Solution to quiz n. 0

gistfile1.rb

# game 0

class Combinator
  def initialize(source)
    @columns = (File.readlines(source) rescue source).map{|line| line.chomp.split(//)}
  end

  def combine
    letters = @columns.shift
    @columns.empty? ? letters : build_words(letters)
  end

  private

  def build_words(letters)
    next_col = combine
    letters.inject([]) do |words, letter|
      next_col.inject(words) do |words, word|
        words << letter + word
      end
    end
  end
end

if ARGV[0]
  puts Combinator.new(ARGV[0]).combine
end

require 'rspec'

describe Combinator do
  describe '#combine' do
    it 'should combine letters in words' do
      Combinator.new(%w[psc oe s t ae]).combine.should =~ %w[sosta soste posta poste costa coste sesta seste pesta peste cesta ceste]
    end
  end
end