I have a list of timestamps, and want to group them together if they are less than a certain duration apart (map them to the durations they represent, so I can sum the durations to get the total amount of time). I feel like there is a stdlib function on List to do this, but I can’t find it.

stdlib `groupBy`/`groupingBy` makes sense for equivalence classes where you can define a key. it doesn't sound like that's the case here, so there isn't really anything in stdlib to help

partition would also work

But shouldn't there be a function for that? It is such a common pattern/use case.

see the KT issue in the playground link I made

Is it really that common?

I think it's reasonably common - I've written it at least 3 times now, and it's in other langauges' standard libraries