From: Logan Capaldo <logancapaldo@...>
Date: 2006-05-10T01:35:06+09:00
Subject: Re: A major ruby annoyance!


On May 9, 2006, at 12:21 PM, dblack@wobblini.net wrote:

> Hi --
>
> On Tue, 9 May 2006, Logan Capaldo wrote:
>
>>
>> On May 8, 2006, at 4:10 PM, dblack@wobblini.net wrote:
>>
>>> I can't help feeling it's a lot of trouble to do this:
>>>
>>>  class C
>>>    def initialize
>>>      self.container = []
>>>    end
>>>
>>>    private
>>>    attr_writer :container
>>>  end
>>> rather than:
>>>
>>>  class C
>>>    def initialize
>>>      @container = []
>>>    end
>>>  end
>>> if you're just using @container as a state variable here and there.
>>> I think the role of the uniform access principle here is open to
>>> question.  As I understand it, that principle states that the  
>>> outside
>>> user shouldn't be able to tell whether a value is stored or  
>>> calculated
>>> -- essentially, an attribute vs. the return value of a method call.
>>> But instance variables are neither attributes nor methods; so  
>>> they're
>>> not really candidates for being evaluated for uniform/non-uniform
>>> access.  And Ruby's attributes *are* methods.  To that extent, Ruby
>>> actually enforces the UA principle; when you do this:
>>>
>>>  obj.something
>>> you know that you've called a method.  There's no other possibility,
>>> so there's no opportunity for divergence of the interface.
>>
>> Well at least if you do it my way, you don't get tripped up by  
>> typos, ;)
>
> Why not? :-)
>
>   class C
>     def initialize
>       self.contanier = []
>     end
>
>     private
>     attr_writer :container
>   end
>
> That will blow up just as much as:
>
>   class C
>     def initialize
>       @contanier = []
>     end
>
>     def insert(x)
>       @container << x
>     end
>   end
>
> (It will happen at a slightly different point, of course.)
>
>
> David
>
Ok, there's _less_ typo trip-ups.


> -- 
> David A. Black (dblack@wobblini.net)
> * Ruby Power and Light, LLC (http://www.rubypowerandlight.com)
>   > Ruby and Rails consultancy and training
> * Author of "Ruby for Rails" from Manning Publications!
>   > http://www.manning.com/black
>