Hi, I have an `either` block from which I want to ...

# functional

[Sourabh Rawat]

Hi, I have an either block from which I want to return a Left value without any bind calls. For example

either<Error, Response> {
 when(foo) {
  1 -> callFunReturningEither().bind()
  else -> Error("foo is in else") <-- How to return this Left value?
 }
}

I have tried Error("foo is in else").left().bind() but it gives Returning type parameter has been inferred to Nothing implicitly. Please specify type arguments explicitly to hide this warning. Nothing can produce an exception at runtime. which I think is expected.

[raulraja]

Hi @Sourabh Rawat, not sure if there is additional code in the mix but if you are not using bind there is no point of wrapping in an either block. It would be in this case just:

val result: Either<Error, Response> = 
  when(foo) {
    1 -> callFunReturningEither()
    else -> Either.Left(Error("foo is in else"))
   }

[simon.vergauwen]

when(foo) {
  1 -> callFunReturningEither()
  else -> Error("foo is in else").left()
 }

[simon.vergauwen]

That is not an error the compiler gave you there though, and the code will work as you expect when doing.

either<Error, Response> {
 when(foo) {
  1 -> callFunReturningEither()
  else -> Error("foo is in else").left().bind()
 }
}

[pakoito]

you have to bind the return of 1 -> I believe

[Sourabh Rawat]

Oh yea sorry, there was a typo in the original code. It does have bind call in 1 -> clause