higherOrderFunction.kt

package com.dav.vendator;
//Author: Dav Vendator
/*
Code for Kotlin: Higher Order Functions, Lambdas and Extension methods
posted at: https://streamofbytes.blogspot.com
 */

fun simpleFun() = println("Hello World")

fun returnFun(mul: Int): (arg: Int) -> Int{
    return fun (arg: Int) = arg * mul
}
//typealias is like typedef in C/C++
typealias  stringPredicate = (str: String) -> Boolean

//Filter list based on predicate
fun takeFun(pred: stringPredicate, list: ArrayList<String>): ArrayList<String>{
   return ArrayList(list.filter { pred(it) })
}

fun main(){
    simpleFun()
    val newFun = returnFun(23)
    
    println("${2} mutliplied by ${23} is ${newFun(2)}")

    val filteredList = takeFun({
         it.endsWith("php")
    }, arrayListOf("https://helloworld.aspx", "https://streamofbytes.php", "1234"))
    println("All the url's ending with *.php ${filteredList}")
}