On Wed, 10 Jul 2019, Zoltán Herczeg wrote:
> > /(?0)/
> As far as I remember, these are detected by the parser.
Some of them are detected by the parser in PCRE1, but not all of them,
so there is a runtime check. Looks like I decided to leave it all to
runtime in PCRE2. The error message "nested recursion at the same
subject position" means that the check is not just for nested recursion,
but also that the subject pointer must advance each time.
