Who unfriended me?

friends.clj

(ns friends
  (:require [cheshire.core :as json]
            [clojure.set :as set]))

;; The way this works is you download your own Facebook data as JSON
;; (Settings -> Privacy -> Your Facebook information -> Download Your Information)
;; All that you need is Connections -> Friends and followers selected.
;; It will be ready in a few minutes and will be less than 1MB.
;; Place 2 files spanning a certain period of time in this folder,
;; and pass the 2 filenames to `friends/unfriended`.
;; Note: Unfortunately there's no way to "look into the past",
;; you can only compare 2 files downloaded at different times.

(defn friends [filename]
  (set (map #(get % "name")
            (-> filename
                slurp
                json/parse-string
                nfirst))))

(defn unfriended [f1 f2]
  (set/difference (friends f1) 
                  (friends f2)))

(comment
  (unfriended "friends.json"
              "friends2.json")
  )