Using instance-function references in Kotlin

InstanceFunctionReferences.kt

// https://pl.kotl.in/rJgInO29m

class MyClass {
    private fun doThing1(name: String) =
        println("Thing1 says: Hello $name")
        
    private fun doThing2(name: String) =
        println("Thing2 says: Hi $name!")
    
    private fun fail(name: String) =
        println("oops $name")
        
    fun doThing(num: Int, name: String) {
        // note the type-annotation with the reciever (type-annotation is only here for clarity)
        val function: MyClass.(String) -> Unit =
            when(num) {
            	1 -> ::doThing1
            	2 -> ::doThing2
            	else -> ::fail
        	}
        
        // and now we can invoke it here, with many-many arguments if required
        this.function(name)
    }
}

fun main(args: Array<String>) {
    val wrapper = MyClass()
    wrapper.doThing(1, "Sally")
    wrapper.doThing(2, "Conrad")
    wrapper.doThing(3, "Cat")
}