How d I go implementing a `List sortedWith` that takes a com

Question

How d I go implementing a `List sortedWith` that takes a comparator which can be suspended Suppose I d need something like this ```someList sortedWith o1 o2 gt suspendedComparison o1 o2 ``` Where `suspendedComparison` is a function which returns `Int` satisfying `Comparator` and is a `suspend fun`

bloodshura · Answer

This as is won t work because `sortedWith` takes a `Comparator` as an argument whose SAM is not suspendable But then what are the alternatives Will I need to implement a sorting algorithm from scratch just to make it suspendable

mbonnin · Answer

Most likely not the answer you expected but you can wrap your `suspendedComparison` in `runBlocking `

bloodshura · Answer

Yeah haha I m looking for something that would not block since these suspended comparisons could take some time even seconds

mbonnin · Answer

I m not sure there s a way to rewrite a regular function into a suspendable one

mbonnin · Answer

Maybe with some IR compiler plugin magic

mbonnin · Answer

That sounds involved though

ephemient · Answer

if performance isn t a major concern as you ll be waiting for your comparator anyway rolling your own sort is easy enough ```suspend fun lt T gt List lt T gt sortedWith comparator suspend a T b T gt Int List lt T gt if size lt = 1 return this val first = first val left right = drop 1 partition comparator first it gt = 0 return left sortedWith comparator + first + right sortedWith comparator ```

ephemient · Answer

heck you could even parallelize it ```suspend fun lt T gt List lt T gt sortedWith scope CoroutineScope comparator suspend a T b T gt Int List lt T gt if size lt = 1 return this val first = first val left right = drop 1 partition comparator first it gt = 0 val sortedLeft = scope async left sortedWith this comparator val sortedRight = scope async right sortedWith this comparator return sortedLeft await + first + sortedRight await ```

ephemient · Answer

you re not going to be able to magically make the existing sort method suspending it boils down to re using platform s e g Java JS standard library sort

ephemient · Answer

K N does have its own sort implementation so you could copy that but it s a bit fancier than the arrow up dumb quicksort above <https github com JetBrains kotlin native blob master runtime src main kotlin kotlin collections ArraySorting kt>

bloodshura · Answer

Thank you very much