Updated State of the Lambda

[Peter Levart]

On 10/18/10, Rémi Forax wrote:
> > Why could the compiler not recognise the use of (lambda) this and
> > provide it as an argument as you suggest?
> 
> Because it's not the same object. If you mutate a method handle, you
> create a new one
> due to its immutable nature.
> 

Ah, now I understand your concern. You would like lambda expressions to be convertible to method handles (java.dyn.MethodHandle) as well as to SAM types. 

> MethodHandle mh = #{ MethodHandle anotherMH -> mh == anotherMH };
> mh.invokeGeneric(mh) // false
> 
> because, it's translated to:
> 
> static boolean lambda$1(MethodHandle mh, MethodHandle anotherMH) {
> return mh == anotherMH;
> }
> 
> MethodHandle mh = #lambda$1;
> mh = mh.bindTo(mh);
> 
> mh.invokeGeneric(mh); // return mh == #lambda$1 => false

Why couldn't compiler translate it to:

static boolean lambda$1(MethodHandle anotherMH) {
  return #lambda$1 == anotherMH;
}
 
MethodHandle mh = #lambda$1;

mh.invokeGeneric(mh); // return #lambda$1 == #lambda$1 => true?


Peter