Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

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

@@ -0,0 +1,115 @@
+//------------------------------------------------------------------------------
+// <copyright file="ExtensionQuery.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.Xsl;
+    using System.Xml.XPath;
+    using System.Diagnostics;
+    using System.Globalization;
+    using System.Collections;
+
+    internal abstract class ExtensionQuery : Query {
+        protected string prefix;
+        protected string name;
+        protected XsltContext xsltContext;
+        private ResetableIterator queryIterator;
+
+        public ExtensionQuery(string prefix, string name) : base() {
+            this.prefix = prefix;
+            this.name   = name;
+        }
+        protected ExtensionQuery(ExtensionQuery other) : base(other) {
+            this.prefix      = other.prefix;
+            this.name        = other.name;
+            this.xsltContext = other.xsltContext;
+            this.queryIterator = (ResetableIterator)Clone(other.queryIterator);
+        }
+
+        public override void Reset() {
+            if (queryIterator != null) {
+                queryIterator.Reset();
+            }
+        }
+
+        public override XPathNavigator Current {
+            get {
+                if (queryIterator == null) {
+                    throw XPathException.Create(Res.Xp_NodeSetExpected);
+                }
+                if (queryIterator.CurrentPosition == 0) {
+                    Advance();
+                }
+                return queryIterator.Current;
+            } 
+        }
+
+        public override XPathNavigator Advance() {
+            if (queryIterator == null) {
+                throw XPathException.Create(Res.Xp_NodeSetExpected);
+            }
+            if (queryIterator.MoveNext()) {
+                return queryIterator.Current;
+            }
+            return null;
+        }
+
+        public override int CurrentPosition { 
+            get { 
+                if (queryIterator != null) {
+                    return queryIterator.CurrentPosition;
+                }
+                return 0;
+            } 
+        }
+
+        protected object ProcessResult(object value) {
+            if (value is string        ) return value;
+            if (value is double        ) return value;
+            if (value is bool          ) return value;
+            if (value is XPathNavigator) return value;
+            if (value is Int32         ) return (double)(Int32)value;
+
+            if (value == null) {
+                queryIterator = XPathEmptyIterator.Instance;
+                return this; // We map null to NodeSet to let $null/foo work well.
+            }
+
+            ResetableIterator resetable = value as ResetableIterator;
+            if (resetable != null) {
+                // We need Clone() value because variable may be used several times 
+                // and they shouldn't 
+                queryIterator = (ResetableIterator)resetable.Clone(); 
+                return this;
+            }
+            XPathNodeIterator nodeIterator = value as XPathNodeIterator;
+            if (nodeIterator != null) {
+                queryIterator = new XPathArrayIterator(nodeIterator);
+                return this;
+            }
+            IXPathNavigable navigable = value as IXPathNavigable;
+            if(navigable != null) {
+                return navigable.CreateNavigator();
+            }
+
+            if (value is Int16 ) return (double)(Int16)value;
+            if (value is Int64 ) return (double)(Int64)value;
+            if (value is UInt32) return (double)(UInt32)value;
+            if (value is UInt16) return (double)(UInt16)value;
+            if (value is UInt64) return (double)(UInt64)value;
+            if (value is Single) return (double)(Single)value;
+            if (value is Decimal) return (double)(Decimal)value;
+            return value.ToString();
+        }
+
+        protected string QName { get { return prefix.Length != 0 ? prefix + ":" + name : name; } }
+
+        public override int Count { get { return queryIterator == null ? 1 : queryIterator.Count; } }
+        public override XPathResultType StaticType { get { return XPathResultType.Any; } }
+    }
+}