Re: Propose a new function - list_is_empty

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Daniel Gustafsson <daniel@yesql.se>
Cc: Peter Smith <smithpb2250@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2022-08-16T13:37:51Z
Lists: pgsql-hackers
Daniel Gustafsson <daniel@yesql.se> writes:
> I think these are nice cleanups to simplify and streamline the code, just a few
> small comments from reading the patch:

>  	/* If no subcommands, don't collect */
> -	if (list_length(currentEventTriggerState->currentCommand->d.alterTable.subcmds) != 0)
> +	if (currentEventTriggerState->currentCommand->d.alterTable.subcmds)
> Here the current coding gives context about the data structure used for the
> subcmds member which is now lost.  I don't mind the change but rewording the
> comment above to indicate that subcmds is a list would be good IMHO.

I think testing for equality to NIL is better where that's a concern.

> Might be personal taste, but I think the parenthesis should be kept here as a
> visual aid for the reader.

+1

			regards, tom lane



Commits

  1. Avoid using list_length() to test for empty list.