Having done a lot of experimentation with Undertow's predicate language, I often times find my self with a text file full of predicates/handlers that is being parsed by my server and I want to bypass or remove a rule for testing.  Add a method to "comment" out a line.  Suggestions:

run-me() -> all-day-long()
# skip-me() -> for-now()

or

run-me() -> all-day-long()
// skip-me() -> for-now()

The implementation would simply require the parser to ignore any lines starting with the comment character.  Ensure the comment character can never be part of the start of an actual predicate or handler name.  (Note, even though I put a space above after the comment character(s), I would not want it to be required)

Mutli-line comments might be nice, but are more complicated so I'm fine with just implementing a single-line comment char.