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kotlinlang

I need to create a list of all the `m`’s produced by this cartesian product. Is there a nice idiomatic way to do this? Am I missing some kind of built in cartesian product function?
```        messages.forEach { message -&gt;
            recipients.forEach { recipient -&gt;
                val m = messagingService.recordMessage(message, listOf(recipient))
            }
        }```

Untitled

Ah, this is much better but I still feel like it could be better…

one solution that comes to mind is to wrap it into `buildList` and just call `add(m)`

I imagine the best way to handle cartesian product cleanly is to just make a generic method for it. do it the ugly but efficient way and hide it in some other file. ezpz

Change the first `map` to a `flatmap` and remove the `flatten`

Skjermbilde 2020-04-15 07.54.35.png

I would make something like this. You could also consider making it an extension method on Iterable<X1>

Replacing
```Pair(first, second)```
with
```first to second```
might be more idiomatic.