TableParseFunc.h

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// # TableParseFunc.h: Class handling TaQL functions
// # Copyright (C) 1994-2022
// # 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.
// #
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// #        Postal address: AIPS++ Project Office
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#ifndef TABLES_TABLEPARSEFUNC_H
#define TABLES_TABLEPARSEFUNC_H
 
// # Includes
#include <casacore/casa/aips.h>
#include <casacore/tables/TaQL/ExprNodeSet.h>
#include <casacore/tables/TaQL/ExprFuncNode.h>
#include <vector>
 
namespace casacore {  // # NAMESPACE CASACORE - BEGIN
 
// # Forward declarations
class TableParseQuery;
class TaQLStyle;
 
// <summary>
// Class containing static functions to handle TaQL functions.
// </summary>
 
// <use visibility=local>
 
// <reviewed reviewer="UNKNOWN" date="before2004/08/25" tests="">
// </reviewed>
 
// <synopsis>
// This class contains a few functions to recognize TaQL functions.
// A function name can be preceded by "shorthand.udflib." telling the
// table to operate on and the UDF shared library containing the function.
// Note that most functions are table agnostic, but a few (such as rowid())
// are not. Also User Defined Functions (UDFs) can be table aware.
// Both shorthand and udflib are optional. If a single part is given, it is
// first tried as a shorthand.
//
// It looks up the function name and creates a TableExprFuncNode object for it.
// If the function name is not standard, it is tried to create a TableExprUDFNode
// object. Otherwise an exception is thrown.
// </synopsis>
 
class TableParseFunc {
 public:
  // Make a function node.
  // The name is split into shorthand, udflib and function as explained
  // in the synopsis.
  static TableExprNode makeFuncNode(TableParseQuery*, const String& name,
                                    const TableExprNodeSet& arguments,
                                    const Vector<int>& ignoreFuncs, const TableExprInfo& tabInfo,
                                    const TaQLStyle&);
 
  // Try to make a UDF function node for the given function name and arguments.
  // The function name can contain "shorthand." and must contain "udflib.".
  static TableExprNode makeUDFNode(TableParseQuery*, const String& name,
                                   const TableExprNodeSet& arguments, const TableExprInfo& tabInfo,
                                   const TaQLStyle&);
 
  // Find the function code belonging to a function name.
  // Functions to be ignored can be given (as function type values).
  // If the function name is unknown, NRFUNC is returned.
  static TableExprFuncNode::FunctionType findFunc(const String& name, uInt narguments,
                                                  const Vector<Int>& ignoreFuncs);
};
 
}  // namespace casacore
 
#endif