On 16/01/2017 17:50, Al Thomas wrote:
> ----- Original Message -----
>> From: Alexandre Oliveira <xinay...@airmail.cc>
>> Sent: Monday, 16 January 2017, 19:27
>> Subject: Re: [Vala] How to check if string is empty
>
>> I tried this in my method, even replacing 'string' for 'string?', but I
>> still get the same message in my terminal.
>
>
>> What is your suggestion to suppress these messages?
>
> Don't suppress them, they are warnings from the runtime that things are wrong.
> Ideally Vala would have warned you when the program was compiled, but
> the valac switch --enable-experimental-non-null is not there yet.
>
>> On 16/01/2017 17:23, Guillaume Poirier-Morency wrote:
>
>>> You should test for nullity before addressing the string.
>
>>>
>>> return str == null || str.length == 0;
>>>
>>> If you expect the string to be potentially 'null', use the 'string?'
>>> type instead.
>
>
> This is sound advice. Works for me:
>
> void main () {
> string? a = null;
> if (is_empty (a)) {
> print ("string is empty\n");
> }
> a = "\0";
> if (is_empty (a)) {
> print ("string is empty\n");
> }
> }
>
> bool is_empty(string? str) {
> return str == null || str == "";
> }
>
>
> Really you should be thinking about avoiding nulls. As C.A.R.Hoare said "I
> call it my billion-dollar mistake. It was the invention of the null reference
> in 1965. This has led to innumerable errors, vulnerabilities, and system
> crashes, which have probably caused a billion dollars of pain and damage in
> the last forty years."
> [https://en.wikipedia.org/wiki/Tony_Hoare#Apologies_and_retractions]
>
Thank you guys, finally solved the issue. Sorry for being a bit stupid
on it.
--
Alexandre Oliveira
167F D82F 514A E8D1 2E9E
C62D 1B63 9D4A 7E9D DA9D
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