Re: Incorrect Syntax in Function Syntax diagram

On Wed, Jun 23, 2021 at 6:31 AM PG Doc comments form <noreply(at)postgresql(dot)org>
wrote:

> The following documentation comment has been logged on the website:
>
> Page: https://www.postgresql.org/docs/13/sql-createfunction.html
> Description:
>
> | IMMUTABLE | STABLE | VOLATILE | [ NOT ] LEAKPROOF
>
> [ NOT ] LEAKPROOF is accepting separately ,
> So why you written [ NOT ] LEAKPROOF with | IMMUTABLE | STABLE | VOLATILE
> |
>
>
The commit message doesn't say - but I can see how from a technical
perspective that the claim that something is immutable is considered
similar to a claim that something has no side effects, thus there is a
connection. As noted below, the fact that the first three are mutually
exclusive while leakproof is not is convincing enough a reason to list
leakproof separately.

Please separate the [ NOT ] LEAKPROOF from the OR list
>

I would agree, and would add that I wonder whether the syntax for the three
mutually exclusive options should be shown as such instead of having to
read that in the description notes. Does writing < | { IMMUTABLE | STABLE
| VOLATILE } > work?

Note: Your documentation must be correct
>

Is that so? It is a good thing then that it is presently correct and that
this is just a readability suggestion. The presence of them all on the
same line does not by itself imply any kind of relationship in the actual
grammar.

David J.