<Swing Dev> Swing and imageio-related types that are candidates to be FunctionalInterfaces in JDK 8

[Brian Goetz]

> Probably the question is not related but why this annotation is named as
> @FunctionalInterface? Why it wasn't named as @Functional? Or in the
> future we could get something like @FunctionalClass?

Because this annotation goes into java.lang and the probability of 
collision with an existing type named Functional is extremely high, 
wherease with FunctionalInterface is much lower.  We like our users and 
we don't want to break their code for no good reason.

Functional is not only an english word, but it is also a term from 
mathematics (http://en.wikipedia.org/wiki/Functional_analysis). 
Guaranteed that it collides with something.