Extended method reference - A proposal

[Brian Goetz]

People requested things like this during the design of lambda.  You've 
got two features mushed together here:

  - Parameterization of method references with values;
  - Scala-style "wunderbar" to turn expressions with holes into lambdas

Both have been proposed individually, but neither is all that attractive 
on their own, and don't benefit from combination.

The first is a sort of "I love method references so much, I want to turn 
things that aren't really method references into method references."  
The result is something you won't love as much. Method references are 
nice because they are _symbolic_; a parameterized method reference is not.

The second is not intrinsically terrible, but is not very compelling.  
It trades away readability for a little extra concision.  Simple uses 
like `_ < 10` are not all that bad, but when extended to multiple 
parameters, you get things like `_ < _`, which are neither that 
readable, *nor* are they good symbols for the `<` function!  (Also, try 
inverting the order; you have to fall off the "cliff" back to `(x, y) -> 
y < x`.)  But, "not all that bad in the simple cases" is not a raving 
endorsement for a language feature.



On 5/17/2022 6:49 AM, Mahdi Mohammadi wrote:
> Hi,
>
> I have a proposal for the Java language to extend the way we use method
> references.
>
> Basically, instead of writing something like "*x -> obj.process(x,5)*" this
> should be simplified to "*obj::process(_,5)*". I believe this will simplify
> code, make it more concise and promote writing functional code.
>
> I'm looking for feedback from the community and also need help to make this
> a JEP. Here<https://cr.openjdk.java.net/~mr/jep/jep-2.0-02.html>  it
> mentions that I need help from an author, committer or reviewer to be able
> to do this.
>
> Thanks,
> Mahdi