erlang - 我如何在 erlang 中拆分二进制文件

Question

我想要的是，我认为，相对简单:

> Bin = <<"Hello.world.howdy?">>.
> split(Bin, ".").
[<<"Hello">>, <<"world">>, <<"howdy?">>]

任何指针？

Answer 1

当前没有等效于 lists:split/2 的 OTP 功能适用于二进制字符串。直到 EEP-9是公开的，您可以编写一个二进制拆分函数，例如:

split(Binary, Chars) ->
    split(Binary, Chars, 0, 0, []).

split(Bin, Chars, Idx, LastSplit, Acc)
  when is_integer(Idx), is_integer(LastSplit) ->
    Len = (Idx - LastSplit),
    case Bin of
        <<_:LastSplit/binary,
         This:Len/binary,
         Char,
         _/binary>> ->
            case lists:member(Char, Chars) of
                false ->
                    split(Bin, Chars, Idx+1, LastSplit, Acc);
                true ->
                    split(Bin, Chars, Idx+1, Idx+1, [This | Acc])
            end;
        <<_:LastSplit/binary,
         This:Len/binary>> ->
            lists:reverse([This | Acc]);
        _ ->
            lists:reverse(Acc)
    end.