Macros for defining constants in Clojure

const-macros.clj

(defmacro defconst [const-name const-val]
  `(def
     ~(with-meta const-name
       (assoc (meta const-name) :const true)) 
     ~const-val))

(defmacro defconsts [bindings]
  `(do
     ~@(map (fn [[const-name const-val]]
               `(defconst ~const-name ~const-val))
          (partition 2 bindings))))

;;

; user=> (defconst pi 3.14)
; #'user/pi
; user=> (meta (var pi))
; {:ns #<Namespace user>, :name pi, :const true, :line 15, :file "NO_SOURCE_PATH"}
; user=> (time (dotimes [_ 1e10] (* pi pi)))
; "Elapsed time: 3025.789399 msecs"
; nil
; user=> (time (dotimes [_ 1e10] (* 3.14 3.14)))
; "Elapsed time: 3014.558959 msecs"
; nil

; user=> (defconsts [e 2.7
;                    e2 (* e 2)])
; #'user/e2
; user=> (time (dotimes [_ 1e10] (* e e2)))
; "Elapsed time: 3017.421303 msecs"
; nil
; user=> (meta (var e))
; {:ns #<Namespace user>, :name e, :const true, :line 20, :file "NO_SOURCE_PATH"}