QilCloneVisitor.cs source code in C# .NET

                        Code:
                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / XmlUtils / System / Xml / Xsl / QIL / QilCloneVisitor.cs / 1305376 / QilCloneVisitor.cs
                        
                        
                            //------------------------------------------------------------------------------ 
// 
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// 
// [....] 
//-----------------------------------------------------------------------------
 
using System; 
using System.Collections.Generic;
using System.Diagnostics; 
using System.Xml;
using System.Xml.Xsl;

namespace System.Xml.Xsl.Qil { 

    // Create an exact replica of a QIL graph 
    internal class QilCloneVisitor : QilScopedVisitor { 
        private QilFactory fac;
        private SubstitutionList subs; 


        //-----------------------------------------------
        // Constructors 
        //-----------------------------------------------
 
        public QilCloneVisitor(QilFactory fac) : this(fac, new SubstitutionList()) { 
        }
 
        public QilCloneVisitor(QilFactory fac, SubstitutionList subs) {
            this.fac = fac;
            this.subs = subs;
        } 

 
        //----------------------------------------------- 
        // Entry
        //----------------------------------------------- 

        public QilNode Clone(QilNode node) {
            // Assume that iterator nodes at the top-level are references rather than definitions
            return VisitAssumeReference(node); 
        }
 
 
        //-----------------------------------------------
        // QilVisitor overrides 
        //-----------------------------------------------

        /// 
        /// Visit all children of "parent", replacing each child with a copy of each child. 
        /// 
        protected override QilNode Visit(QilNode oldNode) { 
            QilNode newNode = null; 

            if (oldNode == null) 
                return null;

            // ShallowClone any nodes which have not yet been cloned
            if (oldNode is QilReference) { 
                // Reference nodes may have been cloned previously and put into scope
                newNode = FindClonedReference(oldNode); 
            } 

            if (newNode == null) 
                newNode = oldNode.ShallowClone(this.fac);

            return base.Visit(newNode);
        } 

        ///  
        /// Visit all children of "parent", replacing each child with a copy of each child. 
        /// 
        protected override QilNode VisitChildren(QilNode parent) { 
            // Visit children
            for (int i = 0; i < parent.Count; i++) {
                QilNode child = parent[i];
 
                // If child is a reference,
                if (IsReference(parent, i)) { 
                    // Visit the reference and substitute its copy 
                    parent[i] = VisitReference(child);
 
                    // If no substutition found, then use original child
                    if (parent[i] == null)
                        parent[i] = child;
                } 
                else {
                    // Otherwise, visit the node and substitute its copy 
                    parent[i] = Visit(child); 
                }
            } 

            return parent;
        }
 
        /// 
        /// If a cloned reference is in scope, replace "oldNode".  Otherwise, return "oldNode". 
        ///  
        protected override QilNode VisitReference(QilNode oldNode) {
            QilNode newNode = FindClonedReference(oldNode); 
            return base.VisitReference(newNode == null ? oldNode : newNode);
        }

 
        //-----------------------------------------------
        // QilScopedVisitor methods 
        //----------------------------------------------- 

        ///  
        /// Push node and its shallow clone onto the substitution list.
        /// 
        protected override void BeginScope(QilNode node) {
            this.subs.AddSubstitutionPair(node, node.ShallowClone(this.fac)); 
        }
 
        ///  
        /// Pop entry from substitution list.
        ///  
        protected override void EndScope(QilNode node) {
            this.subs.RemoveLastSubstitutionPair();
        }
 

        //----------------------------------------------- 
        // QilCloneVisitor methods 
        //-----------------------------------------------
 
        /// 
        /// Find the clone of an in-scope reference.
        /// 
        protected QilNode FindClonedReference(QilNode node) { 
            return this.subs.FindReplacement(node);
        } 
    } 
}

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
Link Menu

Network programming in C#, Network Programming in VB.NET, Network Programming in .NET
This book is available now!
Buy at Amazon US or
Buy at Amazon UK
QilCloneVisitor.cs source code in C# .NET

Source code for the .NET framework in C#

Code:

Link Menu
