Simple but functional dependancy resolution

deps.rb

#!/usr/bin/env ruby

class Graph
  attr_accessor :items, :retv
  def initialize(items=nil)
    if items != nil
      @items = items
      @retv  = []
    end
  end
  
  def get_itm(name=nil)
    @items.each {|rv| return rv if rv[ :name ] == name }
    return nil
  end
  
  def add_dep(dep=nil)
    @retv.each {|i| return false if i[:name] == dep[:name] }
    @retv.push(dep)
    return true
  end

  def resolve(item=nil)
    if item[ :depends ] == nil or item[ :depends ].size == 0
      add_dep(item)
    else
      item[ :depends ].each {|a|
        dep = get_itm(a)
        self.resolve(dep)
        add_dep(dep)
      }
      add_dep(item)
    end
  end
  
  def graph
    @items.each {|item| self.resolve(item) }
  end
end

o = [{:name => 'A', :depends => nil, :provides => ['A']},
     {:name => 'B', :depends => ['A','D'], :provides => ['B']},
     {:name => 'C', :depends => ['D','E'], :provides => ['C']},
     {:name => 'D', :depends => ['A','E'], :provides => ['D']},
     {:name => 'E', :depends => ['A'], :provides => ['E']}]

obj = Graph.new(o)

puts '='*50+"\n\nBefore:\n"+'-'*50
obj.items.each {|t| puts "N: "+t[:name] }

obj.graph

puts "\n"+'='*50+"\n"

puts "\nAfter:\n"+'-'*50+"\n"
obj.retv.each {|t| puts "N: "+t[:name] }