class MyIterator {
  list: MyList<$0>;
  index: i64;

  fun next(self) -> $0 or nothing {
    if self.index < list.len() {
      let result = self.list[self.index];
      self.index += 1;
      result
    } else {
      nothing
    }
  }
}

class MyList {
  list: list<$0>;

  fun get_iterator(self) -> MyIterator {
    new MyIterator {
      list: self.list,
      index: 0,
    }
  }
}

fun test() -> f64 {
  // Type needs to be inferred as MyList<f64>
  let x = MyList { list: [1, 2, 3] };

  let sum = 0;
  for v in x { // Pick up the iterator methods
    sum = sum + v;
  }
  sum
}

// @ignore undesigned garbage, like all generics
// @no-errors