anchor.diff:  unpack_array_(Remain, 0, RetList) -> {lists:reverse(RetList), Remain};
   unpack_array_(Bin, RestLen, RetList) ->
       case unpack(Bin) of
  -	{more, Len} -> {more, Len+RestLen-1};
  +	{more, undefined} -> {more, undefined};
   	{Term, Rest}-> unpack_array_(Rest, RestLen-1, [Term|RetList])
       end.
   
  
positive.code:     pack_map_(Tail, << Acc/binary, (pack(Key))/binary, (pack(Value))/binary>>).
  
  % FIXME: write test for unpack_map/1
  -spec unpack_map_(binary(), non_neg_integer(), [{term(), msgpack_term()}]) ->
      {more, non_neg_integer()} | {any(), binary()}.
  unpack_map_(Bin,  0,  Acc) -> {{lists:reverse(Acc)}, Bin};
  unpack_map_(Bin, Len, Acc) ->
      case unpack(Bin) of
  	{ more, MoreLen } -> { more, MoreLen+Len-1 };
  	{ Key, Rest } ->
  	    case unpack(Rest) of
  		{more, MoreLen} -> { more, MoreLen+Len-1 };
  		{ Value, Rest2 } ->
  		    unpack_map_(Rest2,Len-1,[{Key,Value}|Acc])
  	    end
      end.
  
  
  -spec unpack_(Payload::binary()) -> {more, pos_integer()} | {msgpack_term(), binary()} | {error, reason()}.
  unpack_(<<16#C0, Rest/binary>>) ->
      {nil, Rest};
  unpack_(<<16#C2, Rest/binary>>) ->
      {false, Rest};
  unpack_(<<16#C3, Rest/binary>>) ->
      {true, Rest};
  
  unpack_(<<16#CA, Return:32/float-unit:1, Rest/binary>>) -> % 32bit float
      {Return, Rest};
  unpack_(<<16#CA, Rest/binary>>) ->
      {more, 4-byte_size(Rest)};
  unpack_(<<16#CB, Return:64/float-unit:1, Rest/binary>>) -> % 64bit float
      {Return, Rest};
  unpack_(<<16#CB, Rest/binary>>) ->
      {more, 8-byte_size(Rest)};
  
  unpack_(<<16#CC, Int:8/unsigned-integer, Rest/binary>>) -> % uint 8
      {Int, Rest};
  unpack_(<<16#CC>>) ->
      {more, 1};
  unpack_(<<16#CD, Int:16/big-unsigned-integer-unit:1, Rest/binary>>) -> % uint 16
      {Int, Rest};
  unpack_(<<16#CD, Rest/binary>>) ->
      {more, 2-byte_size(Rest)};
  unpack_(<<16#CE, Int:32/big-unsigned-integer-unit:1, Rest/binary>>) -> % uint 32
      {Int, Rest};
  unpack_(<<16#CE, Rest/binary>>) ->
      {more, 4-byte_size(Rest)};
  unpack_(<<16#CF, Int:64/big-unsigned-integer-unit:1, Rest/binary>>) -> % uint 64
      {Int, Rest};
  unpack_(<<16#CF, Rest/binary>>) ->
      {more, 8-byte_size(Rest)};
  
  unpack_(<<16#D0, Int:8/signed-integer, Rest/binary>>) -> % int 8
      {Int, Rest};
  unpack_(<<16#D0>>) ->
      {more, 1};
  unpack_(<<16#D1, Int:16/big-signed-integer-unit:1, Rest/binary>>) -> % int 16
      {Int, Rest};
  unpack_(<<16#D1, Rest/binary>>) ->
      {more, 2-byte_size(Rest)};
  unpack_(<<16#D2, Int:32/big-signed-integer-unit:1, Rest/binary>>) -> % int 32
      {Int, Rest};
  unpack_(<<16#D2, Rest/binary>>) ->
      {more, 4-byte_size(Rest)};
  unpack_(<<16#D3, Int:64/big-signed-integer-unit:1, Rest/binary>>) -> % int 64
      {Int, Rest};
  unpack_(<<16#D3, Rest/binary>>) ->
      {more, 8-byte_size(Rest)};
  
  unpack_(<<16#DA, Len:16/unsigned-integer-unit:1, Val:Len/binary, Rest/binary>>) -> % raw 16
      {Val, Rest};
  unpack_(<<16#DA, Rest/binary>>) ->
      {more, 16-byte_size(Rest)};
  unpack_(<<16#DB, Len:32/unsigned-integer-unit:1, Val:Len/binary, Rest/binary>>) -> % raw 32
      {Val, Rest};
  unpack_(<<16#DB, Rest/binary>>) ->
      {more, 32-byte_size(Rest)};
  
  unpack_(<<16#DC, Len:16/big-unsigned-integer-unit:1, Rest/binary>>) -> % array 16
      unpack_array_(Rest, Len, []);
  unpack_(<<16#DC, Rest/binary>>) ->
      {more, 2-byte_size(Rest)};
  unpack_(<<16#DD, Len:32/big-unsigned-integer-unit:1, Rest/binary>>) -> % array 32
      unpack_array_(Rest, Len, []);
  unpack_(<<16#DD, Rest/binary>>) ->
      {more, 4-byte_size(Rest)};
  
  unpack_(<<16#DE, Len:16/big-unsigned-integer-unit:1, Rest/binary>>) -> % map 16
      unpack_map_(Rest, Len, []);
  unpack_(<<16#DE, Rest/binary>>) ->
      {more, 2-byte_size(Rest)};
  unpack_(<<16#DF, Len:32/big-unsigned-integer-unit:1, Rest/binary>>) -> % map 32
      unpack_map_(Rest, Len, []);
  unpack_(<<16#DF, Rest/binary>>) ->
      {more, 4-byte_size(Rest)};
  
  unpack_(<<0:1, Value:7, Rest/binary>>) -> % positive fixnum
      {Value, Rest};
  unpack_(<<2#111:3, Value:5, Rest/binary>>) -> % negative fixnum
      {Value - 2#100000, Rest};
  unpack_(<<2#101:3, Len:5, Value:Len/binary, Rest/binary>>) -> % fixraw
      {Value, Rest};
  unpack_(<<2#101:3, Len:5, Rest/binary>>) ->
      {more, Len-byte_size(Rest)};
  unpack_(<<2#1001:4, Len:4, Rest/binary>>) -> % fixarray
      unpack_array_(Rest, Len, []);
  unpack_(<<2#1000:4, Len:4, Rest/binary>>) -> % fixmap
      unpack_map_(Rest, Len, []);
  
  %unpack_(<<F:8, Rest/binary>>) when F==16#C1; F==16#C4; F==16#C5; F==16#C6; F==16#C7; F==16#C8; F==16#C9; F==16#D5; F==16#D6; F==16#D7; F==16#D8; F==16#D9->
  %    {error, {badarg, <<F, Rest/binary>>}}.
  %unpack_(Other) when is_binary(Bin) ->
  %    {more, 1}.
  unpack_(<<>>) ->
      {more, 1}.
  unpack_(Other) ->
      {error, {badarg, Other}}.
  
  
  % ===== test codes ===== %
  
negative.code: 	    << 16#DB:8, Len:32/big-unsigned-integer-unit:1, Bin/binary >>
      end.
  
  % list
  pack_array(L) ->
      case length(L) of
   	Len when Len < 16 ->
  