//# MSCorrParse.h: Classes to hold results from corr grammar parser
//# Copyright (C) 1994,1995,1997,1998,1999,2000,2001,2003
//# Associated Universities, Inc. Washington DC, USA.
//#
//# This library is free software; you can redistribute it and/or modify it
//# under the terms of the GNU Library General Public License as published by
//# the Free Software Foundation; either version 2 of the License, or (at your
//# option) any later version.
//#
//# This library is distributed in the hope that it will be useful, but WITHOUT
//# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
//# FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Library General Public
//# License for more details.
//#
//# You should have received a copy of the GNU Library General Public License
//# along with this library; if not, write to the Free Software Foundation,
//# Inc., 675 Massachusetts Ave, Cambridge, MA 02139, USA.
//#
//# Correspondence concerning AIPS++ should be addressed as follows:
//#        Internet email: casa-feedback@nrao.edu.
//#        Postal address: AIPS++ Project Office
//#                        National Radio Astronomy Observatory
//#                        520 Edgemont Road
//#                        Charlottesville, VA 22903-2475 USA

#ifndef MS_MSUVDISTPARSE_H
#define MS_MSUVDISTPARSE_H

//# Includes
#include <casacore/casa/aips.h>
#include <casacore/ms/MSSel/MSParse.h>

namespace casacore { //# NAMESPACE CASACORE - BEGIN

//# Forward Declarations

// <summary>
// Class to hold values from UV dist grammar parser
// </summary>

// <use visibility=local>

// <reviewed reviewer="" date="" tests="">
// </reviewed>

// <prerequisite>
//# Classes you should understand before using this one.
// </prerequisite>

// <etymology>
// MSCorrParse is the class used to parse a corr command.
// </etymology>

// <synopsis>
// MSCorrParse is used by the parser of UV dist sub-expression statements.
// The parser is written in Bison and Flex in files MSCorrGram.y and .l.
// The statements in there use the routines in this file to act
// upon a reduced rule.
// Since multiple tables can be given (with a shorthand), the table
// names are stored in a list. The variable names can be qualified
// by the table name and will be looked up in the appropriate table.
//
// The class MSCorrParse only contains information about a table
// used in the table command. Global variables (like a list and a vector)
// are used in MSCorrParse.cc to hold further information.
//
// Global functions are used to operate on the information.
// The main function is the global function msCorrCommand.
// It executes the given STaQL command and returns the resulting ms.
// This is, in fact, the only function to be used by a user.
// </synopsis>

// <motivation>
// It is necessary to be able to give a ms command in ASCII.
// This can be used in a CLI or in the table browser to get a subset
// of a table or to sort a table.
// </motivation>

//# <todo asof="$DATE:$">
//# A List of bugs, limitations, extensions or planned refinements.
//# </todo>


class MSCorrParse : public MSParse
{

public:
  // Default constructor
  MSCorrParse ();

  // Associate the ms and the shorthand.
  MSCorrParse (const MeasurementSet* ms);
  
  //  ~MSCorrParse() {if (node_p) delete node_p;node_p=0x0;}
  // MS selection
  const TableExprNode * selectCorrType(const String& corrType);
  
  // Get table expression node object.
  static const TableExprNode* node();
  static void cleanup() {if (node_p) delete node_p;node_p=0x0;}
  
private:
    static TableExprNode *node_p;
};

} //# NAMESPACE CASACORE - END

#endif
