(defn execute-opcode
  [opcode state]

  (def empty-opcode [0 0 0 0])

  (println "OPCODE TYPE: " (type opcode))
  (println "EMPTY-OPCODE TYPE: " (type empty-opcode))

  (if (= empty-opcode opcode)
    (. System exit 0)
    )
  (println "Executing opcode => " opcode "...")
  (assoc state :PC (+ (get state :PC) 0x2)))