Re: Subscript expressions do not have to evaluate to integers

On Fri, Aug 21, 2020 at 07:21:30PM -0700, David G. Johnston wrote:
> On Fri, Aug 21, 2020 at 6:22 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:
> 
>     Bruce Momjian <bruce@momjian.us> writes:
>     > On Wed, Jul 22, 2020 at 02:59:18AM +0000, PG Doc comments form wrote:
>     >> I believe a more appropriate statement would acknowledge that at least
>     some
>     >> values undergo an explicit-style conversion to an integer.
> 
>     > OK, how is the attached patch?
> 
>     "and" is not an improvement over "which".  Otherwise seems OK.

OK, done in the attached patch.

>     (The proposed patch for generic subscripting will probably need to
>     rewrite this completely, but for now this is an improvement.)
> 
> 
> I was going to add that maybe we should link to the round(dp or numeric)
> function in the documentation and let it be explicit about the rounding rules
> pertaining to half - which when I look isn't actually documented:
> 
> round(dp or numeric) (same as input) round to nearest integer
> 
> Maybe everyone just knows that rounding, unless otherwise stated, rounds halves
> away from zero but it doesn't seem like a bad idea to be explicit.

I don't think we use round() directly, to I am hesitant to link to that,
but your idea that we should mention we are rounding to the "nearest"
integer, rather than floor or ceil is a good one, so I mentioned that in
the attached updated patch.

-- 
  Bruce Momjian  <bruce@momjian.us>        https://momjian.us
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  The usefulness of a cup is in its emptiness, Bruce Lee