> From: "Brian Goetz" <brian.go...@oracle.com> > To: "Remi Forax" <fo...@univ-mlv.fr>, "Jim Laskey" <james.las...@oracle.com> > Cc: "amber-spec-experts" <amber-spec-experts@openjdk.java.net> > Sent: Thursday, March 3, 2022 7:29:21 PM > Subject: Re: [External] : Re: Proposal: java.lang.runtime.Carrier
>> For the pattern matching, >> we also need a 'with' method, that return a method handle that takes a >> carrier >> and a value and return a new carrier with the component value updated. > It is not clear to me why we "need" this. Rather than jumping right to "Here > is > the solution", can you instead try to shine some light on the problem you are > trying to solve? When you have nested record patterns, each of these patterns contribute to introduce bindings, so when executing the code of the pattern matching, the code that match a nested pattern needs to add values into the carrier object. Given that the Carrier API is non mutable, we need the equivalent of a functional setter, a wither. Rémi
