~~ is now chaining where it can be; it obviously makes little sense to chain something on both sides that is not a normal data value. So if you include a regex or a closure, it must be the final test. Also, in order to get $a ~~ $b ~~ $c to work, we cannot topicalize $b.
Fix in f457007181bb6e2dcb6aefe857f36d648ae38401 Tests in cf080c9f958bc3153dde217b107c65ddb617afe6