/*
 * Copyright (c) 2001, DecisionSoft Limited All rights reserved.
 * Please see LICENSE.TXT for more information.
 */

/*
The result of a node comparison is defined by applying the following rules, in order:

   1. Both operands must be either a single node or an empty sequence; otherwise the error value is returned.
   2. If either operand is an empty sequence, the result of the comparison is an empty sequence.
   3. A comparison with the is operator is true if the two operands are nodes that have the same identity; otherwise it is false.
      See [XQuery 1.0 and XPath 2.0 Data Model] for a discussion of node identity.
*/

#ifndef _NODECOMPARISON_HPP
#define _NODECOMPARISON_HPP

#include <pathan/Pathan.hpp>

#include <pathan/dataItem/DataItemOperator.hpp>

/** NodeComparison operator function*/
class PATHAN_EXPORT NodeComparison : public DataItemOperator
{
public:
  static const XMLCh name[];

  ///this class returns true if the nodes are the same
  NodeComparison(const VectorOfDataItems &args, XPath2MemoryManager* memMgr);
  
  /** returns true of the nodes are identical */
  Sequence collapseTreeInternal(DynamicContext* context, int flags=0) const;
};

#endif // _FUNCTIONOPPLUS_HPP