From: Dave Thomas <dave@...>
Date: 2003-08-02T09:38:45+09:00
Subject: Re: RDoc now does constants

Hal E. Fulton wrote:


> Well, call me crazy, but I sometimes create a Struct
> and later (usually as an afterthought) add methods
> to it.

Me too - but Structs and classes are different enough to make that 
dangerous at times, so I try not to do it too often.


> Personally, I see nothing wrong with this. Some, though,
> will perhaps say I should refactor and make my Structs
> into "real" classes.

Something that can bite you when you do this is:

   S = Struct.new(:a)
   class S
     def getA
       @a
     end
   end

   s = S.new(123)
   p s.getA     #=> nil

Because of this inconsistency, I now subclass Structs a lot less than I 
used to.

Now what I'm experimenting with is something like this:

   class A
      construct_with :a, :b

      def other_method
        @a += @b ...
      end
   end



This is a simple code generator which works inside a real class, giving 
me the best of both worlds. It generates a default #initialize method 
that sets the instance variables (in this case @a and @b) and generates 
accessor methods for each.



Cheers


Dave