:
module Bar
  def self.bar
    :ok
  end
end

# Another way to write that is:
module Baz
  class << Baz
    def baz
      :ok
    end
  end
end

Baz.baz
#=> :ok

# Which again you'd use `self` with for easlier renaming without changes:
module Wombat
  class << self
    def wombat
      :ok
    end
  end
end

Bar.bar
#=> :ok

# In the case of modules, you might consider #module_function instead:
module Example
  module_function def example
    :ok
  end
end

Example.example
#=> :ok

# Using module_function will have the side effect of making the method private
# when it's included, which tends to be nice for extensibililty.