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
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
|
// © 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
/*
**************************************************************************
* Copyright (C) 1999-2012, International Business Machines Corporation and
* others. All Rights Reserved.
**************************************************************************
* Date Name Description
* 11/17/99 aliu Creation. Ported from java. Modified to
* match current UnicodeString API. Forced
* to use name "handleReplaceBetween" because
* of existing methods in UnicodeString.
**************************************************************************
*/
#ifndef REP_H
#define REP_H
#include "unicode/utypes.h"
#if U_SHOW_CPLUSPLUS_API
#include "unicode/uobject.h"
/**
* \file
* \brief C++ API: Replaceable String
*/
U_NAMESPACE_BEGIN
class UnicodeString;
/**
* <code>Replaceable</code> is an abstract base class representing a
* string of characters that supports the replacement of a range of
* itself with a new string of characters. It is used by APIs that
* change a piece of text while retaining metadata. Metadata is data
* other than the Unicode characters returned by char32At(). One
* example of metadata is style attributes; another is an edit
* history, marking each character with an author and revision number.
*
* <p>An implicit aspect of the <code>Replaceable</code> API is that
* during a replace operation, new characters take on the metadata of
* the old characters. For example, if the string "the <b>bold</b>
* font" has range (4, 8) replaced with "strong", then it becomes "the
* <b>strong</b> font".
*
* <p><code>Replaceable</code> specifies ranges using a start
* offset and a limit offset. The range of characters thus specified
* includes the characters at offset start..limit-1. That is, the
* start offset is inclusive, and the limit offset is exclusive.
*
* <p><code>Replaceable</code> also includes API to access characters
* in the string: <code>length()</code>, <code>charAt()</code>,
* <code>char32At()</code>, and <code>extractBetween()</code>.
*
* <p>For a subclass to support metadata, typical behavior of
* <code>replace()</code> is the following:
* <ul>
* <li>Set the metadata of the new text to the metadata of the first
* character replaced</li>
* <li>If no characters are replaced, use the metadata of the
* previous character</li>
* <li>If there is no previous character (i.e. start == 0), use the
* following character</li>
* <li>If there is no following character (i.e. the replaceable was
* empty), use default metadata.<br>
* <li>If the code point U+FFFF is seen, it should be interpreted as
* a special marker having no metadata<li>
* </li>
* </ul>
* If this is not the behavior, the subclass should document any differences.
* @author Alan Liu
* @stable ICU 2.0
*/
class U_COMMON_API Replaceable : public UObject {
public:
/**
* Destructor.
* @stable ICU 2.0
*/
virtual ~Replaceable();
/**
* Returns the number of 16-bit code units in the text.
* @return number of 16-bit code units in text
* @stable ICU 1.8
*/
inline int32_t length() const;
/**
* Returns the 16-bit code unit at the given offset into the text.
* @param offset an integer between 0 and <code>length()</code>-1
* inclusive
* @return 16-bit code unit of text at given offset
* @stable ICU 1.8
*/
inline char16_t charAt(int32_t offset) const;
/**
* Returns the 32-bit code point at the given 16-bit offset into
* the text. This assumes the text is stored as 16-bit code units
* with surrogate pairs intermixed. If the offset of a leading or
* trailing code unit of a surrogate pair is given, return the
* code point of the surrogate pair.
*
* @param offset an integer between 0 and <code>length()</code>-1
* inclusive
* @return 32-bit code point of text at given offset
* @stable ICU 1.8
*/
inline UChar32 char32At(int32_t offset) const;
/**
* Copies characters in the range [<tt>start</tt>, <tt>limit</tt>)
* into the UnicodeString <tt>target</tt>.
* @param start offset of first character which will be copied
* @param limit offset immediately following the last character to
* be copied
* @param target UnicodeString into which to copy characters.
* @return A reference to <TT>target</TT>
* @stable ICU 2.1
*/
virtual void extractBetween(int32_t start,
int32_t limit,
UnicodeString& target) const = 0;
/**
* Replaces a substring of this object with the given text. If the
* characters being replaced have metadata, the new characters
* that replace them should be given the same metadata.
*
* <p>Subclasses must ensure that if the text between start and
* limit is equal to the replacement text, that replace has no
* effect. That is, any metadata
* should be unaffected. In addition, subclasses are encouraged to
* check for initial and trailing identical characters, and make a
* smaller replacement if possible. This will preserve as much
* metadata as possible.
* @param start the beginning index, inclusive; <code>0 <= start
* <= limit</code>.
* @param limit the ending index, exclusive; <code>start <= limit
* <= length()</code>.
* @param text the text to replace characters <code>start</code>
* to <code>limit - 1</code>
* @stable ICU 2.0
*/
virtual void handleReplaceBetween(int32_t start,
int32_t limit,
const UnicodeString& text) = 0;
// Note: All other methods in this class take the names of
// existing UnicodeString methods. This method is the exception.
// It is named differently because all replace methods of
// UnicodeString return a UnicodeString&. The 'between' is
// required in order to conform to the UnicodeString naming
// convention; API taking start/length are named <operation>, and
// those taking start/limit are named <operationBetween>. The
// 'handle' is added because 'replaceBetween' and
// 'doReplaceBetween' are already taken.
/**
* Copies a substring of this object, retaining metadata.
* This method is used to duplicate or reorder substrings.
* The destination index must not overlap the source range.
*
* @param start the beginning index, inclusive; <code>0 <= start <=
* limit</code>.
* @param limit the ending index, exclusive; <code>start <= limit <=
* length()</code>.
* @param dest the destination index. The characters from
* <code>start..limit-1</code> will be copied to <code>dest</code>.
* Implementations of this method may assume that <code>dest <= start ||
* dest >= limit</code>.
* @stable ICU 2.0
*/
virtual void copy(int32_t start, int32_t limit, int32_t dest) = 0;
/**
* Returns true if this object contains metadata. If a
* Replaceable object has metadata, calls to the Replaceable API
* must be made so as to preserve metadata. If it does not, calls
* to the Replaceable API may be optimized to improve performance.
* The default implementation returns true.
* @return true if this object contains metadata
* @stable ICU 2.2
*/
virtual UBool hasMetaData() const;
/**
* Clone this object, an instance of a subclass of Replaceable.
* Clones can be used concurrently in multiple threads.
* If a subclass does not implement clone(), or if an error occurs,
* then nullptr is returned.
* The caller must delete the clone.
*
* @return a clone of this object
*
* @see getDynamicClassID
* @stable ICU 2.6
*/
virtual Replaceable *clone() const;
protected:
/**
* Default constructor.
* @stable ICU 2.4
*/
inline Replaceable();
/*
* Assignment operator not declared. The compiler will provide one
* which does nothing since this class does not contain any data members.
* API/code coverage may show the assignment operator as present and
* untested - ignore.
* Subclasses need this assignment operator if they use compiler-provided
* assignment operators of their own. An alternative to not declaring one
* here would be to declare and empty-implement a protected or public one.
Replaceable &Replaceable::operator=(const Replaceable &);
*/
/**
* Virtual version of length().
* @stable ICU 2.4
*/
virtual int32_t getLength() const = 0;
/**
* Virtual version of charAt().
* @stable ICU 2.4
*/
virtual char16_t getCharAt(int32_t offset) const = 0;
/**
* Virtual version of char32At().
* @stable ICU 2.4
*/
virtual UChar32 getChar32At(int32_t offset) const = 0;
};
inline Replaceable::Replaceable() {}
inline int32_t
Replaceable::length() const {
return getLength();
}
inline char16_t
Replaceable::charAt(int32_t offset) const {
return getCharAt(offset);
}
inline UChar32
Replaceable::char32At(int32_t offset) const {
return getChar32At(offset);
}
// There is no rep.cpp, see unistr.cpp for Replaceable function implementations.
U_NAMESPACE_END
#endif /* U_SHOW_CPLUSPLUS_API */
#endif
|
