Thread overview
Negative index for arrays
Mar 22, 2006
Muta
Mar 22, 2006
Oskar Linde
Mar 22, 2006
Jacques
March 22, 2006
I see that this is used in Python's strings, to get a char from the end of
the string. Would there be any drawback in implementing the same thing in
D's arrays ? Something like :
array[-x] = array[array.length - x]

March 22, 2006
Muta skrev:
> I see that this is used in Python's strings, to get a char from the end of
> the string. Would there be any drawback in implementing the same thing in
> D's arrays ? Something like :
> array[-x] = array[array.length - x]

The drawback I can see is that it needs a runtime check every time an array is indexed. I would classify that as a stopper. Instead, in D, you can write:

array[$-1]

/Oskar
March 22, 2006
In article <dvrapu$cpd$1@digitaldaemon.com>, Oskar Linde says...
>
>Muta skrev:
>> I see that this is used in Python's strings, to get a char from the end of
>> the string. Would there be any drawback in implementing the same thing in
>> D's arrays ? Something like :
>> array[-x] = array[array.length - x]
>
>The drawback I can see is that it needs a runtime check every time an array is indexed. I would classify that as a stopper. Instead, in D, you can write:
>
>array[$-1]
>
>/Oskar

You can always fake it. In the following code i can be either positive or
negative:
array[(i+$)%$]

Jacques