Re: Document NULL

On Tue, 18 Jun 2024 23:02:14 -0700
"David G. Johnston" <david(dot)g(dot)johnston(at)gmail(dot)com> wrote:

> On Tuesday, June 18, 2024, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>
> > Yugo NAGATA <nagata(at)sraoss(dot)co(dot)jp> writes:
> > > On Tue, 18 Jun 2024 20:56:58 -0700
> > > "David G. Johnston" <david(dot)g(dot)johnston(at)gmail(dot)com> wrote:
> > >> But it is neither a keyword nor an identifier.
> >
> > The lexer would be quite surprised by your claim that NULL isn't
> > a keyword. Per src/include/parser/kwlist.h, NULL is a keyword,
> > and a fully reserved one at that.
> >
> >
> >
>
> Can’t it be both a value and a keyword? I figured the not null constraint
> and is null predicates are why it’s a keyword but the existence of those
> doesn’t cover its usage as a literal value that can be stuck anywhere you
> have an expression.

I still wonder it whould be unnecessary to mention the case-insensitivity here
if we can say NULL is *also* a keyword.

Regards,
Yugo Nagata

> David J.

--
Yugo NAGATA <nagata(at)sraoss(dot)co(dot)jp>