Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.Xml/System/Xml/XPath/XPathExpr.cs

@@ -0,0 +1,76 @@
+//------------------------------------------------------------------------------
+// <copyright file="XPathExpr.cs" company="Microsoft">
+//     Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>                                                                
+// <owner current="true" primary="true">[....]</owner>
+//------------------------------------------------------------------------------
+
+namespace System.Xml.XPath {
+
+    using System;
+    using System.Xml;
+    using System.Collections;
+    using MS.Internal.Xml.XPath;
+
+    public enum XmlSortOrder {
+        Ascending       = 1,
+        Descending      = 2,
+    }
+
+    public enum XmlCaseOrder {
+        None            = 0,
+        UpperFirst      = 1,
+        LowerFirst      = 2,
+    }
+
+    public enum XmlDataType {
+        Text            = 1,
+        Number          = 2,
+    }
+
+    public enum XPathResultType {
+        Number         = 0 ,
+        String          = 1,
+        Boolean         = 2,
+        NodeSet        = 3,
+        Navigator       = XPathResultType.String,
+        Any            = 5,
+        Error
+    };
+
+    public abstract class XPathExpression {
+        internal XPathExpression(){}
+
+        public  abstract string Expression { get; }
+
+        public abstract void AddSort(object expr, IComparer comparer);
+
+        public abstract void AddSort(object expr, XmlSortOrder order, XmlCaseOrder caseOrder, string lang, XmlDataType dataType);
+
+        public abstract XPathExpression Clone();
+
+        public abstract void SetContext(XmlNamespaceManager nsManager);
+
+        public abstract void SetContext(IXmlNamespaceResolver nsResolver);
+
+        public abstract XPathResultType ReturnType { get; }
+        
+        public static XPathExpression Compile(string xpath) {
+            return Compile(xpath, /*nsResolver:*/null);
+        }
+
+        public static XPathExpression Compile(string xpath, IXmlNamespaceResolver nsResolver) {
+            bool hasPrefix;
+            Query query = new QueryBuilder().Build(xpath, out hasPrefix);
+            CompiledXpathExpr expr = new CompiledXpathExpr(query, xpath, hasPrefix);
+            if (null != nsResolver) {
+                expr.SetContext(nsResolver);
+            }
+            return expr;
+        }
+
+        private void PrintQuery(XmlWriter w) {
+            ((CompiledXpathExpr)this).QueryTree.PrintQuery(w);
+        }
+    }
+}