Function xmlXPathBooleanFunction

ThirdParty/libxml2/vtklibxml2/xpath.c:8397–8411

* xmlXPathBooleanFunction: * @ctxt: the XPath Parser context * @nargs: the number of arguments * * Implement the boolean() XPath function * boolean boolean(object) * The boolean function converts its argument to a boolean as follows: * - a number is true if and only if it is neither positive or * negative zero nor NaN * - a node-set is true if and only if it is non-empty

 *    - a string is true if and only if its length is non-zero
 */
void
xmlXPathBooleanFunction(xmlXPathParserContextPtr ctxt, int nargs) {
    xmlXPathObjectPtr cur;

    CHECK_ARITY(1);
    cur = valuePop(ctxt);
    if (cur == NULL) XP_ERROR(XPATH_INVALID_OPERAND);
    if (cur->type != XPATH_BOOLEAN) {
        int boolval = xmlXPathCastToBoolean(cur);

        xmlXPathReleaseObject(ctxt->context, cur);
        cur = xmlXPathCacheNewBoolean(ctxt, boolval);
    }
    valuePush(ctxt, cur);
}

/**
 * xmlXPathNotFunction: