asynchronous - 与 future 一起使用

Question

我想用dartz功能风格，并做这样的事情:

Either<Failure, Response> result = await remoteDataSource.request() // Future<Response> request();
    .then((response) => Right(response))
    .catchError((failure) => Left(failure));

但似乎我不能这样做:

error: A value of type 'Right< dynamic, Response>' can't be assigned to a variable of type 'Either< Failure, Response>'.

那么，我该如何使用 Either与 Future这边走？

Answer 1

都是关于<generics> .

.then((response) => Right(response)) // this is of type Right<dynamic,User>

你必须给编译器所有正确的信息:

.then((response) => Right<Failure, Response>(response))

// or

.then((response) => right(response)) // a helper function which returns an Either