State
case class State(var visited: Set[Effect], path: Vector[Tree], thisClass: ClassSymbol, fieldsInited: Set[Symbol], parentsInited: Set[ClassSymbol], safePromoted: Set[Potential], env: Env)
The checking state
Why visited is a set of effects instead of Symbol? Think the following program:
class C(x: Int, a: A @cold) {
val n = if (x > 0) new C(x - 1, a).m() else 0
val b: Int = this.m()
def m(): Int = b
}