(defclass agent ()
  ((name :accessor name :initarg :name :initform nil
     :documentation "Human-readable name of the agent.")
   (security :accessor security :initarg :security :type keyword
     :documentation "Keyword symbol of the security being traded by the agent.")
   (market-hours :accessor market-hours :initarg :market-hours
     :initform (list (local-time:parse-timestring "09:30:00")
                     (local-time:parse-timestring "15:45:00"))
     :documentation "Hours the market is open. Can be used in conjunction with the MARKET-CLOSED-P method
to close out open positions or prevent trading during high volatility/low liquidity times.")
   (short-size :accessor unblock-short :initform -1)
   (long-size :accessor unblock-long :initform 1)
   (timestamps :accessor timestamps :initform nil
     :documentation "Reverse-chronological series of event timestamps seen by the agent.")
   (revalprices :accessor revalprices :initform nil
     :documentation "Reverse-chronological series of price events seen by the agent.")
   (orders :accessor orders :initform nil
     :documentation "Reverse-chronological series of orders issued by the agent.")
   (positions :accessor positions :initform nil
     :documentation "Reverse-chronological series of positions requested by the agent.")
   (pls :accessor pls :initform nil
     :documentation "Reverse-chronological series of profits/losses. Does not account for slippage.")
   (navs :initform nil
     :documentation "Reverse-chronological series of agent's clock-time Net Asset Value (NAV). Does not account for slippage.")
   (indicators :accessor indicators :initform nil
     :documentation "Reverse-chronological series of indicator values.")
   (fitnesses :accessor fitnesses :initform nil
     :documentation "Reverse-chronological series of trading strategy fitness calculations.")
   (trade-groups-cache :accessor trade-groups-cache :initform nil :type (or list nil)
     :documentation "Cached grouped trades (market entry to exit) in reverse-chronological order.")
   (unprocessed-trades :accessor unprocessed-trades :initform nil
     :documentation "New, unprocessed/grouped trades in reverse-chronological order.")
   (latest-trade-stats :initform nil :type (or 'trade-stats nil)
     :documentation "Cached version of the last computed trade stats.")
   (incoming-messages :accessor incoming-messages :initform nil
     :documentation "Set of messages from other agents.  Used for inter-agent coordination.")
   (outgoing-messages :accessor outgoing-messages :initform nil
     :documentation "Set of messages to be passed to the other agents in the RECIPIENTS-LIST.")
   (recipients-list :accessor recipients-list :initarg :recipients-list :initform nil
     :documentation "Names of other agents that should receive outgoing messages.")
   (fitness-feedback-control :accessor fitness-feedback-control :initarg :fitness-feedback-control :initform nil)))
   
;;Here is a method that uses with-slots to for getting name and security from a agent
 (defmethod print-object ((a agent) stream)
   (with-slots (name security) a
     (print-unreadable-object (a stream :type t :identity t)
        (when (and (slot-boundp a 'name) name)
      		(princ name stream))
    	(when (slot-boundp a 'security)
     		(princ " " stream)
     	 	(princ security stream)))))

;; Here is a method that gets orders from a agent without with-slots
(defmethod cancel-order ((a agent) old-oid)
  (setf (orders a) (remove-if #`(equal (value %) old-oid)
                              (orders a))))