From: ptkwt@...1.aracnet.com (Phil Tomson)
Date: 2003-01-22T12:59:28+09:00
Subject: Re: accessors for module instance vars

In article <3E2DA7AD.6040604@path.berkeley.edu>,
Joel VanderWerf  <vjoel@PATH.Berkeley.EDU> wrote:
>Phil Tomson wrote:
>
>> Now this works ok, but I'm wondering if there's a way to create the 
>> accessor methods for the Evolvable module automatically like with 
>> attr_accessor and attr_reader.  The problem with attr_accessor is that it 
>> creates an instance method, not a module method - is there a way to 
>> automatically create a module method?
>> 
>> Phil
>> 
>> 
>irb(main):001:0> module M
>irb(main):002:1>   class << self; attr_accessor :foo; end
>irb(main):003:1> end
>nil
>irb(main):004:0> M.foo
>nil
>irb(main):005:0> M.foo = 4
>4
>irb(main):006:0> M.foo
>4
>
>

Great!  I wasn't sure if that would work.

Actually, about an hour after I posted I had a different idea which means 
that I cant' use attr_accessor anyway.
I decided that if the modules hadn't been 'initialized' that the 'get' 
methods should do some sort of default initialization:

module Evolvable
  XOVER_DEFAULT = :uniform
  
  #.....

  def Evolvable.set_crossoverType(type=XOVER_DEFAULT)
      @crossoverType = type
  end
    
  def Evolvable.get_crossoverType
    if not defined? @crossoverType
      #default in case it hasn't been set:
      @crossoverType = XOVER_DEFAULT
    end
    @crossoverType
  end

end


....so I can't use attr_accessor anyway if I want this kind of 
functionality.

Phil
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