Code snippets for Duchess-fr Battle Language 2012-02-29 test it on http://tryclj.com/ !

fib-seq-1.clj

(def fib-seq
  "lazy seq of Fibonacci numbers"
  (lazy-cat [0 1] (map + (rest fib-seq) fib-seq)))

fib-seq-2.clj

(def fib-seq
  (map first (iterate (fn[[a b]] [b (+ a b)]) [0 1])))

fizzbuzz.clj

(def fizzbuzz
"lazy seq of fizzbuzz"
  (lazy-seq (map #(let [s (str (if (zero? (rem % 3)) "Fizz")
                               (if (zero? (rem % 5)) "Buzz"))]
                    (if (empty? s) % s))
                 (iterate inc 1))))

fizzbuzzzapp.clj

(def fizzbuzzzapp
"lazy seq of fizzbuzzzapp more interesting (imo)than fizzbuzz
 because it starts to pay off to factor some code "
(lazy-seq (map #(let [s (apply str (for [[val name] [[3 "Fizz"]
                                                     [5 "Buzz"]
                                                     [7 "Zapp"]]]
                                     (if (zero? (rem % val)) name)))]
                  (if (empty? s) % s))
               (iterate inc 1))))

menu.clj

(defn menu [items budget]
  "items is a collection of [food price]
   returns the combination of food and total price with max price <= budget"
  (let [submenus (fn [items]
                   (if-let [[[food price] & xs] (seq items)]
                     (let [menus (submenus xs)]
                       (concat menus (for [[m p] menus 
                                           :let [p (+ p price)]
                                           :when (<= p budget)]
                                       [(conj m food) p])))
                     [[#{} 0]]))]
    (apply max-key second (submenus items))))