Sean, To follow up on what Brian said, you can also do the same thing on a single line with named captures https://docs.raku.org/language/regexes#Named_captures
(This often isn't as good as Brian's method, since breaking things up as Brian showed often helps readability. But it can be a good option if you're trying to keep something concise.) Using that syntax, your example goes from S:g[(x)|(y)] = $0 ?? x-replacement !! y-replacement to S:g[$<x>=[x]|y] = $<x> ?? x-replacement !! y-replacement which is pretty similar. I hope that helps! Best, Daniel -- Daniel Sockwell / codesections Website: www.codesections.com