Broken signal implementation...

SimpleSignal.swift

class SimpleSignal<E> {
    private let _v: Variable<E>
    var value: E { return _v.value }
    private let _disposeBag = DisposeBag()
    
    init(initialValue: E, subsequentValues: Observable<E>) {
        _v = Variable(initialValue)
        subsequentValues.bindTo(self._v).addDisposableTo(_disposeBag)
    }
    
    func map<R>(selector: E -> R) -> SimpleSignal<R> {
        return SimpleSignal<R>(initialValue: selector(value), subsequentValues: _v.asObservable().skip(1).map(selector))
    }
}