So you can update your article to mention `listOf(1, “2”, 3).filterIsInstance<String>().first(...

# announcements

[orangy]

So you can update your article to mention listOf(1, “2”, 3).filterIsInstance<String>().first() which gives you String value

[dawidhyzy]

orangy: how about first/firstOrNull ?

[orangy]

Anything wrong about them? 🙂

[dawidhyzy]

nothing but is there easy way to find first and cast?

[bob]

Post updated, but I still would love smart cast throughout the language 😎

[orangy]

Smart casts are everywhere, where it is possible for compiler to infer them. In an arbitrary function receiving a lambda it cannot deduce it. Well, it could in some cases, if it could see through inline lambda, but not for collections.

[bob]

Yeah but you can still dream 😃
Btw awesome response here! Love it!

Is there anywhere a kotlin-developer like myself can contribute to the language or community?
Where would you recommend that to be?

[orangy]

You might want to ask in #C0BUHC9HD

[orangy]

Also check http://kotlinlang.org/contribute.html

[bob]

Cool, I’ll do that.
I also first solved my problem with Rx with an extension function in kotlin combining filter and map. And than I found that Rx actually has a filter function for it as well: ofType

[bob]

This was my extension solution:

fun <T,U:T> Observable<T>.filterMap( cls:Class<U> ):Observable<U> { 
  return filter { cls.isInstance( it ) }
           .map { cls.cast( it ) }
}