Re: Manua correction

On Tue, Jul 13, 2021 at 02:24:01AM +0000, PG Doc comments form wrote:
> The following documentation comment has been logged on the website:
> 
> Page: https://www.postgresql.org/docs/13/functions-string.html
> Description:
> 
> Hopefully the referrer page was kept. I'm referring to the string functions
> page that reads...
> ==
>  position ( substring text IN string text ) → integer
> Returns starting index of specified substring within string, or zero if it's
> not present.
> position('om' in 'Thomas') → 3
> ==
> 
> should describe the situation where multiple occurrences of substring are in
> the string text... might read...
> 
> Returns starting index of the first occurrence of the specified substring
> within string, or zero if it's not present.

Interesting.  I see several cases where our docs are not clear we
process only the first match:

    SELECT substring ('abc abd' FROM 'b.');
     substring
    -----------
     bc
    
    SELECT regexp_match('abc abd', 'b.');
     regexp_match
    --------------
     {bc}
    
    SELECT regexp_replace ('abc abf', 'b.', 'dd');
     regexp_replace
    ----------------
     add abf
    
    SELECT strpos('abcb', 'b');
     strpos
    --------
          2
    
    SELECT position('a' IN 'abca');
     position
    ----------
            1

The attached patch improves these.  I can backpatch this were
appropriate.

-- 
  Bruce Momjian  <bruce@momjian.us>        https://momjian.us
  EDB                                      https://enterprisedb.com

  If only the physical world exists, free will is an illusion.