Event-listener setters should have signature onClick[U](f: View ⇒ U) instead of onClick(f: View ⇒ Unit)

[nadavwr]

I find myself adding superfluous unit literals at the end of event handlers.

Compare the following two examples:

Using Scaloid's onClick:

button.onClick {
  dir.mkdir() // ← returns Boolean, not Unit
  () // ← boilerplate required to conform with Unit result type
}

Compared to trivial usage of Scala's foreach:

dirs.foreach { dir ⇒
  dir.mkdir() // ← returns Boolean, which is discarded
}

The latter is preferable.

This is really easy to implement, as seen from foreach's definition:

def foreach[U](f: A ⇒ U): Unit

Where U clearly stands for Unit, but is actually more liberal.

Applying this to (e.g.) 'onClick', the signature would look like so:

def onClick[U](f: View ⇒ U)

[pocorall]

Good suggestion, thanks!
I am working on this issue.