Re: [PATCH] Combine same ternary types in GIN and TSearch

Heikki Linnakangas <hlinnaka(at)iki(dot)fi> writes:
> On 13/11/2020 11:04, Pavel Borisov wrote:
>> For historical reasons, now we have two differently named but similar
>> ternary data types in TSearch and Gin text-related types. Before v13
>> there was also Gin's private TS_execute() version, from which we
>> eventually shifted to Tsearch's TS_execute().
>> To make things more even and beautiful I've made a minor refactor to
>> combine two left ternary types into one.

> GIN is not just for full-text search, so using TSTernaryValue in
> GinScanKeyData is wrong. And it would break existing extensions.

> I didn't look much further than that, but I've got a feeling that
> combining those is a bad idea. TSTernaryValue is used in text-search
> code, even when there is no GIN involved. It's a separate concept, even
> though it happens to have the same values.

I'm definitely not on board with importing a TS-specific type into GIN,
and even less with requiring major GIN headers to import random
TS-related headers.

There might be a case for having just one neutrally-named "ternary" enum
type, declared in a neutral (probably new) header, that both areas of
the code could use. But it's not clear that it'd be worth the code
thrashing to do that. As Heikki says, this will surely break some
extensions; and I'd prefer that there be some non-cosmetic benefit
if we ask extension authors to cope with that.

regards, tom lane