Question

The following Java code sets up a Guice binding. It uses an anonymous subclass of AbstractModule that provides an implementation of configure to set the bindings, and anonymous subclasses of TypeLiteral to create a binding of Map to HashMap for specific type parameters (as described here).

injector = Guice.createInjector(new AbstractModule() {
    @Override protected void configure() {
        bind(new TypeLiteral<Map<String, Event>>() {})
            .to(new TypeLiteral<HashMap<String, Event>>() {});
    }
});

How could I write this in Xtend?

As far as I can see, Xtend doesn’t support implementing anonymous classes or nested classes (they aren’t mentioned in the doc and I haven’t been able to guess a working syntax). So I would have to define my AbstractModule and each of my TypeLiteral implementations in separate Xtend files… not very terse. Am I missing an Xtend or a Guice trick to make this work well?

Answer 1

You could use a closure to implement the module interface:

injector = Guice.createInjector [
bind(typeof(SomeType)).to(typeof(AnImplementation))
]

However, this will not solve the problem for the type literals. You’d have to use Java for that one, but I think it will not hurt.