Weather update client in CL

;;; -*- Mode:Lisp; Syntax:ANSI-Common-Lisp; -*-
;;; Weather update client in Common Lisp
;;; Connects SUB socket to tcp://localhost:5556
;;; Collects weather updates and finds avg temp in zipcode
;;; Kamil Shakirov <moc.liamg|08slimak#moc.liamg|08slimak>

(defpackage #:zguide.wuclient
(:nicknames #:wuclient)
(:use #:cl #:zhelpers)
(:export #:main))

(in-package :zguide.wuclient)

(defun main ()
(zmq:with-context (context 1)
(message "Collecting updates from weather server…~%")

;; Socket to talk to server
(zmq:with-socket (subscriber context zmq:sub)
(zmq:connect subscriber "tcp://localhost:5556")

;; Subscribe to zipcode, default is NYC, 10001
(let ((filter (or (first (cmd-args)) "10001 ")))
(zmq:setsockopt subscriber zmq:subscribe filter)

;; Process 100 updates
(let ((number-updates 100)
(total-temp 0.0))

(loop :repeat number-updates :do
(let ((update (make-instance 'zmq:msg)))
(zmq:recv subscriber update)

(destructuring-bind (zipcode_ temperature relhumidity_)
(split-sequence:split-sequence #\Space (zmq:msg-data-as-string update))

(declare (ignore zipcode_ relhumidity_))
(incf total-temp (parse-integer temperature)))))

(message "Average temperature for zipcode ~A was ~FF~%"
filter (/ total-temp number-updates))))))