Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.Xml/System/Xml/XPath/Internal/NodeFunctions.cs

@@ -0,0 +1,105 @@
+//------------------------------------------------------------------------------
+// <copyright file="NodeFunctions.cs" company="Microsoft">
+//     Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>                                                                
+// <owner current="true" primary="true">[....]</owner>
+//------------------------------------------------------------------------------
+
+namespace MS.Internal.Xml.XPath {
+    using System;
+    using System.Xml;
+    using System.Xml.XPath;
+    using System.Diagnostics;
+    using System.Globalization;
+    using System.Xml.Xsl;
+    using FT = MS.Internal.Xml.XPath.Function.FunctionType;
+
+    internal sealed class NodeFunctions : ValueQuery {
+        Query arg = null;
+        FT funcType;
+        XsltContext xsltContext;
+
+        public NodeFunctions(FT funcType, Query arg) {
+            this.funcType = funcType;
+            this.arg = arg; 
+        }
+
+        public override void SetXsltContext(XsltContext context){
+            this.xsltContext = context.Whitespace ? context : null;
+            if (arg != null) {
+                arg.SetXsltContext(context);
+            }
+        }
+        
+        private XPathNavigator EvaluateArg(XPathNodeIterator context) {
+            if (arg == null) {
+                return context.Current;
+            }
+            arg.Evaluate(context);
+            return arg.Advance();
+        }
+
+        public override object Evaluate(XPathNodeIterator context)  {
+            XPathNavigator argVal;
+
+            switch (funcType) {
+            case FT.FuncPosition:
+                return (double)context.CurrentPosition;
+            case FT.FuncLast:
+                return (double)context.Count;
+            case FT.FuncNameSpaceUri:
+                argVal = EvaluateArg(context);
+                if (argVal != null) {
+                    return argVal.NamespaceURI;
+                }
+                break;
+            case FT.FuncLocalName:
+                argVal = EvaluateArg(context);
+                if (argVal != null) {
+                    return argVal.LocalName;
+                }
+                break;
+            case FT.FuncName :
+                argVal = EvaluateArg(context);
+                if (argVal != null) {
+                    return argVal.Name;
+                }
+                break;
+            case FT.FuncCount:
+                arg.Evaluate(context);
+                int count = 0;
+                if (xsltContext != null) {
+                    XPathNavigator nav;
+                    while ((nav = arg.Advance()) != null) {
+                        if (nav.NodeType != XPathNodeType.Whitespace || xsltContext.PreserveWhitespace(nav)) {
+                            count++;
+                        }
+                    }
+                } else {
+                    while (arg.Advance() != null) {
+                        count++;
+                    }
+                }
+                return (double) count;
+            }
+            return string.Empty;
+        }
+
+        public override XPathResultType StaticType { get { return Function.ReturnTypes[(int)funcType]; } }
+
+        public override XPathNodeIterator Clone() {
+            NodeFunctions method = new NodeFunctions(funcType, Clone(arg));
+            method.xsltContext = this.xsltContext;
+            return method;
+       }
+
+        public override void PrintQuery(XmlWriter w) {
+            w.WriteStartElement(this.GetType().Name);
+            w.WriteAttributeString("name", funcType.ToString());
+            if (arg != null) {
+                arg.PrintQuery(w);
+            }
+            w.WriteEndElement();
+        }
+    }
+}