On 2016-12-16 00:15, Stefan Monnier wrote:
> What about the one in glibc?

Paul pointed to it too.  Is it documented anywhere?  That is, are its implementation details documented anywhere?

The only thing I can find is this:

  https://www.gnu.org/software/libc/manual/html_node/Regular-Expressions.html#Regular-Expressions

Clément.