MS.Internal.Xml.XPath.Query.Evaluate C# (CSharp) Метод

        public abstract object Evaluate(XPathNodeIterator nodeIterator);
        public abstract XPathNavigator Advance();

        internal bool toBoolean(XPathNodeIterator nodeIterator)
        {
            object result = _arg.Evaluate(nodeIterator);

            if (result is XPathNodeIterator)
            {
                return(_arg.Advance() != null);
            }

            string str = result as string;

            if (str != null)
            {
                return(toBoolean(str));
            }

            if (result is double)
            {
                return(toBoolean((double)result));
            }
            if (result is bool)
            {
                return((bool)result);
            }
            Debug.Assert(result is XPathNavigator, "Unknown value type");
            return(true);
        }