This page is part of the web mail archives of SRFI 115 from before July 7th, 2015. The new archives for SRFI 115 contain all messages, not just those from before July 7th, 2015.
Alex Shinn scripsit:
It's awfully handy for things like /<([a-zA-Z][a-zA-Z0-9-]*>[^<]*</\1>/,
> Expensive is the O(n^3) for the next step up the Chomsky hierarchy.
> I think exponential warrants the use of "prohibitively." The feature
> is included mostly for completeness, for round-trip conversion from
> existing PCRE libraries, and I think the advice that it should never
> actually be used is warranted.
though (given some restrictions that often apply in practice, like no
recursive elements and no non-ASCII element names).