casacore
ExprUDFNode.h
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1 //# ExprUDFNode.h: Class representing a scalar UDF in select expression
2 //# Copyright (C) 2010
3 //# Associated Universities, Inc. Washington DC, USA.
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26 //# $Id$
27 
28 #ifndef TABLES_EXPRUDFNODE_H
29 #define TABLES_EXPRUDFNODE_H
30 
31 //# Includes
32 #include <casacore/casa/aips.h>
33 #include <casacore/tables/TaQL/ExprNodeRep.h>
34 #include <casacore/tables/TaQL/UDFBase.h>
35 
36 namespace casacore { //# NAMESPACE CASACORE - BEGIN
37 
38  //# Forward Declarations
39  class TableExprNodeSet;
40 
41  // <summary>
42  // Class representing a scalar UDF in select expression
43  // </summary>
44 
45  // <use visibility=local>
46 
47  // <reviewed reviewer="UNKNOWN" date="before2004/08/25" tests="">
48  // </reviewed>
49  // <prerequisite>
50  //# Classes you should understand before using this one.
51  // <li> <linkto class=TableExprNodeMulti>TableExprNodeMulti</linkto>
52  // </prerequisite>
53 
54  // <synopsis>
55  // This class represents a function in a table select tree.
56  // The <src>rownumber</src> function is represented by class
57  // <linkto class=TableExprNodeRownr>TableExprNodeRownr</linkto>.
58  // The <src>rowid</src> function is represented by class
59  // <linkto class=TableExprNodeRowid>TableExprNodeRowid</linkto>.
60  // The <src>rand</src> function is represented by class
61  // <linkto class=TableExprNodeRandom>TableExprNodeRandom</linkto>.
62  // <p>
63  // When one wants to add a function to the table selection grammar,
64  // the following has to be done:
65  // <ul>
66  // <li> Add the function to the enum below.
67  // <li> Implement the function in the get functions in ExprFuncNode(Array).cc.
68  // <li> Implement the function in the checkOperands in ExprFuncNode.cc.
69  // <li> Declare and define the function in ExprNode.h (for C++ binding).
70  // <li> Add the function to findFunc in TableParse.cc (for TaQL).
71  // </ul>
72  // </synopsis>
73 
74 
76  {
77  public:
78 
79  // Constructor
81  const TableExprNodeSet& source);
82 
83  // Destructor
84  virtual ~TableExprUDFNode();
85 
86  // Is the UDF an aggregate function?
87  Bool isAggregate() const
88  { return itsUDF->isAggregate(); }
89 
90  // Get the nodes representing an aggregate function.
91  virtual void getAggrNodes (std::vector<TableExprNodeRep*>& aggr);
92 
93  // Get the nodes representing a table column.
94  virtual void getColumnNodes (std::vector<TableExprNodeRep* >& cols);
95 
96  // Do not apply the selection.
97  virtual void disableApplySelection();
98 
99  // If needed, let the UDF re-create column objects for a selection of rows.
100  // It calls the function recreateColumnObjects.
101  virtual void applySelection (const Vector<rownr_t>& rownrs);
102 
103  // UDFs do not need a TableExprGroupFuncBase,
104  // so TableExprGroupNull is returned.
106 
107  // Functions to get the desired result of a function
108  // <group>
109  virtual Bool getBool (const TableExprId& id);
110  virtual Int64 getInt (const TableExprId& id);
111  virtual Double getDouble (const TableExprId& id);
112  virtual DComplex getDComplex (const TableExprId& id);
113  virtual String getString (const TableExprId& id);
114  virtual TaqlRegex getRegex (const TableExprId& id);
115  virtual MVTime getDate (const TableExprId& id);
116  // </group>
117 
118  private:
120  };
121 
122 
123 } //# NAMESPACE CASACORE - END
124 
125 #endif
Referenced counted pointer for constant data.
Definition: CountedPtr.h:81
String: the storage and methods of handling collections of characters.
Definition: String.h:225
Abstract base class for a node having multiple child nodes.
Definition: ExprNodeRep.h:661
Class to hold multiple table expression nodes.
Definition: ExprNodeSet.h:311
virtual Bool getBool(const TableExprId &id)
Functions to get the desired result of a function.
CountedPtr< TableExprGroupFuncBase > makeGroupAggrFunc()
UDFs do not need a TableExprGroupFuncBase, so TableExprGroupNull is returned.
virtual MVTime getDate(const TableExprId &id)
virtual DComplex getDComplex(const TableExprId &id)
virtual String getString(const TableExprId &id)
virtual void getColumnNodes(std::vector< TableExprNodeRep * > &cols)
Get the nodes representing a table column.
Bool isAggregate() const
Is the UDF an aggregate function?
Definition: ExprUDFNode.h:87
virtual void applySelection(const Vector< rownr_t > &rownrs)
If needed, let the UDF re-create column objects for a selection of rows.
virtual Int64 getInt(const TableExprId &id)
virtual TaqlRegex getRegex(const TableExprId &id)
virtual ~TableExprUDFNode()
Destructor.
virtual void getAggrNodes(std::vector< TableExprNodeRep * > &aggr)
Get the nodes representing an aggregate function.
virtual Double getDouble(const TableExprId &id)
TableExprUDFNode(UDFBase *udf, const Table &, const TableExprNodeSet &source)
Constructor.
virtual void disableApplySelection()
Do not apply the selection.
Bool isAggregate() const
Tell if the UDF is an aggregate function.
Definition: UDFBase.h:355
this file contains all the compiler specific defines
Definition: mainpage.dox:28
long long Int64
Define the extra non-standard types used by Casacore (like proposed uSize, Size)
Definition: aipsxtype.h:38
bool Bool
Define the standard types used by Casacore.
Definition: aipstype.h:42
double Double
Definition: aipstype.h:55