[erlang-questions] efficient binary escape

[Dmitry Kolesnikov]

Hello Erlangers!

I'd like to get your opinion on the binary escaping techniques using erlang-only.

Let's say that I have binary   <<"ab,cdef,qwert,yuiop,....">> I wish to escape (substitute) comma by \, to get <<"ab\\,cdef\\,qwert\\,yuiop,....">>. In other words, a single byte of binary sequence has to be replaced by multiple bytes. 

and I do have about 35 - 50M tokens to procedure. The straight forward approaches like
 * binary:replace 
 * sub(<<$,, Rest/binary>>, Acc) ->
      sub(Rest, <<Acc/binary, $\, $,>>)
    ....   
two slow for me! 

Do you have any suggestion? What is you experience?

Thanks is advanced!

- Dmitry