Re: Making tab-complete.c easier to maintain

On Mon, Dec 14, 2015 at 8:10 AM, Thomas Munro
<thomas.munro@enterprisedb.com> wrote:
> I've also add (very) primitive negative pattern support and used it in
> 5 places.  Improvement?  Examples:
>
>         /* ALTER TABLE xxx RENAME yyy */
> -       else if (TailMatches5("ALTER", "TABLE", MatchAny, "RENAME", MatchAny) &&
> -                        !TailMatches1("CONSTRAINT|TO"))
> +       else if (TailMatches5("ALTER", "TABLE", MatchAny, "RENAME",
> "!CONSTRAINT|TO"))
>                 COMPLETE_WITH_CONST("TO");
>
>         /* If we have CLUSTER <sth>, then add "USING" */
> -       else if (TailMatches2("CLUSTER", MatchAny) &&
> !TailMatches1("VERBOSE|ON"))
> +       else if (TailMatches2("CLUSTER", "!VERBOSE|ON"))
>                 COMPLETE_WITH_CONST("USING");

+       /* Handle negated patterns. */
+       if (*pattern == '!')
+               return !word_matches(pattern + 1, word);

Yeah, I guess that's an improvement for those cases, and there is no
immediate need for a per-keyword NOT operator in our cases to allow
things of the type (foo1 OR NOT foo2). Still, in the case of this
patch !foo1|foo2 actually means (NOT foo1 AND NOT foo2). It does not
seem that much intuitive. Reading straight this expression it seems
that !foo1|foo2 means actually (NOT foo1 OR foo2) because the lack of
parenthesis. Thoughts?
-- 
Michael