CODEWITHSUNDEEP
scala
messy
messy

Reputation: 915

Simplify method: Merge two Options to one result

Can this be simplified? The return value should be Option[State].

updateStateOne(state, "SomeData") match {
    case Some(updatedState) => Some(updateStateTwo(updatedState, "SomeOtherData").getOrElse(updatedState))
    case None               => updateStateTwo(state, "SomeOtherData")
}

I wonder if it's possible without the match ... case?

Upvotes: 2

Views: 63

Answers (3)

Assen Kolov
Assen Kolov

Reputation: 4403

def update[S](f: (S, String) => Option[S]): (S, String) => S =
     (state, data) => f((state, data)).getOrElse(state)

val s1 = update(updateStateOne)(state, "SomeData")
val s2 = update(updateStateTwo)(s1, "SomeOtherData")

Upvotes: 1

mdm
mdm

Reputation: 3988

You could use fold as mentioned in other answers, or orElse:

updateStateOne(state, "SomeData").orElse(Some(state)).map(updateStateTwo(_,"SomeOtherData"))

Or map and getOrElse (which is completely equivalent to fold):

updateStateOne(state, "SomeData").map(s => updateStateTwo(s, "SomeOtherData")).getOrElse(updateStateTwo(state, "SomeOtherData"))

At the end of the day, it depends on your style preferences and on what your team finds more readable.

Upvotes: 2

jwvh
jwvh

Reputation: 51271

It's a little hard to tell, but I think this is what you want:

updateStateOne(state, "SomeData").fold(updateStateTwo(state, "SomeOtherData")
                                      )(s => updateStateTwo(s, "SomeOtherData"))

Upvotes: 2

Related Questions