How does one check to see if a property value that...

# getting-started

[Soren Valle]

How does one check to see if a property value that is declared as type Any has been initialized with a function? i.e.

class SomeClass {
    var someProp: Any? = null
}

fun main() {
   val someClass = SomeClass()
    someClass.someProp = {
        println("I do things")
    }

    // else where

    if(someClass.someProp is Function<*>){
        someClass.someProp() // invoke not found...
    }
}

[Andrey Chernov]

Seems you cast it to function without parameters and result type, so there is really nothing to invoke

[Soren Valle]

That maybe, what I'm looking for is a way to check at runtime that the property is callable. The is Function<*> where it isn't doing what I would expect doesn't mean it isn't doing what it was intended to do and I just need to learn it. I meant it only as, "how do I accomplish this"?

[Soren Valle]

For instance is Lambda would be nice.

[molikuner]

First of all: Don't use Any if you aren't forced to do so.
But anyways, there is a solution to your problem:

https://pl.kotl.in/aFGOJVOh3

The problem is that you just chekc for Function and not for Function0 (number of args). The second problem is that theoretically an other coroutine / Thread could reassign the var. That's the reason why your smart cast isn't working. If you assign it to a val it isn't mutable, which means smart cast is working now.

[Soren Valle]

@molikuner Thank you! I had not yet learned about FunctionN. Perfect.