[re-sent to amber-spec-experts instead of amber-dev] ----- Original Message ----- > From: "Brian Goetz" <brian.go...@oracle.com> > To: "Vikram Bakshi" <vab2...@gmail.com>, "amber-dev" > <amber-...@openjdk.java.net> > Sent: Samedi 25 Septembre 2021 17:28:11 > Subject: Re: Feedback on pattern matching (preview feature)
> The example you cite is a peek into a feature not yet implemented (its a > "and beyond" talk), so not only is there no "as patterns", but no > patterns yet for which "as patterns" would be sensible. > > When we have deconstruction patterns as per the example, you'll be able > to provide an optional binding: > > case Point(var x, var y): // don't care about the point > > case Point(var x, var y) p: // bind the point too > > which we believe will cover the need in a less "nailed on the side" way. In that case (pun intended), we may want to make the binding of the type pattern optional too. case Type: // type pattern with no binding case Type variable: // type pattern + binding This look like the dual of '_', instead of asking for a binding, make it optional. If we follow that rabbit hole, then we should be able to write case Point(var, var): Rémi > > On 9/25/2021 10:21 AM, Vikram Bakshi wrote: >> Hello, >> >> I was playing around with the new pattern matching and wondered about the >> current absence of "as-patterns". Are there any plans to bring them to Java >> in a future JEP? >> >> An example use case where they could be useful is demonstrated in the >> recent video from the official Java YouTube channel ( >> https://youtu.be/UlFFKkq6fyU) at 17:22. >> >> >> Regards, > > Vikram
