Using Type Functions gives error for html5 build

Help
#1

I am trying to make this work:

package myapp;

//import haxe.Constraints.Function;
import flash.display.*;
import openfl.utils.Function;

class Main extends Sprite {


	public var a: Function;


	public function new() {

		super();


		a = new Function();

		a = function (val: Float): String {
			return "abc";
		};
		a(123);

	}
}

I get this error:

haxe.Function does not have a constructor

#2

There’s no reason to use Function here to begin with, you should use a proper function type instead. In this case where the function takes a Float and returns a String, it would look like this:

public var a: Float->String;
#3

Is their any way I can create an instance of “a” as it is a function ?

public var a:Float -> String

The reason I want to store the instance of function instead of assigning it as a value, is so that I can assign a new function to addEventListener. Like this:

package myapp;
 
//import haxe.Constraints.Function;
import flash.display.*;
import openfl.events.MouseEvent;
import openfl.utils.Function; 
  
class Main extends Sprite 
{
 	public var oldListener:MouseEvent->String   ;


public function new() {
	
super();
 

      //a = new Float->String();
        
        oldListener = function(e:MouseEvent): String 
                {
                    trace("abc");
					return "";
                };
				
        		
          
		stage.addEventListener( MouseEvent.CLICK, oldListener);
		
				
		var newListener:MouseEvent->String = function(e:MouseEvent): String 
                {
                    trace("def");
					return "";
                };
				
		 
		  changeListener(newListener) ;
 }
 
 function changeListener(param:MouseEvent->String ) 
 {
	 oldListener = param ;
 }
 
}

If you see, in the above case I will always get “abc” , as the listener function is assigned ( by value ) instead of an instance being shared ( by reference).

#4

you can try to stage.removeEventListener(MouseEvent.CLICK, oldListener) (if oldListener is set) then stage.addEventListener(MouseEvent.CLICK, newListener).

#5

Yes, but that is 2 more lines every time I need to change the listener. Also I need to know what is the way to do the same in Haxe. As I use it in AS3 without any problem. And what and how type “function” is used?