# We have slices, do we have Strides?

Jonathan M Davis jmdavisProg at gmx.com
Mon Aug 8 17:13:12 PDT 2011

```> 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 ][]));

LOL. Yes. Since he's dealing with arrays rather than a generic input range,
that works great.

- Jonathan M Davis
```