kotlin MutableList sort

fun MutableList<Int>.swap(index1: Int, index2: Int) {
val tmp = this[index1] // 'this' corresponds to the list
this[index1] = this[index2]
this[index2] = tmp
}

fun main(args: Array<String>) {

val l = mutableListOf(1, 2, 3,9,60,54,8,21)

l.forEachIndexed {index, value ->run{
l.forEachIndexed { index, value ->
run{

if(((index+1)<l.size) && (l[index+1]>=l[index])){
// println(""+l[index+1]+">"+""+l[index])
l.swap(index,index+1)
}

}
}
}}

println("--------------------")

for(t in l.indices){println(l[t])}

println("--------------------")
}