Get callers namespace in clojure

Question

I wrapped a logging library in Clojure; Let's call the namespace of this foo.logger. Now I have another namespace like bar.baz and from there I call the logger.

Is there some idiomatic/nice way, that I can determine the namespace of the callers namespace inside the logger? I don't want to set this as parameter for the logger ;-)

Answer 1

This is one of those rare cases where using a macro is a solid choice.

Making that a macro that prints the value of *ns will get the value of *ns* in the callers space because the macro will expand and run in that namespace.

(defmacro log [msg]
  `(printf "%s:%s\n" ~*ns* ~msg))

Try to be aware of "macro contagion" around this because anything that wants to extend this function will need to also be a macro, though I have been doing this for the last six years and it hasn't been a problem often.