Re: regexp_split_to_array hangs backend

"Pavel Stehule" <pavel(dot)stehule(at)gmail(dot)com> writes:
> I found small bug

> regexp_split_to_array('123456','1');
> regexp_split_to_array('123456','6');
> regexp_split_to_array('123456','.');

> these parameters hangs backend.

This code's got more problems than that :-(

The one that's bothering me right now is that regexp_match() and
regexp_split() cache a compiled regex on first entry to the function,
and then blithely assume it will still be there on repeated calls.

I think probably the best thing to do is do all the matching on the
first call, and have the saved state include an array of character
positions of matches; then repeat calls to the SRF just iterate through
the array.

It seems a bit short of comments too. Working on it now.

regards, tom lane