Nice!

This language called Nice is one of the few new languages I've seen recently that really looks like next step on from Java. It adds a lot of expressive, functional capabilities that I've wanted for a while, while not gratuitously inventing its own alien syntax.

One of the really neat things are multi-methods, which might sound dull, but actually address a real problem I've had in Java for a while: how to implement extensible "utility" methods that aren't logically part of a class. For exanple in Java you might do this (taken from this tutorial wiki):

package my.package;



import geometry.*;



class Tools

{

  static boolean overlap(Shape s1, Shape s2)

  {

    if (s1 instanceof Rectangle && s2 instanceof Rectangle)

    {

       ...

       // return the result in this case

    }

    throw new Error("Case not supported: " + s1.getClass() + " and " + s2,getClass());

  }

}

But in Nice you can do this:

package my.package;



import geometry;



boolean overlap(Shape s1, Shape s2);



overlap(Rectangle s1, Rectangle s2)

{

  // Here s1 and s2 are both rectangles. We don't need to use instanceof or cast.

  ...

  // return the result

}

Which is far neater and extensible: you can add new sorts of Shape and new versions of overlap (), which wouldn't be possible in the Java version.