buffer.rb

class Buffer
  def initialize(initial_bytes = '')
    @bytes = initial_bytes
  end

  %w[size empty? clear].each do |method|
    define_method(method) do
      @bytes.send(method)
    end
  end

  def size
    @bytes.size
  end

  def empty?
    @bytes.empty?
  end

  def append(new_bytes)
    @bytes << new_bytes
  end

  def retrieve(n = -1)
    if n == -1  # retrieve all bytes
      all = @bytes.dup
      self.clear
      all
    else  # retrieve n bytes
      @bytes.slice!(0, n)
    end
  end

  def peek(n = 1)
    @bytes.slice(0, n)
  end

  def clear
    @bytes.clear
  end
end