Is it standard practice to name a `fun interface` ...

# codingconventions

[Mark]

Is it standard practice to name a fun interface as a verb when the function is invoke? Or maybe as a noun like here:

fun interface ItemSelector {
    operator fun invoke(items: List<String>): String
}

val selectItem = object : ItemSelector { ... }
val itemSelected = selectItem( ... )

1. Verb
2. Noun

[Paul Griffith]

If I had a fun interface operator fun invoke, I would probably just use a typealias instead

[Paul Griffith]

Although as you're using it in that example I think 'as a noun' makes sense

[Paul Griffith]

https://pl.kotl.in/iW9VEDZ-k
Typealias vs fun interface

[Mark]

Thanks Paul. I think the main downside of typealias is that named arguments are not allowed.

[Paul Griffith]

Does your selector function actually need the context of all elements? I think a more idiomatic style would be to implement a predicate interface (less common), or just match the signature (more common) - that has the benefit of slotting into a bunch of common collection operations automatically:
https://pl.kotl.in/u29AcEU-j

[Mark]

I’m not actually dealing with collections. This was just a random example off the top of my head.

[Shawn]

naming interfaces in general as agent nouns is something folks have been doing for a while; I think it’s a fine convention to keep in this case