feat(third_party/lisp/s-xml): Check in sources & derivation

Checked in the sources for this because it is tracked upstream in CVS
and I can't be bothered to deal with that right now.

third_party/lisp/s-xml/examples/counter.lisp

@@ -0,0 +1,47 @@
+;;;; -*- mode: lisp -*-
+;;;;
+;;;; $Id: counter.lisp,v 1.2 2004/06/11 11:14:43 scaekenberghe Exp $
+;;;;
+;;;; A simple SSAX counter example that can be used as a performance test
+;;;;
+;;;; Copyright (C) 2004 Sven Van Caekenberghe, Beta Nine BVBA.
+;;;;
+;;;; You are granted the rights to distribute and use this software
+;;;; as governed by the terms of the Lisp Lesser General Public License
+;;;; (http://opensource.franz.com/preamble.html), also known as the LLGPL.
+
+(in-package :s-xml)
+
+(defclass count-xml-seed ()
+  ((elements :initform 0)
+   (attributes :initform 0)
+   (characters :initform 0)))
+
+(defun count-xml-new-element-hook (name attributes seed)
+  (declare (ignore name))
+  (incf (slot-value seed 'elements))
+  (incf (slot-value seed 'attributes) (length attributes))
+  seed)
+
+(defun count-xml-text-hook (string seed)
+  (incf (slot-value seed 'characters) (length string))
+  seed)
+  
+(defun count-xml (in)
+  "Parse a toplevel XML element from stream in, counting elements, attributes and characters"
+  (start-parse-xml in
+		   (make-instance 'xml-parser-state
+				  :seed (make-instance 'count-xml-seed)
+				  :new-element-hook #'count-xml-new-element-hook
+				  :text-hook #'count-xml-text-hook)))
+
+(defun count-xml-file (pathname)
+  "Parse XMl from the file at pathname, counting elements, attributes and characters"
+  (with-open-file (in pathname)
+    (let ((result (count-xml in)))
+      (with-slots (elements attributes characters) result
+        (format t 
+                "~a contains ~d XML elements, ~d attributes and ~d characters.~%" 
+                pathname elements attributes characters)))))
+
+;;;; eof