> From: "Brian Goetz" <brian.go...@oracle.com> > To: "Remi Forax" <fo...@univ-mlv.fr> > Cc: "amber-spec-experts" <amber-spec-experts@openjdk.java.net> > Sent: Thursday, May 19, 2022 3:05:07 PM > Subject: Re: Pattern matching: next steps after JEP 405
>> When you have a type pattern X in a middle of a pattern *and* you have >> conversions, then there is an ambiguity, >> does instanceof Box(X x) means >> Box(var v) && v instanceof X x >> or >> Box(var v) && X x = (X) v; > This is not an ambiguity in the language, it is confusion on the part of the > reader :) > In any case, I'm not following your argument here. If you have both a type pattern and allow conversions, you have Box(X) is equivalent to Box(var v) && v instanceof Y y && X x = (X) y How do you find Y ? And yes, the bar is not only that Y has to be unique for the compiler, it has also to be obvious for the human reader too. Rémi
