EvenBetterNestedSet

this is an alternative to ActsAsNestedSet, and BetterNestedSet which is just a little bit less stupid.

class Directory < ActiveRecord::Base

  acts_as_nested_set

end

d = Directory.new

d.children.create!(:name => 'blah')
d.children.create!(:name => 'gurr')
d.children.create!(:name => 'doh')

d.bounds #=> 1..8
d.children[1].bounds #=> 4..5
d.children[1].name #=> 'gurr'
d.children[1].parent #=> d

c = Directory.create!(:name => 'test', :parent => d.directory[1]