SAMs and lambdas

[eparejatobes]

See

• http://www.scala-lang.org/files/archive/spec/2.12/06-expressions.html#sam-conversion
• http://www.scala-lang.org/news/2.12.0/#lambda-syntax-for-sam-types
• http://www.scala-lang.org/news/2.12.0/#java-8-style-bytecode-for-lambdas

[eparejatobes]

It looks like we could have something like

private[stuff] final class Function[X, Y] {

  def apply(a: X): Y
}

and we would not need any λ { x => ... }; we can directly assign a function literal

def id[X]: X -> X =
  x => x

[eparejatobes]

Looks to be working. Nice! I'll submit a PR later.