Re: PATCH: recursive json_populate_record()

On Thu, Jan 26, 2017 at 6:49 AM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Nikita Glukhov <n(dot)gluhov(at)postgrespro(dot)ru> writes:
>> On 25.01.2017 23:58, Tom Lane wrote:
>>> I think you need to take a second look at the code you're producing
>>> and realize that it's not so clean either. This extract from
>>> populate_record_field, for example, is pretty horrid:
>
>> But what if we introduce some helper macros like this:
>
>> #define JsValueIsNull(jsv) \
>> ((jsv)->is_json ? !(jsv)->val.json.str \
>> : !(jsv)->val.jsonb || (jsv)->val.jsonb->type == jbvNull)
>
>> #define JsValueIsString(jsv) \
>> ((jsv)->is_json ? (jsv)->val.json.type == JSON_TOKEN_STRING \
>> : (jsv)->val.jsonb && (jsv)->val.jsonb->type == jbvString)
>
> Yeah, I was wondering about that too. I'm not sure that you can make
> a reasonable set of helper macros that will fix this, but if you want
> to try, go for it.
>
> BTW, just as a stylistic thing, I find "a?b:c||d" unreadable: I have
> to go back to the manual every darn time to convince myself whether
> that means (a?b:c)||d or a?b:(c||d). It's better not to rely on
> the reader (... or the author) having memorized C's precedence rules
> in quite that much detail. Extra parens help.

Moved to CF 2017-03 as discussion is going on and more review is
needed on the last set of patches.
--
Michael