``` val closure = { (a: Int -> Int) -> a...

# announcements

[iex]

val closure = { (a: Int -> Int) ->
    a * 2
}

[louiscad]

You can't. You can specify the type of closure explicitly though, and the IDE can even do that for you with an intention (alt/option + enter)

[iex]

😕 type inference is failing

[louiscad]

? Can you tell more details?

[Shawn]

val closure: (Int) -> Int = { a -> a * 2 }

is the closest you can get to what you’re asking for, I think

[elizarov]

Expected type is one way. You can also use anonymous function literal instead:

val closure = fun(a: Int): Int { ... }

[streetsofboston]

@iex What is the type of closure if you would provide it explicitly?

[streetsofboston]

You could end your last expression in your lambda with `as MyReturnType`….

[streetsofboston]

E.g. val closure = { a: Int -> (a + 5) as Number }
Is this what you try to accomplish?

[iex]

yeah but I prefer to avoid casting, even in this case

[iex]

managed to solve it with an extension function

[streetsofboston]

Now i’m curious … 🙂

[iex]

it's a bit too custom to post it I think...

[iex]

declaring a local variable with the correct type and returning it also solved it, but that was 2 lines of code 😄

[streetsofboston]

Providing the type explicitly is probably less typing … 🙂

[iex]

that's basically what I'm doing with the extension

[iex]

have a chain of map and flatmap which seemed to confuse the compiler

[streetsofboston]

It could be that the new type inference system, that is still a bit in flux, may help with that.

https://www.youtube.com/watch?v=MyljSWm0Y_k▾

(fast forward to the type inference section)

[iex]

thanks, will watch it later 👍