Anagram Kode Kata

anagram.rb

require 'digest/sha1'

class Anagram
  attr :anagrams

  def initialize(file)
    @anagrams = {}
    File.open(file).each do |word|
      add_word_to_anagrams_hash(build_key(word.chomp),word.chomp)
    end
    filter_anagrams
  end

  def pretty_print
    @anagrams.each do |anagram_array|
      puts anagram_array.join(", ")
    end
    return "\n"
  end

  private
  def build_key(word)
    Digest::SHA1.hexdigest(word.split("").sort.join(""))
  end

  def add_word_to_anagrams_hash(key,word)
    @anagrams.key?(key) ? @anagrams[key] << word : @anagrams[key] = [word]
  end

  def filter_anagrams
    @anagrams = @anagrams.values.select{|a| a.length > 1}
  end

end

a = Anagram.new("wordlist.txt")
a.pretty_print