[erlang-questions] Booleans in bit syntax

[Jacob]

On 20.01.2018 14:32, Viktor Söderqvist wrote:
> Adding a boolean type specifier in the bit syntax would be useful, I
> think. Then you could write
> 
>     decode_stuff(<<Flag1/boolean, Flag2/boolean, 0:6, Rest/binary>>) ->
>         {Flag1, Flag2, Rest}.
> 
> instead of
> 
>     decode_stuff(<<F1:1, F2:1, 0:6, Rest/binary>>) ->
>         Flag1 = case F1 of 1 -> true;
>                            0 -> false
>                 end,
>         Flag2 = case F2 of 1 -> true;
>                            0 -> false;
>                 end,
>         {Flag1, Flag2, Rest}.

What about

  decode_stuff(<<F1:1, F2:1, 0:6, Rest/binary>>) ->
      {F1 =:= 1, F2 =:= 1, Rest}

it's even shorter than your proposal and already works (okay, encoding
bools is a different thing).

> What do you think? Any reason for not adding it?

In my opinion, it changes much without really filling a gap. So far, the
<<>> expressions/matches only convert numbers to binaries/bitstrings and
vice versa.

Also, encoding 'true' as 1 and 'false' as 0 is just one possible
encoding (even if it is common).

I prefer to have explicit conversions, IMO they are much better to
maintain than using conversion magic.

Jacob