1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
|
// Scintilla source code edit control
/** @file SparseVector.h
** Hold data sparsely associated with elements in a range.
**/
// Copyright 2016 by Neil Hodgson <neilh@scintilla.org>
// The License.txt file describes the conditions under which this software may be distributed.
#ifndef SPARSEVECTOR_H
#define SPARSEVECTOR_H
namespace Scintilla::Internal {
// SparseVector is similar to RunStyles but is more efficient for cases where values occur
// for one position instead of over a range of positions.
// There are always elements at the start and end, so the element type should have
// a reasonable empty value that will cause no problems.
// The element type should have a noexcept default constructor as that allows methods to
// be noexcept.
template <typename T>
class SparseVector {
private:
Partitioning<Sci::Position> starts;
SplitVector<T> values;
T empty; // Return from ValueAt when no element at a position.
void ClearValue(Sci::Position partition) noexcept {
values.SetValueAt(partition, T());
}
public:
SparseVector() : empty() {
starts = Partitioning<Sci::Position>(8);
values = SplitVector<T>();
values.InsertEmpty(0, 2);
}
Sci::Position Length() const noexcept {
return starts.Length();
}
Sci::Position Elements() const noexcept {
return starts.Partitions();
}
Sci::Position PositionOfElement(Sci::Position element) const noexcept {
return starts.PositionFromPartition(element);
}
Sci::Position ElementFromPosition(Sci::Position position) const noexcept {
if (position < Length()) {
return starts.PartitionFromPosition(position);
} else {
return starts.Partitions();
}
}
const T& ValueAt(Sci::Position position) const noexcept {
assert(position <= Length());
const Sci::Position partition = ElementFromPosition(position);
const Sci::Position startPartition = starts.PositionFromPartition(partition);
if (startPartition == position) {
return values.ValueAt(partition);
} else {
return empty;
}
}
template <typename ParamType>
void SetValueAt(Sci::Position position, ParamType &&value) {
assert(position <= Length());
const Sci::Position partition = ElementFromPosition(position);
const Sci::Position startPartition = starts.PositionFromPartition(partition);
if (value == T()) {
// Setting the empty value is equivalent to deleting the position
if (position == 0 || position == Length()) {
ClearValue(partition);
} else if (position == startPartition) {
// Currently an element at this position, so remove
ClearValue(partition);
starts.RemovePartition(partition);
values.Delete(partition);
}
// Else element remains empty
} else {
if (position == startPartition) {
// Already a value at this position, so replace
ClearValue(partition);
values.SetValueAt(partition, std::forward<ParamType>(value));
} else {
// Insert a new element
starts.InsertPartition(partition + 1, position);
values.Insert(partition + 1, std::forward<ParamType>(value));
}
}
}
void InsertSpace(Sci::Position position, Sci::Position insertLength) {
assert(position <= Length());
const Sci::Position partition = starts.PartitionFromPosition(position);
const Sci::Position startPartition = starts.PositionFromPartition(partition);
if (startPartition == position) {
const bool positionOccupied = values.ValueAt(partition) != T();
// Inserting at start of run so make previous longer
if (partition == 0) {
// Inserting at start of document so ensure start empty
if (positionOccupied) {
starts.InsertPartition(1, 0);
values.InsertEmpty(0, 1);
}
starts.InsertText(partition, insertLength);
} else {
if (positionOccupied) {
starts.InsertText(partition - 1, insertLength);
} else {
// Insert at end of run so do not extend style
starts.InsertText(partition, insertLength);
}
}
} else {
starts.InsertText(partition, insertLength);
}
}
void DeletePosition(Sci::Position position) {
assert(position < Length());
Sci::Position partition = starts.PartitionFromPosition(position);
const Sci::Position startPartition = starts.PositionFromPartition(partition);
if (startPartition == position) {
if (partition == 0) {
ClearValue(0);
if (starts.PositionFromPartition(1) == 1) {
// Removing all space of first partition, so remove next partition
// and move value if not last
if (Elements() > 1) {
starts.RemovePartition(partition + 1);
values.Delete(partition);
}
}
} else if (partition == starts.Partitions()) {
// This should not be possible
ClearValue(partition);
throw std::runtime_error("SparseVector: deleting end partition.");
} else {
ClearValue(partition);
starts.RemovePartition(partition);
values.Delete(partition);
// Its the previous partition now that gets smaller
partition--;
}
}
starts.InsertText(partition, -1);
Check();
}
void DeleteAll() {
starts = Partitioning<Sci::Position>(8);
values = SplitVector<T>();
values.InsertEmpty(0, 2);
}
void DeleteRange(Sci::Position position, Sci::Position deleteLength) {
// For now, delete elements in range - may want to leave value at start
// or combine onto position.
if (position > Length() || (deleteLength == 0)) {
return;
}
const Sci::Position positionEnd = position + deleteLength;
assert(positionEnd <= Length());
if (position == 0) {
// Remove all partitions in range, moving values to start
while ((Elements() > 1) && (starts.PositionFromPartition(1) <= deleteLength)) {
starts.RemovePartition(1);
values.Delete(0);
}
starts.InsertText(0, -deleteLength);
if (Length() == 0) {
ClearValue(0);
}
} else {
const Sci::Position partition = starts.PartitionFromPosition(position);
const bool atPartitionStart = position == starts.PositionFromPartition(partition);
const Sci::Position partitionDelete = partition + (atPartitionStart ? 0 : 1);
assert(partitionDelete > 0);
for (;;) {
const Sci::Position positionAtIndex = starts.PositionFromPartition(partitionDelete);
assert(position <= positionAtIndex);
if (positionAtIndex >= positionEnd) {
break;
}
assert(partitionDelete <= Elements());
starts.RemovePartition(partitionDelete);
values.Delete(partitionDelete);
}
starts.InsertText(partition - (atPartitionStart ? 1 : 0), -deleteLength);
}
Check();
}
Sci::Position PositionNext(Sci::Position start) const noexcept {
const Sci::Position element = ElementFromPosition(start);
if (element < Elements()) {
return PositionOfElement(element + 1);
}
return Length() + 1; // Out of bounds to terminate
}
Sci::Position IndexAfter(Sci::Position position) const noexcept {
assert(position < Length());
if (position < 0)
return 0;
const Sci::Position partition = starts.PartitionFromPosition(position);
return partition + 1;
}
void Check() const {
#ifdef CHECK_CORRECTNESS
starts.Check();
if (starts.Partitions() != values.Length() - 1) {
throw std::runtime_error("SparseVector: Partitions and values different lengths.");
}
#endif
}
};
}
#endif
|
