I have a function which makes an external call and returns nothing, but I need to do something based...

# functional

[João Gabriel Zó]

I have a function which makes an external call and returns nothing, but I need to do something based on if it succeeded or not.
Is returning Result<Unit> the best thing to do here or is there anything else in the std library?

[wakingrufus]

could do

sealed class ExternalCallResult {
object Success : ExternalCallResult
object Failure : ExternalCallResult
}

[wakingrufus]

if you dont need the value and exceptions parts of Result

[andylamax]

If it returns nothing, you can also go with Result<Nothing?>

[simon.vergauwen]

I would personally go for Result<Unit> where Unit represents a side-effect without any meaningful result, so "succes" and the Result.failure holds the failure.

The only value that can be given to Nothing? is null since Nothing has not value, so you can only fill in null. So it's isomorphic to Unit.

[simon.vergauwen]

Arrow has typealias Null = Nothing? since Nothing? is the generic way to represent only null can be a valid value.