From: John Barnette <jbarnette@...>
Date: 2009-04-28T07:39:54+09:00
Subject: Re: Why does attr_accessor in module require 'self.'?

Hi,

On Apr 27, 2009, at 3:30 PM, Brian Hartin wrote:
> When a class mixes in a module containing 'attr_accessor :foo', it  
> must
> then use 'self.foo = ...' instead of simply 'foo = ...'.  While I  
> prefer
> 'self.foo' for clarity's sake, I am stumped as to _why_ this is
> required.  [snip]

It's because Ruby automatically creates local variables upon  
assignment. Given a class with a method "foo":

class C
   attr_accessor :a

   def foo
     a = 42 # this is a local variable assignment
     self.a = 42 # this is a call to the "a=" method
   end
end


~ j.