Re: TRIM_ARRAY

On 3/2/21 1:02 AM, Dian M Fay wrote:
> On Mon Mar 1, 2021 at 6:53 PM EST, Vik Fearing wrote:
>>> This basically does what it says, and the code looks good. The
>>> documentation is out of alphabetical order (trim_array should appear
>>> under cardinality rather than over)) but good otherwise.
>>
>> Hmm. It appears between cardinality and unnest in the source code and
>> also my compiled html. Can you say more about where you're seeing the
>> wrong order?
>
> I applied the patch to the latest commit, ffd3944ab9. Table 9.52 is
> ordered:
>
> array_to_string
> array_upper
> trim_array
> cardinality
> unnest

So it turns out I must have fixed it locally after I posted the patch
and then forgot I did that. Attached is a new patch with the order
correct. Thanks for spotting it!

>> The problem here is that postgres needs to know what the return
>> type is and it can only determine that from the input.
>>
>> If you give the function a typed null, it returns null as expected.
>>
>>> The new status of this patch is: Waiting on Author
>>
>> I put it back to Needs Review without a new patch because I don't know
>> what I would change.
>
> I'd thought that checking v and returning null instead of raising the
> error would be more friendly, should it be possible to pass an untyped
> null accidentally instead of on purpose, and I couldn't rule that out.

As Tom said, that is something that does not belong in this patch.
--
Vik Fearing