On Thursday, 6 November 2014 at 16:57:50 UTC, Marc Schütz wrote:
On Thursday, 6 November 2014 at 15:53:27 UTC, Jack Applegame
wrote:
I have rectangular forward range of forward ranges (not
arrays):
[
[a11, a12, ... a1N],
[a21, a22, ... a2N],
...
[aM1, aM2, ... aMN]
]
I need lazy forward range:
[
a11 + a21 + ... aM1,
a12 + a22 + ... aM2,
...
a1N + a2N + ... aMN
]
Range of sum elements of every columns;
M, N - runtime values;
Is there a way to do this using only Phobos algorithms and
range functions?
Untested:
import std.algorithm: map, sum;
auto rangeOfSums = rectangularRange.map!(r => r.sum);
Sorry, I see you want columns...
I thought about std.range.frontTransversal, but it only returns a
range of values, not a range of ranges. That's... unhelpful :-(
