Probably a stupid question, but how do I find the length of each
dimension in a multidimensional array?

On Friday, 5 June 2015 at 07:53:52 UTC, Ralf the Bat wrote:
> Probably a stupid question, but how do I find the length of each
> dimension in a multidimensional array?

I slightly modified the function deepDup, who came up Ali Çehreli :)
http://beta.forum.dlang.org/post/mihl6m$1che$1@digitalmars.com

import std.stdio, std.traits, std.range, std.algorithm;

auto deepLen(A)(A arr)
    if (isArray!A)
{
    writefln("%s.len = %s", arr, arr.length);
    static if (isArray!(ElementType!A)) {
        return arr.map!(a => a.deepLen).array;
    } else {
        return arr;
    }
}

void main() {
    auto arr = [[[[[1, 2, 3, 4], [0]], [[4, 3], [5, 6, 7]]]]];
    arr.deepLen;
}

[[[[[1, 2, 3, 4], [0]], [[4, 3], [5, 6, 7]]]]].len = 1
[[[[1, 2, 3, 4], [0]], [[4, 3], [5, 6, 7]]]].len = 1
[[[1, 2, 3, 4], [0]], [[4, 3], [5, 6, 7]]].len = 2
[[1, 2, 3, 4], [0]].len = 2
[1, 2, 3, 4].len = 4
[0].len = 1
[[4, 3], [5, 6, 7]].len = 2
[4, 3].len = 2
[5, 6, 7].len = 3

On 6/5/15 3:53 AM, Ralf the Bat wrote:
> Probably a stupid question, but how do I find the length of each
> dimension in a multidimensional array?

if you mean a static array, you can get each dimension using .length:

int[2][3] arr;

static assert(arr.length == 3);
static assert(arr[0].length == 2);

There is likely a way you can get a tuple of the lengths at compile time.

If you mean a dynamic multidim array, each array element can have its own independent set of dimensions.

-Steve