arrow-core-data / arrow.core / kotlin.collections.Iterable / leftPadZip

leftPadZip

inline fun <A, B, C> Iterable<A>.leftPadZip(other: Iterable<B>, fab: (A?, B) -> C): List<C>

Returns a List containing the result of applying some transformation (A?, B) -> C on a zip, excluding all cases where the right value is null.

Example:

import arrow.core.*

//sampleStart
val left = listOf(1, 2).leftPadZip(listOf("a")) { l, r -> l to r }      // Result: [Pair(1, "a")]
val right = listOf(1).leftPadZip(listOf("a", "b")) { l, r -> l to r }   // Result: [Pair(1, "a"), Pair(null, "b")]
val both = listOf(1, 2).leftPadZip(listOf("a", "b")) { l, r -> l to r } // Result: [Pair(1, "a"), Pair(2, "b")]
//sampleEnd

fun main() {
  println("left = $left")
  println("right = $right")
  println("both = $both")
}

fun <A, B> Iterable<A>.leftPadZip(other: Iterable<B>): List<Pair<A?, B>>

Returns a ListPairA?,B containing the zipped values of the two lists with null for padding on the left.

Example:

import arrow.core.*

//sampleStart
val padRight = listOf(1, 2).leftPadZip(listOf("a"))        // Result: [Pair(1, "a")]
val padLeft = listOf(1).leftPadZip(listOf("a", "b"))       // Result: [Pair(1, "a"), Pair(null, "b")]
val noPadding = listOf(1, 2).leftPadZip(listOf("a", "b"))  // Result: [Pair(1, "a"), Pair(2, "b")]
//sampleEnd

fun main() {
  println("left = $left")
  println("right = $right")
  println("both = $both")
}