arrays: if(null == [ ])

[Steven Schveighoffer]

On Mon, 14 May 2012 18:07:24 -0400, Timon Gehr <timon.gehr at gmx.ch> wrote:

> On 05/14/2012 01:51 PM, deadalnix wrote:
>> Le 14/05/2012 12:49, Gor Gyolchanyan a écrit :
>>> So, null arrays and empty arrays are always the same, except for an
>>> empty string, which is a valid non-nill array of characters with length
>>> 0, right?
>>>
>>
>> If it is the current behavior, it deserve a WAT !
>
> I agree, but it is explained easily. Built-in string literals are always  
> zero-terminated, therefore an empty string literal must point into  
> accessible memory. I'd like to have [] !is null as well, so that null  
> can reliably be used as a sentinel value.

This would mean either a) allocating memory for a 0 length array, or b)  
pointing it at non-null but non-heap memory.

a) is certainly out of the question.

b) is possible, but I still think we should discourage using null as a  
sentinel, it leads to confusing code.

Regardless, we should fix if(!arr) to mean if(!arr.length).

-Steve