weather.ss

#! /home/bh/local/bin/mzscheme -r

;; weather.ss
;; This script spits out an HTML fragment reporting weather in your area with
;; with a link to the World Weather Information Service.

(require (lib "xml.ss" "xml")
         (lib "match.ss")
         (lib "url.ss" "net"))

;; See http://www.undergroundlondon.com/weather/
;; for finding the RSS feed for your city.
;; This script works on the "title" feed type.
(define url
  (string->url
   "http://www.undergroundlondon.com/weather/world.rss/093/c00729f?type=title"))

(define (get-rss)
  (xml->xexpr
   ((eliminate-whitespace '(|rdf:RDF| channel item) (lambda (x) x))
    (document-element (call/input-url url get-pure-port read-xml)))))

(match (get-rss)
  (('|rdf:RDF| _  ('channel . _) . items)
   (map
    (match-lambda
      (('item _
         ('title _ title)
         ('link _ link)
         ('description _ desc) . _)
       (printf "<p><em><a href=\"~a\">~a</a></em>: ~a</p>~n"
               link title desc)))
    items)))