add class queue, implement LIFO queue (Last In, First Out), must be used with Undo/redo functions

@queue/display.m

+function display(self)
+%DISPLAY Display a queue table object
+%   display(queue)
+
+% Copyright (c) 2004 Matthew Krauski (mkrauski@uci.edu), CNLM, UC Irvine
+
+%isLoose = strcmp(get(0,'FormatSpacing'),'loose');
+isLoose = 0;
+
+if(length(inputname(1)) ~= 0)
+    if isLoose, disp(' '), end
+    disp( sprintf('%s =', inputname(1)) );
+end
+
+if isLoose, disp(' '), end
+
+disp(struct(self));
+
+%fprintf('\thashtable\n' );
+% if isempty(self)
+%     fprintf('\tEmpty\n\n' );
+% else
+% %    disp( sprintf('\tElements:') );
+%     display( self.index );
+% end
+

@queue/get.m

+function data = get(self)
+%GET Get last data from the queue table
+%   data = get(queue)
+
+% $Id$
+
+data = self.data;

@queue/isempty.m

+function bool = isempty(self)
+%ISEMPTY Check to see if the queue is empty
+%   bool = isempty(queue)
+
+% 
+
+bool = isempty(self.lifo);
+

@queue/pop.m

+function self = pop(self)
+%PUT get data from the queue 
+%   [queue data] = get(queue,data)
+%
+% $Id$
+
+if self.index==0
+  self.data = [];
+  self.lifo = [];
+  return
+end
+
+self.data = self.lifo(self.index,:);  
+
+self.lifo(self.index,:) = [];
+self.index = self.index-1;

@queue/push.m

+function self = push(self,data)
+%PUT Put data in the queue 
+%   queue = put(queue,data)
+%
+% $Id$
+
+if isempty(data)
+  return
+end
+
+if isequal(data, self.data)
+  return
+end
+
+self.index = self.index+1;
+self.lifo(end+1,:) = data; 
+self.data = data;

@queue/queue.m

+function queue = queue(varargin)
+%HASHTABLE Constructor for LIFO queue class
+%   q  = queue    - Default constructor, empty queue table
+%   mq = queue(q) - Copy constructor 
+
+% $Id$
+
+if nargin == 1 && isa(varargin{1},'queue')
+    queue = varargin{1};
+    return;
+elseif nargin == 0
+    q.index = 0;
+		q.data = [];
+    q.lifo = [];
+else
+    error('queue:queue', 'Invalid arguments.');
+end
+    
+queue = class(q,'queue');

@queue/view.m

+function data = view(self)
+%GET Get last data from the queue table
+%   data = get(queue)
+
+% $Id$
+
+self.index
+
+self.lifo
+
+self.data
\ No newline at end of file