RI update: division of bridging responsibility between VM and compiler

Brian Goetz brian.goetz at oracle.com
Thu May 9 08:56:54 PDT 2013

> I more worry about existing third party libraries that uses already
> existing interfaces like List or Map
> because these libraries may need to be re-compiled.
> I agree that they need to be recompiled only in a corner case,
> the third party library need to extends an already existing interface
> and have a public method
> with a name and parameter types that make the method an override of a
> default method listed below,
> but this corner case will appear.

OK, but bear in mind that this is a problem we've had since Java 5, when 
the abomination that is bridges was deemed to be a good idea.  We're not 
creating new problems here, and the existing problems have not turned 
out to be big problems in practice.  (We've been in "recompile your 
code" mode since Java 5, but the number of times people have actually 
had to is quite small, small enough to make us all believe we're not 
actually in that mode.)

> By example, a comparator defined like this will cause trouble:
> public class FooComparator extends Comparator<Foo> {
>    public FooComparator reverseOrder() { ... }
> }
> this code must be be recompiled because javac need to insert a bridge.

Try it with the lambda compiler!  We guard against this case, and it 
works fine.  Decompile the code to find out how :)

More information about the lambda-spec-experts mailing list