"Rui Martins" <Rui.Martins@PDMFC.com> writes:
> Even though this can me though as argumentative, think about this expression:
> (something)?
> Will "match" with an empty string in the context of a full expression, and
> will return an EMPTY String. So by analogy, I would expect it, to return
> the same as a sub-expression when it actually has a "match" even if with
> an empty sub-string.
Uh, no, it *won't* match if there is not "something" in the string.
The behavior you are looking for is properly obtained this way:
((something)?)
This will return either "something" or an empty string (assuming
we have a globally successful match). The point is there's a difference
between what X matches (or doesn't) and what X? matches.
regards, tom lane
