From: Jim Freeze <jim@...>
Date: 2005-09-28T00:49:49+09:00
Subject: Class and Iterator Design Question

This may be a silly design question, but I always balk at
the right answer when I am confronted with it.

I have a class that manages a list and users need to iterate over that list.
The way I see it, I have to basic alternatives:

  # Give user access to the array and let them iterate over Array
  class Pea
    attr_reader :pods
  end
  Pea.new.pods.each { |pod| ..do stuff.. }

or

  # Provide a custom iterator
  class Pea
    def each_pod
      @pods.each { |pod| yield pod }
    end
  end
  Pea.new.each_pod  { |pod| ..do stuff.. }
end

In other words, for classes that manage a list of items,
do people prefer to see a custom iterator, such as #each_<item>,
or do they prefer getting back an array and iterating
over it themselves, such as #<items>.each?

  Pea.new.each_pod  { |pod| ..do stuff.. }
  Pea.new.pods.each { |pod| ..do stuff.. }

Cheers
--
Jim Freeze