Is there a specific reason why the common

StringBuilder

is append-only? I.e. no replace/delete.

we are talking about https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.text/-string-builder/index.html ?

yes

good question... in javascript its String-backed. i dont see any easin why the delete methods shouldn't be possible to implement that way 🤔

I basically have to do something like this: https://gist.github.com/fluidsonic/1a356448e20db7ee26b1fd43b94f570c