Hello Kotlin experts, I am trying to obtain the re...
# announcementsv
visakha
04/26/2018, 6:24 AMHello Kotlin experts, I am trying to obtain the result from a
flatMap -> comparatori
ilya.gorbunov
04/26/2018, 12:37 PMSo, what is your question? Do you have some problem with that code? Or do you want to know, how to make it more idiomatic in Kotlin?
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visakha
04/26/2018, 1:14 PM@ilya.gorbunov I want to have this side effect of updating the reason4Pick attribute, so I can run the jUnit assert
visakha
04/26/2018, 1:15 PMso far, I could not figure the reason, or what rule was winning
i
ilya.gorbunov
04/26/2018, 1:15 PMIf
maxRatingreasonForPickv
visakha
04/26/2018, 1:18 PMyes it should be called maxRatingOrLowerMileage, that name would be more approp for that val, however, how could I know if maxRating or lowerMileage was the reason
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ilya.gorbunov
04/26/2018, 1:23 PMOh, you can check if there are several items with the same max rating. If there're more than one, then the decision was made based on mileage.
if (v1.count { it.rating == maxRating.rating } > 1)ilya.gorbunov
04/26/2018, 1:26 PMAlso I recommend to study standard library collection extensions and use them instead of stream operations.
For example: groupBy, maxBy/maxWith, compareBy, thenByDescending
http://kotlinlang.org/api/latest/jvm/stdlib/kotlin.collections/group-by.html
http://kotlinlang.org/api/latest/jvm/stdlib/kotlin.collections/max-by.html
http://kotlinlang.org/api/latest/jvm/stdlib/kotlin.collections/max-with.html
http://kotlinlang.org/api/latest/jvm/stdlib/kotlin.comparisons/compare-by.html
http://kotlinlang.org/api/latest/jvm/stdlib/kotlin.comparisons/then-by-descending.html
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visakha
04/26/2018, 1:29 PMThank you, I will check that, but since I have about 70% java projects and 30%Kotlin projects, I am trying to stick with Java 8 streams std lib, so the knowledge is transferable between.
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