Re: Fix tab completion after EXCEPT (...) in IMPORT FOREIGN SCHEMA - Mailing list pgsql-hackers

On Thu, 16 Apr 2026 at 22:39, Fujii Masao <masao.fujii@gmail.com> wrote:
>
> On Thu, Apr 16, 2026 at 1:00 PM shveta malik <shveta.malik@gmail.com> wrote:
> >
> > On Wed, Apr 15, 2026 at 8:45 PM vignesh C <vignesh21@gmail.com> wrote:
> > >
> > > Hi all,
> > >
> > > While reviewing tab completion behavior, I noticed an issue after
> > > EXCEPT (...) support was added to CREATE PUBLICATION.
> > > Currently, after typing:
> > > IMPORT FOREIGN SCHEMA public EXCEPT (t1)
> > >
> > > psql correctly suggests FROM SERVER. However, the existing completion
> > > rule uses a generic:
> > > TailMatches("EXCEPT", "(*)")
> > >
> > > Previously this was safe because no other command used EXCEPT (...).
> > > Now that CREATE PUBLICATION also supports EXCEPT (...), the same rule
> > > can incorrectly match publication commands and suggest FROM SERVER
> > > there as well.
> > >
> > > The attached patch fixes this by restricting the EXCEPT (...) path to
> > > IMPORT FOREIGN SCHEMA using HeadMatches(), while preserving the
> > > existing LIMIT TO (...) behavior.
>
> Thanks for the patch!
>
> - else if (TailMatches("LIMIT", "TO", "(*)") ||
> + else if (HeadMatches("IMPORT", "FOREIGN", "SCHEMA", MatchAny) &&
>   TailMatches("EXCEPT", "(*)"))
>   COMPLETE_WITH("FROM SERVER");
> + else if (TailMatches("LIMIT", "TO", "(*)"))
> + COMPLETE_WITH("FROM SERVER");
>
> Do we really need to split this into two conditions? Wouldn't it be simpler
> to keep a single condition?, for example:
>
> -------------------
> else if (TailMatches("LIMIT", "TO", "(*)") ||
> - TailMatches("EXCEPT", "(*)"))
> + Matches("IMPORT", "FOREIGN", "SCHEMA", MatchAny, "EXCEPT", "(*)"))
>   COMPLETE_WITH("FROM SERVER");
> -------------------

Yes, this is better. The attached v2 version patch has the changes for the same.

Regards,
Vignesh