Re: IF (NOT) EXISTS in psql-completion

Thank you for reviewing!

At Mon, 19 Sep 2016 11:11:03 +0200, Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com> wrote in <CAFj8pRCpoYMoUzZ74p0JvX=orUxs7o88UR0z0-Lqt6W6bS9DaQ(at)mail(dot)gmail(dot)com>
> >> 2. Make keywords' case follow to input
> >>
> >> Allow the keywords suggested along with databse objects to
> >> follow the input letter case. The core part of this patch is a
> >> new function additional_kw_query(), which dynamically generates
> >> additional query string with specified keywords in the desired
> >> letter case. COMPLETE_WITH_* macros are modified to accept the
> >> function.
> >>
> >>
> second patch is working, but I don't think it is enough documented

Mmm. I should admit that. I will add comments in it.

> what is addon in COMPLETE_WITH_QUERY(query, addon)? semantics, usage?

Original COMPLETE_WITH_QUERY gets only query, but it is used in
the form when additional keywords are needed.

| COMPLETE_WITH_QUERY(Query_for_list_of_roles " UNION SELECT 'DEFAULT'");

This is a string literal concatenation which is available only on
compile time. Letter case modification needs this done in
runtime. So it should be given as a separate parameter from the
main query.

> in 99% the addon is "" when macro
> COMPLETE_WITH_SCHEMA_QUERY,COMPLETE_WITH_QUERY is used. Maybe a
> introduction of new macros with nonempty addon parameter should be better.

That looks better. I'll change the API as the following.

COMPLETE_WITH_QUERY(query);
COMPLETE_WITH_QUERY_KW(query, kwlist);
COMPLETE_WITH_SCHEMA_QUERY(squery);
COMPLETE_WITH_SCHEMA_QUERY_KW(squery, kwlist);

> > 3. Fix suggested keywords to follow input in tab-completion session 2
> >>
> >> The 2nd patch above leaves some query string containing static
> >> keyword strings, which results in failure to follow input
> >> letter cases. Most of them are naturally removed but role names
> >> are a bother. This patch puts additional query strings for
> >> several usage of roles but it might be overdone.
> >>
> >
> this patch looks well
>
>
> >
> >> 4. Introduce word shift and removal feature to psql-completion
> >>
> >> This is the second core for the flexibility of completion code.
> >> The word shift feature is the ability to omit first several
> >> words in *MatchesN macros. For example this allows complete
> >> create-schema's schema elements in a natural code. (Currently
> >> those syntaxes that can be a schema elements are using
> >> TailMatches instead of Matches, as the result HeadMatches are
> >> not available there). The words removing feature is the ability
> >> to (desructively) clip multiple suceessive words in the
> >> previous_words list. This feature allows suceeding completion
> >> code not to care about the removed words, such like UNIQUE,
> >> CONCURRENTLY, VERBOSE and so on.
> >>
> >
> I am thinking so commit's description should be inside README

Currently psql or tab-complete.c/psql_completion() have no such
document. If this should be written as README, perhaps I should
write about completion in general. On the other hand, per-macro
explanations are written in tab-complete-macros.h but the usages
are not. I'll try to write README.

regards,

--
Kyotaro Horiguchi
NTT Open Source Software Center