Hi,

If I have multiple ranges, say:

auto a = [1, 2, 3];
auto b = ["a", "b", "c"];
auto c = ["x", "y", "z"];

I'd like a composition range that enumerate all combinations of these ranges,
having the same effect as a nested foreach loop:

foreach (i; a) {
  foreach (j; b) {
    foreach (k; c) {
       writlen(i, j, k);
    }
  }
}

Is there such a generic function in std lib?

On Wednesday, 11 November 2015 at 02:38:19 UTC, puming wrote:
> Hi,
>
> If I have multiple ranges, say:
>
> auto a = [1, 2, 3];
> auto b = ["a", "b", "c"];
> auto c = ["x", "y", "z"];
>
> I'd like a composition range that enumerate all combinations of these ranges,
> having the same effect as a nested foreach loop:
>
> foreach (i; a) {
>   foreach (j; b) {
>     foreach (k; c) {
>        writlen(i, j, k);
>     }
>   }
> }
>
> Is there such a generic function in std lib?

http://dlang.org/phobos/std_algorithm_setops.html#.cartesianProduct ?

On Wednesday, 11 November 2015 at 02:55:25 UTC, cym13 wrote:
> On Wednesday, 11 November 2015 at 02:38:19 UTC, puming wrote:
>> Hi,
>>
>> If I have multiple ranges, say:
>>
>> auto a = [1, 2, 3];
>> auto b = ["a", "b", "c"];
>> auto c = ["x", "y", "z"];
>>
>> I'd like a composition range that enumerate all combinations of these ranges,
>> having the same effect as a nested foreach loop:
>>
>> foreach (i; a) {
>>   foreach (j; b) {
>>     foreach (k; c) {
>>        writlen(i, j, k);
>>     }
>>   }
>> }
>>
>> Is there such a generic function in std lib?
>
> http://dlang.org/phobos/std_algorithm_setops.html#.cartesianProduct ?

Thanks :-)