On Monday, 9 May 2016 at 18:50:32 UTC, Jay Norwood wrote:
I noticed some discussion of Cartesian indexes in Julia, where
the index is a tuple, along with some discussion of optimizing
the index created for cache efficiency. I could find
foreach(ref val, m.byElement()), but didn't find an example
that returned a tuple index. Is that supported?
http://julialang.org/blog/2016/02/iteration
http://julialang.org/blog/2016/03/arrays-iteration
This example is form documentation:
http://dlang.org/phobos/std_experimental_ndslice_selection.html#.byElement
import std.experimental.ndslice.slice;
auto slice = new long[20].sliced(5, 4);
for(auto elems = slice.byElement; !elems.empty; elems.popFront)
{
size_t[2] index = elems.index;
elems.front = index[0] * 10 + index[1] * 3;
}
assert(slice ==
[[ 0, 3, 6, 9],
[10, 13, 16, 19],
[20, 23, 26, 29],
[30, 33, 36, 39],
[40, 43, 46, 49]]);
ndslice does not have opApply, because it overrides range
primitives.
Iteration with byElement may be a little bit slower then
iteration with common foreach loops. A method, say, `forElement`
for `foreach` loops may be added, thought.
Best regards,
llya
