| 1 |
|
%% Copyright (c) 2023 Peter Morgan <peter.james.morgan@gmail.com> |
| 2 |
|
%% |
| 3 |
|
%% Licensed under the Apache License, Version 2.0 (the "License"); |
| 4 |
|
%% you may not use this file except in compliance with the License. |
| 5 |
|
%% You may obtain a copy of the License at |
| 6 |
|
%% |
| 7 |
|
%% http://www.apache.org/licenses/LICENSE-2.0 |
| 8 |
|
%% |
| 9 |
|
%% Unless required by applicable law or agreed to in writing, software |
| 10 |
|
%% distributed under the License is distributed on an "AS IS" BASIS, |
| 11 |
|
%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 12 |
|
%% See the License for the specific language governing permissions and |
| 13 |
|
%% limitations under the License. |
| 14 |
|
|
| 15 |
|
%% @doc An unsigned integer represented by a fixed number of little |
| 16 |
|
%% endian bytes. |
| 17 |
|
|
| 18 |
|
-module(msmp_integer_fixed). |
| 19 |
|
|
| 20 |
|
|
| 21 |
|
-feature(maybe_expr, enable). |
| 22 |
|
|
| 23 |
|
|
| 24 |
|
-export([decode/1]). |
| 25 |
|
-export([encode/1]). |
| 26 |
|
|
| 27 |
|
|
| 28 |
|
%% @doc Decode a fixed size little endian unsigned integer. |
| 29 |
|
-spec decode(pos_integer() | scran_number:uparser()) -> scran:parser(binary(), non_neg_integer()). |
| 30 |
|
|
| 31 |
|
decode(Bytes) when is_integer(Bytes) -> |
| 32 |
2515 |
scran_number:u(little, Bytes * 8); |
| 33 |
|
|
| 34 |
|
decode(ByteLengthParser) -> |
| 35 |
5 |
fun |
| 36 |
|
(Input) -> |
| 37 |
5 |
maybe |
| 38 |
5 |
{Remaining, Bytes} ?= ByteLengthParser(Input), |
| 39 |
5 |
(decode(Bytes))(Remaining) |
| 40 |
|
end |
| 41 |
|
end. |
| 42 |
|
|
| 43 |
|
|
| 44 |
|
%% @doc Encode a fixed size little endian unsigned integer. |
| 45 |
|
-spec encode(pos_integer()) -> narcs:encoder(non_neg_integer(), binary()). |
| 46 |
|
|
| 47 |
|
encode(Bytes) -> |
| 48 |
69 |
narcs_number:u(little, Bytes * 8). |