From: Christoph Rippel <crippel@...>
Date: 2001-03-06T06:39:24+09:00
Subject: [ruby-talk:12063] Re: RCR: shortcut for instance variable initialization

> From: dave@thomases.com [mailto:dave@thomases.com]On Behalf Of Dave
> Thomas
> Sent: Monday, March 05, 2001 01:12 PM
> To: ruby-talk ML; ruby-talk@netlab.co.jp
> Subject: [ruby-talk:12060] Re: RCR: shortcut for instance variable
> initialization
> 
> 
> "Christoph Rippel" <crippel@primenet.com> writes:
> 
> > class Whatever
> > 
> > def will_be_rounded=(number)
> > 	raise 'Not a number' unless kind_of? Numeric
> > 	@will_be_number = number.round
> > end
> > 
> > def initialize(will_be_rounded@)
> > 	...
> > end
> > attr_accessor :will_be_rounded
> > end
> > 
> > does a call to initialize invoke ``@will_be_rounded=''
> > or```will_be_rounded=''? 
> 
> There is no such method as '@will_be_rounded='.  The attr_accessor
Besides that,

it should have been ``@will_be_rounded = number.round'' 
the question in my mind was if the line 

``@will_be_rounded = number''

is created,  or the function  

``will_be_rounded=(number)''

is called (but you can always cook up a convention;-)

> call will overwrite the method you defined with it's own:
> 
>   class Dave
>     def val=(n)
>       puts "in my val"
>       @val = 123
>     end
>     attr_accessor :val
>   end
> 
>   d = Dave.new
>   d.val = 432
>   p d.val     #=> 432
> 
> 
> > Ps. I sometimes wonder if Ruby could have done without
> > variables at all (I believe this) and only use attributes 
> > but this is a different matter.
> 
> Attributes are simply accessor functions to instance variables.
I know this,

I was thinking that would have been forced 
into writing (basically reviving standard 
variable declaration I still prefer;-)

def bla(right)
attr_accessor :left
left = right
end 


Christoph 
[..]