I'd seen some goofy syntax referred to in Kotlin posts and books and today I figured out how to use it!

I had some code that looked like this:

    @Test
    fun `when a lambda is passed to subscribe it can receive a broadcast`() {
        val dispatcher = Dispatcher()

        var passedValue = ""
        val subscribeFunction: (String) -> Unit = { event ->
            passedValue = event
        }

        dispatcher.subscribe(subscribeFunction)
        dispatcher.broadcast("event")

        assertEquals("event", passedValue)
    }

The whole thing with (String) ->Unit didn't seem necessary. It seems like the type should be inferred. Do I even need subscribeFunction? I was pretty sure I'd seen something in the Big Nerd Ranch Kotlin book about a simple syntax for functions. I started clicking through it. After a few trips around the same chapters I found a section title "Shorthand syntax"! That's it! that's what I'm looking for!

Ecstatic, I flipped back to my editor and updated my code to look like so:

    @Test
    fun `when a lambda is passed to subscribe it can receive a broadcast`() {
        val dispatcher = Dispatcher()

        var passedValue = ""

        dispatcher.subscribe { event -> passedValue = event }
        dispatcher.broadcast("event")

        assertEquals("event", passedValue)
    }

Notice how I was able to get rid of the function's type signature (String) -> Unit and remove the variable subscribeFunction. All I need is the simple block { event -> passedValue = event }.

What a day my friends! What. A. Day.

What nifty uses have you come up with for the shorthand syntax for functions? Let me know by dropping me a line on the contact page.