Re: [PATCHES] writing new regexp functions

On Sun, 4 Feb 2007, David Fetter wrote:

> On Fri, Feb 02, 2007 at 07:01:33PM -0800, Jeremy Drake wrote:
>
> > Let me know if you see any bugs or issues with this code, and I am
> > open to suggestions for further regression tests ;)

I have not heard anything, so I guess at this point I should figure out
where to go next with this. I see a couple options:

* Set this up as a pgfoundry project or contrib. This would require
merging the patch to expose some functions from regexp.c outside that
file, which has raised some concerns about maintainability.

* Put together a patch to add these functions to core. I could put them
directly in regexp.c, so the support functions could stay static. My
concern here is that I don't know if there are any functions currently
in core with OUT parameters. I don't know the acceptable style for
handling this: OUT parameters, a named composite type, ...?

Does anyone have any opinions either way, as to how I should proceed
from here?

> > * maybe a join function that works as an aggregate
> > SELECT join(',', col) FROM tbl
> > currently can be written as
> > SELECT array_to_string(ARRAY(SELECT col FROM tbl), ',')
>
> The array_accum() aggregate in the docs works OK for this purpose.

I have decided not to pursue this function, I think the array construct,
or the array_accum option, is about the best possible currently. If it
should become possible in the future to write aggregates with a non-sql
state type (structs with pointers) it may be worthwhile to re-evaluate
this.

--
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