We have slices, do we have Strides?

[Steven Schveighoffer]

On Mon, 08 Aug 2011 18:33:55 -0400, Kai Meyer <kai at unixlords.com> wrote:

> On 08/08/2011 12:55 PM, Jonathan M Davis wrote:
>>> I have a problem I'd really like to use Strides for to simplify my  
>>> code.
>>> Currently, I do this:
>>> foreach(n; 0..chunks)
>>> comp_arr[n] = values[(n * step_size) + n]
>>> if(!all_same(comp_arr, comp_arr[0]))
>>>
>>> It would eliminate an entire 2 lines of code for each time I want
>>> strides, to be able to do this:
>>> if(!all_same(bytes[i..$..step_size])
>>>
>>> Meaning, start with i, grab all elements at i + block_size * n until
>>> block_size * n>  bytes.length. Right?
>>>
>>> -Kai Meyer
>>
>> Would std.range.stride work for you?
>>
>> - Jonathan M Davis
>
> It would, if there was a way to give it an offset:
>
> int[] a = [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 ];

fixed:

> assert(equal(stride(a, 3), [ 1, 4, 7, 10 ][]));
> assert(equal(stride(a[1..$], 3), [ 2, 5, 8, 11 ][]));
> assert(equal(stride(a[2..$], 3), [ 3, 6, 9 ][]));
> assert(equal(stride(a[3..$], 3), [ 4, 7, 10 ][]));

-Steve