Re: regexp_replace 'g' flag

On Thu, Sep  5, 2013 at 09:59:13PM -0400, Tom Lane wrote:
> Bruce Momjian <bruce@momjian.us> writes:
> > On Thu, Sep  5, 2013 at 08:37:44PM -0400, Bruce Momjian wrote:
> >> Why doesn't the 'g' flag appear in this table?
> >> http://www.postgresql.org/docs/9.2/static/functions-matching.html#POSIX-EMBEDDED-OPTIONS-TABLE
>
> > Is it because the table has generic pattern modififers and 'g' only is
> > relevant for regexp_replace?  I assume so.
>
> The table is specifically about ARE options, and 'g' is *not* one of
> those.  Adding 'g' to the table would be wrong.
>
> It does seem to me to be a bit confusing that the text description of
> substring() mentions 'i' and 'g' explicitly, when only 'i' is listed in
> the table.  You could make a case for phrasing along the line of
> "substring() supports the 'g' flag that specifies ..., as well as all the
> flags listed in Table 9-19".  On the other hand, 'i' is the most useful of
> the flags listed in the table by several country miles, and it doesn't
> seem quite right to make people go off and consult the table to find out
> about it.
>
> Not sure whether there's any real improvement that can be made here,
> but I suppose it'd be nice if the text descriptions of substring() and
> regexp_replace() handled this matter in the same way ...

I went ahead and just explicitly documented that 'g' is not in the
table.

--
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

  + Everyone has their own god. +