From: David Alan Black <dblack@...>
Date: 2001-08-04T19:56:29+09:00
Subject: [ruby-talk:19123] Re: Something nicer than @?

Hello --

On Sat, 4 Aug 2001, MikkelFJ wrote:

> One of the things I like least about Ruby is they way @ spoils otherwise
> clean code visually.
> Ruby is almost like an algorithmic specification from a textbook, except for
> the @ in many places.

I know what you mean, though in the case of class variables
particularly, it's sort of useful to have something that's really
noticeable, because it discourages having too many of them :-)

If you want to avoid @@var syntax, you could create class accessor
methods:

   class Module
     def cl_attr_accessor(*syms)
       syms.each do |s|
	 instance_eval <<-EOE
	 def #{s}
	     @@#{s}
	 end
	 def #{s}=(v)
	     @@#{s} = v
	 end
	 EOE
       end
     end
   end

   class Thing
     cl_attr_accessor :cvar

     def initialize
       Thing.cvar = 123
       p Thing.cvar
     end

   end

   t = Thing.new  # => 123


plus whatever read/write-specific flavors one wants.

(Do we really not have that already?)


> I suggest that we try to find a cleaner syntax for handling scope object
> scope and class scope.
>
> One suggestion, that is harder to parse, is to use postfix '
> There is a conflict with strings, but using postfix (as opposed to prefix)
> might make it work.
>   x' instead of @x and x'' instead of @@x
>
> class Point
>   def initialize x
>     x' = x
>     y' = y
>     last_x'' = x'
>     last_y'' = y'
>   end
> end

I don't know, but I suspect it would be literally impossible to parse.
It's pretty easy to come up with examples that look like what you're
describing, but which already mean something else:

  class Thing
    def abc(str); puts str; end

    def initialize
      abc' = "hello"
      puts abc'
    end
  end

  Thing.new

=>
 = "hello"
    puts abc

I certainly wouldn't want to have to write an editor mode to handle it
:-)


David

-- 
David Alan Black
home: dblack@candle.superlink.net
work: blackdav@shu.edu
Web:  http://pirate.shu.edu/~blackdav