infer-recursive.scala

scala> def drop[T](xs: List[T], n: Int) = if (xs.isEmpty || n <= 0) xs else drop(xs.tail, n - 1)
drop: [T](xs: List[T], n: Int)List[T]

scala> drop(List(1,2,3,4,5), 3)
res0: List[Int] = List(4, 5)

What happens to the inferred type of h if you define it as "def h() = if (true) h() else 123"?

scala> def h() = if (true) h() else 123
h: ()Int

Or to the limit:

scala> def h() = if (true) h() else h()
h: ()Nothing

scala> def rand = scala.util.Random.nextBoolean
rand: Boolean

scala> def f[A <: String, B <: String](x: A, y: B) = (
     |   if (rand) f(x, y)
     |   else if (rand) f(y, y)
     |   else x -> y
     | )
f: [A <: String, B <: String](x: A, y: B)(String, B)

So... who do I have to kill to get this into scala/master ?

I'm no longer in the scalac game. If someone wants to try to dredge it from my inevitable fork they will be welcome.

For this to happen you should upload your branches to github.

I'm aware of the prerequisite.