How can I evaluate both of these in a single opera...

# codereview

[chansek]

How can I evaluate both of these in a single operator chain?

val adminOf = user.roles
    .filter { it.isAdmin() }
    .map { it.entityId to it.entity }
    .toMap()
val serviceProviderOf = user.roles
    .filter { it.isServiceProvider() }
    .map { it.entityId to it.entity }
    .toMap()

[Joffrey]

Are admins and service providers the only 2 options? Are they mutually exclusive? You might be able to use partition instead of filter if the answer is yes

[Matteo Mirk]

.map { it.entityId to it.entity }
    .toMap()

can be simplified to

.associate { it.entityId to it.entity }

[ephemient]

or

.associateBy(
    keySelector = { it.entityId },
    valueTransform = { it.entity }
)

which doesn't require building a Pair and whose lambdas could be replaced with bound references (e.g. User::entityId etc.), but that's not really the important part of the question…

[ephemient]

partition can work if they're exclusive (no user is in both) but if there's potential overlap, you're not gonna get something much clearer. you could update two mutable maps from a single for loop, whether that's better or not, depends…