Hi Jim, ----- Mail original ----- > De: "Jim Laskey" <james.las...@oracle.com> > À: "core-libs-dev" <core-libs-dev@openjdk.java.net> > Cc: "Remi Forax" <fo...@univ-mlv.fr>, "Brian Goetz" <brian.go...@oracle.com>, > "Paul Sandoz" <paul.san...@oracle.com> > Envoyé: Vendredi 18 Mai 2018 20:48:35 > Objet: Re: RFR: CSR - JDK-8203428 Predicate::not
> I’m going to pull a Brian here and say, “not” should stand on its own merits. > The “of” discussion should diverge to it’s own RFE. :-) i agree, sorry to not have been crystal clear, it my head it was clear that that everything i've written was a way to avoid Predicate.of() and not something should stop the inclusion of Predicate.not, stackoverflow has already decided that Predicate.not was the right method [1]. Rémi [1] https://stackoverflow.com/questions/21488056/how-to-negate-a-method-reference-predicate > >> On May 18, 2018, at 3:41 PM, Remi Forax <fo...@univ-mlv.fr> wrote: >> >> ----- Mail original ----- >>> De: "Brian Goetz" <brian.go...@oracle.com> >>> À: "Paul Sandoz" <paul.san...@oracle.com>, "Jim Laskey" >>> <james.las...@oracle.com> >>> Cc: "core-libs-dev" <core-libs-dev@openjdk.java.net> >>> Envoyé: Vendredi 18 Mai 2018 20:08:42 >>> Objet: Re: RFR: CSR - JDK-8203428 Predicate::not >> >>> We did discover that default methods on FIs combined with subtyping of >>> FIs caused trouble. But static methods are fine. >>> >>> If we're going to do Xxx.of(...), we should do it uniformly across FIs, >>> not just for Predicate. I think this is a reasonable move, but we don't >>> have to do it right now. (The benefit is mostly that we pick up >>> inference of the type parameters.) >> >> we can also: >> - allow diamond syntax on cast >> - teach the inference that when a method is called on a method reference, >> it's >> maybe an automorphism, so the target type could be back-propagated as the >> target type of the method reference and then the method can be checked from >> left to right (it's maybe too magical but it seems to work great in >> practice) >> - when inference fails, pick the closest interface from java.util.function >> to >> the function type, i.e we abandon the idea to introduce real function type >> in >> the future for more convenience. >> >> regards, >> Rémi >> >>> >>> On 5/18/2018 1:54 PM, Paul Sandoz wrote: >>>> >>>>> On May 18, 2018, at 9:35 AM, Jim Laskey <james.las...@oracle.com> wrote: >>>>> >>>>> Introduce a new static method Predicate::not which will allow developers >>>>> to >>>>> negate predicate lambdas trivially. >>>>> >>>>> >>>>> csr: https://bugs.openjdk.java.net/browse/JDK-8203428 >>>> >>>> +1 thank you for taking action on this. >>>> >>>> Predicate not captures the majority use case very concisely and clearly. >>>> >>>> I am reluctant to go for an alternative or companion Predicate.of, and >>>> would >>>> need to think carefully about that idiom and it's application on other >>>> functional interfaces (perhaps we went too far adding such default methods >>>> to >>>> these interfaces…). >>>> > >>> Paul.
