I have a `List<Pair<A,B?>>` Is there a...
# announcementsp
pavel
10/31/2019, 9:29 PMI have a
List<Pair<A,B?>>second==nullList<Pair<A,B>>k
karelpeeters
10/31/2019, 9:35 PMNot, you'll have to cast it.
b
bezrukov
10/31/2019, 9:35 PMYou can try mapNotNull - convert
Pair<A,B?>Pair<A,B>?k
karelpeeters
10/31/2019, 9:35 PMHow to express this is still an open question for contracts: https://github.com/Kotlin/KEEP/blob/master/proposals/kotlin-contracts.md#open-questions
p
pavel
10/31/2019, 9:37 PMThanks
b
bezrukov
10/31/2019, 9:37 PMSomething like
list.mapNotNull{if (it.second != null) it.first to it.second else null}p
pavel
10/31/2019, 9:41 PMnope, that didn’t work. The inferred type is still
List<Pair<A,B?>>k
karelpeeters
10/31/2019, 9:45 PMYou need an intermediate variable, something like
Copy code
list.mapNotNull {
val second = it.second
if (second == null) null else it.first to second
}b
bezrukov
10/31/2019, 9:48 PMlist.mapNotNull { (first, second) -> second?.let { first to second } }➕ 1
p
pavel
10/31/2019, 9:54 PMooo, nice
pavel
10/31/2019, 9:54 PMthank you
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