I'm working on updating the Caddyfile lexer, to fix bugs and support new syntax features we've implemented in the past couple years.

We've added heredocs support https://caddyserver.com/docs/caddyfile/concepts#heredocs. I'm trying to figure out how to implement this in the lexer.

How do I store the heredoc marker (the part after <<), push into a "heredoc" state, and then pop the stack once that same string is found again? Is there somekind of storage mechanism in the state?

I see that Raku uses a custom mutator func. Is that my only option? Looks complicated.

I also noticed that since last time I contributed, most of the lexers got translated to XML. Is this something we should aim to do (tbh, ew 😬 looks like much worse UX to develop than the Go DSL) or is it fine for me to keep using Go?