lil anagram finder

anagrams.rb

# Anagram: a word, phrase, or name formed by rearranging the letters of another.
# Usage: Anagrams.new.find("anemic")
#        ["anemic", "iceman", "cinema"]
class Anagrams
  def initialize
    @words = {}
    File.open("/usr/share/dict/words") do |file|
      file.each do |line|
        @words[line.strip] = true
      end
    end; nil
  end

  def find(word)
    letters = word.split('')
    possible_words = letters.permutation.to_a.map(&:join)
    possible_words.select {|w| @words.include?(w) }.sort
  end
end