From: Dave Thomas <dave@...>
Date: 2008-01-26T04:31:53+09:00
Subject: Re: Prefixes _ and __ for object and class constants proposed


On Jan 25, 2008, at 1:24 PM, Xeno Campanoli wrote:

> I may have brought this up before, a long time ago, but something I  
> want
> is a prefix, like @ and @@, for constants that designates them as  
> object
> or class constants respectively.  That way I could make a lot of  
> things
> constants that I am now just making variables and it would be obvious
> that they are constants only available for that context.  I really  
> don't
> like the underscore perfectly, but I've thought about it and it  
> seems to
> be the best choice of available characters.  Has anybody every thought
> about this (barring my possibly bringing it up two years ago), and  
> does
> anyone else think this is a reasonable suggestion?  If so, I would  
> think
> it would be a small change that could be implemented in parallel with
> existing prefix syntax handling.

I'm not sure I've ever bumped into the need for an object constant,  
but if I had, I'd probably have simply implemented an instance method

class Dave
   def initialize(new_pi)
     @pi = new_pi
   end
   def PI
     @pi
   end
end

d1 = Dave.new(3)
d2 = Dave.new(3.14159)
d3 = Dave.new(22.0/7.0)

puts d1.PI, d2.PI, d3.PI


Dave