Reverse

Reverse takes any function and returns it with its parameter in the reverse order (in other languages, this function is known as flip). Let's look at the following code:

import arrow.syntax.function.partially3
import arrow.syntax.function.reverse

fun main(args: Array<String>) {
   val strong: (String, String, String) -> String = { body, id, style -> "<strong id=\"$id\" style=\"$style\">$body</strong>" }

   val redStrong: (String, String) -> String = strong.partially3("font: red") //Explicit

   println(redStrong("Red Sonja", "movie1"))

   println(redStrong.reverse()("movie2", "The Hunt for Red October"))

}

Our redStrong function is awkward to use, as we'll expect to have id first and then body, but, is easily fixable with the reverse extension function. The reverse function can be applied to functions from parameters 1 to 22.