zipWithNext

fun CharSequence.zipWithNext(): List<Pair<Char, Char>>(source)

fun main() {
    val text = "hello"

    val pairs = text.zipWithNext()          // ["h" to "e", "e" to "l", "l" to "l", "l" to "o"]
    println(pairs)

    // Iterate over the pairs
    pairs.forEach { (first, second) ->
        println("$first -> $second")
    }
}