From: Jeff Nyman <jeffnyman_nospam@..._gmail.com>
Date: 2006-10-09T20:50:13+09:00
Subject: Re: Removing Duplicate Objects from Object List

"gaspode" <stephendl@gmail.com> wrote in message 
news:1160393869.844030.8080@m7g2000cwm.googlegroups.com...

> How are you storing the Rules in your RuleSet at the moment? Personally
> I'd use an Array (or simply subclass Array) and then you get to use
> Array.uniq without shifting objects back and forth.

Essentially, I have a RuleList class like this:

<code>
class RuleList
  def initialize
    @rules = Array.new
  end

  def append(this_rule)
    @rules.push(this_rule)
  end

  def selection
    @rules.find_all { |rule| rule }
  end
end
</code>

Then I have a Rule class like this:

<code>
class Rule
  attr_accessor :point, :filter, :value

  def initialize(point, filter, value)
    @point = point
    @filter = filter
    @value = value
  end

  def to_s
    "#@point, #@filter, #@value"
  end
end
</code>

When a rule object needs to be added to the list, I do this:

$ruleList.append(Rule.new(step.point2, rule, value))

Does that give enough detail?

In playing around a bit more, I tried this:

rules_array = $ruleList.selection.collect { |rule| rule }

Then I tried:

rules_array.uniq!

The problem is that this finds nothing as a duplicate. But that makes sense 
(I think) because the object ID is probably being considered as part of the 
test and those will, of course, not be duplicates.

It sounds like you're saying it would be better to not use a Rule class in 
the first place. Is that accurate?

- Jeff