A modern programming language that makes developers happier.

kotlinlang

No there isnt. And even if, i don't know how that may help you. For example If you have an ext fun that can access your data class, which method or properties would you want to access.. data classes per se share only a paramless copy method.. that doesn't help you. There are also no common propeties. A function alone at all seems to be Not too helpful, because it doesn't represent an introspectable data structure you can use eg to calculate a delta (or at least it would be very complicated)

I think what you need is a list of pairs of property accessor and value. The value and property can then share the type. You can then implement for example validation only for the properties that are changed, although i don't know how the validation is implemented and so on.