Singletoned

cache = {}

def memoize(func):
    "This is a decorator."
    def _inner(num):
        if num in cache:
            value = cache[num]
        else:
            value = func(num)
            cache[num] = value

Singletoned

function_map = {}

def register_doer(name):
    "This is a decorator factory. It should create and return a decorator"
    def inner(func):
        function_map[name] = func
        return func
    return inner

@register_doer("Do Flibble!")

Singletoned

(import [collections [OrderedDict]])

(defn lru-cache [&optional [limit 100]]
  (defn inner [func]
    (setv cache (OrderedDict))
    (defn cached-fn [&rest args]
      (let [[result nil]]
        (try
         (setv result (.pop cache args))
         (catch [e KeyError]