# include/xapian/positioniterator.h

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    00001
    00004 /* Copyright 1999,2000,2001 BrightStation PLC
    00005  * Copyright 2002 Ananova Ltd
    00006  * Copyright 2003,2004,2007 Olly Betts
    00007  *
    00008  * This program is free software; you can redistribute it and/or
    00009  * modify it under the terms of the GNU General Public License as
    00010  * published by the Free Software Foundation; either version 2 of the
    00011  * License, or (at your option) any later version.
    00012  *
    00013  * This program is distributed in the hope that it will be useful,
    00014  * but WITHOUT ANY WARRANTY; without even the implied warranty of
    00015  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    00016  * GNU General Public License for more details.
    00017  *
    00018  * You should have received a copy of the GNU General Public License
    00019  * along with this program; if not, write to the Free Software
    00020  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301
    00021  * USA
    00022  */
    00023
    00024 #ifndef XAPIAN_INCLUDED_POSITIONITERATOR_H
    00025 #define XAPIAN_INCLUDED_POSITIONITERATOR_H
    00026
    00027 #include <iterator>
    00028 #include <string>
    00029
    00030 #include <xapian/base.h>
    00031 #include <xapian/types.h>
    00032 #include <xapian/visibility.h>
    00033
    00034 namespace Xapian {
    00035
    00036 class Database;
    00037 class PostingIterator;
    00038 class TermIterator;
    00039
    00043 class TermPosWrapper {
    00044     private:
    00045         termpos pos;
    00046     public:
    00047         explicit TermPosWrapper(termpos pos_) : pos(pos_) { }
    00048         termpos operator*() const { return pos; }
    00049 };
    00050
    00053 class XAPIAN_VISIBILITY_DEFAULT PositionIterator {
    00054     private:
    00055         // friend classes which need to be able to construct us
    00056         friend class PostingIterator;
    00057         friend class TermIterator;
    00058         friend class Database;
    00059
    00060     public:
    00061         class Internal;
    00063         Xapian::Internal::RefCntPtr<Internal> internal;
    00064
    00065         friend bool operator==(const PositionIterator &a, const PositionIterator &b);
    00066
    00067         // FIXME: ought to be private
    00068         explicit PositionIterator(Internal *internal_);
    00069
    00071         PositionIterator();
    00072
    00074         ~PositionIterator();
    00075
    00079         PositionIterator(const PositionIterator &o);
    00080
    00084         void operator=(const PositionIterator &o);
    00085
    00086         Xapian::termpos operator *() const;
    00087
    00088         PositionIterator & operator++();
    00089
    00090         TermPosWrapper operator++(int) {
    00091             Xapian::termpos tmp = **this;
    00092             operator++();
    00093             return TermPosWrapper(tmp);
    00094         }
    00095
    00096         // extra method, not required for an input_iterator
    00097         void skip_to(Xapian::termpos pos);
    00098
    00102         std::string get_description() const;
    00103
    00104         // Allow use as an STL iterator
    00105         typedef std::input_iterator_tag iterator_category;
    00106         typedef Xapian::termpos value_type;
    00107         typedef Xapian::termpos_diff difference_type;  // "om_termposcount"
    00108         typedef Xapian::termpos * pointer;
    00109         typedef Xapian::termpos & reference;
    00110 };
    00111
    00113 inline bool
    00114 operator==(const PositionIterator &a, const PositionIterator &b)
    00115 {
    00116     return (a.internal.get() == b.internal.get());
    00117 }
    00118
    00120 inline bool
    00121 operator!=(const PositionIterator &a, const PositionIterator &b)
    00122 {
    00123     return !(a == b);
    00124 }
    00125
    00126 }
    00127
    00128 #endif /* XAPIAN_INCLUDED_POSITIONITERATOR_H */