On Tuesday, June 18, 2024, Tom Lane <
tgl@sss.pgh.pa.us> wrote:
Yugo NAGATA <nagata@sraoss.co.jp> writes:
> On Tue, 18 Jun 2024 20:56:58 -0700
> "David G. Johnston" <david.g.johnston@gmail.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.
David J.