Long chains of collection operations will have a performance penalty due to a new list being created for each call. Consider using sequences instead. Read more about this in the https://kotlinlang.org/docs/sequences.html

Noncompliant Code

listOf(1, 2, 3, 4).map { it*2 }.filter { it < 4 }.map { it*it }

Compliant Code

listOf(1, 2, 3, 4).asSequence().map { it*2 }.filter { it < 4 }.map { it*it }.toList()
listOf(1, 2, 3, 4).map { it*2 }

Options

• threshold (default: 3)

  the number of chained collection operations required to trigger rule