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/src/xml-struct-dom.lisp

@@ -0,0 +1,125 @@
+;;;; -*- mode: lisp -*-
+;;;;
+;;;; $Id: xml-struct-dom.lisp,v 1.2 2005/08/29 15:01:47 scaekenberghe Exp $
+;;;;
+;;;; XML-STRUCT implementation of the generic DOM parser and printer.
+;;;;
+;;;; Copyright (C) 2002, 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)
+
+;;; xml-element struct datastructure and API
+
+(defstruct xml-element
+  name        ; :tag-name
+  attributes  ; a assoc list of (:attribute-name . "attribute-value")
+  children    ; a list of children/content either text strings or xml-elements
+  )
+
+(setf (documentation 'xml-element-p 'function)
+      "Return T when the argument is an xml-element struct"
+      (documentation 'xml-element-attributes 'function)
+      "Return the alist of attribute names and values dotted pairs from an xml-element struct"
+      (documentation 'xml-element-children 'function)
+      "Return the list of children from an xml-element struct"
+      (documentation 'xml-element-name 'function)
+      "Return the name from an xml-element struct"
+      (documentation 'make-xml-element 'function)
+      "Make and return a new xml-element struct")
+
+(defun xml-element-attribute (xml-element key)
+  "Return the string value of the attribute with name the keyword :key
+  of xml-element if any, return null if not found"
+  (let ((pair (assoc key (xml-element-attributes xml-element) :test #'eq)))
+    (when pair (cdr pair))))
+
+(defun (setf xml-element-attribute) (value xml-element key)
+  "Set the string value of the attribute with name the keyword :key of
+  xml-element, creating a new attribute if necessary or overwriting an
+  existing one, returning the value"
+  (let ((attributes (xml-element-attributes xml-element)))
+    (if (null attributes)
+	(push (cons key value) (xml-element-attributes xml-element))
+      (let ((pair (assoc key attributes :test #'eq)))
+	(if pair
+	    (setf (cdr pair) value)
+	  (push (cons key value) (xml-element-attributes xml-element)))))
+    value))
+
+(defun new-xml-element (name &rest children)
+  "Make a new xml-element with name and children"
+  (make-xml-element :name name :children children))
+
+(defun first-xml-element-child (xml-element)
+  "Get the first child of an xml-element"
+  (first (xml-element-children xml-element)))
+
+(defun xml-equal (xml-1 xml-2)
+  (and (xml-element-p xml-1)
+       (xml-element-p xml-2)
+       (eq (xml-element-name xml-1)
+	   (xml-element-name xml-2))
+       (equal (xml-element-attributes xml-1)
+	      (xml-element-attributes xml-2))
+       (reduce #'(lambda (&optional (x t) (y t)) (and x y))
+	       (mapcar #'(lambda (x y)
+			   (or (and (stringp x) (stringp y) (string= x y))
+			       (xml-equal x y)))
+		       (xml-element-children xml-1)
+		       (xml-element-children xml-2)))))
+
+;;; printing xml structures
+
+(defmethod print-xml-dom (xml-element (input-type (eql :xml-struct)) stream pretty level)
+  (declare (special *namespaces*))
+  (let ((*namespaces* (extend-namespaces (xml-element-attributes xml-element)
+                                         *namespaces*)))
+    (write-char #\< stream)
+    (print-identifier (xml-element-name xml-element) stream)
+    (loop :for (name . value) :in (xml-element-attributes xml-element)
+          :do (print-attribute name value stream))
+    (let ((children (xml-element-children xml-element))) 
+      (if children
+          (progn
+            (write-char #\> stream)
+            (if (and (= (length children) 1) (stringp (first children)))
+                (print-string-xml (first children) stream)
+              (progn
+                (dolist (child children)
+                  (when pretty (print-spaces (* 2 level) stream))
+                  (if (stringp child)
+                      (print-string-xml child stream)
+                    (print-xml-dom child input-type stream pretty (1+ level))))
+                (when pretty (print-spaces (* 2 (1- level)) stream))))
+            (print-closing-tag (xml-element-name xml-element) stream))
+        (write-string "/>" stream)))))
+
+;;; the standard hooks to generate xml-element structs
+
+(defun standard-new-element-hook (name attributes seed)
+  (declare (ignore name attributes seed))
+  '())
+
+(defun standard-finish-element-hook (name attributes parent-seed seed)
+  (let ((xml-element (make-xml-element :name name
+				       :attributes attributes
+				       :children (nreverse seed))))
+    (cons xml-element parent-seed)))
+
+(defun standard-text-hook (string seed)
+  (cons string seed))
+
+;;; top level standard parser interfaces
+
+(defmethod parse-xml-dom (stream (output-type (eql :xml-struct)))
+  (car (start-parse-xml stream
+			(make-instance 'xml-parser-state
+				       :new-element-hook #'standard-new-element-hook
+				       :finish-element-hook #'standard-finish-element-hook
+				       :text-hook #'standard-text-hook))))
+
+;;;; eof