00001 00004 /* ----START-LICENCE---- 00005 * Copyright 1999,2000,2001 BrightStation PLC 00006 * Copyright 2002 Ananova Ltd 00007 * Copyright 2003,2004 Olly Betts 00008 * 00009 * This program is free software; you can redistribute it and/or 00010 * modify it under the terms of the GNU General Public License as 00011 * published by the Free Software Foundation; either version 2 of the 00012 * License, or (at your option) any later version. 00013 * 00014 * This program is distributed in the hope that it will be useful, 00015 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00016 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00017 * GNU General Public License for more details. 00018 * 00019 * You should have received a copy of the GNU General Public License 00020 * along with this program; if not, write to the Free Software 00021 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 00022 * USA 00023 * -----END-LICENCE----- 00024 */ 00025 00026 #ifndef XAPIAN_INCLUDED_POSITIONITERATOR_H 00027 #define XAPIAN_INCLUDED_POSITIONITERATOR_H 00028 00029 #include <iterator> 00030 #include <string> 00031 00032 #include <xapian/base.h> 00033 #include <xapian/types.h> 00034 00035 namespace Xapian { 00036 00037 class Database; 00038 class PostingIterator; 00039 class TermIterator; 00040 00044 class TermPosWrapper { 00045 private: 00046 termpos pos; 00047 public: 00048 TermPosWrapper(termpos pos_) : pos(pos_) { } 00049 termpos operator*() const { return pos; } 00050 }; 00051 00054 class PositionIterator { 00055 private: 00056 // friend classes which need to be able to construct us 00057 friend class PostingIterator; 00058 friend class TermIterator; 00059 friend class Database; 00060 00061 public: 00062 class Internal; 00064 Xapian::Internal::RefCntPtr<Internal> internal; 00065 00066 friend bool operator==(const PositionIterator &a, const PositionIterator &b); 00067 00068 // FIXME: ought to be private 00069 explicit PositionIterator(Internal *internal_); 00070 00072 PositionIterator(); 00073 00075 ~PositionIterator(); 00076 00080 PositionIterator(const PositionIterator &o); 00081 00085 void operator=(const PositionIterator &o); 00086 00087 Xapian::termpos operator *() const; 00088 00089 PositionIterator & operator++(); 00090 00091 TermPosWrapper operator++(int) { 00092 Xapian::termpos tmp = **this; 00093 operator++(); 00094 return TermPosWrapper(tmp); 00095 } 00096 00097 // extra method, not required for an input_iterator 00098 void skip_to(Xapian::termpos pos); 00099 00103 std::string get_description() const; 00104 00105 // Allow use as an STL iterator 00106 typedef std::input_iterator_tag iterator_category; 00107 typedef Xapian::termpos value_type; 00108 typedef Xapian::termpos_diff difference_type; // "om_termposcount" 00109 typedef Xapian::termpos * pointer; 00110 typedef Xapian::termpos & reference; 00111 }; 00112 00114 inline bool 00115 operator==(const PositionIterator &a, const PositionIterator &b) 00116 { 00117 return (a.internal.get() == b.internal.get()); 00118 } 00119 00121 inline bool 00122 operator!=(const PositionIterator &a, const PositionIterator &b) 00123 { 00124 return !(a == b); 00125 } 00126 00127 } 00128 00129 #endif /* XAPIAN_INCLUDED_POSITIONITERATOR_H */