Making obs from stuff

gistfile1.cs

public class Examples {
    public void Foo() {
        // these vars are all IObservable<string>
        var src1 = Obs.Unit("one");

        var src2 = Obs.Create(
            new[] { "one", "two", "three" });

        var src3 = Obs.Create<string>(write => {
            write("one");
            write("two");
            write("three");
        });

        var src4 = Obs.Create(Bar());
    }

    IEnumerable<string> Bar() {
        yield return "one";
        yield return "two";
        yield return "three";
    }
}

public static class Obs {

    public static IObservable<T> Create<T>(IEnumerable<T> enumerable) {
        return new SyncObservable<T>(next => {
            foreach (var item in enumerable) { next(item); }
        });
    }

    public static IObservable<T> Create<T>(Action<Action<T>> produce) {
        return new SyncObservable<T>(produce);
    }

    public static IObservable<T> Unit<T>(T value) {
        return new SyncObservable<T>(next => next(value));
    }

    class SyncObservable<T> : IObservable<T> {
        private readonly Action<Action<T>> _produce;

        public SyncObservable(Action<Action<T>> produce) {
            _produce = produce;
        }

        public IDisposable Subscribe(IObserver<T> observer) {
            try {
                _produce(observer.OnNext);
                observer.OnCompleted();
            }
            catch (Exception ex) {
                observer.OnError(ex);
            }
            return new Disposable();
        }
    }

    class Disposable : IDisposable {
        private readonly Action _dispose;
        public Disposable() : this(() => { }) { }
        public Disposable(Action dispose) { _dispose = dispose; }
        public void Dispose() { _dispose(); }
    }
}