Re: patch adding new regexp functions - Mailing list pgsql-patches

From Peter Eisentraut
Subject Re: patch adding new regexp functions
Date
Msg-id 200702170902.26138.peter_e@gmx.net
Whole thread Raw
In response to Re: patch adding new regexp functions  (Jeremy Drake <pgsql@jdrake.com>)
Responses Re: patch adding new regexp functions  (David Fetter <david@fetter.org>)
Re: patch adding new regexp functions  (Jeremy Drake <pgsql@jdrake.com>)
List pgsql-patches
Jeremy Drake wrote:
> In case you haven't noticed, I am rather averse to making this return
> text[] because it is much easier in my experience to use the results
> when returned in SETOF rather than text[],

The primary use case I know for string splitting is parsing
comma/pipe/whatever separated fields into a row structure, and the way
I see it your API proposal makes that exceptionally difficult.

I don't know what your use case is, though.  All of this is missing
actual use cases.

> While, if you
> really really wanted a text[], you could use the (fully documented)
> ARRAY(select resultstr from regexp_split(...) order by startpos)
> construct.

I think, however, that we should be providing simple primitives that can
be combined into complex expressions rather than complex primitives
that have to be dissected apart to get simple results.

> > As for the regexp_matches() function, it seems to me that it
> > returns too much information at once.  What is the use case for
> > getting all of prematch, fullmatch, matches, and postmatch in one
> > call?
>
> It was requested by David Fetter:
> http://archives.postgresql.org/pgsql-hackers/2007-02/msg00056.php
>
> It was not horribly difficult to provide, and it seemed reasonable to
> me. I have no need for them personally.

David Fetter has also repeated failed to offer a use case for this, so I
hesitate to accept this.

--
Peter Eisentraut
http://developer.postgresql.org/~petere/

pgsql-patches by date:

Previous
From: Bruce Momjian
Date:
Subject: Re: Table function support
Next
From: Peter Eisentraut
Date:
Subject: Re: \prompt for psql