Observable.Create from Boo 的类型问题

发布于 2024-10-23 13:03:15 字数 513 浏览 9 评论 0原文

我正在尝试使用 Boo 的反应式扩展，但遇到了类型问题。这是基本示例：

def OnSubscribe(observer as IObservable[of string]) as callable:
    print "subscribing"

    def Dispose():
        print "disposing"

    return Dispose

observable = System.Linq.Observable.Create[of string](OnSubscribe)
observer = System.Linq.Observer.Create[of string]({x as string | print x})
observable.Subscribe(observer)

此处的 Subscribe 给出了 System.InvalidCastException：无法从源类型转换为目标类型。问题似乎在于我如何创建可观察的，但我一直在努力找出类型问题的根源。

有想法吗？

原文

I'm trying to use Reactive Extensions from Boo and am running into type problems. Here's the basic example:

def OnSubscribe(observer as IObservable[of string]) as callable:
    print "subscribing"

    def Dispose():
        print "disposing"

    return Dispose

observable = System.Linq.Observable.Create[of string](OnSubscribe)
observer = System.Linq.Observer.Create[of string]({x as string | print x})
observable.Subscribe(observer)

The Subscribe here gives a System.InvalidCastException: Cannot cast from source type to destination type. The issue appears to be with how I'm creating the observable, but I've struggled to see where the type problem arises from.

Ideas?

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夕色琉璃 2024-10-30 13:03:15

Observable.Create 采用 Func，但您的 OnSubscribe 接受 IObservable。

试试这个：

def OnSubscribe(observer as IObserver[of string]) as callable():
    print "subscribing"

    observer.OnNext("first and only value")
    observer.OnCompleted()

    def Dispose():
        print "disposing"

    return Dispose

observable = System.Linq.Observable.Create[of string](OnSubscribe)
observer = System.Linq.Observer.Create[of string]({x as string | print x})
observable.Subscribe(observer)

Observable.Create takes Func<IObserver,Action>, but your OnSubscribe accepts an IObservable.

Try this:

def OnSubscribe(observer as IObserver[of string]) as callable():
    print "subscribing"

    observer.OnNext("first and only value")
    observer.OnCompleted()

    def Dispose():
        print "disposing"

    return Dispose

observable = System.Linq.Observable.Create[of string](OnSubscribe)
observer = System.Linq.Observer.Create[of string]({x as string | print x})
observable.Subscribe(observer)

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