Hi :wave: I'd like to declare a data class propert...

# announcements

[tim]

Hi 👋 I'd like to declare a data class property as a function: matcher: (x: Any) -> Boolean . Later when i pass in a lambda for matcher, I have to cast from Any to the concrete type as per blew. Is there a better way to do this?

data class Query(
 matcher: (x: Any) -> Boolean
)
...
val query = Query(
 matcher: { x: Any? ->
   val value = x as Int?
   if(value == null || value == 0) false else true
 }
)

[Mark Murphy]

Use generics:

class Query<T>(
 val matcher: (x: T) -> Boolean
)

val query = Query { value: Int ->
   if (value == 0) false else true
}

fun main() {
  println(query.matcher(0))
  println(query.matcher(1))
}

[tim]

perfect thank you 🙏

[Kroppeb]

You should probably use class Query<in T>