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https://github.com/xiaoyifang/goldendict-ng.git
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186 lines
5.4 KiB
C
186 lines
5.4 KiB
C
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/** @file
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* @brief Class for iterating over a list of terms
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*/
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/* Copyright (C) 2007,2008,2009,2010,2011,2012,2013,2014,2015 Olly Betts
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 2 of the
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* License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301
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* USA
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*/
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#ifndef XAPIAN_INCLUDED_TERMITERATOR_H
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#define XAPIAN_INCLUDED_TERMITERATOR_H
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#if !defined XAPIAN_IN_XAPIAN_H && !defined XAPIAN_LIB_BUILD
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# error Never use <xapian/termiterator.h> directly; include <xapian.h> instead.
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#endif
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#include <iterator>
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#include <string>
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#include <xapian/attributes.h>
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#include <xapian/derefwrapper.h>
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#include <xapian/positioniterator.h>
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#include <xapian/types.h>
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#include <xapian/visibility.h>
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namespace Xapian {
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/// Class for iterating over a list of terms.
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class XAPIAN_VISIBILITY_DEFAULT TermIterator {
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public:
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/// Class representing the TermIterator internals.
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class Internal;
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/// @private @internal Reference counted internals.
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Internal * internal;
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/// @private @internal Construct given internals.
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explicit TermIterator(Internal *internal_);
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/// Copy constructor.
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TermIterator(const TermIterator & o);
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/// Assignment.
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TermIterator & operator=(const TermIterator & o);
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#ifdef XAPIAN_MOVE_SEMANTICS
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/// Move constructor.
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TermIterator(TermIterator && o)
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: internal(o.internal) {
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o.internal = nullptr;
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}
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/// Move assignment operator.
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TermIterator & operator=(TermIterator && o) {
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if (this != &o) {
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if (internal) decref();
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internal = o.internal;
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o.internal = nullptr;
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}
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return *this;
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}
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#endif
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/** Default constructor.
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*
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* Creates an uninitialised iterator, which can't be used before being
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* assigned to, but is sometimes syntactically convenient.
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*/
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XAPIAN_NOTHROW(TermIterator())
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: internal(0) { }
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/// Destructor.
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~TermIterator() {
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if (internal) decref();
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}
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/// Return the term at the current position.
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std::string operator*() const;
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/// Return the wdf for the term at the current position.
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Xapian::termcount get_wdf() const;
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/// Return the term frequency for the term at the current position.
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Xapian::doccount get_termfreq() const;
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/// Return the length of the position list for the current position.
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Xapian::termcount positionlist_count() const;
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/// Return a PositionIterator for the current term.
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PositionIterator positionlist_begin() const;
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/// Return an end PositionIterator for the current term.
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PositionIterator XAPIAN_NOTHROW(positionlist_end() const) {
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return PositionIterator();
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}
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/// Advance the iterator to the next position.
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TermIterator & operator++();
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/// Advance the iterator to the next position (postfix version).
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DerefWrapper_<std::string> operator++(int) {
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const std::string & term(**this);
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operator++();
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return DerefWrapper_<std::string>(term);
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}
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/** Advance the iterator to term @a term.
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*
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* If the iteration is over an unsorted list of terms, then this method
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* will throw Xapian::InvalidOperationError.
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*
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* @param term The term to advance to. If this term isn't in
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* the stream being iterated, then the iterator is moved
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* to the next term after it which is.
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*/
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void skip_to(const std::string &term);
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/// Return a string describing this object.
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std::string get_description() const;
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/** @private @internal TermIterator is what the C++ STL calls an
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* input_iterator.
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*
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* The following typedefs allow std::iterator_traits<> to work so that
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* this iterator can be used with the STL.
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*
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* These are deliberately hidden from the Doxygen-generated docs, as the
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* machinery here isn't interesting to API users. They just need to know
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* that Xapian iterator classes are compatible with the STL.
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*/
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// @{
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/// @private
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typedef std::input_iterator_tag iterator_category;
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/// @private
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typedef std::string value_type;
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/// @private
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typedef Xapian::termcount_diff difference_type;
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/// @private
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typedef std::string * pointer;
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/// @private
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typedef std::string & reference;
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// @}
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private:
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void decref();
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void post_advance(Internal * res);
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};
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bool
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XAPIAN_NOTHROW(operator==(const TermIterator &a, const TermIterator &b));
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/// Equality test for TermIterator objects.
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inline bool
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operator==(const TermIterator &a, const TermIterator &b) XAPIAN_NOEXCEPT
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{
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// Use a pointer comparison - this ensures both that (a == a) and correct
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// handling of end iterators (which we ensure have NULL internals).
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return a.internal == b.internal;
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}
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bool
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XAPIAN_NOTHROW(operator!=(const TermIterator &a, const TermIterator &b));
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/// Inequality test for TermIterator objects.
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inline bool
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operator!=(const TermIterator &a, const TermIterator &b) XAPIAN_NOEXCEPT
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{
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return !(a == b);
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}
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}
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#endif // XAPIAN_INCLUDED_TERMITERATOR_H
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