Hi Thom:
On Sat, Oct 25, 2014 at 11:55 AM, Thom Brown <thom@xxxxxxxxx> wrote:
Ah, I knew I missed something:# SELECT regexp_matches('postgres','(?:g)(r)');
...snip, snip...
Yes. It's one fo the things I strongly dislike of some of the semantics of postgres ( and others ) regular engine functions. Their return value ''semantics'' depends on data, which makes them difficult to use properly when the pattern argument is unknown. I would prefer to have it always return a list with the full match in the first element, the grouped captures behind it ( i.e., {gr} for '(?:g)r', {gr,g} for '(g)r' . But I think it's dessigned more for interactive use with constant patterns than for programmatic use.
....
I'm familiar with regular _expression_ syntax, just famliarising myself with PostgreSQL's syntax flavour.
Sorry, got confused by the question, and by the fact that I do not know of any
regular _expression_ engine with an access function which when presented
with non-capturing-group1+unmarked2 returns unmarked2. Even in perl I do
not know how to it.
Regards.
Regards.
Francisco Olarte.
