janet/examples/frequencies.dst

# Get the number of occurences of elements in a set

(defn frequencies
 "Get the number of occurences of each value in a indexed structure."
 [ind]
 (def freqs @{})
 (map (fn [x] 
    (let [n (get freqs x)]
     (put freqs x (if n (+ 1 n) 1)))) ind)
 freqs)