How would I best achieve something similar to java's

TreeMap

for non-jvm/native sourcecode? (or at least sort a MutableMap by key in non-jvm code)

If you need it to be sorted after each modification I'd probably pull in a JS lib and implement a MutableMap wrapper around it I don't know the JS landscape but something like https://www.npmjs.com/package/ncollections#SortedMap If you are only sorting once then

val orderedMap = map.keys.sorted().associateWith { map[it] }

yes, that'll work for my case. Thanx. (actually not Js, but WasmJs where I did miss it, but also for native unix/MacOS/windows)

sorry don't know why I assumed JS