# include/xapian/postingiterator.h

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    00001
    00004 /* Copyright 1999,2000,2001 BrightStation PLC
    00005  * Copyright 2002 Ananova Ltd
    00006  * Copyright 2003,2004,2005,2007 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_POSTINGITERATOR_H
    00025 #define XAPIAN_INCLUDED_POSTINGITERATOR_H
    00026
    00027 #include <iterator>
    00028 #include <string>
    00029
    00030 #include <xapian/base.h>
    00031 #include <xapian/types.h>
    00032 #include <xapian/positioniterator.h>
    00033 #include <xapian/visibility.h>
    00034
    00035 namespace Xapian {
    00036
    00037 class Database;
    00038
    00042 class DocIDWrapper {
    00043     private:
    00044         docid did;
    00045     public:
    00046         explicit DocIDWrapper(docid did_) : did(did_) { }
    00047         docid operator*() const { return did; }
    00048 };
    00049
    00052 class XAPIAN_VISIBILITY_DEFAULT PostingIterator {
    00053     public:
    00054         class Internal;
    00056         Xapian::Internal::RefCntPtr<Internal> internal;
    00057
    00058     private:
    00059         friend class Database; // So Database can construct us
    00060
    00061         explicit PostingIterator(Internal *internal_);
    00062
    00063     public:
    00064         friend bool operator==(const PostingIterator &a,
    00065                                const PostingIterator &b);
    00066
    00068         PostingIterator();
    00069
    00071         ~PostingIterator();
    00072
    00076         PostingIterator(const PostingIterator &other);
    00077
    00081         void operator=(const PostingIterator &other);
    00082
    00083         PostingIterator & operator++();
    00084
    00085         DocIDWrapper operator++(int) {
    00086             Xapian::docid tmp = **this;
    00087             operator++();
    00088             return DocIDWrapper(tmp);
    00089         }
    00090
    00094         void skip_to(Xapian::docid did);
    00095
    00096 // Get the weight of the posting at the current position: will
    00097 // need to set a weight object for this to work.
    00098 // Xapian::weight get_weight() const;
    00099
    00101         Xapian::docid operator *() const;
    00102
    00112         Xapian::doclength get_doclength() const;
    00113
    00117         Xapian::termcount get_wdf() const;
    00118
    00122         PositionIterator positionlist_begin() const;
    00123
    00127         PositionIterator positionlist_end() const {
    00128             return PositionIterator(NULL);
    00129         }
    00130
    00131         // Don't expose these methods here.  A container iterator doesn't
    00132         // provide a method to find the size of the container...
    00133         // Xapian::doccount get_termfreq() const;
    00134         // Xapian::termcount get_collection_freq() const;
    00135
    00137         std::string get_description() const;
    00138
    00140
    00141         typedef std::input_iterator_tag iterator_category;
    00142         typedef Xapian::docid value_type;
    00143         typedef Xapian::doccount_diff difference_type;
    00144         typedef Xapian::docid * pointer;
    00145         typedef Xapian::docid & reference;
    00147 };
    00148
    00150 inline bool operator==(const PostingIterator &a, const PostingIterator &b)
    00151 {
    00152     return (a.internal.get() == b.internal.get());
    00153 }
    00154
    00156 inline bool operator!=(const PostingIterator &a, const PostingIterator &b)
    00157 {
    00158     return !(a == b);
    00159 }
    00160
    00161 }
    00162
    00163 #endif /* XAPIAN_INCLUDED_POSTINGITERATOR_H */