Clojure keyword arguments

Question

In Common Lisp you can do this:

(defun foo (bar &key baz quux)
  (list bar baz quux))

(foo 1 :quux 3 :baz 2) ; => (1 2 3)

Clojure doesn't have keyword arguments. One alternative is this:

(defn foo [bar {:keys [baz quux]}] 
  (list bar baz quux))

(foo 1 {:quux 3 :baz 2}) ; => (1 2 3)

That's too many nested brackets to have to type and read all the time. It also requires an explicit hash-map to be passed in as an argument rather than a flat list.

What's the most idiomatic Clojure equivalent of keyword arguments that doesn't look someone set off a punctuation bomb?

Answer 1

To update this answer for Clojure 1.2 there is now full keyword arg support with defaults provided by the map forms of destructuring binding:

user> (defn foo [bar &{ :keys [baz quux] 
                        :or {baz "baz_default" quux "quux_default"}}]
         (list bar baz quux))
#'user/foo

user> (foo 1 :quux 3)
(1 "baz_default" 3)