From: "Gerardo Santana Gómez Garrido" <gerardo.santana@...>
Date: 2005-12-29T14:04:03+09:00
Subject: Re: Locking classes?

2005/12/28, Max Eskin <kurtkilgor@yahoo.com>:
> Hi,
> I am just starting to use Ruby. I'm wondering, once a class has been
> declared, is there any way to lock it to prevent further methods from
> being defined? In other words is there a way to make Ruby act like a
> static language for some classes?

Use Module#freeze

class A
  def self.f(a)
    a + 1
  end
end

puts A.f(1)   # => 2

A.freeze

#=> runtime error: "can't modify frozen object (TypeError)"
class A
  def self.f(a)
    a - 1
  end
end

puts A.f(1)


--
Gerardo Santana
"Between individuals, as between nations, respect for the rights of
others is peace" - Don Benito Ju�rez
http://santanatechnotes.blogspot.com/