The AC-3 algorithm, the ruby way

gistfile1.rb

def calculate_worklist(bishops)
  worklist = Array.new
  bishops.each { |b|
    worklist.unshift("#{b[0]}") && next if b[1] != [nil, nil]
    worklist << b[0]
  }
  worklist.combination(2).to_a
end

def pick_position(positions)
  # Assign position to bishop
  positions.delete_at(0)
end

def init_ac3
  bishops = Hash.new

  bishops["a"] = bishops["b"] = bishops["c"] = [nil,nil]

  positions = Array.new
  3.times do |i|
    3.times do |j|
      positions << [i,j]
    end
  end

  bishops["a"] = pick_position(positions)

  worklist = calculate_worklist(bishops)

  [bishops, worklist]
end