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

#ifndef _FUNCTIONSUBTRACTDATETIMESYIELDINGYEARMONTHDURATION_HPP
#define _FUNCTIONSUBTRACTDATETIMESYIELDINGYEARMONTHDURATION_HPP

#include <pathan/Pathan.hpp>

#include <pathan/dataItem/DataItemFunction.hpp>

/**
 * Calculates the yearMonthDuration that is the difference between two 
 * dateTimes.
 *
 *  subtract-dateTimes-yielding-yearMonthDuration(dateTime $srcval1, i
 *  dateTime $srcval2) => yearMonthDuration
 */
class PATHAN_EXPORT FunctionSubtractDateTimesYieldingYearMonthDuration : public DataItemFunction
{
public:
  static const XMLCh name[];

  /**
   * Constructor.
   */
  FunctionSubtractDateTimesYieldingYearMonthDuration(const VectorOfDataItems &args, XPath2MemoryManager* memMgr);

  DataItem* staticResolution(StaticContext *context, StaticResolutionContext *src);

  /**
   * Returns the yearMonthDuration that corresponds to the difference between the
   * value of $srcval1 and the value of $srcval2.
   */
  Sequence collapseTreeInternal(DynamicContext* context, int flags=0) const;
};

#endif // _FUNCTIONSUBTRACTDATETIMESYIELDINGYEARMONTHDURATION_HPP