Re: Getting PSQL in Windows to support TAB/Autocomplete via modified readline...

Andres Freund <andres@anarazel.de> writes:
> On 2022-11-23 18:11:22 -0500, Tom Lane wrote:
>> Huh ... do you recall the details?  Large as tab-complete is, it's
>> far smaller than gram.y:

> So It might just be that we need to split up that very long "else if" chain in
> psql_completion().

Could be, yeah.  Related point: I've wondered for awhile how long that
chain can get before we start noticing performance issues on slower
machines.  Even when the standard is just human reaction time, there's
a limit to how many cycles you can throw away.  So I'd like to see it
refactored somehow to be a bit less stupid --- but I have a nagging
feeling that we'd end up building some special-purpose program generator,
which is something I've not wanted to do.  OTOH, in the best of all
possible worlds such a tool might make it easier to add tab
completions?

(In the past I've fantasized about auto-generating tab completion
logic from the backend grammar, but I fear it's just fantasy.
The backend grammar isn't factored right, and too many of its names
don't have clear traceability to what-kind-of-object-is-that.)

            regards, tom lane