Re: [HACKERS] string_to_array with empty input

Leif B. Kristensen wrote:
> On Thursday 2. April 2009, Steve Crawford wrote:
>
>> Currently string_to_array(null, ',') yields a null result -
>> indistinguishable from string_to_array('',','). Wrapping in coalesce
>> does not help distinguish true null input from empty-string input. I'm
>> not sure at the moment what other cases exist where non-null input
>> generates null output.
>>
>
> Somehow this reminds me of the old "division by zero" problem.
>
> IMO, the proper way to handle this kind of anomaly would be to test if
> the length of the string is non-zero before submitting it to the
> string_to_array() function.
>
Quite the opposite. Where division by zero is simply illegal as is, say,
string_to_array(1234, ','), string_to_array('', ',') is legal.
Unfortunately it is legal, and legal and legal.... with numerous
reasonable interpretations of which legal is most appropriate/consistent.

I would argue against a change to have string_to_array('',',') throw an
error.

Cheers,
Steve