Elegant bitwise number generator

elegant_bitwise_random.rb

lambda(m, n) do
  seed = (rand(2).even?) ? 0b0 : 0b1

  num_bit_1_left = (seed == 0b1) ? n-1 : n

  bits_length = 1

  (m-1).times do
    bit_mask = if num_bit_1_left > 0
      ((m - bits_length) > num_bit_1_left) ? ((rand(2).even?) ? 0b0 : 0b1) : 0b1
    else
      0b0
    end

    seed = (seed << 1) | (bit_mask >> bits_length) # ETO NO TENA RESAKA BITWISE

    num_bit_1_left -= 1 if bit_mask == 0b1
    bits_length += 1
  end

  seed
end.call(m_value, n_value)