Exponential type checking

Bar.java

class Tuple<T, R> {
}

class Bar<T> {
    public Bar<Tuple<T, T>> d() {
        return null;
    }

    public void bar() {
        Bar<Integer> x = d().d().d().d().d().d().d().d().d().d().d().d().d().d().d().d().d().d().d().d().d().d().d().d().d().d().d().d().d().d().d().d().d().d().d().d().d().d().d().d();
    }
}

doubling_method.scala

class Bar[T] {
  def d(): Bar[(T, T)] = null

  def bar() {
    val x: Bar[Integer] = d().d().d().d().d().d().d().d().d().d().d().d().d().d().d().d().d().d().d().d().d().d().d().d().d().d().d().d().d().d().d().d().d().d().d().d().d().d().d().d()
  }
}

Foo.java

class Foo<T, R> {
    public <T> Foo<T, T> d(T t) {
        return null;
    }

    public void foo() {
        Foo<Integer, Integer> foo = d(d(d(d(d(d(d(d(d(dd(d(d(d(d(d(d(d(d(d(d(d(d(d(d(d(d(d(d(d(1)))))))))))))))))))))))))))));
    }
}

tuple_inference.scala

// scalac -J-Xmx4G -J-server exp.scala

class Foo {
  val t0 = (0, 0)
  val t1 = (t0, t0)
  val t2 = (t1, t1)
  val t3 = (t2, t2)
  val t4 = (t3, t3)
  val t5 = (t4, t4)
  val t6 = (t5, t5)
  val t7 = (t6, t6)
  val t8 = (t7, t7)
  val t9 = (t8, t8)
  val t10 = (t9, t9)
  val t11 = (t10, t10)
  val t12 = (t11, t11)
  val t13 = (t12, t12)
  val t14 = (t13, t13)
  val t15 = (t14, t14)
  val t16 = (t15, t15)
  val t17 = (t16, t16)
  val t18 = (t17, t17)
  val t19 = (t18, t18)
  val t20 = (t19, t19)
  val t21 = (t20, t20)
  val t22 = (t21, t21)
  val t23 = (t22, t22)
  val t24 = (t23, t23)
  val t25: (Int, Int) = (t24, t24)
  // val t26 = (t25, t25)
  // val t27 = (t26, t26)
  // val t28 = (t27, t27)
  // val t29 = (t28, t28)
  // val t30 = (t29, t29)
  // val t31 = (t30, t30)
}