Accessing a function bound to a var in clojure

Question

So if I understand this correctly, when I write:

(defn foo [x] (+ (* (- x 3) 2) (- x 3)))

foo gets bound to:

(fn [x] (+ (* (- x 3) 2) (- x 3)))

How do I access the function from foo? My intention is to change something in the function and return a new function.

Answer 1

If you want to use the function value stored in the Var foo, just write foo, for example:

(def foo2 (comp - foo))
(foo 4) ;;=> 3
(foo2 4) ;;=> -3

There is no special deref notation for Vars: just use their name and they get resolved to their bound value. Functions are not something you change, but you can build functions out of other ones, like above.