typescript 邻9.ts

Posted 2021-05-20

class Observable {
  ...
  
  mergeMap(project: (value) => Observable) {
    return new Observable(observer => {
      return this.subscribe({
        next(outerValue) {
          project(outerValue).subscribe({
            next(innerValue) {
              observer.next(innerValue);
            }
          });
        },
        ...
      });
    });
  }

}