From: ara howard <ara.t.howard@...>
Date: 2008-02-02T03:05:22+09:00
Subject: Re: @var = change to accessor method? Why?


On Feb 1, 2008, at 10:54 AM, Day wrote:

> class Thing
>  attr_accessor :a
>
>  def do_something(arg)
>    @a = arg
>  end
> end
>
> to...
>
> class Thing
>  attr_accessor :a
>
>  def do_something(arg)
>    self.a = arg
>  end
> end



imagine that you now want to know everywhere @a is set, perhaps  
because you have a bug.  you can start greping or simply

   def a= value

     p caller
     @a = 42
   end

done.

also,  i don't use 'self.a', but via attributes or fatter

   class C
     size 42
   end

where 'size' is a getter defined thusly

   def a *value
     if value.empty?
       @a
     else
       send 'a=', value.first
    end
  end

which eliminates the oh so tiresome self.


another huge advantage if using uniform access is that you can do  
things like

   class C
      attributes 'a, 'b', 'c'
   end

   p C.new.attributes => ['a', 'b' , 'c']

which is to say you can keep track of what state and object is likely  
to contain.  making things like serialization trivial to write.

regards.

a @ http://codeforpeople.com/
--
it is not enough to be compassionate.  you must act.
h.h. the 14th dalai lama