;;; xml.scm - a simple scheme XML library
;;;
;;; Copyright (c) 2012 Johan Ceuppens
;;;
;;; All rights reserved.
;;;
;;; Redistribution and use in source and binary forms, with or without
;;; modification, are permitted provided that the following conditions
;;; are met:
;;; 1. Redistributions of source code must retain the above copyright
;;;    notice, this list of conditions and the following disclaimer.
;;; 2. Redistributions in binary form must reproduce the above copyright
;;;    notice, this list of conditions and the following disclaimer in the
;;;    documentation and/or other materials provided with the distribution.
;;; 3. The name of the authors may not be used to endorse or promote products
;;;    derived from this software without specific prior written permission.
;;;
;;; THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
;;; IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
;;; OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
;;; IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
;;; INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
;;; NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
;;; DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
;;; THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
;;; (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
;;; THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

(define (xml-load-tree! filename)
  (let ((in (open-input-file filename))
        (contents ""))

    (define (tagify! c tagged)
      (cond ((> tagged 0) "")
            ((= tagged 0) (if (eq? c #\>) "" (string c)))
            ;; FIXME make node, descend one level
            (else "")))

    (define (xml-read-in-file contents)
      (let ((tagged 0))
        (do ((c (read-char in) (read-char in)))
            ((eof-object? c) contents)
          (cond ((and (= tagged 0)(eq? c #\<))
                 (set! tagged (+ tagged 1)))
                ((and (> tagged 0)(eq? c #\<))
                 (set! tagged (+ tagged 1)))
                ((and (= tagged 0)(eq? c #\>))
                 (set! tagged (- tagged 1)))
                ((and (> tagged 0)(eq? c #\>))
                 (set! tagged (- tagged 1)))
                ((< tagged 0)
                 (display "xml : bad xml file - broken tags.")(newline)
                 (set! tagged 0))
                )
          (set! contents (string-append contents (tagify! c tagged))))))
    (xml-read-in-file contents)))