I've been thinking of better mechanism for tab-compltion for these days since I found some bugs in it.
At Fri, 23 Oct 2015 14:50:58 -0300, Alvaro Herrera <alvherre@2ndquadrant.com> wrote in <20151023175058.GA3391@alvherre.pgsql> > Jeff Janes wrote: > > > For the bigger picture, I don't think we should not apply this patch simply > > because there is something even better we might theoretically do at some > > point in the future. > > Agreed.
Auto-generating from grammer should be the ultimate solution but I don't think it will be available. But still I found that the word-splitting-then-match-word-by-word-for-each-matching is terriblly unmaintainable and poorly capable. So, how about regular expressions?
I tried to use pg_regex in frontend and found that it is easily doable. As a proof of the concept, the two patches attached to this message does that changes.
Simply replaces existing matching rules almost one-by-one with regular expression matches.
I made these patches not to change the behavior except inevitable ones.
We would have far powerful matching capability using regular expressions and it makes tab-complete.c look simpler. On the other hand, regular expressions - which are stashed away into new file by this patch - is a chunk of complexity and (also) error prone. For all that I think this is better than the current situation in terms of maintainability and capability.
This should look stupid because it really be replaced stupidly and of course this can be more sane/effective/maintainable by refactoring. But before that issue, I'm not confident at all that this is really a alternative with *gigantic* improvement.
Any opinions?
It's an interesting idea to use regular expressions, but it's a shame to move the patterns so far away from the actions they trigger.
