Split_Part w/negative integer does not work

On 24/03/2023 21:45 CET PG Doc comments form <noreply@postgresql.org> wrote:

The following documentation comment has been logged on the website:

Page: https://www.postgresql.org/docs/15/functions-string.html
Description:

When n is negative, an error occurs.

Documentation
split_part ( string text, delimiter text, n integer ) → text
Splits string at occurrences of delimiter and returns the n'th field
(counting from one), or when n is negative, returns the |n|'th-from-last
field.
split_part('abc~@~def~@~ghi', '~@~', 2) → def
split_part('abc,def,ghi,jkl', ',', -2) → ghi

Observation
SELECT split_part('abc,def,ghi,jkl', ',', -1);
generates
ERROR: field position must be greater than zero
SQL state: 22023

Works on 14 and 15. Support for negative indexes was added in 14. What
version do you use?

https://www.postgresql.org/docs/14/release-14.html#id-1.11.6.12.5.8

--
Erik

PG Doc comments form <noreply@postgresql.org> writes:

Page: https://www.postgresql.org/docs/15/functions-string.html
Documentation
split_part ( string text, delimiter text, n integer ) → text
Splits string at occurrences of delimiter and returns the n'th field
(counting from one), or when n is negative, returns the |n|'th-from-last
field.
split_part('abc~@~def~@~ghi', '~@~', 2) → def
split_part('abc,def,ghi,jkl', ',', -2) → ghi

Observation
SELECT split_part('abc,def,ghi,jkl', ',', -1);
generates
ERROR: field position must be greater than zero
SQL state: 22023

Apparently, you are reading the v15 documentation and expecting it
to be exactly correct for some older server version. The described
behavior came in in v14.

regards, tom lane