require 'cbor'

class CBORIO
  include Enumerable
  def orig_io() @io end
  def unpacker() @un end
  def close() @io.close end
  def write( obj) @io.write CBOR.pack( obj) end
  def sync() @io.sync end
  def sync( v) @io.sync = v end
  def self.pipe() IO.pipe.map &self.method(:new) end
  def self.popen &exe
    rd, wr = self.pipe
    pid =
      fork do
        rd.close
        yield wr
        exit 0
      end
    wr.close
    [pid, rd]
  end

  def initialize io
    @io, @un = io, CBOR::Unpacker.new
    @io.sync = true
  end

  def self.open io, &exe
    if block_given?
      s = self.new io
      begin yield s
      ensure s.close
      end
    else self.new io
    end
  end

  def read
    return @un.read  rescue EOFError
    loop do
      @un.feed @io.readpartial( 1024)
      return @un.read  rescue EOFError
    end
  end

  def each &exe
    return to_enum __method__  unless block_given?
    loop { yield read }
    self
  rescue EOFError
    self
  end
end