scala-functions.scala

object looksLikeAFunction{
  def apply(s:String):Int=1
}
object nowAFunction extends Function[String,Int]{
  def apply(s:String):Int=1
}

object TestMethods {
   implicit def  functionToAnother(f:Function[String,Int]):Function[Int,String] = 
                                                          (i:Int)=> f(i.toString()).toString()

  def someMethod(s:String):Int=1
  def someFunction:Function[String,Int]= s=>1
  def main(args:Array[String]){
        // Actually will compile if you pass it a String:
        println("someMethod: " + someMethod("1"))

        // Objects don't have to implement the Function trait:
        println("looksLikeAFunction: " + looksLikeAFunction("1"))

        // an object that is a function
        println("nowAFunction: " + nowAFunction(1))

        //a function
        println("someFunction: " + someFunction(1))
  }
}

Actually the point was to show the difference between 1,2 and 3,4
3,4 the implicit conversion applies since they have the desired types. This is not true for 1 and 2