From: Guillaume Cottenceau <gc@...>
Date: 2001-07-06T06:24:15+09:00
Subject: [ruby-talk:17348] Adding a method to a class at the top-level

Comrades,


I'm looking for the "fastest" way to add a method to an existing class, in
a Ruby program.

At first I thought there would be an elegant one-liner to do that, but
unfortunately, the following adds a Class method, not an Instance method:

def Demo.aClassMethod; end


So the best way so far is:

class Demo; def aclassMethod; end; end


Which I don't find very elegant.


The FAQ talks more or less about that problem:

----8<------------8<------------8<------------8<------------8<--------[1]
http://www.rubycentral.com/faq/rubyfaq-8.html#ss8.11

8.11 Why are there two ways of defining class methods?

You can define a class method in the class definition, and you can define
a class method at the top level?

class Demo
  def Demo.classMethod
  end
end

def Demo.anotherClassMethod
end

There is only one significant difference between the two. In the class
definition you can refer to the class's constants directly, as the
constants are within scope. At the top level, you have to use the
Class::CONST notation.
----8<------------8<------------8<------------8<------------8<--------

My question is, why is it so? Maybe Matz thought that the most common case
in adding one small method in the top-level would be a Class method rather
than an Instance method. While I would think the contrary :-). 

Maybe we could find a smarter syntax to add an instance method at
top-level when you want it to be short and elegant? (or maybe there is one
and I'm missing it?)



Ref: 
[1] matju style :-)

-- 
Guillaume Cottenceau - http://mandrakesoft.com/~gc/