ANTLR Support Libraries 2.7.1+
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CircularQueue.hpp
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1#ifndef INC_CircularQueue_hpp__
2#define INC_CircularQueue_hpp__
3
4/* ANTLR Translator Generator
5 * Project led by Terence Parr at http://www.jGuru.com
6 * Software rights: http://www.antlr.org/license.html
7 *
8 * $Id: //depot/code/org.antlr/release/antlr-2.7.7/lib/cpp/antlr/CircularQueue.hpp#2 $
9 */
10
11#include <antlr/config.hpp>
12#include <antlr/Token.hpp>
13#include <vector>
14#include <cassert>
15
16#ifdef ANTLR_CXX_SUPPORTS_NAMESPACE
17namespace antlr {
18#endif
19
20// Resize every 5000 items
21#define OFFSET_MAX_RESIZE 5000
22
23template <class T>
25public:
27 : storage()
28 , m_offset(0)
29 {
30 }
32 {
33 }
34
36 inline void clear( void )
37 {
38 m_offset = 0;
39 storage.clear();
40 }
41
43 inline T elementAt( size_t idx ) const
44 {
45 return storage[idx+m_offset];
46 }
48 {
49 if (m_offset >= OFFSET_MAX_RESIZE)
50 {
51 storage.erase( storage.begin(), storage.begin() + m_offset + 1 );
52 m_offset = 0;
53 }
54 else
55 ++m_offset;
56 }
57 inline void removeItems( size_t nb )
58 {
59 // it would be nice if we would not get called with nb > entries
60 // (or to be precise when entries() == 0)
61 // This case is possible when lexer/parser::recover() calls
62 // consume+consumeUntil when the queue is empty.
63 // In recover the consume says to prepare to read another
64 // character/token. Then in the subsequent consumeUntil the
65 // LA() call will trigger
66 // syncConsume which calls this method *before* the same queue
67 // has been sufficiently filled.
68 if( nb > entries() )
69 nb = entries();
70
71 if (m_offset >= OFFSET_MAX_RESIZE)
72 {
73 storage.erase( storage.begin(), storage.begin() + m_offset + nb );
74 m_offset = 0;
75 }
76 else
77 m_offset += nb;
78 }
79 inline void append(const T& t)
80 {
81 storage.push_back(t);
82 }
83 inline size_t entries() const
84 {
85 return storage.size() - m_offset;
86 }
87
88private:
90 size_t m_offset;
91
94};
95
96#ifdef ANTLR_CXX_SUPPORTS_NAMESPACE
97}
98#endif
99
100#endif //INC_CircularQueue_hpp__
#define OFFSET_MAX_RESIZE
Definition CircularQueue.hpp:21
Definition CircularQueue.hpp:24
T elementAt(size_t idx) const
Definition CircularQueue.hpp:43
void removeItems(size_t nb)
Definition CircularQueue.hpp:57
const CircularQueue & operator=(const CircularQueue &)
void removeFirst()
Definition CircularQueue.hpp:47
CircularQueue(const CircularQueue &)
void clear(void)
Clear the queue.
Definition CircularQueue.hpp:36
void append(const T &t)
Definition CircularQueue.hpp:79
~CircularQueue()
Definition CircularQueue.hpp:31
std ::vector< T > storage
Definition CircularQueue.hpp:89
size_t entries() const
Definition CircularQueue.hpp:83
size_t m_offset
Definition CircularQueue.hpp:90
CircularQueue()
Definition CircularQueue.hpp:26
#define ANTLR_USE_NAMESPACE(_x_)
Definition config.hpp:18
#define ANTLR_API
Definition config.hpp:22
Definition ANTLRException.hpp:15