NewSpeak at JavaZone

Best presentation at JavaZone so far was Gilad Bracha’s talk about NewSpeak. I might be one of a few number of people who thinks this of course, since for most Java developers NewSpeak is quite out there. For language geeks though, it’s a gold mine of interesting ideas, realized in a very nice way.

So, what is it? Well, NewSpeak is a new language created by Gilad Bracha (who used to work as Language Theologist for Sun – meaning he was one of the theory geeks for Java). NewSpeak actually doesn’t have anything to do with Java. It doesn’t run on the JVM. It’s not written in Java. It doesn’t look like Java. In fact, it’s closest relatives are Smalltalk, Self and Beta. It runs on top of Squeak, but there are plans to make it run outside too – probably targeting V8 for this.

If you were just to glance at the language, it looks a lot like Smalltalk. Gilad has based the syntax on Smalltalk, but have no problem with adding or removing things to make more code more readable, more accessible, and so on. But as it turns out, many choices in Smalltalk happened to be there for a reason, and having them gives lots of benefits.

So what are the nice features of it (except that it’s based on Smalltalk?) Well, these are the things that I took notice of:

  • No global state. Really. No global state at all. So how does it work? How do you create a library for example? Well, a library is actually a method. That method will be called with something called a platform. This platform gives you access to common resources, but note that the platform is also an instance – there is no global state there. It also means that you can inject any kind of platform into a specific library. What really makes this powerful is that it allows security by capabilities. What it means is that since there is no global state, a library can’t get access to something unless you inject it into that library. Gilad uses the example of the File object. If a File class haven’t been injected into your library, you can’t actually use any files. Or if someone injects something that looks like a File object but only allows reading, the library can only read from files. Neat. Security just comes as a side effect of this design choice. And btw, dependency injection frameworks doesn’t exist in NewSpeak, since everything is injected in the language in the normal course of coding in it.
  • Scoped injected super classes. This one is a bit complicated to understand, but it’s really powerful. In fact, it looks a bit like categories. An example you say? Well, say a library has a Foo class, a Bar that extends Foo, and a Baz that extends Foo. Then a piece of code that uses this library have a Foo2 class that is a subclass of Foo. But the kicker is that in this piece of code Foo2 is called Foo. In NewSpeak this means that in reality, the super class of Bar and Baz will actually be Foo2 – but only inside of the piece of code where Foo has been reset to be Foo2. This is a side effect of using interfaces for everything in the system.
  • Mirror reflection. One of the problems with building a secure system that still have powerful reflection capabilities is that it’s quite hard to scope this functionality in a secure way. So NewSpeak solves this by doing the same kind of injection for reflection as it does for all other things. That means you can’t do reflection on a specific class by itself – you will have to get a Mirror object for that class. And the way you get a mirror is by calling a method on a Mirror class to get it. This means that to use mirrors you need to inject a mirror class. And since you can inject a ReadableMirror for example, this means you can handle security for reflection as you do everything else in NewSpeak. Really cool.

In conclusion, I really like what I see in NewSpeak. I look forward to when it’s released (it will be open sourced under Apache 2.0). It’s got some fresh new ideas about how to approach language design.

Read more at Gilad’s blog:, or at