Function xmlXPathDifference

ThirdParty/libxml2/vtklibxml2/xpath.c:3509–3536

* xmlXPathDifference: * @nodes1: a node-set * @nodes2: a node-set * * Implements the EXSLT - Sets difference() function: * node-set set:difference (node-set, node-set) * * Returns the difference between the two node sets, or nodes1 if * nodes2 is empty */

 *         nodes2 is empty
 */
xmlNodeSetPtr
xmlXPathDifference (xmlNodeSetPtr nodes1, xmlNodeSetPtr nodes2) {
    xmlNodeSetPtr ret;
    int i, l1;
    xmlNodePtr cur;

    if (xmlXPathNodeSetIsEmpty(nodes2))
	return(nodes1);

    ret = xmlXPathNodeSetCreate(NULL);
    if (ret == NULL)
        return(NULL);
    if (xmlXPathNodeSetIsEmpty(nodes1))
	return(ret);

    l1 = xmlXPathNodeSetGetLength(nodes1);

    for (i = 0; i < l1; i++) {
	cur = xmlXPathNodeSetItem(nodes1, i);
	if (!xmlXPathNodeSetContains(nodes2, cur)) {
	    if (xmlXPathNodeSetAddUnique(ret, cur) < 0) {
                xmlXPathFreeNodeSet(ret);
	        return(NULL);
            }
	}
    }
    return(ret);
}

/**
 * xmlXPathIntersection: