I would like to discuss the MethodHandles factory

[John Rose]

On May 27, 2009, at 9:16 PM, Charles Oliver Nutter wrote:

> we *must* give the keys to the castle to language
> developers, by opening up the very guts of the JVM's optimizing
> pipeline

I agree that static type checking for method handles would be very  
useful, but the language design work is difficult and subtle.

As method handles become useful, they may tip the scales in favor of  
adopting more (or all) of Neal Gafter's closures proposals.

If Neal's design is adapted so that that various function-type  
interfaces are not guaranteed to reify a closure's type at runtime, I  
think we could fit method handles under closures.  I'm not sure how  
much of a distortion that would be; there will be some.

So this:
	x instanceof {int => String}
would translate to something like
	x instanceof MethodHandle
	&& ((MethodHandle)x).type()
		.isAssignableTo(MethodType.make(String.class, int.class))

And {int => String}.class would either be illegal or produce an  
interface with lots of special magic treatment.

Or maybe {int => String}.class would be a MethodType.  As I said, some  
distortion is likely.

-- John