TaQLNodeRep.h

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// # TaQLNodeRep.h: Representation of a node in the raw TaQL parse tree
// # Copyright (C) 2005
// # 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 TABLES_TAQLNODEREP_H
#define TABLES_TAQLNODEREP_H
 
// # Includes
#include <casacore/casa/aips.h>
#include <casacore/tables/TaQL/TaQLNodeResult.h>
#include <casacore/tables/TaQL/TaQLStyle.h>
#include <casacore/casa/BasicSL/String.h>
#include <iosfwd>
 
namespace casacore {  // # NAMESPACE CASACORE - BEGIN
 
// # Forward Declaration.
class AipsIO;
class TaQLNodeVisitor;
 
// <summary>
// Representation of a node in the raw TaQL parse tree.
// </summary>
 
// <use visibility=local>
 
// <reviewed reviewer="" date="" tests="tTaQLNode">
// </reviewed>
 
// <prerequisite>
// # Classes you should understand before using this one.
//   <li> <linkto class=TaQLNode>TaQLNode</linkto>
//   <li> Note 199 describing
//        <a href="../notes/199.html">
//        TaQL</a>
// </prerequisite>
 
// <synopsis>
// TaQLNode/TaQLNodeRep form an envelope/letter pair.
// TaQLNodeRep is the abstract base class for all classes used in the
// raw TaQL parse tree
// (e.g. <linkto class=TaQLConstNodeRep>TaQLConstNodeRep</linkto>).
// </synopsis>
 
// <motivation>
// The envelope/letter idiom (aka counted referencing) is a nice means
// to pass an object around by value, so to ensure that an object is deleted
// in case of an exception.
// Furthermore it makes copying an object very cheap and memory
// management straightforward.
// </motivation>
 
class TaQLNodeRep {
 public:
// Define the various derived types (to be stored with AipsIO).
// # They are easier to use than an enum.
// # Do not change these definitions, since these values are stored in files.
// <group>
#define TaQLNode_Null char(0)
#define TaQLNode_Const char(1)
#define TaQLNode_Unary char(2)
#define TaQLNode_Binary char(3)
#define TaQLNode_Multi char(4)
#define TaQLNode_Func char(5)
#define TaQLNode_Range char(6)
#define TaQLNode_Index char(7)
#define TaQLNode_KeyCol char(8)
#define TaQLNode_Table char(9)
#define TaQLNode_Col char(10)
#define TaQLNode_Columns char(11)
#define TaQLNode_Join char(12)
#define TaQLNode_SortKey char(13)
#define TaQLNode_Sort char(14)
#define TaQLNode_LimitOff char(15)
#define TaQLNode_Giving char(16)
#define TaQLNode_UpdExpr char(17)
#define TaQLNode_Select char(18)
#define TaQLNode_Update char(19)
#define TaQLNode_Insert char(20)
#define TaQLNode_Delete char(21)
#define TaQLNode_Calc char(22)
#define TaQLNode_CreTab char(23)
#define TaQLNode_ColSpec char(24)
#define TaQLNode_RecFld char(25)
#define TaQLNode_Unit char(26)
#define TaQLNode_Regex char(27)
#define TaQLNode_Count char(28)
#define TaQLNode_Groupby char(29)
#define TaQLNode_AltTab char(30)
#define TaQLNode_AddCol char(31)
#define TaQLNode_SetKey char(32)
#define TaQLNode_RenDrop char(33)
#define TaQLNode_AddRow char(34)
#define TaQLNode_ConcTab char(35)
#define TaQLNode_Show char(36)
#define TaQLNode_CopyCol char(37)
#define TaQLNode_DropTab char(38)
  // </group>
 
  // Constructor for derived classes specifying the type.
  explicit TaQLNodeRep(int nodeType);
 
  virtual ~TaQLNodeRep();
 
  // Letter objects cannot be copied.
  // <group>
  TaQLNodeRep(const TaQLNodeRep&) = delete;
  TaQLNodeRep& operator=(const TaQLNodeRep&) = delete;
  // </group>
 
  // Get the node type of the derived class.
  char nodeType() const { return itsNodeType; }
 
  // Get the TaQL style.
  const TaQLStyle& style() const { return itsStyle; }
 
  // Visit a node for tree traversal.
  virtual TaQLNodeResult visit(TaQLNodeVisitor&) const = 0;
 
  // Print the object in an ostream.
  virtual void show(std::ostream& os) const = 0;
 
  // Save the object.
  virtual void save(AipsIO& aio) const = 0;
 
  // Check the data type string and return its standard form.
  static String checkDataType(const String&);
 
  // Add escape characters to a table name where needed.
  String addEscape(const String& str) const;
 
 private:
  char itsNodeType;
  TaQLStyle itsStyle;
};
 
}  // namespace casacore
 
#endif