tvl-depot/third_party/lisp/s-xml/examples/tracer.lisp

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;;;; -*- mode: lisp -*-
;;;;
;;;; $Id: tracer.lisp,v 1.2 2004/06/11 11:14:43 scaekenberghe Exp $
;;;;
;;;; A simple SSAX tracer example that can be used to understand how the hooks are called
;;;;
;;;; 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)
(defun trace-xml-log (level msg &rest args)
(indent *standard-output* level)
(apply #'format *standard-output* msg args)
(terpri *standard-output*))
(defun trace-xml-new-element-hook (name attributes seed)
(let ((new-seed (cons (1+ (car seed)) (1+ (cdr seed)))))
(trace-xml-log (car seed)
"(new-element :name ~s :attributes ~:[()~;~:*~s~] :seed ~s) => ~s"
name attributes seed new-seed)
new-seed))
(defun trace-xml-finish-element-hook (name attributes parent-seed seed)
(let ((new-seed (cons (1- (car seed)) (1+ (cdr seed)))))
(trace-xml-log (car parent-seed)
"(finish-element :name ~s :attributes ~:[()~;~:*~s~] :parent-seed ~s :seed ~s) => ~s"
name attributes parent-seed seed new-seed)
new-seed))
(defun trace-xml-text-hook (string seed)
(let ((new-seed (cons (car seed) (1+ (cdr seed)))))
(trace-xml-log (car seed)
"(text :string ~s :seed ~s) => ~s"
string seed new-seed)
new-seed))
(defun trace-xml (in)
"Parse and trace a toplevel XML element from stream in"
(start-parse-xml in
(make-instance 'xml-parser-state
:seed (cons 0 0)
;; seed car is xml element nesting level
;; seed cdr is ever increasing from element to element
:new-element-hook #'trace-xml-new-element-hook
:finish-element-hook #'trace-xml-finish-element-hook
:text-hook #'trace-xml-text-hook)))
(defun trace-xml-file (pathname)
"Parse and trace XMl from the file at pathname"
(with-open-file (in pathname)
(trace-xml in)))
;;;; eof