From: John Joyce <dangerwillrobinsondanger@...>
Date: 2007-03-16T21:10:53+09:00
Subject: Re: to_a

It also of course depends on the method. That is why everyone said  
"most of the time"...
It is possible to write your own code where a method call/message  
could actually change the reciever object.
It just isn't usual in Ruby.
Also do understand that methods are often oversimplified in human  
language.
The truth is, we "send a message" to an object. The object is the  
"reciever". If the object knows what to do with that message (if it  
has the method inside) it will do it. Otherwise the Ruby interpreter  
(the runtime environment in any OOP language) will move up the  
responder chain, to the object's parent class/super class. We say it  
sends the message there. The message will continue being sent until  
it reaches the root object class or finds a responder.
Some of the specifics are different with different languages, and it  
can get pretty abstract, but it is always the same.