From: Alexandru Popescu <the.mindstorm.mailinglist@...>
Date: 2005-08-21T18:11:27+09:00
Subject: Re: include and extend Module - Ruby Way

#: Charles Steinman changed the world a bit at a time by saying on  8/21/2005 9:51 AM :#
> Alexandru Popescu wrote:
>> As pointed above the em#moduleMethod is failing. Being a class method I expect it to be available
>> also on every instance. What I wrongly understood?
> 
> Class methods are members of the class, not of instances of the class.
> For instance, Object.new calls the class method new of Object, but you
> can't do Object.new.new, because new is not an instance method.
> 

Thanks Charles. I start to see the end tunnel light. It is the same as:

[code]
class ClassExample
	def ClassExample.do_something
		p "class method too"
	end
end

ClassExample.do_something # class method too
cls= ClassExample.new
cls.do_something # => NoMethodError
[/code]

Coming from the Java world, for me a class method is a (static) method available withouth a self 
(this) reference, but it is available/callable from any instance. (is this available in Ruby?)

It seems that in Ruby the class method is a method belonging to the class ClassExample object.

How can I avoid this term confusion? (at least in my head).

:alex |.::the_mindstorm::.|

>> Later I can read the following:
>>
>> [quote page=275]
>> The extend method will mix a module into an object. The instance methods from the module become
>> instance methods for the object.
>> [/quote]
>>
>> Isn't this in contradiction with the first quote?
> 
> The first quote had to do with classes; this one is talking about
> instances. Telling an object "extend SomeModule" tells it to add the
> methods in SomeModule to itself. In the case of a class, these will
> become methods of that class. In the case of a class instance, they
> will become methods of that instance.
> 
> Does that make more sense?
> 
> 
>