Is there some API in stdlib to do that in a cleane...

# announcements

[Davide Giuseppe Farella]

Is there some API in stdlib to do that in a cleaner way?

@Suppress("UNCHECKED_CAST")
pairsListOfNullableApiParamAndNullableString
        .filterNot { it.first == null || it.second == null }
        .map { it as Pair<ApiParam, String> }

[elizarov]

Could be this:

pairsListOfNullableApiParamAndNullableString
        .mapNotNull { if (it.first != null && it.second != null) Pair(it.first, it.second) else null }

[Davide Giuseppe Farella]

Better but still not what I was hoping for 😋 I'll go with an extension, thank 🥂

[arekolek]

@elizarov should that smart cast work if pairsListOfNullableApiParamAndNullableString: List<Pair<ApiParam?, String?>>? I’d think that it should, since first and second are val, but somehow it doesn’t work https://pl.kotl.in/BJqjvQPXE

[arekolek]

for what it’s worth, @Davide Giuseppe Farella you can also do:

pairsListOfNullableApiParamAndNullableString
    .mapNotNull { (first, second) ->
        first?.let { second?.let { first to second } }
    }

[hmole]

inline fun <A, B, R> zip(a: A?, b: B?, func: (A, B) -> R): R? =
  if (a != null && b != null)
    func(a, b) else null

val list: List<Pair<String?, String?>> = emptyList()
val result: List<Pair<String, String>> = list.mapNotNull { (first, second) -> zip(first, second, ::Pair) }

[Davide Giuseppe Farella]

Yep, thanks for the hints, I was just wondering if there was something on the stdlib 🥂