Re: remaining sql/json patches

On Thu, Dec 7, 2023 at 7:39 PM jian he <jian.universality@gmail.com> wrote:
> based on:
> json_behavior_clause_opt:
> json_behavior ON EMPTY_P
> { $$ = list_make2($1, NULL); }
> | json_behavior ON ERROR_P
> { $$ = list_make2(NULL, $1); }
> | json_behavior ON EMPTY_P json_behavior ON ERROR_P
> { $$ = list_make2($1, $4); }
> | /* EMPTY */
> { $$ = list_make2(NULL, NULL); }
> ;
> so
> + if (func->behavior)
> + {
> + on_empty = linitial(func->behavior);
> + on_error = lsecond(func->behavior);
> + }

Yeah, maybe.

> `if (func->behavior)` will always be true?
> By the way, in the above "{ $$ = list_make2($1, $4); }" what does $4
> refer to? (I don't know gram.y....)

$1 and $4 refer to the 1st and 4th symbols in the following:

json_behavior ON EMPTY_P json_behavior ON ERROR_P

So $1 gives the json_behavior (JsonBehavior) node for ON EMPTY and $4
gives that for ON ERROR.

--
Thanks, Amit Langote
EDB: http://www.enterprisedb.com