On Monday, 17 June 2013 at 23:48:36 UTC, Ali Çehreli wrote:
On 06/17/2013 04:34 PM, Colin Grogan wrote:
> Wondering what way I'd go about this, I want to slice an
array into two
> arrays. First array containing every even index (i.e.
0,2,4,6,8..$)
> Second slice containing every odd index (i.e. 1,3,5,7,9..$)
<-- be some
> issue with using $ depending on if orig length is odd or
even. Can work
> that out easily enough...
>
> Reading the articles on array slicing its not clear if its
possible.
>
> Ideally, I could do something like the following:
>
> auto orig = [1,2,3,4,5,6,7];
> auto sliceEven = orig[0..$..2];
> auto sliceOdd = orig[1..$..2];
If you want the data sit where it is but simply have different
views in it, then you must use ranges. There are multiple ways.
Here is one using std.range.stride:
import std.stdio;
import std.range;
void main()
{
auto orig = [0, 1, 2, 3, 4, 5, 6, 7];
auto sliceEven = orig.stride(2);
auto sliceOdd = orig.dropOne.stride(2);
writeln(sliceEven);
writeln(sliceOdd);
}
The output:
[0, 2, 4, 6]
[1, 3, 5, 7]
Or you can generate the indexes and then get a view that way:
auto sliceEven = orig.indexed(iota(0, orig.length, 2));
auto sliceOdd = orig.indexed(iota(1, orig.length, 2));
Ali
Thats perfect folks. Should have known to look in std.range.
This works for me perfectly.
3 answers all within a couple minutes of each other, what a good
community! ;)
