Why functions have priority over the Property-like callables in the same scope?

Question

I just noticed something interesting when testing a code and I would like more explanation. Why functions have the priority over lambdas when they are in the same scope ?

For example :

fun sum(x: Int, y:Int) = x + y
val sum = { x: Int, y: Int -> x + y }
// here, the compiler use the fonction (first line) and not the lambda
println(sum(1, 2))

In this case, I use invoke() to call the lambda instead of the function.

Answer 1

The Overload resolution section of kotlin language specification does touch on this, it states

When calculating overload candidate sets, member callables produce the following separate sets (ordered by higher priority first):

Member function-like callables;
Member property-like callables.

but the specification still seems to be a work in progress as it contains a lot of TODO's, one specific TODO that would be relevant to your question is in the Callable references section

TODO(We might get new ambiguity between props and funs with the same name)

So it seems to get a definite answer, you will have to wait until the language specification matures.