Re: SQL:2023 JSON simplified accessor support

> On Aug 27, 2025, at 15:26, Chao Li <li(dot)evan(dot)chao(at)gmail(dot)com> wrote:
>
> diff --git a/src/include/parser/parse_node.h b/src/include/parser/parse_node.h
> index f7d07c84542..58a4b9df157 100644
> --- a/src/include/parser/parse_node.h
> +++ b/src/include/parser/parse_node.h
> @@ -361,7 +361,7 @@ extern SubscriptingRef *transformContainerSubscripts(ParseState *pstate,
> Node *containerBase,
> Oid containerType,
> int32 containerTypMod,
> - List *indirection,
> + List **indirection,
> bool isAssignment);
>
> Here we change “indirection” from * to **, I guess the reason is to indicate if the indirection list is fully processed. In case of fully processed, set it to NULL, then caller gets NULL via **.
>
> As “indirection” is of type “List *”, can we just set “indirection->length = 0”? I checked pg_list.h, there is not a function or macro to cleanup a list (free elements and reset length to 0). There is a “list_free(List *list)”, but it will free “list” itself as well. Maybe we can add a new function, say “list_reset(List *list)” or “list_cleanup(List *list)”. This way will keep the function interface unchanged, and less changes would be involved.

After revisiting the changes, I take back this comment. Given the nature that List are always used in pointer form, my comment would just make things much more complicated.

Best regards,
--
Chao Li (Evan)
HighGo Software Co., Ltd.
https://www.highgo.com/