anonymous function with arguments in unityscript

How do you do anonymous functions with arguments in unityscript.

I’m trying to translate this from CS.

webViewObject.Init((msg)=>{Debug.Log(string.Format("CallFromJS[{0}]", msg));});

I've tried this 

I get
Expression ‘self.webViewObject.Init’ cannot be assigned to.

I guess the type of webViewObject.Init is wrong. This works:

var foo = function(msg:String){Debug.Log("CallFromJS["+msg+"]");};

Or if you want to explicitly declare the type:

var foo : function(String) = function(msg:String){Debug.Log("CallFromJS["+msg+"]");};

Did you try this?
webViewObject.Init( function(msg:String) {Debug.Log(“CallFromJS[”+msg+“]”);} );