Edwin Smith
fd881ac637
One more step in the renaming arc. Depends on D925182 Differential Revision: D927227
70 linhas
2.2 KiB
C++
70 linhas
2.2 KiB
C++
/*
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+----------------------------------------------------------------------+
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| HipHop for PHP |
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+----------------------------------------------------------------------+
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| Copyright (c) 2010-2013 Facebook, Inc. (http://www.facebook.com) |
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+----------------------------------------------------------------------+
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| This source file is subject to version 3.01 of the PHP license, |
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| that is bundled with this package in the file LICENSE, and is |
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| available through the world-wide-web at the following url: |
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| http://www.php.net/license/3_01.txt |
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| If you did not receive a copy of the PHP license and are unable to |
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| obtain it through the world-wide-web, please send a note to |
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| license@php.net so we can mail you a copy immediately. |
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+----------------------------------------------------------------------+
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*/
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#ifndef incl_HPHP_UTIL_MAPWALKER_H_
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#define incl_HPHP_UTIL_MAPWALKER_H_
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namespace HPHP {
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/*
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* MapWalker is designed to iterate over an ordered map and an ordered list of
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* keys in parallel. Once created with a reference to a map, hasNext(key) will
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* return true iff the next item in the map matches the given key. If it
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* returns true, next() will return a reference to that element and advance its
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* internal iterator. hasNext() can be used to check if the internal iterator
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* is at the end of the map.
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*/
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template<typename Map>
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struct MapWalker {
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typedef typename Map::key_type Key;
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typedef typename Map::mapped_type Value;
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typedef typename Map::const_iterator ConstIter;
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explicit MapWalker(const Map& m)
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: m_map(m)
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, m_iter(m.begin())
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{}
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bool hasNext() const {
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return m_iter != m_map.end();
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}
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bool hasNext(const Key& key) const {
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assert(m_iter == m_map.end() || key <= m_iter->first);
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return m_iter != m_map.end() && m_iter->first == key;
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}
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const Value& next() {
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assert(m_iter != m_map.end());
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auto const& val = m_iter->second;
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++m_iter;
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return val;
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}
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private:
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const Map& m_map;
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ConstIter m_iter;
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};
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template<typename Map>
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MapWalker<Map> makeMapWalker(const Map& m) {
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return MapWalker<Map>(m);
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}
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}
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#endif
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