skip binary encoded term

erlang_skip_term.erl

skip_n_terms(Bin, N) ->
    lists:foldl(fun(_, {Acc, Bin}) ->
        {Skipped, R} = skip_term(Bin),
        {Skipped + Acc, R}
    end, {0, Bin}, lists:seq(1, N)).

skip_term(<<97, _:1/binary, Rest/binary>>) -> %%  SMALL_INTEGER_EXT
    {2, Rest};
skip_term(<<98, _:4/binary, Rest/binary>>) -> %% INTEGER_EXT
    {5, Rest};
skip_term(<<99, _:31/binary, Rest/binary>>) -> %% FLOAT_EXT
    {32, Rest};
skip_term(<<100, Len:16/integer, Rest/binary>>) -> %% ATOM_EXT
    <<_Name:Len/binary, Rest1/binary>> = Rest,
    {Len + 3, Rest1};
skip_term(<<101, Rest/binary>>) -> %% REFERENCE_EXT
    {NodeSize, <<_ID:4/binary, _Create:1/binary, Rest1/binary>>} = skip_term(Rest), %% skip Node
    {NodeSize + 6, Rest1};
skip_term(<<102, Rest/binary>>) -> %% PORT_EXT
    {NodeSize, <<_ID:4/binary, _Create:1/binary, Rest1/binary>>} = skip_term(Rest), %% skip Node
    {NodeSize + 6, Rest1};
skip_term(<<103, Rest/binary>>) -> %% PID_EXT
    {NodeSize, <<_ID:4/binary, _Serial:4/binary, _Create:1/binary, Rest1/binary>>} =
        skip_term(Rest), %% skip Node
    {NodeSize + 10, Rest1};
skip_term(<<104, Arity:8/integer, Rest/binary>>) -> %% SMALL_TUPLE_EXT
    {Skipped, Rest1} = skip_n_terms(Rest, Arity),
    {Skipped + 2, Rest1};
skip_term(<<105, Arity:32/integer, Rest/binary>>) -> %% LARGE_TUPLE_EXT
    {Skipped, Rest1} = skip_n_terms(Rest, Arity),
    {Skipped + 5, Rest1};
skip_term(<<116, Arity:32/integer, Rest/binary>>) -> %% MAP_EXT
    {Skipped, Rest1} = skip_n_terms(Rest, Arity),
    {Skipped + 5, Rest1};
skip_term(<<106, Rest/binary>>) -> %% NIL_EXT
    {1, Rest};
skip_term(<<107, Len:16/integer, Rest/binary>>) -> %% STRING_EXT
    <<_:Len/binary, Rest1/binary>> = Rest,
    {Len + 3, Rest1};
skip_term(<<108, Len:32/integer, Rest/binary>>) -> %% LIST_EXT
    {Skipped, Rest1} = skip_n_terms(Rest, Len),
    {TailSize, Rest2} = skip_term(Rest1),
    {Skipped + TailSize + 5, Rest2}; %% skip tail
skip_term(<<109, Len:32/integer, Rest/binary>>) -> %% BINARY_EXT
    <<_:Len/binary, Rest1/binary>> = Rest,
    {Len + 5, Rest1};
skip_term(<<110, Len:8/integer, _Sign:1/binary, Rest/binary>>) -> %% SMALL_BIG_EXT
    <<_:Len/binary, Rest1/binary>> = Rest,
    {Len + 3, Rest1};
skip_term(<<111, Len:32/integer, _Sign:1/binary, Rest/binary>>) -> %% LARGE_BIG_EXT
    <<_:Len/binary, Rest1/binary>> = Rest,
    {Len + 6, Rest1};
skip_term(<<114, Len:16/integer, Rest/binary>>) -> %% NEW_REFERENCE_EXT
    IdLen = Len * 4,
    {NodeSize, <<_ID:4/binary, _Create:1/binary, _ID:IdLen/binary, Rest1/binary>>} =
        skip_term(Rest), %% skip Node
    {NodeSize + 8 + IdLen, Rest1};
skip_term(<<115, Len:8/integer, Rest/binary>>) -> %% SMALL_ATOM_EXT
    <<_:Len/binary, Rest1/binary>> = Rest,
    {Len + 2, Rest1};
skip_term(<<117, NumFree:32/integer, Rest/binary>>) -> %% FUN_EXT
    {PidSize, Rest1} = skip_term(Rest), %% skip Pid
    {ModuleSize, Rest2} = skip_term(Rest1), %% skip Module
    {IndexSize, Rest3} = skip_term(Rest2), %% skip Index
    {UniqSize, Rest4} = skip_term(Rest3), %% skip Uniq
    {Skipped, Rest5} = skip_n_terms(Rest4, NumFree),
    {PidSize + ModuleSize + IndexSize + UniqSize + Skipped + 5, Rest5};
skip_term(<<112, Size:32/integer, Rest/binary>>) -> %% NEW_FUN_EXT
    Len = Size - 4,
    <<_:Len/binary, Rest1/binary>> = Rest,
    {Len + 5, Rest1};
skip_term(<<113, Rest/binary>>) -> %% EXPORT_EXT
    {ModuleSize, Rest1} = skip_term(Rest), %% skip Module
    {FunctionSize, Rest2} = skip_term(Rest1), %% skip Function
    {AritySize, Rest3} = skip_term(Rest2), %% skip Arity
    {ModuleSize + FunctionSize + AritySize, Rest3};
skip_term(<<77, Len:32/integer, _:1/binary, Rest/binary>>) -> %% BIT_BINARY_EXT
    <<_:Len/binary, Rest1/binary>> = Rest,
    {Len + 6, Rest1};
skip_term(<<70, Len:64/integer, Rest/binary>>) -> %% NEW_FLOAT_EXT
    {9, Rest};
skip_term(<<118, Len:16/integer, Rest/binary>>) -> %% ATOM_UTF8_EXT
    <<_:Len/binary, Rest1/binary>> = Rest,
    {Len + 3, Rest1};
skip_term(<<119, Len:8/integer, Rest/binary>>) -> %% SMAL_ATOM_UTF8_EXT
    <<_:Len/binary, Rest1/binary>> = Rest,
    {Len + 2, Rest1};
skip_term(<<>>) -> {0, <<>>}.