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+#ifndef _QTJOINITERATOR_
+#define _QTJOINITERATOR_
+
+#ifndef CPPSTDLIB
+#include <ospace/string.h> // STL<ToolKit>
+#else
+#include <string>
+#endif
+
+#include "qlparser/qtiterator.hh"
+#include "qlparser/qtoperation.hh"
+
+/*
+* This file is part of rasdaman community.
+*
+* Rasdaman community is free software: you can redistribute it and/or modify
+* it under the terms of the GNU General Public License as published by
+* the Free Software Foundation, either version 3 of the License, or
+* (at your option) any later version.
+*
+* Rasdaman community 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 General Public License for more details.
+*
+* You should have received a copy of the GNU General Public License
+* along with rasdaman community. If not, see <http://www.gnu.org/licenses/>.
+*
+* Copyright 2003, 2004, 2005, 2006, 2007, 2008, 2009 Peter Baumann /
+rasdaman GmbH.
+*
+* For more information please see <http://www.rasdaman.org>
+* or contact Peter Baumann via <baumann@rasdaman.com>.
+*/
+/*************************************************************
+ *
+ *
+ * COMMENTS:
+ *
+ ************************************************************/
+
+//@ManMemo: Module: {\bf qlparser}
+
+/*@Doc:
+
+An object of this class takes its inputs and computes a tupel for every element
+of the cross product. The result is passed to the output stream.
+The class represents the FROM part of a query.
+
+*/
+
+class QtJoinIterator : public QtIterator
+{
+ public:
+ /// default constructor
+ QtJoinIterator();
+
+ /// constructor getting a pointer to the parent
+ QtJoinIterator( QtNode* node );
+
+ /// virtual destructor
+ virtual ~QtJoinIterator();
+
+ /// prints the tree
+ virtual void printTree( int tab, std::ostream& s = std::cout, QtChildType mode = QT_ALL_NODES );
+
+ /// prints the algebraic expression
+ virtual void printAlgebraicExpression( std::ostream& s = std::cout );
+
+ //@Man: Operations of the ONC protocol:
+ //@{
+ ///
+ void open();
+ ///
+ QtDataList* next();
+ /**
+ According to the producer/consumer protocol of ONC streams, the {/tt next()}
+ method has to store the last tupel of the crossproduct and update it with a new
+ element everytime it is invoked. Than it makes a copy of the tupel and pass
+ it to the caller.
+ */
+ ///
+ void close();
+ ///
+ void reset();
+ ///
+ //@}
+
+ //@Man: Read/Write methods:
+ //@{
+ ///
+ //inline virtual void setParents();
+ //@}
+
+ /// method for identification of nodes
+ inline virtual const QtNodeType getNodeType() const;
+
+ /// type checking
+ virtual const QtTypeTuple& checkType();
+
+ private:
+ /// inidicates if the output stream is empty or not
+ bool outputStreamIsEmpty;
+ /** The output stream is empty if at least one of the input streams is empty.
+ In that case, the cross product has no elements. This is indicated
+ by the variable {\tt outputStreamIsEmpty} which is set in the method
+ {\tt open()}.
+ */
+
+ /// pointer to a copy of the last passed tupel
+ QtDataList* actualTupel;
+
+ /// attribute for identification of nodes
+ static const QtNodeType nodeType;
+};
+
+#include "qlparser/qtjoiniterator.icc"
+
+#endif
+