如何将同步函数调用转换为可观察的？

Question

Is there a standard way or creater in RxJS 6 lib which would convert a function invocation into an observable like this ?

const liftFun = fun => {
    try {
        return of(fun())
    } catch (err) {
        return throwError(err)
    }
}

Answer 1

To observable

 const liftFun=fun=>new Observable(obs=>{
        try {
            return obs.next(fun)
        } catch (err) {
            return obs.error(err)
        }
    })

Or you want to convert to operator function to be used in pipe chain

const liftFun = fun => mergeMap(fun=>({
    try {
        return of(fun())
    } catch (err) {
        return throwError(err)
    }
})