/trunk/managed/csharpsqlite/TCL/src/commands/NamespaceCmd.cs

#undef DEBUG
/*
* NamespaceCmd.java
*
* Copyright (c) 1993-1997 Lucent Technologies.
* Copyright (c) 1997 Sun Microsystems, Inc.
* Copyright (c) 1998-1999 by Scriptics Corporation.
* Copyright (c) 1999 Moses DeJong
*
* Originally implemented by
*   Michael J. McLennan
*   Bell Labs Innovations for Lucent Technologies
*   mmclennan@lucent.com
*
* See the file "license.terms" for information on usage and
* redistribution of this file, and for a DISCLAIMER OF ALL
* WARRANTIES.
*
* Included in SQLite3 port to C# for use in testharness only;  2008 Noah B Hart
* $Header$
* RCS @(#) $Id: NamespaceCmd.java,v 1.12 2001/05/05 22:38:13 mdejong Exp $
*/
using System;
using System.Collections;

namespace tcl.lang
{
	
	/// <summary> This class implements the built-in "namespace" command in Tcl.
	/// See the user documentation for details on what it does.
	/// </summary>
	
	
	public class NamespaceCmd : InternalRep, Command
	{
		
		// Flag passed to getNamespaceForQualName to indicate that it should
		// search for a namespace rather than a command or variable inside a
		// namespace. Note that this flag's value must not conflict with the values
		// of TCL.VarFlag.GLOBAL_ONLY, TCL.VarFlag.NAMESPACE_ONLY, or TCL.VarFlag.CREATE_NS_IF_UNKNOWN.
		
		
		// Initial size of stack allocated space for tail list - used when resetting
		// shadowed command references in the functin: TclResetShadowedCmdRefs.
		
		//private static final int NUM_TRAIL_ELEMS = 5;
		
		// Count of the number of namespaces created. This value is used as a
		// unique id for each namespace.
		
		private static long numNsCreated = 0;
				private static Object nsMutex;
    
    //
		// Flags used to represent the status of a namespace:
		//
		// NS_DYING -	1 means deleteNamespace has been called to delete the
		//		namespace but there are still active call frames on the Tcl
		//		stack that refer to the namespace. When the last call frame
		//		referring to it has been popped, it's variables and command
		//		will be destroyed and it will be marked "dead" (NS_DEAD).
		//		The namespace can no longer be looked up by name.
		// NS_DEAD -	1 means deleteNamespace has been called to delete the
		//		namespace and no call frames still refer to it. Its
		//		variables and command have already been destroyed. This bit
		//		allows the namespace resolution code to recognize that the
		//		namespace is "deleted". When the last namespaceName object
		//		in any byte code code unit that refers to the namespace has
		//		been freed (i.e., when the namespace's refCount is 0), the
		//		namespace's storage will be freed.
		
		internal const int NS_DYING = 0x01;
		internal const int NS_DEAD = 0x02;
		
		
		// Flag passed to getNamespaceForQualName to have it create all namespace
		// components of a namespace-qualified name that cannot be found. The new
		// namespaces are created within their specified parent. Note that this
		// flag's value must not conflict with the values of the flags
		// TCL.VarFlag.GLOBAL_ONLY, TCL.VarFlag.NAMESPACE_ONLY, and TCL.VarFlag.FIND_ONLY_NS
		
		// internal const int TCL.VarFlag.CREATE_NS_IF_UNKNOWN = 0x800;
		
		
		// This value corresponds to the Tcl_Obj.otherValuePtr pointer used
		// in the C version of Tcl 8.1. Use it to keep track of a ResolvedNsName.
		
		private ResolvedNsName otherValue = null;
		
		
		/*
		*----------------------------------------------------------------------
		*
		* Tcl_GetCurrentNamespace -> getCurrentNamespace
		*
		*	Returns a reference to an interpreter's currently active namespace.
		*
		* Results:
		*	Returns a reference to the interpreter's current namespace.
		*
		* Side effects:
		*	None.
		*
		*----------------------------------------------------------------------
		*/
		
		internal static Namespace getCurrentNamespace(Interp interp)
		{
			if (interp.varFrame != null)
			{
				return interp.varFrame.ns;
			}
			else
			{
				return interp.globalNs;
			}
		}
		
		/*
		*----------------------------------------------------------------------
		*
		* Tcl_GetGlobalNamespace -> getGlobalNamespace
		*
		*	Returns a reference to an interpreter's global :: namespace.
		*
		* Results:
		*	Returns a reference to the specified interpreter's global namespace.
		*
		* Side effects:
		*	None.
		*
		*----------------------------------------------------------------------
		*/
		
		internal static Namespace getGlobalNamespace(Interp interp)
		{
			return interp.globalNs;
		}
		
		
		/*
		*----------------------------------------------------------------------
		*
		* Tcl_PushCallFrame -> pushCallFrame
		*
		*	Pushes a new call frame onto the interpreter's Tcl call stack.
		*	Called when executing a Tcl procedure or a "namespace eval" or
		*	"namespace inscope" command. 
		*
		* Results:
		*  Returns if successful, raises TclException if something goes wrong.
		*
		* Side effects:
		*	Modifies the interpreter's Tcl call stack.
		*
		*----------------------------------------------------------------------
		*/
		
		internal static void  pushCallFrame(Interp interp, CallFrame frame, Namespace namespace_Renamed, bool isProcCallFrame)
		// If true, the frame represents a
		// called Tcl procedure and may have local
		// vars. Vars will ordinarily be looked up
		// in the frame. If new variables are
		// created, they will be created in the
		// frame. If false, the frame is for a
		// "namespace eval" or "namespace inscope"
		// command and var references are treated
		// as references to namespace variables.
		{
			Namespace ns;
			
			if (namespace_Renamed == null)
			{
				ns = getCurrentNamespace(interp);
			}
			else
			{
				ns = namespace_Renamed;
				if ((ns.flags & NS_DEAD) != 0)
				{
					throw new TclRuntimeError("Trying to push call frame for dead namespace");
				}
			}
			
			ns.activationCount++;
			frame.ns = ns;
			frame.isProcCallFrame = isProcCallFrame;
			frame.objv = null;
			
			frame.caller = interp.frame;
			frame.callerVar = interp.varFrame;
			
			if (interp.varFrame != null)
			{
				frame.level = (interp.varFrame.level + 1);
			}
			else
			{
				frame.level = 1;
			}
			
			// FIXME : does Jacl need a procPtr in the CallFrame class?
			//frame.procPtr = null; 	   // no called procedure
			
			frame.varTable = null; // and no local variables
			
			// Compiled locals are not part of Jacl's CallFrame
			
			// Push the new call frame onto the interpreter's stack of procedure
			// call frames making it the current frame.
			
			interp.frame = frame;
			interp.varFrame = frame;
		}
		
		
		
		/*
		*----------------------------------------------------------------------
		*
		* Tcl_PopCallFrame -> popCallFrame
		*
		*	Removes a call frame from the Tcl call stack for the interpreter.
		*	Called to remove a frame previously pushed by Tcl_PushCallFrame.
		*
		* Results:
		*	None.
		*
		* Side effects:
		*	Modifies the call stack of the interpreter. Resets various fields of
		*	the popped call frame. If a namespace has been deleted and
		*	has no more activations on the call stack, the namespace is
		*	destroyed.
		*
		*----------------------------------------------------------------------
		*/
		
		internal static void  popCallFrame(Interp interp)
		{
			CallFrame frame = interp.frame;
			int saveErrFlag;
			Namespace ns;
			
			// It's important to remove the call frame from the interpreter's stack
			// of call frames before deleting local variables, so that traces
			// invoked by the variable deletion don't see the partially-deleted
			// frame.
			
			interp.frame = frame.caller;
			interp.varFrame = frame.callerVar;
			
			// Delete the local variables. As a hack, we save then restore the
			// ERR_IN_PROGRESS flag in the interpreter. The problem is that there
			// could be unset traces on the variables, which cause scripts to be
			// evaluated. This will clear the ERR_IN_PROGRESS flag, losing stack
			// trace information if the procedure was exiting with an error. The
			// code below preserves the flag. Unfortunately, that isn't really
			// enough: we really should preserve the errorInfo variable too
			// (otherwise a nested error in the trace script will trash errorInfo).
			// What's really needed is a general-purpose mechanism for saving and
			// restoring interpreter state.
			
			saveErrFlag = (interp.flags & Parser.ERR_IN_PROGRESS);
			
			if (frame.varTable != null)
			{
				Var.deleteVars(interp, frame.varTable);
				frame.varTable = null;
			}
			
			interp.flags |= saveErrFlag;
			
			// Decrement the namespace's count of active call frames. If the
			// namespace is "dying" and there are no more active call frames,
			// call Tcl_DeleteNamespace to destroy it.
			
			ns = frame.ns;
			ns.activationCount--;
			if (((ns.flags & NS_DYING) != 0) && (ns.activationCount == 0))
			{
				deleteNamespace(ns);
			}
			frame.ns = null;
		}
		
		/*
		*----------------------------------------------------------------------
		*
		* Tcl_CreateNamespace --
		*
		*	Creates a new namespace with the given name. If there is no
		*	active namespace (i.e., the interpreter is being initialized),
		*	the global :: namespace is created and returned.
		*
		* Results:
		*	Returns a reference to the new namespace if successful. If the
		*	namespace already exists or if another error occurs, this routine
		*	returns null, along with an error message in the interpreter's
		*	result object.
		*
		* Side effects:
		*	If the name contains "::" qualifiers and a parent namespace does
		*	not already exist, it is automatically created. 
		*
		*----------------------------------------------------------------------
		*/
		
		internal static Namespace createNamespace(Interp interp, string name, DeleteProc deleteProc)
		{
			Namespace ns, ancestor;
			Namespace parent;
			Namespace globalNs = getGlobalNamespace(interp);
			string simpleName;
			System.Text.StringBuilder buffer1, buffer2;
			
			// If there is no active namespace, the interpreter is being
			// initialized. 
			
			if ((globalNs == null) && (interp.varFrame == null))
			{
				// Treat this namespace as the global namespace, and avoid
				// looking for a parent.
				
				parent = null;
				simpleName = "";
			}
			else if (name.Length == 0)
			{
				/*
				TclObject tobj = interp.getResult();
				// FIXME : is there a test case to check this error result?
				TclString.append(tobj,
				"can't create namespace \"\": only global namespace can have empty name");
				*/
				
				// FIXME : is there a test case to check this error result?
				interp.setResult("can't create namespace \"\": only global namespace can have empty name");
				return null;
			}
			else
			{
				// Find the parent for the new namespace.
				
				// Java does not support passing an address so we pass
				// an array of size 1 and then assign arr[0] to the value
				Namespace[] parentArr = new Namespace[1];
				Namespace[] dummyArr = new Namespace[1];
				string[] simpleArr = new string[1];
				
				getNamespaceForQualName(interp, name, null, (TCL.VarFlag.CREATE_NS_IF_UNKNOWN | TCL.VarFlag.LEAVE_ERR_MSG), parentArr, dummyArr, dummyArr, simpleArr);
				
				// Get the values out of the arrays!
				parent = parentArr[0];
				simpleName = simpleArr[0];
				
				
				// If the unqualified name at the end is empty, there were trailing
				// "::"s after the namespace's name which we ignore. The new
				// namespace was already (recursively) created and is referenced
				// by parent.
				
				if (simpleName.Length == 0)
				{
					return parent;
				}
				
				// Check for a bad namespace name and make sure that the name
				// does not already exist in the parent namespace.
				
				if (parent.childTable[simpleName] != null)
				{
					/*
					TclObject tobj = interp.getResult();
					// FIXME : is there a test case to check this error result?
					TclString.append(tobj,
					"can't create namespace \"" + name + "\": already exists");
					*/
					
					// FIXME : is there a test case to check this error result?
					interp.setResult("can't create namespace \"" + name + "\": already exists");
					return null;
				}
			}
			
			// Create the new namespace and root it in its parent. Increment the
			// count of namespaces created.
			
			ns = new Namespace();
			ns.name = simpleName;
			ns.fullName = null; // set below
			//ns.clientData       = clientData;
			ns.deleteProc = deleteProc;
			ns.parent = parent;
			ns.childTable = new Hashtable();
			lock (nsMutex)
			{
				numNsCreated++;
				ns.nsId = numNsCreated;
			}
			ns.interp = interp;
			ns.flags = 0;
			ns.activationCount = 0;
			// FIXME : there was a problem with the refcount because
			// when the namespace was deleted the refocount was 0.
			// We avoid this by just using a refcount of 1 for now.
			// We can do ignore the refCount because GC will reclaim mem.
			//ns.refCount           = 0;
			ns.refCount = 1;
			ns.cmdTable = new Hashtable();
			ns.varTable = new Hashtable();
			ns.exportArray = null;
			ns.numExportPatterns = 0;
			ns.maxExportPatterns = 0;
			
			// Jacl does not use these tcl compiler specific members
			//ns.cmdRefEpoch        = 0;
			//ns.resolverEpoch      = 0;
			
			ns.resolver = null;
			
			if (parent != null)
			{
				SupportClass.PutElement(parent.childTable, simpleName, ns);
			}
			
			// Build the fully qualified name for this namespace.
			
			buffer1 = new System.Text.StringBuilder();
			buffer2 = new System.Text.StringBuilder();
			for (ancestor = ns; ancestor != null; ancestor = ancestor.parent)
			{
				if (ancestor != globalNs)
				{
					buffer1.Append("::");
					buffer1.Append(ancestor.name);
				}
				buffer1.Append(buffer2);
				
				buffer2.Length = 0;
				buffer2.Append(buffer1);
				buffer1.Length = 0;
			}
			
			name = buffer2.ToString();
			ns.fullName = name;
			
			// Return a reference to the new namespace.
			
			return ns;
		}
		
		/*
		*----------------------------------------------------------------------
		*
		* Tcl_DeleteNamespace -> deleteNamespace
		*
		*	Deletes a namespace and all of the commands, variables, and other
		*	namespaces within it.
		*
		* Results:
		*	None.
		*
		* Side effects:
		*	When a namespace is deleted, it is automatically removed as a
		*	child of its parent namespace. Also, all its commands, variables
		*	and child namespaces are deleted.
		*
		*----------------------------------------------------------------------
		*/
		
		internal static void  deleteNamespace(Namespace namespace_Renamed)
		{
			Namespace ns = namespace_Renamed;
			Interp interp = ns.interp;
			Namespace globalNs = getGlobalNamespace(interp);
			
			// If the namespace is on the call frame stack, it is marked as "dying"
			// (NS_DYING is OR'd into its flags): the namespace can't be looked up
			// by name but its commands and variables are still usable by those
			// active call frames. When all active call frames referring to the
			// namespace have been popped from the Tcl stack, popCallFrame will
			// call this procedure again to delete everything in the namespace.
			// If no nsName objects refer to the namespace (i.e., if its refCount 
			// is zero), its commands and variables are deleted and the storage for
			// its namespace structure is freed. Otherwise, if its refCount is
			// nonzero, the namespace's commands and variables are deleted but the
			// structure isn't freed. Instead, NS_DEAD is OR'd into the structure's
			// flags to allow the namespace resolution code to recognize that the
			// namespace is "deleted".
			
			if (ns.activationCount > 0)
			{
				ns.flags |= NS_DYING;
				if (ns.parent != null)
				{
					ns.parent.childTable.Remove(ns.name);
				}
				ns.parent = null;
			}
			else
			{
				// Delete the namespace and everything in it. If this is the global
				// namespace, then clear it but don't free its storage unless the
				// interpreter is being torn down.
				
				teardownNamespace(ns);
				
				if ((ns != globalNs) || ((interp.flags & Parser.DELETED) != 0))
				{
					// If this is the global namespace, then it may have residual
					// "errorInfo" and "errorCode" variables for errors that
					// occurred while it was being torn down.  Try to clear the
					// variable list one last time.
					
					Var.deleteVars(ns.interp, ns.varTable);
					
					ns.childTable.Clear();
					ns.cmdTable.Clear();
					
					// If the reference count is 0, then discard the namespace.
					// Otherwise, mark it as "dead" so that it can't be used.
					
					if (ns.refCount == 0)
					{
						free(ns);
					}
					else
					{
						ns.flags |= NS_DEAD;
					}
				}
			}
		}
		
		
		/*
		*----------------------------------------------------------------------
		*
		* TclTeardownNamespace -> teardownNamespace
		*
		*	Used internally to dismantle and unlink a namespace when it is
		*	deleted. Divorces the namespace from its parent, and deletes all
		*	commands, variables, and child namespaces.
		*
		*	This is kept separate from Tcl_DeleteNamespace so that the global
		*	namespace can be handled specially. Global variables like
		*	"errorInfo" and "errorCode" need to remain intact while other
		*	namespaces and commands are torn down, in case any errors occur.
		*
		* Results:
		*	None.
		*
		* Side effects:
		*	Removes this namespace from its parent's child namespace hashtable.
		*	Deletes all commands, variables and namespaces in this namespace.
		*	If this is the global namespace, the "errorInfo" and "errorCode"
		*	variables are left alone and deleted later.
		*
		*----------------------------------------------------------------------
		*/
		
		internal static void  teardownNamespace(Namespace ns)
		{
			Interp interp = ns.interp;
			IEnumerator search;
			Namespace globalNs = getGlobalNamespace(interp);
			int i;
			
			// Start by destroying the namespace's variable table,
			// since variables might trigger traces.
			
			if (ns == globalNs)
			{
				// This is the global namespace, so be careful to preserve the
				// "errorInfo" and "errorCode" variables. These might be needed
				// later on if errors occur while deleting commands. We are careful
				// to destroy and recreate the "errorInfo" and "errorCode"
				// variables, in case they had any traces on them.
				
				string errorInfoStr, errorCodeStr;
				
				try
				{
					
					errorInfoStr = interp.getVar("errorInfo", TCL.VarFlag.GLOBAL_ONLY).ToString();
				}
				catch (TclException e)
				{
					errorInfoStr = null;
				}
				
				try
				{
					
					errorCodeStr = interp.getVar("errorCode", TCL.VarFlag.GLOBAL_ONLY).ToString();
				}
				catch (TclException e)
				{
					errorCodeStr = null;
				}
				
				Var.deleteVars(interp, ns.varTable);
				
				if ((System.Object) errorInfoStr != null)
				{
					try
					{
						interp.setVar("errorInfo", errorInfoStr, TCL.VarFlag.GLOBAL_ONLY);
					}
					catch (TclException e)
					{
						// ignore an exception while setting this var
					}
				}
				if ((System.Object) errorCodeStr != null)
				{
					try
					{
						interp.setVar("errorCode", errorCodeStr, TCL.VarFlag.GLOBAL_ONLY);
					}
					catch (TclException e)
					{
						// ignore an exception while setting this var
					}
				}
			}
			else
			{
				// Variable table should be cleared.
				Var.deleteVars(interp, ns.varTable);
			}
			
			// Remove the namespace from its parent's child hashtable.
			
			if (ns.parent != null)
			{
				ns.parent.childTable.Remove(ns.name);
			}
			ns.parent = null;
			
			// Delete all the child namespaces.
			//
			// BE CAREFUL: When each child is deleted, it will divorce
			//    itself from its parent. You can't traverse a hash table
			//    properly if its elements are being deleted. We use only
			//    the Tcl_FirstHashEntry function to be safe.
			
			foreach (Namespace childNs in new ArrayList(ns.childTable.Values))
			{
				deleteNamespace(childNs);
			}
			
			// Delete all commands in this namespace. Be careful when traversing the
			// hash table: when each command is deleted, it removes itself from the
			// command table.
			
			// FIXME : double check that using an enumeration for a hashtable
			// that changes is ok in Java! Also call deleteCommand... correctly!
			foreach(WrappedCommand cmd in new ArrayList(ns.cmdTable.Values))
			{
				interp.deleteCommandFromToken(cmd);
			}
			
			ns.cmdTable.Clear();
			
			// Free the namespace's export pattern array.
			
			if (ns.exportArray != null)
			{
				ns.exportArray = null;
				ns.numExportPatterns = 0;
				ns.maxExportPatterns = 0;
			}
			
			// Callback invoked when namespace is deleted
			
			if (ns.deleteProc != null)
			{
				ns.deleteProc.delete();
			}
			ns.deleteProc = null;
			
			// Reset the namespace's id field to ensure that this namespace won't
			// be interpreted as valid by, e.g., the cache validation code for
			// cached command references in Tcl_GetCommandFromObj.
			
			ns.nsId = 0;
		}
		
		
		/*
		*----------------------------------------------------------------------
		*
		* NamespaceFree -> free
		*
		*	Called after a namespace has been deleted, when its
		*	reference count reaches 0.  Frees the data structure
		*	representing the namespace.
		*
		* Results:
		*	None.
		*
		* Side effects:
		*	None.
		*
		*----------------------------------------------------------------------
		*/
		
		internal static void  free(Namespace ns)
		{
			// Most of the namespace's contents are freed when the namespace is
			// deleted by Tcl_DeleteNamespace. All that remains is to free its names
			// (for error messages), and the structure itself.
			
			ns.name = null;
			ns.fullName = null;
		}
		
		/*
		*----------------------------------------------------------------------
		*
		* Tcl_Export -> exportList
		*
		*	Makes all the commands matching a pattern available to later be
		*	imported from the namespace specified by namespace (or the
		*	current namespace if namespace is null). The specified pattern is
		*	appended onto the namespace's export pattern list, which is
		*	optionally cleared beforehand.
		*
		* Results:
		*  Returns if successful, raises TclException if something goes wrong.
		*
		* Side effects:
		*	Appends the export pattern onto the namespace's export list.
		*	Optionally reset the namespace's export pattern list.
		*
		*----------------------------------------------------------------------
		*/
		
		internal static void  exportList(Interp interp, Namespace namespace_Renamed, string pattern, bool resetListFirst)
		{
						int INIT_EXPORT_PATTERNS = 5;
			Namespace ns, exportNs;
			Namespace currNs = getCurrentNamespace(interp);
			string simplePattern, patternCpy;
			int neededElems, len, i;
			
			// If the specified namespace is null, use the current namespace.
			
			if (namespace_Renamed == null)
			{
				ns = currNs;
			}
			else
			{
				ns = namespace_Renamed;
			}
			
			// If resetListFirst is true (nonzero), clear the namespace's export
			// pattern list.
			
			if (resetListFirst)
			{
				if (ns.exportArray != null)
				{
					for (i = 0; i < ns.numExportPatterns; i++)
					{
						ns.exportArray[i] = null;
					}
					ns.exportArray = null;
					ns.numExportPatterns = 0;
					ns.maxExportPatterns = 0;
				}
			}
			
			// Check that the pattern doesn't have namespace qualifiers.
			
			// Java does not support passing an address so we pass
			// an array of size 1 and then assign arr[0] to the value
			Namespace[] exportNsArr = new Namespace[1];
			Namespace[] dummyArr = new Namespace[1];
			string[] simplePatternArr = new string[1];
			
			getNamespaceForQualName(interp, pattern, ns, TCL.VarFlag.LEAVE_ERR_MSG, exportNsArr, dummyArr, dummyArr, simplePatternArr);
			
			// get the values out of the arrays
			
			exportNs = exportNsArr[0];
			simplePattern = simplePatternArr[0];
			
			if ((exportNs != ns) || (pattern.CompareTo(simplePattern) != 0))
			{
				throw new TclException(interp, "invalid export pattern \"" + pattern + "\": pattern can't specify a namespace");
			}
			
			// Make sure there is room in the namespace's pattern array for the
			// new pattern.
			
			neededElems = ns.numExportPatterns + 1;
			if (ns.exportArray == null)
			{
				ns.exportArray = new string[INIT_EXPORT_PATTERNS];
				ns.numExportPatterns = 0;
				ns.maxExportPatterns = INIT_EXPORT_PATTERNS;
			}
			else if (neededElems > ns.maxExportPatterns)
			{
				int numNewElems = 2 * ns.maxExportPatterns;
				string[] newArray = new string[numNewElems];
				Array.Copy((System.Array) ns.exportArray, 0, (System.Array) newArray, 0, ns.numExportPatterns);
				ns.exportArray = newArray;
				ns.maxExportPatterns = numNewElems;
			}
			
			// Add the pattern to the namespace's array of export patterns.
			
			ns.exportArray[ns.numExportPatterns] = pattern;
			ns.numExportPatterns++;
			return ;
		}
		
		
		/*
		*----------------------------------------------------------------------
		*
		* Tcl_AppendExportList -> appendExportList
		*
		*	Appends onto the argument object the list of export patterns for the
		*	specified namespace.
		*
		* Results:
		*	The method will return when successful; in this case the object
		*	referenced by obj has each export pattern appended to it. If an
		*	error occurs, an exception and the interpreter's result
		*	holds an error message.
		*
		* Side effects:
		*	If necessary, the object referenced by obj is converted into
		*	a list object.
		*
		*----------------------------------------------------------------------
		*/
		
		internal static void  appendExportList(Interp interp, Namespace namespace_Renamed, TclObject obj)
		{
			Namespace ns;
			int i;
			
			// If the specified namespace is null, use the current namespace.
			
			if (namespace_Renamed == null)
			{
				ns = getCurrentNamespace(interp);
			}
			else
			{
				ns = namespace_Renamed;
			}
			
			// Append the export pattern list onto objPtr.
			
			for (i = 0; i < ns.numExportPatterns; i++)
			{
				TclList.append(interp, obj, TclString.newInstance(ns.exportArray[i]));
			}
			return ;
		}
		
		
		/*
		*----------------------------------------------------------------------
		*
		* Tcl_Import -> importList
		*
		*	Imports all of the commands matching a pattern into the namespace
		*	specified by namespace (or the current namespace if namespace
		*	is null). This is done by creating a new command (the "imported
		*	command") that points to the real command in its original namespace.
		*
		*      If matching commands are on the autoload path but haven't been
		*	loaded yet, this command forces them to be loaded, then creates
		*	the links to them.
		*
		* Results:
		*  Returns if successful, raises TclException if something goes wrong.
		*
		* Side effects:
		*	Creates new commands in the importing namespace. These indirect
		*	calls back to the real command and are deleted if the real commands
		*	are deleted.
		*
		*----------------------------------------------------------------------
		*/
		
		internal static void  importList(Interp interp, Namespace namespace_Renamed, string pattern, bool allowOverwrite)
		{
			Namespace ns, importNs;
			Namespace currNs = getCurrentNamespace(interp);
			string simplePattern, cmdName;
			IEnumerator search;
			WrappedCommand cmd, realCmd;
			ImportRef ref_Renamed;
			WrappedCommand autoCmd, importedCmd;
			ImportedCmdData data;
			bool wasExported;
			int i, result;
			
			// If the specified namespace is null, use the current namespace.
			
			if (namespace_Renamed == null)
			{
				ns = currNs;
			}
			else
			{
				ns = namespace_Renamed;
			}
			
			// First, invoke the "auto_import" command with the pattern
			// being imported.  This command is part of the Tcl library.
			// It looks for imported commands in autoloaded libraries and
			// loads them in.  That way, they will be found when we try
			// to create links below.
			
			autoCmd = findCommand(interp, "auto_import", null, TCL.VarFlag.GLOBAL_ONLY);
			
			if (autoCmd != null)
			{
				TclObject[] objv = new TclObject[2];
				
				objv[0] = TclString.newInstance("auto_import");
				objv[0].preserve();
				objv[1] = TclString.newInstance(pattern);
				objv[1].preserve();
				
				cmd = autoCmd;
				try
				{
					// Invoke the command with the arguments
					cmd.cmd.cmdProc(interp, objv);
				}
				finally
				{
					objv[0].release();
					objv[1].release();
				}
				
				interp.resetResult();
			}
			
			// From the pattern, find the namespace from which we are importing
			// and get the simple pattern (no namespace qualifiers or ::'s) at
			// the end.
			
			if (pattern.Length == 0)
			{
				throw new TclException(interp, "empty import pattern");
			}
			
			// Java does not support passing an address so we pass
			// an array of size 1 and then assign arr[0] to the value
			Namespace[] importNsArr = new Namespace[1];
			Namespace[] dummyArr = new Namespace[1];
			string[] simplePatternArr = new string[1];
			
			getNamespaceForQualName(interp, pattern, ns, TCL.VarFlag.LEAVE_ERR_MSG, importNsArr, dummyArr, dummyArr, simplePatternArr);
			
			importNs = importNsArr[0];
			simplePattern = simplePatternArr[0];
			
			if (importNs == null)
			{
				throw new TclException(interp, "unknown namespace in import pattern \"" + pattern + "\"");
			}
			if (importNs == ns)
			{
				if ((System.Object) pattern == (System.Object) simplePattern)
				{
					throw new TclException(interp, "no namespace specified in import pattern \"" + pattern + "\"");
				}
				else
				{
					throw new TclException(interp, "import pattern \"" + pattern + "\" tries to import from namespace \"" + importNs.name + "\" into itself");
				}
			}
			
			// Scan through the command table in the source namespace and look for
			// exported commands that match the string pattern. Create an "imported
			// command" in the current namespace for each imported command; these
			// commands redirect their invocations to the "real" command.
			
			
			for (search = importNs.cmdTable.Keys.GetEnumerator(); search.MoveNext(); )
			{
				
				cmdName = ((string) search.Current);
				if (Util.stringMatch(cmdName, simplePattern))
				{
					// The command cmdName in the source namespace matches the
					// pattern. Check whether it was exported. If it wasn't,
					// we ignore it.
					
					wasExported = false;
					for (i = 0; i < importNs.numExportPatterns; i++)
					{
						if (Util.stringMatch(cmdName, importNs.exportArray[i]))
						{
							wasExported = true;
							break;
						}
					}
					if (!wasExported)
					{
						continue;
					}
					
					// Unless there is a name clash, create an imported command
					// in the current namespace that refers to cmdPtr.
					
					if ((ns.cmdTable[cmdName] == null) || allowOverwrite)
					{
						// Create the imported command and its client data.
						// To create the new command in the current namespace, 
						// generate a fully qualified name for it.
						
						System.Text.StringBuilder ds;
						
						ds = new System.Text.StringBuilder();
						ds.Append(ns.fullName);
						if (ns != interp.globalNs)
						{
							ds.Append("::");
						}
						ds.Append(cmdName);
						
						// Check whether creating the new imported command in the
						// current namespace would create a cycle of imported->real
						// command references that also would destroy an existing
						// "real" command already in the current namespace.
						
						cmd = (WrappedCommand) importNs.cmdTable[cmdName];
						
						if (cmd.cmd is ImportedCmdData)
						{
							// This is actually an imported command, find
							// the real command it references
							realCmd = getOriginalCommand(cmd);
							if ((realCmd != null) && (realCmd.ns == currNs) && (currNs.cmdTable[cmdName] != null))
							{
								throw new TclException(interp, "import pattern \"" + pattern + "\" would create a loop containing command \"" + ds.ToString() + "\"");
							}
						}
						
						data = new ImportedCmdData();
						
						// Create the imported command inside the interp
						interp.createCommand(ds.ToString(), data);
						
						// Lookup in the namespace for the new WrappedCommand
						importedCmd = findCommand(interp, ds.ToString(), ns, (TCL.VarFlag.NAMESPACE_ONLY | TCL.VarFlag.LEAVE_ERR_MSG));
						
						data.realCmd = cmd;
						data.self = importedCmd;
						
						// Create an ImportRef structure describing this new import
						// command and add it to the import ref list in the "real"
						// command.
						
						ref_Renamed = new ImportRef();
						ref_Renamed.importedCmd = importedCmd;
						ref_Renamed.next = cmd.importRef;
						cmd.importRef = ref_Renamed;
					}
					else
					{
						throw new TclException(interp, "can't import command \"" + cmdName + "\": already exists");
					}
				}
			}
			return ;
		}
		
		/*
		*----------------------------------------------------------------------
		*
		* Tcl_ForgetImport -> forgetImport
		*
		*	Deletes previously imported commands. Given a pattern that may
		*	include the name of an exporting namespace, this procedure first
		*	finds all matching exported commands. It then looks in the namespace
		*	specified by namespace for any corresponding previously imported
		*	commands, which it deletes. If namespace is null, commands are
		*	deleted from the current namespace.
		*
		* Results:
		*  Returns if successful, raises TclException if something goes wrong.
		*
		* Side effects:
		*	May delete commands. 
		*
		*----------------------------------------------------------------------
		*/
		
		internal static void  forgetImport(Interp interp, Namespace namespace_Renamed, string pattern)
		{
			Namespace ns, importNs, actualCtx;
			string simplePattern, cmdName;
			IEnumerator search;
			WrappedCommand cmd;
			
			// If the specified namespace is null, use the current namespace.
			
			if (namespace_Renamed == null)
			{
				ns = getCurrentNamespace(interp);
			}
			else
			{
				ns = namespace_Renamed;
			}
			
			// From the pattern, find the namespace from which we are importing
			// and get the simple pattern (no namespace qualifiers or ::'s) at
			// the end.
			
			// Java does not support passing an address so we pass
			// an array of size 1 and then assign arr[0] to the value
			Namespace[] importNsArr = new Namespace[1];
			Namespace[] dummyArr = new Namespace[1];
			Namespace[] actualCtxArr = new Namespace[1];
			string[] simplePatternArr = new string[1];
			
			getNamespaceForQualName(interp, pattern, ns, TCL.VarFlag.LEAVE_ERR_MSG, importNsArr, dummyArr, actualCtxArr, simplePatternArr);
			
			// get the values out of the arrays
			importNs = importNsArr[0];
			actualCtx = actualCtxArr[0];
			simplePattern = simplePatternArr[0];
			
			// FIXME : the above call passes TCL.VarFlag.LEAVE_ERR_MSG, but
			// it seems like this will be a problem when exception is raised!
			if (importNs == null)
			{
				throw new TclException(interp, "unknown namespace in namespace forget pattern \"" + pattern + "\"");
			}
			
			// Scan through the command table in the source namespace and look for
			// exported commands that match the string pattern. If the current
			// namespace has an imported command that refers to one of those real
			// commands, delete it.
			
			
			for (search = importNs.cmdTable.Keys.GetEnumerator(); search.MoveNext(); )
			{
				
				cmdName = ((string) search.Current);
				if (Util.stringMatch(cmdName, simplePattern))
				{
					cmd = (WrappedCommand) ns.cmdTable[cmdName];
					if (cmd != null)
					{
						// cmd of same name in current namespace
						if (cmd.cmd is ImportedCmdData)
						{
							interp.deleteCommandFromToken(cmd);
						}
					}
				}
			}
			return ;
		}
		
		
		/*
		*----------------------------------------------------------------------
		*
		* TclGetOriginalCommand -> getOriginalCommand
		*
		*	An imported command is created in a namespace when a "real" command
		*	is imported from another namespace. If the specified command is an
		*	imported command, this procedure returns the original command it
		*	refers to.
		*
		* Results:
		*	If the command was imported into a sequence of namespaces a, b,...,n
		*	where each successive namespace just imports the command from the
		*	previous namespace, this procedure returns the Tcl_Command token in
		*	the first namespace, a. Otherwise, if the specified command is not
		*	an imported command, the procedure returns null.
		*
		* Side effects:
		*	None.
		*
		*----------------------------------------------------------------------
		*/
		
		internal static WrappedCommand getOriginalCommand(WrappedCommand command)
		{
			WrappedCommand cmd = command;
			ImportedCmdData data;
			
			if (!(cmd.cmd is ImportedCmdData))
			{
				return null;
			}
			
			while (cmd.cmd is ImportedCmdData)
			{
				data = (ImportedCmdData) cmd.cmd;
				cmd = data.realCmd;
			}
			return cmd;
		}
		
		
		/*
		*----------------------------------------------------------------------
		*
		* InvokeImportedCmd -> invokeImportedCmd
		*
		*	Invoked by Tcl whenever the user calls an imported command that
		*	was created by Tcl_Import. Finds the "real" command (in another
		*	namespace), and passes control to it.
		*
		* Results:
		*	Returns if successful, raises TclException if something goes wrong.
		*
		* Side effects:
		*	Returns a result in the interpreter's result object. If anything
		*	goes wrong, the result object is set to an error message.
		*
		*----------------------------------------------------------------------
		*/
		
		internal static void  invokeImportedCmd(Interp interp, ImportedCmdData data, TclObject[] objv)
		{
			WrappedCommand realCmd = data.realCmd;
			realCmd.cmd.cmdProc(interp, objv);
		}
		
		
		/*
		*----------------------------------------------------------------------
		*
		* DeleteImportedCmd -> deleteImportedCmd
		*
		*	Invoked by Tcl whenever an imported command is deleted. The "real"
		*	command keeps a list of all the imported commands that refer to it,
		*	so those imported commands can be deleted when the real command is
		*	deleted. This procedure removes the imported command reference from
		*	the real command's list, and frees up the memory associated with
		*	the imported command.
		*
		* Results:
		*	None.
		*
		* Side effects:
		*	Removes the imported command from the real command's import list.
		*
		*----------------------------------------------------------------------
		*/
		
		internal static void  deleteImportedCmd(ImportedCmdData data)
		// The data object for this imported command
		{
			WrappedCommand realCmd = data.realCmd;
			WrappedCommand self = data.self;
			ImportRef ref_Renamed, prev;
			
			prev = null;
			for (ref_Renamed = realCmd.importRef; ref_Renamed != null; ref_Renamed = ref_Renamed.next)
			{
				if (ref_Renamed.importedCmd == self)
				{
					// Remove ref from real command's list of imported commands
					// that refer to it.
					
					if (prev == null)
					{
						// ref is first in list
						realCmd.importRef = ref_Renamed.next;
					}
					else
					{
						prev.next = ref_Renamed.next;
					}
					ref_Renamed = null;
					data = null;
					return ;
				}
				prev = ref_Renamed;
			}
			
			throw new TclRuntimeError("DeleteImportedCmd: did not find cmd in real cmd's list of import references");
		}
		
		/*
		*----------------------------------------------------------------------
		*
		* TclGetNamespaceForQualName -> getNamespaceForQualName
		*
		*	Given a qualified name specifying a command, variable, or namespace,
		*	and a namespace in which to resolve the name, this procedure returns
		*	a pointer to the namespace that contains the item. A qualified name
		*	consists of the "simple" name of an item qualified by the names of
		*	an arbitrary number of containing namespace separated by "::"s. If
		*	the qualified name starts with "::", it is interpreted absolutely
		*	from the global namespace. Otherwise, it is interpreted relative to
		*	the namespace specified by cxtNsPtr if it is non-null. If cxtNsPtr
		*	is null, the name is interpreted relative to the current namespace.
		*
		*	A relative name like "foo::bar::x" can be found starting in either
		*	the current namespace or in the global namespace. So each search
		*	usually follows two tracks, and two possible namespaces are
		*	returned. If the procedure sets either nsPtrPtr[0] or altNsPtrPtr[0] to
		*	null, then that path failed.
		*
		*	If "flags" contains TCL.VarFlag.GLOBAL_ONLY, the relative qualified name is
		*	sought only in the global :: namespace. The alternate search
		*	(also) starting from the global namespace is ignored and
		*	altNsPtrPtr[0] is set null. 
		*
		*	If "flags" contains TCL.VarFlag.NAMESPACE_ONLY, the relative qualified
		*	name is sought only in the namespace specified by cxtNsPtr. The
		*	alternate search starting from the global namespace is ignored and
		*	altNsPtrPtr[0] is set null. If both TCL.VarFlag.GLOBAL_ONLY and
		*	TCL.VarFlag.NAMESPACE_ONLY are specified, TCL.VarFlag.GLOBAL_ONLY is ignored and
		*	the search starts from the namespace specified by cxtNsPtr.
		*
		*	If "flags" contains TCL.VarFlag.CREATE_NS_IF_UNKNOWN, all namespace
		*	components of the qualified name that cannot be found are
		*	automatically created within their specified parent. This makes sure
		*	that functions like Tcl_CreateCommand always succeed. There is no
		*	alternate search path, so altNsPtrPtr[0] is set null.
		*
		*	If "flags" contains TCL.VarFlag.FIND_ONLY_NS, the qualified name is treated as a
		*	reference to a namespace, and the entire qualified name is
		*	followed. If the name is relative, the namespace is looked up only
		*	in the current namespace. A pointer to the namespace is stored in
		*	nsPtrPtr[0] and null is stored in simpleNamePtr[0]. Otherwise, if
		*	TCL.VarFlag.FIND_ONLY_NS is not specified, only the leading components are
		*	treated as namespace names, and a pointer to the simple name of the
		*	final component is stored in simpleNamePtr[0].
		*
		* Results:
		*	It sets nsPtrPtr[0] and altNsPtrPtr[0] to point to the two possible
		*	namespaces which represent the last (containing) namespace in the
		*	qualified name. If the procedure sets either nsPtrPtr[0] or altNsPtrPtr[0]
		*	to null, then the search along that path failed.  The procedure also
		*	stores a pointer to the simple name of the final component in
		*	simpleNamePtr[0]. If the qualified name is "::" or was treated as a
		*	namespace reference (TCL.VarFlag.FIND_ONLY_NS), the procedure stores a pointer
		*	to the namespace in nsPtrPtr[0], null in altNsPtrPtr[0], and sets
		*	simpleNamePtr[0] to an empty string.
		*
		*	If there is an error, this procedure returns TCL_ERROR. If "flags"
		*	contains TCL_LEAVE_ERR_MSG, an error message is returned in the
		*	interpreter's result object. Otherwise, the interpreter's result
		*	object is left unchanged.
		*
		*	actualCxtPtrPtr[0] is set to the actual context namespace. It is
		*	set to the input context namespace pointer in cxtNsPtr. If cxtNsPtr
		*	is null, it is set to the current namespace context.
		*
		* Side effects:
		*	If "flags" contains TCL.VarFlag.CREATE_NS_IF_UNKNOWN, new namespaces may be
		*	created.
		*
		*----------------------------------------------------------------------
		*/
		
		internal static void  getNamespaceForQualName(Interp interp, string qualName, Namespace cxtNsPtr, TCL.VarFlag flags, Namespace[] nsPtrPtr, Namespace[] altNsPtrPtr, Namespace[] actualCxtPtrPtr, string[] simpleNamePtr)
		{
			
			
			// FIXME : remove extra method call checks when we are sure this works!
			
			if (true)
			{
				// check invariants
				if ((nsPtrPtr == null) || (nsPtrPtr.Length != 1))
				{
					
					throw new System.SystemException("nsPtrPtr " + nsPtrPtr);
				}
				if ((altNsPtrPtr == null) || (altNsPtrPtr.Length != 1))
				{
					
					throw new System.SystemException("altNsPtrPtr " + altNsPtrPtr);
				}
				if ((actualCxtPtrPtr == null) || (actualCxtPtrPtr.Length != 1))
				{
					
					throw new System.SystemException("actualCxtPtrPtr " + actualCxtPtrPtr);
				}
				if ((simpleNamePtr == null) || (simpleNamePtr.Length != 1))
				{
					
					throw new System.SystemException("simpleNamePtr " + simpleNamePtr);
				}
			}
			
			
			
			
			Namespace ns = cxtNsPtr;
			Namespace altNs;
			Namespace globalNs = getGlobalNamespace(interp);
			Namespace entryNs;
			string start, end;
			string nsName;
			int len;
			int start_ind, end_ind, name_len;
			
			// Determine the context namespace ns in which to start the primary
			// search. If TCL.VarFlag.NAMESPACE_ONLY or TCL.VarFlag.FIND_ONLY_NS was specified, search
			// from the current namespace. If the qualName name starts with a "::"
			// or TCL.VarFlag.GLOBAL_ONLY was specified, search from the global
			// namespace. Otherwise, use the given namespace given in cxtNsPtr, or
			// if that is null, use the current namespace context. Note that we
			// always treat two or more adjacent ":"s as a namespace separator.
			
			if ((flags & (TCL.VarFlag.NAMESPACE_ONLY | TCL.VarFlag.FIND_ONLY_NS)) != 0)
			{
				ns = getCurrentNamespace(interp);
			}
			else if ((flags & TCL.VarFlag.GLOBAL_ONLY) != 0)
			{
				ns = globalNs;
			}
			else if (ns == null)
			{
				if (interp.varFrame != null)
				{
					ns = interp.varFrame.ns;
				}
				else
				{
					ns = interp.globalNs;
				}
			}
			
			
			
			start_ind = 0;
			name_len = qualName.Length;
			
			if ((name_len >= 2) && (qualName[0] == ':') && (qualName[1] == ':'))
			{
				start_ind = 2; // skip over the initial ::
				
				while ((start_ind < name_len) && (qualName[start_ind] == ':'))
				{
					start_ind++; // skip over a subsequent :
				}
				
				ns = globalNs;
				if (start_ind >= name_len)
				{
					// qualName is just two or more ":"s
					nsPtrPtr[0] = globalNs;
					altNsPtrPtr[0] = null;
					actualCxtPtrPtr[0] = globalNs;
					simpleNamePtr[0] = ""; // points to empty string
					return ;
				}
			}
			actualCxtPtrPtr[0] = ns;
			
			
			// Start an alternate search path starting with the global namespace.
			// However, if the starting context is the global namespace, or if the
			// flag is set to search only the namespace cxtNs, ignore the
			// alternate search path.
			
			
			altNs = globalNs;
			if ((ns == globalNs) || ((flags & (TCL.VarFlag.NAMESPACE_ONLY | TCL.VarFlag.FIND_ONLY_NS)) != 0))
			{
				altNs = null;
			}
			
			
			// Loop to resolve each namespace qualifier in qualName.	
			
			end_ind = start_ind;
			
			while (start_ind < name_len)
			{
				// Find the next namespace qualifier (i.e., a name ending in "::")
				// or the end of the qualified name  (i.e., a name ending in "\0").
				// Set len to the number of characters, starting from start,
				// in the name; set end to point after the "::"s or at the "\0".
				
				len = 0;
				for (end_ind = start_ind; end_ind < name_len; end_ind++)
				{
					if (((name_len - end_ind) > 1) && (qualName[end_ind] == ':') && (qualName[end_ind + 1] == ':'))
					{
						end_ind += 2; // skip over the initial ::
						while ((end_ind < name_len) && (qualName[end_ind] == ':'))
						{
							end_ind++; // skip over a subsequent :
						}
						break;
					}
					len++;
				}
				
				
				if ((end_ind == name_len) && !((end_ind - start_ind >= 2) && ((qualName[end_ind - 1] == ':') && (qualName[end_ind - 2] == ':'))))
				{
					
					// qualName ended with a simple name at start. If TCL.VarFlag.FIND_ONLY_NS
					// was specified, look this up as a namespace. Otherwise,
					// start is the name of a cmd or var and we are done.
					
					if ((flags & TCL.VarFlag.FIND_ONLY_NS) != 0)
					{
						// assign the string from start_ind to the end of the name string
						nsName = qualName.Substring(start_ind);
					}
					else
					{
						nsPtrPtr[0] = ns;
						altNsPtrPtr[0] = altNs;
						simpleNamePtr[0] = qualName.Substring(start_ind);
						return ;
					}
				}
				else
				{
					// start points to the beginning of a namespace qualifier ending
					// in "::". Create new string with the namespace qualifier.
					
					nsName = qualName.Substring(start_ind, (start_ind + len) - (start_ind));
				}
				
				
				
				// Look up the namespace qualifier nsName in the current namespace
				// context. If it isn't found but TCL.VarFlag.CREATE_NS_IF_UNKNOWN is set,
				// create that qualifying namespace. This is needed for procedures
				// like Tcl_CreateCommand that cannot fail.
				
				if (ns != null)
				{
					entryNs = (Namespace) ns.childTable[nsName];
					if (entryNs != null)
					{
						ns = entryNs;
					}
					else if ((flags & TCL.VarFlag.CREATE_NS_IF_UNKNOWN) != 0)
					{
						CallFrame frame = interp.newCallFrame();
						
						pushCallFrame(interp, frame, ns, false);
						ns = createNamespace(interp, nsName, null);
						
						popCallFrame(interp);
						if (ns == null)
						{
							throw new System.SystemException("Could not create namespace " + nsName);
						}
					}
					else
					{
						ns = null; // namespace not found and wasn't created
					}
				}
				
				
				// Look up the namespace qualifier in the alternate search path too.
				
				if (altNs != null)
				{
					altNs = (Namespace) altNs.childTable[nsName];
				}
				
				// If both search paths have failed, return null results.
				
				if ((ns == null) && (altNs == null))
				{
					nsPtrPtr[0] = null;
					altNsPtrPtr[0] = null;
					simpleNamePtr[0] = null;
					return ;
				}
				
				start_ind = end_ind;
			}
			
			
			// We ignore trailing "::"s in a namespace name, but in a command or
			// variable name, trailing "::"s refer to the cmd or var named {}.
			
			if (((flags & TCL.VarFlag.FIND_ONLY_NS) != 0) || ((end_ind > start_ind) && (qualName[end_ind - 1] != ':')))
			{
				simpleNamePtr[0] = null; // found namespace name
			}
			else
			{
				// FIXME : make sure this does not throw exception when end_ind is at the end of the string 
				simpleNamePtr[0] = qualName.Substring(end_ind); // found cmd/var: points to empty string
			}
			
			
			// As a special case, if we are looking for a namespace and qualName
			// is "" and the current active namespace (ns) is not the global
			// namespace, return null (no namespace was found). This is because
			// namespaces can not have empty names except for the global namespace.
			
			if (((flags & TCL.VarFlag.FIND_ONLY_NS) != 0) && (name_len == 0) && (ns != globalNs))
			{
				ns = null;
			}
			
			nsPtrPtr[0] = ns;
			altNsPtrPtr[0] = altNs;
			return ;
		}
		
		
		/*
		*----------------------------------------------------------------------
		*
		* Tcl_FindNamespace -> findNamespace
		*
		*	Searches for a namespace.
		*
		* Results:T
		*	Returns a reference to the namespace if it is found. Otherwise,
		*	returns null and leaves an error message in the interpreter's
		*	result object if "flags" contains TCL.VarFlag.LEAVE_ERR_MSG.
		*
		* Side effects:
		*	None.
		*
		*----------------------------------------------------------------------
		*/
		
		internal static Namespace findNamespace(Interp interp, string name, Namespace contextNs, TCL.VarFlag flags)
		{
			Namespace ns;
			
			// Java does not support passing an address so we pass
			// an array of size 1 and then assign arr[0] to the value
			Namespace[] nsArr = new Namespace[1];
			Namespace[] dummy1Arr = new Namespace[1];
			string[] dummy2Arr = new string[1];
			
			// Find the namespace(s) that contain the specified namespace name.
			// Add the TCL.VarFlag.FIND_ONLY_NS flag to resolve the name all the way down
			// to its last component, a namespace.
			
			getNamespaceForQualName(interp, name, contextNs, (flags | TCL.VarFlag.FIND_ONLY_NS), nsArr, dummy1Arr, dummy1Arr, dummy2Arr);
			
			
			// Get the values out of the arrays!
			ns = nsArr[0];
			
			if (ns != null)
			{
				return ns;
			}
			else if ((flags & TCL.VarFlag.LEAVE_ERR_MSG) != 0)
			{
				/*
				interp.resetResult();
				TclString.append(interp.getResult(), "unknown namespace \"" + name + "\"");
				*/
				
				// FIXME : is there a test case for this error?
				interp.setResult("unknown namespace \"" + name + "\"");
			}
			return null;
		}
		
		
		
		/*
		*----------------------------------------------------------------------
		*
		* Tcl_FindCommand -> findCommand
		*
		*	Searches for a command.
		*
		* Results:
		*	Returns a token for the command if it is found. Otherwise, if it
		*	can't be found or there is an error, returns null and leaves an
		*	error message in the interpreter's result object if "flags"
		*	contains TCL.VarFlag.LEAVE_ERR_MSG.
		*
		* Side effects:
		*	None.
		*
		*----------------------------------------------------------------------
		*/
		
		internal static WrappedCommand findCommand(Interp interp, string name, Namespace contextNs, TCL.VarFlag flags)
		{
			Interp.ResolverScheme res;
			Namespace cxtNs;
			Namespace[] ns = new Namespace[2];
			string simpleName;
			int search;
			//int result;
			WrappedCommand cmd;
			
			// If this namespace has a command resolver, then give it first
			// crack at the command resolution.  If the interpreter has any
			// command resolvers, consult them next.  The command resolver
			// procedures may return a Tcl_Command value, they may signal
			// to continue onward, or they may signal an error.
			
			if ((flags & TCL.VarFlag.GLOBAL_ONLY) != 0)
			{
				cxtNs = getGlobalNamespace(interp);
			}
			else if (contextNs != null)
			{
				cxtNs = contextNs;
			}
			else
			{
				cxtNs = getCurrentNamespace(interp);
			}
			
			if (cxtNs.resolver != null || interp.resolvers != null)
			{
				try
				{
					if (cxtNs.resolver != null)
					{
						cmd = cxtNs.resolver.resolveCmd(interp, name, cxtNs, flags);
					}
					else
					{
						cmd = null;
					}
					
					if (cmd == null && interp.resolvers != null)
					{
						IEnumerator enum_Renamed = interp.resolvers.GetEnumerator();
						while (cmd == null && enum_Renamed.MoveNext())
						{
							res = (Interp.ResolverScheme) enum_Renamed.Current;
							cmd = res.resolver.resolveCmd(interp, name, cxtNs, flags);
						}
					}
					
					if (cmd != null)
					{
						return cmd;
					}
				}
				catch (TclException e)
				{
					return null;
				}
			}
			
			// Java does not support passing an address so we pass
			// an array of size 1 and then assign arr[0] to the value
			Namespace[] ns0Arr = new Namespace[1];
			Namespace[] ns1Arr = new Namespace[1];
			Namespace[] cxtNsArr = new Namespace[1];
			string[] simpleNameArr = new string[1];
			
			
			// Find the namespace(s) that contain the command.
			
			getNamespaceForQualName(interp, name, contextNs, flags, ns0Arr, ns1Arr, cxtNsArr, simpleNameArr);
			
			// Get the values out of the arrays!
			ns[0] = ns0Arr[0];
			ns[1] = ns1Arr[0];
			cxtNs = cxtNsArr[0];
			simpleName = simpleNameArr[0];
			
			
			
			// Look for the command in the command table of its namespace.
			// Be sure to check both possible search paths: from the specified
			// namespace context and from the global namespace.
			
			cmd = null;
			for (search = 0; (search < 2) && (cmd == null); search++)
			{
				if ((ns[search] != null) && ((System.Object) simpleName != null))
				{
					cmd = (WrappedCommand) ns[search].cmdTable[simpleName];
				}
			}
			if (cmd != null)
			{
				return cmd;
			}
			else if ((flags & TCL.VarFlag.LEAVE_ERR_MSG) != 0)
			{
				throw new TclException(interp, "unknown command \"" + name + "\"");
			}
			
			return null;
		}
		
		
		
		/*
		*----------------------------------------------------------------------
		*
		* Tcl_FindNamespaceVar -> findNamespaceVar
		*
		*	Searches for a namespace variable, a variable not local to a
		*	procedure. The variable can be either a scalar or an array, but
		*	may not be an element of an array.
		*
		* Results:
		*	Returns a token for the variable if it is found. Otherwise, if it
		*	can't be found or there is an error, returns null and leaves an
		*	error message in the interpreter's result object if "flags"
		*	contains TCL.VarFlag.LEAVE_ERR_MSG.
		*
		* Side effects:
		*	None.
		*
		*----------------------------------------------------------------------
		*/
		
		internal static Var findNamespaceVar(Interp interp, string name, Namespace contextNs,TCL.VarFlag flags)
		{
			Interp.ResolverScheme res;
			Namespace cxtNs;
			Namespace[] ns = new Namespace[2];
			string simpleName;
			int search;
			//int result;
			Var var;
			
			// If this namespace has a variable resolver, then give it first
			// crack at the variable resolution.  It may return a Tcl_Var
			// value, it may signal to continue onward, or it may signal
			// an error.
			
			if ((flags & TCL.VarFlag.GLOBAL_ONLY) != 0)
			{
				cxtNs = getGlobalNamespace(interp);
			}
			else if (contextNs != null)
			{
				cxtNs = contextNs;
			}
			else
			{
				cxtNs = getCurrentNamespace(interp);
			}
			
			if (cxtNs.resolver != null || interp.resolvers != null)
			{
				try
				{
					if (cxtNs.resolver != null)
					{
						var = cxtNs.resolver.resolveVar(interp, name, cxtNs, flags);
					}
					else
					{
						var = null;
					}
					
					if (var == null && interp.resolvers != null)
					{
						IEnumerator enum_Renamed = interp.resolvers.GetEnumerator();
						while (var == null && enum_Renamed.MoveNext())
						{
							res = (Interp.ResolverScheme) enum_Renamed.Current;
							var = res.resolver.resolveVar(interp, name, cxtNs, flags);
						}
					}
					
					if (var != null)
					{
						return var;
					}
				}
				catch (TclException e)
				{
					return null;
				}
			}
			
			// Java does not support passing an address so we pass
			// an array of size 1 and then assign arr[0] to the value
			Namespace[] ns0Arr = new Namespace[1];
			Namespace[] ns1Arr = new Namespace[1];
			Namespace[] cxtNsArr = new Namespace[1];
			string[] simpleNameArr = new string[1];
			
			
			// Find the namespace(s) that contain the variable.
			
			getNamespaceForQualName(interp, name, contextNs, flags, ns0Arr, ns1Arr, cxtNsArr, simpleNameArr);
			
			// Get the values out of the arrays!
			ns[0] = ns0Arr[0];
			ns[1] = ns1Arr[0];
			cxtNs = cxtNsArr[0];
			simpleName = simpleNameArr[0];
			
			
			// Look for the variable in the variable table of its namespace.
			// Be sure to check both possible search paths: from the specified
			// namespace context and from the global namespace.
			
			var = null;
			for (search = 0; (search < 2) && (var == null); search++)
			{
				if ((ns[search] != null) && ((System.Object) simpleName != null))
				{
					var = (Var) ns[search].varTable[simpleName];
				}
			}
			if (var != null)
			{
				return var;
			}
			else if ((flags & TCL.VarFlag.LEAVE_ERR_MSG) != 0)
			{
				/*
				interp.resetResult();
				TclString.append(interp.getResult(), "unknown variable \"" + name + "\"");
				*/
				
				// FIXME : is there a test case for this error?
				interp.setResult("unknown variable \"" + name + "\"");
			}
			return null;
		}
		
		/*
		*----------------------------------------------------------------------
		*
		* GetNamespaceFromObj -> getNamespaceFromObj
		*
		*	Returns the namespace specified by the name in a TclObject.
		*
		* Results:
		*  This method will return the Namespace object whose name
		*  is stored in the obj argument. If the namespace can't be found,
		*  a TclException is raised.
		*
		* Side effects:
		*	May update the internal representation for the object, caching the
		*	namespace reference. The next time this procedure is called, the
		*	namespace value can be found quickly.
		*
		*	If anything goes wrong, an error message is left in the
		*	interpreter's result object.
		*
		*----------------------------------------------------------------------
		*/
		
		internal static Namespace getNamespaceFromObj(Interp interp, TclObject obj)
		{
			ResolvedNsName resName;
			Namespace ns;
			Namespace currNs = getCurrentNamespace(interp);
			int result;
			
			// Get the internal representation, converting to a namespace type if
			// needed. The internal representation is a ResolvedNsName that points
			// to the actual namespace.
			
			// FIXME : if NamespaceCmd is not the internal rep this needs to be changed!
			if (!(obj.InternalRep is NamespaceCmd))
			{
				setNsNameFromAny(interp, obj);
			}
			resName = ((NamespaceCmd) obj.InternalRep).otherValue;
			
			// Check the context namespace of the resolved symbol to make sure that
			// it is fresh. If not, then force another conversion to the namespace
			// type, to discard the old rep and create a new one. Note that we
			// verify that the namespace id of the cached namespace is the same as
			// the id when we cached it; this insures that the namespace wasn't
			// deleted and a new one created at the same address.
			
			ns = null;
			if ((resName != null) && (resName.refNs == currNs) && (resName.nsId == resName.ns.nsId))
			{
				ns = resName.ns;
				if ((ns.flags & NS_DEAD) != 0)
				{
					ns = null;
				}
			}
			if (ns == null)
			{
				// try again
				setNsNameFromAny(interp, obj);
				resName = ((NamespaceCmd) obj.InternalRep).otherValue;
				if (resName != null)
				{
					ns = resName.ns;
					if ((ns.flags & NS_DEAD) != 0)
					{
						ns = null;
					}
				}
			}
			return ns;
		}
		
		/// <summary>----------------------------------------------------------------------
		/// 
		/// Tcl_SetNamespaceResolvers -> setNamespaceResolver
		/// 
		/// Sets the command/variable resolution object for a namespace,
		/// thereby changing the way that command/variable names are
		/// interpreted.  This allows extension writers to support different
		/// name resolution schemes, such as those for object-oriented
		/// packages.
		/// 
		/// Command resolution is handled by the following method:
		/// 
		/// resolveCmd (Interp interp, String name,
		/// NamespaceCmd.Namespace context, int flags)
		/// throws TclException;
		/// 
		/// Whenever a command is executed or NamespaceCmd.findCommand is invoked
		/// within the namespace, this method is called to resolve the
		/// command name.  If this method is able to resolve the name,
		/// it should return the corresponding WrappedCommand.  Otherwise,
		/// the procedure can return null, and the command will
		/// be treated under the usual name resolution rules.  Or, it can
		/// throw a TclException, and the command will be considered invalid.
		/// 
		/// Variable resolution is handled by the following method:
		/// 
		/// resolveVar (Interp interp, String name,
		/// NamespaceCmd.Namespace context, int flags)
		/// throws TclException;
		/// 
		/// If this method is able to resolve the name, it should return
		/// the variable as Var object.  The method may also
		/// return null, and the variable will be treated under the usual
		/// name resolution rules.  Or, it can throw a TclException,
		/// and the variable will be considered invalid.
		/// 
		/// Results:
		/// See above.
		/// 
		/// Side effects:
		/// None.
		/// 
		/// ----------------------------------------------------------------------
		/// </summary>
		
		internal static void  setNamespaceResolver(Namespace namespace_Renamed, Resolver resolver)
		// command and variable resolution
		{
			//  Plug in the new command resolver.
			
			namespace_Renamed.resolver = resolver;
		}
		
		/// <summary>----------------------------------------------------------------------
		/// 
		/// Tcl_GetNamespaceResolvers -> getNamespaceResolver
		/// 
		/// Returns the current command/variable resolution object
		/// for a namespace.  By default, these objects are null.
		/// New objects can be installed by calling setNamespaceResolver,
		/// to provide new name resolution rules.
		/// 
		/// Results:
		/// Returns the esolver object assigned to this namespace.
		/// Returns null otherwise.
		/// 
		/// Side effects:
		/// None.
		/// 
		/// ----------------------------------------------------------------------
		/// </summary>
		
		internal static Resolver getNamespaceResolver(Namespace namespace_Renamed)
		// Namespace whose resolution rules
		// are being queried.
		{
			return namespace_Renamed.resolver;
		}
		
		/*
		*----------------------------------------------------------------------
		*
		* Tcl_NamespaceObjCmd -> cmdProc
		*
		*	Invoked to implement the "namespace" command that creates, deletes,
		*	or manipulates Tcl namespaces. Handles the following syntax:
		*
		*	    namespace children ?name? ?pattern?
		*	    namespace code arg
		*	    namespace current
		*	    namespace delete ?name name...?
		*	    namespace eval name arg ?arg...?
		*	    namespace export ?-clear? ?pattern pattern...?
		*	    namespace forget ?pattern pattern...?
		*	    namespace import ?-force? ?pattern pattern...?
		*	    namespace inscope name arg ?arg...?
		*	    namespace origin name
		*	    namespace parent ?name?
		*	    namespace qualifiers string
		*	    namespace tail string
		*	    namespace which ?-command? ?-variable? name
		*
		* Results:
		*	Returns if the command is successful. Raises Exception if
		*	anything goes wrong.
		*
		* Side effects:
		*	Based on the subcommand name (e.g., "import"), this procedure
		*	dispatches to a corresponding member commands in this class.
		*  This method's side effects depend on whatever that subcommand does.
		*----------------------------------------------------------------------
		*/
		
		private static readonly string[] validCmds = new string[]{"children", "code", "current", "delete", "eval", "export", "forget", "import", "inscope", "origin", "parent", "qualifiers", "tail", "which"};
		
		private const int OPT_CHILDREN = 0;
		private const int OPT_CODE = 1;
		private const int OPT_CURRENT = 2;
		private const int OPT_DELETE = 3;
		private const int OPT_EVAL = 4;
		private const int OPT_EXPORT = 5;
		private const int OPT_FORGET = 6;
		private const int OPT_IMPORT = 7;
		private const int OPT_INSCOPE = 8;
		private const int OPT_ORIGIN = 9;
		private const int OPT_PARENT = 10;
		private const int OPT_QUALIFIERS = 11;
		private const int OPT_TAIL = 12;
		private const int OPT_WHICH = 13;
		
		
		public TCL.CompletionCode cmdProc(Interp interp, TclObject[] objv)
		{
			
			int i, opt;
			
			if (objv.Length < 2)
			{
				throw new TclNumArgsException(interp, 1, objv, "subcommand ?arg ...?");
			}
			
			opt = TclIndex.get(interp, objv[1], validCmds, "option", 0);
			
			switch (opt)
			{
				
				case OPT_CHILDREN:  {
						childrenCmd(interp, objv);
            return TCL.CompletionCode.RETURN;
					}
				
				case OPT_CODE:  {
						codeCmd(interp, objv);
            return TCL.CompletionCode.RETURN;
					}
				
				case OPT_CURRENT:  {
						currentCmd(interp, objv);
            return TCL.CompletionCode.RETURN;
					}
				
				case OPT_DELETE:  {
						deleteCmd(interp, objv);
            return TCL.CompletionCode.RETURN;
					}
				
				case OPT_EVAL:  {
						evalCmd(interp, objv);
            return TCL.CompletionCode.RETURN;
					}
				
				case OPT_EXPORT:  {
						exportCmd(interp, objv);
            return TCL.CompletionCode.RETURN;
					}
				
				case OPT_FORGET:  {
						forgetCmd(interp, objv);
            return TCL.CompletionCode.RETURN;
					}
				
				case OPT_IMPORT:  {
						importCmd(interp, objv);
            return TCL.CompletionCode.RETURN;
					}
				
				case OPT_INSCOPE:  {
						inscopeCmd(interp, objv);
            return TCL.CompletionCode.RETURN;
					}
				
				case OPT_ORIGIN:  {
						originCmd(interp, objv);
            return TCL.CompletionCode.RETURN;
					}
				
				case OPT_PARENT:  {
						parentCmd(interp, objv);
            return TCL.CompletionCode.RETURN;
					}
				
				case OPT_QUALIFIERS:  {
						qualifiersCmd(interp, objv);
            return TCL.CompletionCode.RETURN;
					}
				
				case OPT_TAIL:  {
						tailCmd(interp, objv);
            return TCL.CompletionCode.RETURN;
					}
				
				case OPT_WHICH:  {
						whichCmd(interp, objv);
            return TCL.CompletionCode.RETURN;
					}
				} // end switch(opt)
        return TCL.CompletionCode.RETURN;
      }
		
		
		/*
		*----------------------------------------------------------------------
		*
		* NamespaceChildrenCmd -> childrenCmd
		*
		*	Invoked to implement the "namespace children" command that returns a
		*	list containing the fully-qualified names of the child namespaces of
		*	a given namespace. Handles the following syntax:
		*
		*	    namespace children ?name? ?pattern?
		*
		* Results:
		*  Nothing.
		*
		* Side effects:
		*	Returns a result in the interpreter's result object. If anything
		*	goes wrong, the result is an error message.
		*
		*----------------------------------------------------------------------
		*/
		
		private static void  childrenCmd(Interp interp, TclObject[] objv)
		{
			Namespace namespace_Renamed;
			Namespace ns;
			Namespace globalNs = getGlobalNamespace(interp);
			string pattern = null;
			System.Text.StringBuilder buffer;
			IEnumerator search;
			TclObject list, elem;
			
			// Get a pointer to the specified namespace, or the current namespace.
			
			if (objv.Length == 2)
			{
				ns = getCurrentNamespace(interp);
			}
			else if ((objv.Length == 3) || (objv.Length == 4))
			{
				ns = getNamespaceFromObj(interp, objv[2]);
				if (ns == null)
				{
					
					throw new TclException(interp, "unknown namespace \"" + objv[2].ToString() + "\" in namespace children command");
				}
			}
			else
			{
				throw new TclNumArgsException(interp, 2, objv, "?name? ?pattern?");
			}
			
			// Get the glob-style pattern, if any, used to narrow the search.
			
			buffer = new System.Text.StringBuilder();
			if (objv.Length == 4)
			{
				
				string name = objv[3].ToString();
				
				if (name.StartsWith("::"))
				{
					pattern = name;
				}
				else
				{
					buffer.Append(ns.fullName);
					if (ns != globalNs)
					{
						buffer.Append("::");
					}
					buffer.Append(name);
					pattern = buffer.ToString();
				}
			}
			
			// Create a list containing the full names of all child namespaces
			// whose names match the specified pattern, if any.
			
			list = TclList.newInstance();
			foreach (Namespace childNs in ns.childTable.Values) {
				if (((System.Object) pattern == null) || Util.stringMatch(childNs.fullName, pattern))
				{
					elem = TclString.newInstance(childNs.fullName);
					TclList.append(interp, list, elem);
				}
			}
			interp.setResult(list);
			return ;
		}
		
		
		/*
		*----------------------------------------------------------------------
		*
		* NamespaceCodeCmd -> codeCmd
		*
		*	Invoked to implement the "namespace code" command to capture the
		*	namespace context of a command. Handles the following syntax:
		*
		*	    namespace code arg
		*
		*	Here "arg" can be a list. "namespace code arg" produces a result
		*	equivalent to that produced by the command
		*
		*	    list namespace inscope [namespace current] $arg
		*
		*	However, if "arg" is itself a scoped value starting with
		*	"namespace inscope", then the result is just "arg".
		*
		* Results:
		*  Nothing.
		*
		* Side effects:
		*	If anything goes wrong, this procedure returns an error
		*	message as the result in the interpreter's result object.
		*
		*----------------------------------------------------------------------
		*/
		
		
		private static void  codeCmd(Interp interp, TclObject[] objv)
		{
			Namespace currNs;
			TclObject list, obj;
			string arg, p;
			int length;
			int p_ind;
			
			if (objv.Length != 3)
			{
				throw new TclNumArgsException(interp, 2, objv, "arg");
			}
			
			// If "arg" is already a scoped value, then return it directly.
			
			
			arg = objv[2].ToString();
			length = arg.Length;
			
			// FIXME : we need a test for this inscope code if there is not one already!
			if ((length > 17) && (arg[0] == 'n') && arg.StartsWith("namespace"))
			{
				for (p_ind = 9; (p_ind < length) && (arg[p_ind] == ' '); p_ind++)
				{
					// empty body: skip over spaces
				}
				if (((length - p_ind) >= 7) && (arg[p_ind] == 'i') && arg.Substring(p_ind).StartsWith("inscope"))
				{
					interp.setResult(objv[2]);
					return ;
				}
			}
			
			// Otherwise, construct a scoped command by building a list with
			// "namespace inscope", the full name of the current namespace, and 
			// the argument "arg". By constructing a list, we ensure that scoped
			// commands are interpreted properly when they are executed later,
			// by the "namespace inscope" command.
			
			list = TclList.newInstance();
			TclList.append(interp, list, TclString.newInstance("namespace"));
			TclList.append(interp, list, TclString.newInstance("inscope"));
			
			currNs = getCurrentNamespace(interp);
			if (currNs == getGlobalNamespace(interp))
			{
				obj = TclString.newInstance("::");
			}
			else
			{
				obj = TclString.newInstance(currNs.fullName);
			}
			
			TclList.append(interp, list, obj);
			TclList.append(interp, list, objv[2]);
			
			interp.setResult(list);
			return ;
		}
		
		/*
		*----------------------------------------------------------------------
		*
		* NamespaceCurrentCmd -> currentCmd
		*
		*	Invoked to implement the "namespace current" command which returns
		*	the fully-qualified name of the current namespace. Handles the
		*	following syntax:
		*
		*	    namespace current
		*
		* Results:
		*  Returns if successful, raises TclException if something goes wrong.
		*
		* Side effects:
		*	Returns a result in the interpreter's result object. If anything
		*	goes wrong, the result is an error message.
		*
		*----------------------------------------------------------------------
		*/
		
		private static void  currentCmd(Interp interp, TclObject[] objv)
		{
			
			Namespace currNs;
			
			if (objv.Length != 2)
			{
				throw new TclNumArgsException(interp, 2, objv, null);
			}
			
			// The "real" name of the global namespace ("::") is the null string,
			// but we return "::" for it as a convenience to programmers. Note that
			// "" and "::" are treated as synonyms by the namespace code so that it
			// is still easy to do things like:
			//
			//    namespace [namespace current]::bar { ... }
			
			currNs = getCurrentNamespace(interp);
			
			if (currNs == getGlobalNamespace(interp))
			{
				// FIXME : appending to te result really screws everything up!
				// need to figure out how to disallow this!
				//TclString.append(interp.getResult(), "::");
				interp.setResult("::");
			}
			else
			{
				//TclString.append(interp.getResult(), currNs.fullName);
				interp.setResult(currNs.fullName);
			}
		}
		
		/*
		*----------------------------------------------------------------------
		*
		* NamespaceDeleteCmd -> deleteCmd
		*
		*	Invoked to implement the "namespace delete" command to delete
		*	namespace(s). Handles the following syntax:
		*
		*	    namespace delete ?name name...?
		*
		*	Each name identifies a namespace. It may include a sequence of
		*	namespace qualifiers separated by "::"s. If a namespace is found, it
		*	is deleted: all variables and procedures contained in that namespace
		*	are deleted. If that namespace is being used on the call stack, it
		*	is kept alive (but logically deleted) until it is removed from the
		*	call stack: that is, it can no longer be referenced by name but any
		*	currently executing procedure that refers to it is allowed to do so
		*	until the procedure returns. If the namespace can't be found, this
		*	procedure returns an error. If no namespaces are specified, this
		*	command does nothing.
		*
		* Results:
		*  Returns if successful, raises TclException if something goes wrong.
		*
		* Side effects:
		*	Deletes the specified namespaces. If anything goes wrong, this
		*	procedure returns an error message in the interpreter's
		*	result object.
		*
		*----------------------------------------------------------------------
		*/
		
		private static void  deleteCmd(Interp interp, TclObject[] objv)
		{
			Namespace namespace_Renamed;
			string name;
			int i;
			
			if (objv.Length < 2)
			{
				throw new TclNumArgsException(interp, 2, objv, "?name name...?");
			}
			
			// Destroying one namespace may cause another to be destroyed. Break
			// this into two passes: first check to make sure that all namespaces on
			// the command line are valid, and report any errors.
			
			for (i = 2; i < objv.Length; i++)
			{
				
				name = objv[i].ToString();
				namespace_Renamed = findNamespace(interp, name, null, 0);
				
				if (namespace_Renamed == null)
				{
					
					throw new TclException(interp, "unknown namespace \"" + objv[i].ToString() + "\" in namespace delete command");
				}
			}
			
			// Okay, now delete each namespace.
			
			for (i = 2; i < objv.Length; i++)
			{
				
				name = objv[i].ToString();
				namespace_Renamed = findNamespace(interp, name, null, 0);
				
				if (namespace_Renamed != null)
				{
					deleteNamespace(namespace_Renamed);
				}
			}
		}
		
		/*
		*----------------------------------------------------------------------
		*
		* NamespaceEvalCmd -> evalCmd
		*
		*	Invoked to implement the "namespace eval" command. Executes
		*	commands in a namespace. If the namespace does not already exist,
		*	it is created. Handles the following syntax:
		*
		*	    namespace eval name arg ?arg...?
		*
		*	If more than one arg argument is specified, the command that is
		*	executed is the result of concatenating the arguments together with
		*	a space between each argument.
		*
		* Results:
		*  Returns if successful, raises TclException if something goes wrong.
		*
		* Side effects:
		*	Returns the result of the command in the interpreter's result
		*	object. If anything goes wrong, this procedure returns an error
		*	message as the result.
		*
		*----------------------------------------------------------------------
		*/
		
		private static void  evalCmd(Interp interp, TclObject[] objv)
		{
			Namespace namespace_Renamed;
			CallFrame frame;
			string cmd;
			string name;
			int length;
			
			if (objv.Length < 4)
			{
				throw new TclNumArgsException(interp, 2, objv, "name arg ?arg...?");
			}
			
			// Try to resolve the namespace reference, caching the result in the
			// namespace object along the way.
			
			namespace_Renamed = getNamespaceFromObj(interp, objv[2]);
			
			// If the namespace wasn't found, try to create it.
			
			if (namespace_Renamed == null)
			{
				
				name = objv[2].ToString();
				namespace_Renamed = createNamespace(interp, name, null);
				if (namespace_Renamed == null)
				{
					// FIXME : result hack, we get the interp result and throw it!
					
					throw new TclException(interp, interp.getResult().ToString());
				}
			}
			
			// Make the specified namespace the current namespace and evaluate
			// the command(s).
			
			frame = interp.newCallFrame();
			pushCallFrame(interp, frame, namespace_Renamed, false);
			
			try
			{
				if (objv.Length == 4)
				{
					interp.eval(objv[3], 0);
				}
				else
				{
					cmd = Util.concat(3, objv.Length, objv);
					
					// eval() will delete the object when it decrements its
					// refcount after eval'ing it.
					
					interp.eval(cmd); // do not pass TCL_EVAL_DIRECT, for compiler only
				}
			}
			catch (TclException ex)
			{
				if (ex.getCompletionCode() == TCL.CompletionCode.ERROR)
				{
					interp.addErrorInfo("\n    (in namespace eval \"" + namespace_Renamed.fullName + "\" script line " + interp.errorLine + ")");
				}
				throw ex;
			}
			finally
			{
				popCallFrame(interp);
			}
			
			return ;
		}
		
		
		/*
		*----------------------------------------------------------------------
		*
		* NamespaceExportCmd -> exportCmd
		*
		*	Invoked to implement the "namespace export" command that specifies
		*	which commands are exported from a namespace. The exported commands
		*	are those that can be imported into another namespace using
		*	"namespace import". Both commands defined in a namespace and
		*	commands the namespace has imported can be exported by a
		*	namespace. This command has the following syntax:
		*
		*	    namespace export ?-clear? ?pattern pattern...?
		*
		*	Each pattern may contain "string match"-style pattern matching
		*	special characters, but the pattern may not include any namespace
		*	qualifiers: that is, the pattern must specify commands in the
		*	current (exporting) namespace. The specified patterns are appended
		*	onto the namespace's list of export patterns.
		*
		*	To reset the namespace's export pattern list, specify the "-clear"
		*	flag.
		*
		*	If there are no export patterns and the "-clear" flag isn't given,
		*	this command returns the namespace's current export list.
		*
		* Results:
		*  Returns if successful, raises TclException if something goes wrong.
		*
		* Side effects:
		*	Returns a result in the interpreter's result object. If anything
		*	goes wrong, the result is an error message.
		*
		*----------------------------------------------------------------------
		*/
		
		
		private static void  exportCmd(Interp interp, TclObject[] objv)
		{
			Namespace currNs = getCurrentNamespace(interp);
			string pattern, inString;
			bool resetListFirst = false;
			int firstArg, patternCt, i;
			
			if (objv.Length < 2)
			{
				throw new TclNumArgsException(interp, 2, objv, "?-clear? ?pattern pattern...?");
			}
			
			// Process the optional "-clear" argument.
			
			firstArg = 2;
			if (firstArg < objv.Length)
			{
				
				inString = objv[firstArg].ToString();
				if (inString.Equals("-clear"))
				{
					resetListFirst = true;
					firstArg++;
				}
			}
			
			// If no pattern arguments are given, and "-clear" isn't specified,
			// return the namespace's current export pattern list.
			
			patternCt = (objv.Length - firstArg);
			if (patternCt == 0)
			{
				if (firstArg > 2)
				{
					return ;
				}
				else
				{
					// create list with export patterns
					TclObject list = TclList.newInstance();
					appendExportList(interp, currNs, list);
					interp.setResult(list);
					return ;
				}
			}
			
			// Add each pattern to the namespace's export pattern list.
			
			for (i = firstArg; i < objv.Length; i++)
			{
				
				pattern = objv[i].ToString();
				exportList(interp, currNs, pattern, ((i == firstArg)?resetListFirst:false));
			}
			return ;
		}
		
		
		/*
		*----------------------------------------------------------------------
		*
		* NamespaceForgetCmd -> forgetCmd
		*
		*	Invoked to implement the "namespace forget" command to remove
		*	imported commands from a namespace. Handles the following syntax:
		*
		*	    namespace forget ?pattern pattern...?
		*
		*	Each pattern is a name like "foo::*" or "a::b::x*". That is, the
		*	pattern may include the special pattern matching characters
		*	recognized by the "string match" command, but only in the command
		*	name at the end of the qualified name; the special pattern
		*	characters may not appear in a namespace name. All of the commands
		*	that match that pattern are checked to see if they have an imported
		*	command in the current namespace that refers to the matched
		*	command. If there is an alias, it is removed.
		*	
		* Results:
		*  Returns if successful, raises TclException if something goes wrong.
		*
		* Side effects:
		*	Imported commands are removed from the current namespace. If
		*	anything goes wrong, this procedure returns an error message in the
		*	interpreter's result object.
		*
		*----------------------------------------------------------------------
		*/
		
		
		private static void  forgetCmd(Interp interp, TclObject[] objv)
		{
			
			string pattern;
			int i;
			
			if (objv.Length < 2)
			{
				throw new TclNumArgsException(interp, 2, objv, "?pattern pattern...?");
			}
			
			for (i = 2; i < objv.Length; i++)
			{
				
				pattern = objv[i].ToString();
				forgetImport(interp, null, pattern);
			}
			return ;
		}
		
		
		/*
		*----------------------------------------------------------------------
		*
		* NamespaceImportCmd -> importCmd
		*
		*	Invoked to implement the "namespace import" command that imports
		*	commands into a namespace. Handles the following syntax:
		*
		*	    namespace import ?-force? ?pattern pattern...?
		*
		*	Each pattern is a namespace-qualified name like "foo::*",
		*	"a::b::x*", or "bar::p". That is, the pattern may include the
		*	special pattern matching characters recognized by the "string match"
		*	command, but only in the command name at the end of the qualified
		*	name; the special pattern characters may not appear in a namespace
		*	name. All of the commands that match the pattern and which are
		*	exported from their namespace are made accessible from the current
		*	namespace context. This is done by creating a new "imported command"
		*	in the current namespace that points to the real command in its
		*	original namespace; when the imported command is called, it invokes
		*	the real command.
		*
		*	If an imported command conflicts with an existing command, it is
		*	treated as an error. But if the "-force" option is included, then
		*	existing commands are overwritten by the imported commands.
		*	
		* Results:
		*  Returns if successful, raises TclException if something goes wrong.
		*
		* Side effects:
		*	Adds imported commands to the current namespace. If anything goes
		*	wrong, this procedure returns an error message in the interpreter's
		*	result object.
		*
		*----------------------------------------------------------------------
		*/
		
		
		private static void  importCmd(Interp interp, TclObject[] objv)
		{
			
			bool allowOverwrite = false;
			string inString, pattern;
			int i;
			int firstArg;
			
			if (objv.Length < 2)
			{
				throw new TclNumArgsException(interp, 2, objv, "?-force? ?pattern pattern...?");
			}
			
			// Skip over the optional "-force" as the first argument.
			
			firstArg = 2;
			if (firstArg < objv.Length)
			{
				
				inString = objv[firstArg].ToString();
				if (inString.Equals("-force"))
				{
					allowOverwrite = true;
					firstArg++;
				}
			}
			
			// Handle the imports for each of the patterns.
			
			for (i = firstArg; i < objv.Length; i++)
			{
				
				pattern = objv[i].ToString();
				importList(interp, null, pattern, allowOverwrite);
			}
			return ;
		}
		
		
		/*
		*----------------------------------------------------------------------
		*
		* NamespaceInscopeCmd -> inscopeCmd
		*
		*	Invoked to implement the "namespace inscope" command that executes a
		*	script in the context of a particular namespace. This command is not
		*	expected to be used directly by programmers; calls to it are
		*	generated implicitly when programs use "namespace code" commands
		*	to register callback scripts. Handles the following syntax:
		*
		*	    namespace inscope name arg ?arg...?
		*
		*	The "namespace inscope" command is much like the "namespace eval"
		*	command except that it has lappend semantics and the namespace must
		*	already exist. It treats the first argument as a list, and appends
		*	any arguments after the first onto the end as proper list elements.
		*	For example,
		*
		*	    namespace inscope ::foo a b c d
		*
		*	is equivalent to
		*
		*	    namespace eval ::foo [concat a [list b c d]]
		*
		*	This lappend semantics is important because many callback scripts
		*	are actually prefixes.
		*
		* Results:
		*  Returns if successful, raises TclException if something goes wrong.
		*
		* Side effects:
		*	Returns a result in the Tcl interpreter's result object.
		*
		*----------------------------------------------------------------------
		*/
		
		private static void  inscopeCmd(Interp interp, TclObject[] objv)
		{
			Namespace namespace_Renamed;
			CallFrame frame;
			int i, result;
			
			if (objv.Length < 4)
			{
				throw new TclNumArgsException(interp, 2, objv, "name arg ?arg...?");
			}
			
			// Resolve the namespace reference.
			
			namespace_Renamed = getNamespaceFromObj(interp, objv[2]);
			if (namespace_Renamed == null)
			{
				
				throw new TclException(interp, "unknown namespace \"" + objv[2].ToString() + "\" in inscope namespace command");
			}
			
			// Make the specified namespace the current namespace.
			
			frame = interp.newCallFrame();
			pushCallFrame(interp, frame, namespace_Renamed, false);
			
			
			// Execute the command. If there is just one argument, just treat it as
			// a script and evaluate it. Otherwise, create a list from the arguments
			// after the first one, then concatenate the first argument and the list
			// of extra arguments to form the command to evaluate.
			
			try
			{
				if (objv.Length == 4)
				{
					interp.eval(objv[3], 0);
				}
				else
				{
					TclObject[] concatObjv = new TclObject[2];
					TclObject list;
					string cmd;
					
					list = TclList.newInstance();
					for (i = 4; i < objv.Length; i++)
					{
						try
						{
							TclList.append(interp, list, objv[i]);
						}
						catch (TclException ex)
						{
							list.release(); // free unneeded obj
							throw ex;
						}
					}
					
					concatObjv[0] = objv[3];
					concatObjv[1] = list;
					cmd = Util.concat(0, 1, concatObjv);
					interp.eval(cmd); // do not pass TCL_EVAL_DIRECT, for compiler only
					list.release(); // we're done with the list object
				}
			}
			catch (TclException ex)
			{
				if (ex.getCompletionCode() == TCL.CompletionCode.ERROR)
				{
					interp.addErrorInfo("\n    (in namespace inscope \"" + namespace_Renamed.fullName + "\" script line " + interp.errorLine + ")");
				}
				throw ex;
			}
			finally
			{
				popCallFrame(interp);
			}
			
			return ;
		}
		
		
		/*
		*----------------------------------------------------------------------
		*
		* NamespaceOriginCmd -> originCmd
		*
		*	Invoked to implement the "namespace origin" command to return the
		*	fully-qualified name of the "real" command to which the specified
		*	"imported command" refers. Handles the following syntax:
		*
		*	    namespace origin name
		*
		* Results:
		*	An imported command is created in an namespace when that namespace
		*	imports a command from another namespace. If a command is imported
		*	into a sequence of namespaces a, b,...,n where each successive
		*	namespace just imports the command from the previous namespace, this
		*	command returns the fully-qualified name of the original command in
		*	the first namespace, a. If "name" does not refer to an alias, its
		*	fully-qualified name is returned. The returned name is stored in the
		*	interpreter's result object. This procedure returns TCL_OK if
		*	successful, and TCL_ERROR if anything goes wrong.
		*
		* Side effects:
		*	If anything goes wrong, this procedure returns an error message in
		*	the interpreter's result object.
		*
		*----------------------------------------------------------------------
		*/
		
		private static void  originCmd(Interp interp, TclObject[] objv)
		{
			WrappedCommand command, origCommand;
			
			if (objv.Length != 3)
			{
				throw new TclNumArgsException(interp, 2, objv, "name");
			}
			
			// FIXME : is this the right way to search for a command?
			
			//command = Tcl_GetCommandFromObj(interp, objv[2]);
			
			command = NamespaceCmd.findCommand(interp, objv[2].ToString(), null, 0);
			
			if (command == null)
			{
				
				throw new TclException(interp, "invalid command name \"" + objv[2].ToString() + "\"");
			}
			
			origCommand = getOriginalCommand(command);
			if (origCommand == null)
			{
				// The specified command isn't an imported command. Return the
				// command's name qualified by the full name of the namespace it
				// was defined in.
				
				interp.setResult(interp.getCommandFullName(command));
			}
			else
			{
				interp.setResult(interp.getCommandFullName(origCommand));
			}
			return ;
		}
		
		
		/*
		*----------------------------------------------------------------------
		*
		* NamespaceParentCmd -> parentCmd
		*
		*	Invoked to implement the "namespace parent" command that returns the
		*	fully-qualified name of the parent namespace for a specified
		*	namespace. Handles the following syntax:
		*
		*	    namespace parent ?name?
		*
		* Results:
		*  Returns if successful, raises TclException if something goes wrong.
		*
		* Side effects:
		*	Returns a result in the interpreter's result object. If anything
		*	goes wrong, the result is an error message.
		*
		*----------------------------------------------------------------------
		*/
		
		private static void  parentCmd(Interp interp, TclObject[] objv)
		{
			Namespace ns;
			
			if (objv.Length == 2)
			{
				ns = getCurrentNamespace(interp);
			}
			else if (objv.Length == 3)
			{
				ns = getNamespaceFromObj(interp, objv[2]);
				if (ns == null)
				{
					
					throw new TclException(interp, "unknown namespace \"" + objv[2].ToString() + "\" in namespace parent command");
				}
			}
			else
			{
				throw new TclNumArgsException(interp, 2, objv, "?name?");
			}
			
			// Report the parent of the specified namespace.
			
			if (ns.parent != null)
			{
				interp.setResult(ns.parent.fullName);
			}
		}
		
		
		/*
		*----------------------------------------------------------------------
		*
		* NamespaceQualifiersCmd -> qualifiersCmd
		*
		*	Invoked to implement the "namespace qualifiers" command that returns
		*	any leading namespace qualifiers in a string. These qualifiers are
		*	namespace names separated by "::"s. For example, for "::foo::p" this
		*	command returns "::foo", and for "::" it returns "". This command
		*	is the complement of the "namespace tail" command. Note that this
		*	command does not check whether the "namespace" names are, in fact,
		*	the names of currently defined namespaces. Handles the following
		*	syntax:
		*
		*	    namespace qualifiers string
		*
		* Results:
		*  Returns if successful, raises TclException if something goes wrong.
		*
		* Side effects:
		*	Returns a result in the interpreter's result object. If anything
		*	goes wrong, the result is an error message.
		*
		*----------------------------------------------------------------------
		*/
		
		private static void  qualifiersCmd(Interp interp, TclObject[] objv)
		{
			string name;
			int p;
			
			if (objv.Length != 3)
			{
				throw new TclNumArgsException(interp, 2, objv, "string");
			}
			
			// Find the end of the string, then work backward and find
			// the start of the last "::" qualifier.
			
			
			name = objv[2].ToString();
			p = name.Length;
			
			while (--p >= 0)
			{
				if ((name[p] == ':') && (p > 0) && (name[p - 1] == ':'))
				{
					p -= 2; // back up over the ::
					while ((p >= 0) && (name[p] == ':'))
					{
						p--; // back up over the preceeding :
					}
					break;
				}
			}
			
			if (p >= 0)
			{
				interp.setResult(name.Substring(0, (p + 1) - (0)));
			}
			// When no result is set the empty string is the result
			return ;
		}
		
		
		/*
		*----------------------------------------------------------------------
		*
		* NamespaceTailCmd -> tailCmd
		*
		*	Invoked to implement the "namespace tail" command that returns the
		*	trailing name at the end of a string with "::" namespace
		*	qualifiers. These qualifiers are namespace names separated by
		*	"::"s. For example, for "::foo::p" this command returns "p", and for
		*	"::" it returns "". This command is the complement of the "namespace
		*	qualifiers" command. Note that this command does not check whether
		*	the "namespace" names are, in fact, the names of currently defined
		*	namespaces. Handles the following syntax:
		*
		*	    namespace tail string
		*
		* Results:
		*  Returns if successful, raises TclException if something goes wrong.
		*
		* Side effects:
		*	Returns a result in the interpreter's result object. If anything
		*	goes wrong, the result is an error message.
		*
		*----------------------------------------------------------------------
		*/
		
		
		private static void  tailCmd(Interp interp, TclObject[] objv)
		{
			string name;
			int p;
			
			if (objv.Length != 3)
			{
				throw new TclNumArgsException(interp, 2, objv, "string");
			}
			
			// Find the end of the string, then work backward and find the
			// last "::" qualifier.
			
			
			name = objv[2].ToString();
			p = name.Length;
			
			while (--p > 0)
			{
				if ((name[p] == ':') && (name[p - 1] == ':'))
				{
					p++; // just after the last "::"
					break;
				}
			}
			
			if (p >= 0)
			{
				interp.setResult(name.Substring(p));
			}
			return ;
		}
		
		
		/*
		*----------------------------------------------------------------------
		*
		* NamespaceWhichCmd -> whichCmd
		*
		*	Invoked to implement the "namespace which" command that returns the
		*	fully-qualified name of a command or variable. If the specified
		*	command or variable does not exist, it returns "". Handles the
		*	following syntax:
		*
		*	    namespace which ?-command? ?-variable? name
		*
		* Results:
		*  Returns if successful, raises TclException if something goes wrong.
		*
		* Side effects:
		*	Returns a result in the interpreter's result object. If anything
		*	goes wrong, the result is an error message.
		*
		*----------------------------------------------------------------------
		*/
		
		
		private static void  whichCmd(Interp interp, TclObject[] objv)
		{
			string arg;
			WrappedCommand cmd;
			Var variable;
			int argIndex, lookup;
			
			if (objv.Length < 3)
			{
				throw new TclNumArgsException(interp, 2, objv, "?-command? ?-variable? name");
			}
			
			// Look for a flag controlling the lookup.
			
			argIndex = 2;
			lookup = 0; // assume command lookup by default
			
			arg = objv[2].ToString();
			if ((arg.Length > 1) && (arg[0] == '-'))
			{
				if (arg.Equals("-command"))
				{
					lookup = 0;
				}
				else if (arg.Equals("-variable"))
				{
					lookup = 1;
				}
				else
				{
					throw new TclNumArgsException(interp, 2, objv, "?-command? ?-variable? name");
				}
				argIndex = 3;
			}
			if (objv.Length != (argIndex + 1))
			{
				throw new TclNumArgsException(interp, 2, objv, "?-command? ?-variable? name");
			}
			
			// FIXME : check that this implementation works!
			
			switch (lookup)
			{
				
				case 0: 
					
					arg = objv[argIndex].ToString();
					
					// FIXME : is this the right way to lookup a Command token?
					//cmd = Tcl_GetCommandFromObj(interp, objv[argIndex]);
					cmd = NamespaceCmd.findCommand(interp, arg, null, 0);
					
					if (cmd == null)
					{
						return ; // cmd not found, just return (no error)
					}
					interp.setResult(interp.getCommandFullName(cmd));
					return ;
				
				
				case 1: 
					
					arg = objv[argIndex].ToString();
					variable = NamespaceCmd.findNamespaceVar(interp, arg, null, 0);
					if (variable != null)
					{
						interp.setResult(Var.getVariableFullName(interp, variable));
					}
					return ;
				}
			
			return ;
		}
		
		
		/*
		*----------------------------------------------------------------------
		*
		* FreeNsNameInternalRep -> dispose
		*
		*	Frees the resources associated with a object's internal
		*	representation. See src/tcljava/tcl/lang/InternalRep.java
		*
		* Results:
		*	None.
		*
		* Side effects:
		*	Decrements the ref count of any Namespace structure pointed
		*	to by the nsName's internal representation. If there are no more
		*	references to the namespace, it's structure will be freed.
		*
		*----------------------------------------------------------------------
		*/
		
		public  void  dispose()
		{
						bool debug;
			System.Diagnostics.Debug.WriteLine("dispose() called for namespace object " + (otherValue == null?null:otherValue.ns));
			
			ResolvedNsName resName = otherValue;
			Namespace ns;
			
			// Decrement the reference count of the namespace. If there are no
			// more references, free it up.
			
			if (resName != null)
			{
				resName.refCount--;
				if (resName.refCount == 0)
				{
					
					// Decrement the reference count for the cached namespace.  If
					// the namespace is dead, and there are no more references to
					// it, free it.
					
					ns = resName.ns;
					ns.refCount--;
					if ((ns.refCount == 0) && ((ns.flags & NS_DEAD) != 0))
					{
						free(ns);
					}
					otherValue = null;
				}
			}
		}
		
		
		/*
		*----------------------------------------------------------------------
		*
		* DupNsNameInternalRep -> duplicate
		*
		*	Get a copy of this Object for copy-on-write
		*	operations. We just increment its useCount and return the same
		*	ReflectObject because ReflectObject's cannot be modified, so
		*	they don't need copy-on-write protections.
		*
		* Results:
		*	None.
		*
		* Side effects:
		*  None.
		*
		*----------------------------------------------------------------------
		*/
		
		public  InternalRep duplicate()
		{
			System.Diagnostics.Debug.WriteLine("duplicate() called for namespace object " + (otherValue == null?null:otherValue.ns));
			
			ResolvedNsName resName = otherValue;
			
			if (resName != null)
			{
				resName.refCount++;
			}
			
			return this;
		}
		
		
		/*
		*----------------------------------------------------------------------
		*
		* SetNsNameFromAny -> setNsNameFromAny
		*
		*	Attempt to generate a nsName internal representation for a
		*	TclObject.
		*
		* Results:
		*	Returns if the value could be converted to a proper
		*	namespace reference. Otherwise, raises TclException.
		*
		* Side effects:
		*	If successful, the object is made a nsName object. Its internal rep
		*	is set to point to a ResolvedNsName, which contains a cached pointer
		*	to the Namespace. Reference counts are kept on both the
		*	ResolvedNsName and the Namespace, so we can keep track of their
		*	usage and free them when appropriate.
		*
		*----------------------------------------------------------------------
		*/
		
		private static void  setNsNameFromAny(Interp interp, TclObject tobj)
		{
			string name;
			Namespace ns;
			ResolvedNsName resName;
			
			// Java does not support passing an address so we pass
			// an array of size 1 and then assign arr[0] to the value
			Namespace[] nsArr = new Namespace[1];
			Namespace[] dummy1Arr = new Namespace[1];
			string[] dummy2Arr = new string[1];
			
			// Get the string representation.
			
			name = tobj.ToString();
			
			// Look for the namespace "name" in the current namespace. If there is
			// an error parsing the (possibly qualified) name, return an error.
			// If the namespace isn't found, we convert the object to an nsName
			// object with a null ResolvedNsName internal rep.
			
			getNamespaceForQualName(interp, name, null, TCL.VarFlag.FIND_ONLY_NS, nsArr, dummy1Arr, dummy1Arr, dummy2Arr);
			
			
			// Get the values out of the arrays!
			ns = nsArr[0];
			
			// If we found a namespace, then create a new ResolvedNsName structure
			// that holds a reference to it.
			
			if (ns != null)
			{
				Namespace currNs = getCurrentNamespace(interp);
				
				ns.refCount++;
				resName = new ResolvedNsName();
				resName.ns = ns;
				resName.nsId = ns.nsId;
				resName.refNs = currNs;
				resName.refCount = 1;
			}
			else
			{
				resName = null;
			}
			
			// By setting the new internal rep we free up the old one.
			
			// FIXME : should a NamespaceCmd wrap a ResolvedNsName?
			// this is confusing because it seems like the C code uses
			// a ResolvedNsName like it is the InternalRep.
			
			NamespaceCmd wrap = new NamespaceCmd();
			wrap.otherValue = resName;
			tobj.InternalRep = wrap;
			
			return ;
		}
		
		
		/*
		*----------------------------------------------------------------------
		*
		* UpdateStringOfNsName -> toString
		*
		*	Return the string representation for a nsName object.
		*  This method is called only by TclObject.toString()
		*  when TclObject.stringRep is null.
		*
		* Results:
		*	None.
		*
		* Side effects:
		*   None.
		*
		*----------------------------------------------------------------------
		*/
		
		public override string ToString()
		{
						bool debug;
			
			System.Diagnostics.Debug.WriteLine("toString() called for namespace object " + (otherValue == null?null:otherValue.ns));
			
			ResolvedNsName resName = otherValue;
			Namespace ns;
			string name = "";
			
			if ((resName != null) && (resName.nsId == resName.ns.nsId))
			{
				ns = resName.ns;
				if ((ns.flags & NS_DEAD) != 0)
				{
					ns = null;
				}
				if (ns != null)
				{
					name = ns.fullName;
				}
			}
			
			return name;
		}
		
		
		// This interface is used to provide a callback when a namespace is deleted
		// (ported Tcl_NamespaceDeleteProc to NamespaceCmd.DeleteProc)
		
		internal interface DeleteProc
			{
				void  delete();
			}
		
		
		// This structure contains a cached pointer to a namespace that is the
		// result of resolving the namespace's name in some other namespace. It is
		// the internal representation for a nsName object. It contains the
		// pointer along with some information that is used to check the cached
		// pointer's validity. (ported Tcl_Namespace to NamespaceCmd.Namespace)
		
		public class Namespace
		{
			internal string name; // The namespace's simple (unqualified)
			// name. This contains no ::'s. The name of
			// the global namespace is "" although "::"
			// is an synonym.
			
			internal string fullName; // The namespace's fully qualified name.
			// This starts with ::.
			
			internal DeleteProc deleteProc; // method to invoke when namespace is deleted
			
			internal Namespace parent; // reference to the namespace that contains
			// this one. null is this is the global namespace.
			
			internal Hashtable childTable; // Contains any child namespaces. Indexed
			// by strings; values are references to
			// Namespace objects
			
			internal long nsId; // Unique id for the namespace.
			internal Interp interp; // The interpreter containing this namespace.
			
			internal int flags; // OR-ed combination of the namespace
			// status flags NS_DYING and NS_DEAD (listed below)
			
			internal int activationCount; // Number of "activations" or active call
			// frames for this namespace that are on
			// the Tcl call stack. The namespace won't
			// be freed until activationCount becomes zero.
			
			internal int refCount; // Count of references by nsName
			// objects. The namespace can't be freed
			// until refCount becomes zero.
			
			internal Hashtable cmdTable; // Contains all the commands currently
			// registered in the namespace. Indexed by
			// strings; values have type (WrappedCommand).
			// Commands imported by Tcl_Import have
			// Command structures that point (via an
			// ImportedCmdRef structure) to the
			// Command structure in the source
			// namespace's command table.
			
			internal Hashtable varTable; // Contains all the (global) variables
			// currently in this namespace. Indexed
			// by strings; values have type (Var).
			
			internal string[] exportArray; // Reference to an array of string patterns
			// specifying which commands are exported.
			// A pattern may include "string match"
			// style wildcard characters to specify
			// multiple commands; however, no namespace
			// qualifiers are allowed. null if no
			// export patterns are registered.
			
			internal int numExportPatterns; // Number of export patterns currently
			// registered using "namespace export".
			
			internal int maxExportPatterns; // Mumber of export patterns for which
			// space is currently allocated.
			
			
			internal Resolver resolver;
			// If non-null, this object overrides the
			// usual command and variable resolution
			// mechanism in Tcl. This procedure is invoked
			// within findCommand and findNamespaceVar to
			// resolve all command and variable references
			// within the namespace.
			
			// When printing out a Namespace use the full namespace name string
			
			public override string ToString()
			{
				return fullName;
			}
		}
		
		
		// (ported ResolvedNsName to NamespaceCmd.ResolvedNsName)
		
		internal class ResolvedNsName
		{
			internal Namespace ns; // reference to namespace object
			internal long nsId; // sPtr's unique namespace id. Used to
			// verify that ns is still valid
			// (e.g., it's possible that the namespace
			// was deleted and a new one created at
			// the same address).
			
			internal Namespace refNs; // reference to the namespace containing the
			// reference (not the namespace that
			// contains the referenced namespace).
			internal int refCount; // Reference count: 1 for each nsName
			// object that has a pointer to this
			// ResolvedNsName structure as its internal
			// rep. This structure can be freed when
			// refCount becomes zero.
		}
		static NamespaceCmd()
		{
			nsMutex = new System.Object();
		}
	}
}