Change representation of dynamic arrays?

[Bill Baxter]

Jascha Wetzel wrote:
> Janice Caron wrote:
>> On 10/20/07, Jascha Wetzel <firstname at mainia.de> wrote:
>>> Walter Bright wrote:
>>>> Janice Caron wrote:
>>>>> That said, someone posted that you always allocate an extra byte. If
>>>>> that's true, problem solved.
>>>> Yes, an extra byte is allocated for just this reason.
>>> couldn't the end pointer just point to the last element?
>>
>> Oooh yuk. How horrible. I'd rather that didn't happen. For one thing,
>> it means that empty arrays (and empty collection ranges generally)
>> would have to have a different representation.
>>
>> No, I like the "standard" way of doing things, whereby the end
>> iterator refences the last+1 element (and therefore cannot be
>> dereferenced).
> 
> one can argue, that this way, empty arrays have an unambiguous 
> representation (they are always null).
> there is enough code like
> if ( str is null || str == "" )
> which wouldn't be necessary.
> the current semantics deal with null arrays in the same way as with 
> empty arrays (length == 0, appending works alike). 


Not quite true.  if(str){} tests only the .ptr part and ignores the 
length (as I quite painfully discovered recently... Sure wish there were 
an easy way to find all the places in my code where I used that 
expression instead of .length==0.).

--bb