/src/skia/third_party/externals/icu/source/common/unicode/rep.h
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1 | | // © 2016 and later: Unicode, Inc. and others. |
2 | | // License & terms of use: http://www.unicode.org/copyright.html |
3 | | /* |
4 | | ************************************************************************** |
5 | | * Copyright (C) 1999-2012, International Business Machines Corporation and |
6 | | * others. All Rights Reserved. |
7 | | ************************************************************************** |
8 | | * Date Name Description |
9 | | * 11/17/99 aliu Creation. Ported from java. Modified to |
10 | | * match current UnicodeString API. Forced |
11 | | * to use name "handleReplaceBetween" because |
12 | | * of existing methods in UnicodeString. |
13 | | ************************************************************************** |
14 | | */ |
15 | | |
16 | | #ifndef REP_H |
17 | | #define REP_H |
18 | | |
19 | | #include "unicode/utypes.h" |
20 | | |
21 | | #if U_SHOW_CPLUSPLUS_API |
22 | | |
23 | | #include "unicode/uobject.h" |
24 | | |
25 | | /** |
26 | | * \file |
27 | | * \brief C++ API: Replaceable String |
28 | | */ |
29 | | |
30 | | U_NAMESPACE_BEGIN |
31 | | |
32 | | class UnicodeString; |
33 | | |
34 | | /** |
35 | | * <code>Replaceable</code> is an abstract base class representing a |
36 | | * string of characters that supports the replacement of a range of |
37 | | * itself with a new string of characters. It is used by APIs that |
38 | | * change a piece of text while retaining metadata. Metadata is data |
39 | | * other than the Unicode characters returned by char32At(). One |
40 | | * example of metadata is style attributes; another is an edit |
41 | | * history, marking each character with an author and revision number. |
42 | | * |
43 | | * <p>An implicit aspect of the <code>Replaceable</code> API is that |
44 | | * during a replace operation, new characters take on the metadata of |
45 | | * the old characters. For example, if the string "the <b>bold</b> |
46 | | * font" has range (4, 8) replaced with "strong", then it becomes "the |
47 | | * <b>strong</b> font". |
48 | | * |
49 | | * <p><code>Replaceable</code> specifies ranges using a start |
50 | | * offset and a limit offset. The range of characters thus specified |
51 | | * includes the characters at offset start..limit-1. That is, the |
52 | | * start offset is inclusive, and the limit offset is exclusive. |
53 | | * |
54 | | * <p><code>Replaceable</code> also includes API to access characters |
55 | | * in the string: <code>length()</code>, <code>charAt()</code>, |
56 | | * <code>char32At()</code>, and <code>extractBetween()</code>. |
57 | | * |
58 | | * <p>For a subclass to support metadata, typical behavior of |
59 | | * <code>replace()</code> is the following: |
60 | | * <ul> |
61 | | * <li>Set the metadata of the new text to the metadata of the first |
62 | | * character replaced</li> |
63 | | * <li>If no characters are replaced, use the metadata of the |
64 | | * previous character</li> |
65 | | * <li>If there is no previous character (i.e. start == 0), use the |
66 | | * following character</li> |
67 | | * <li>If there is no following character (i.e. the replaceable was |
68 | | * empty), use default metadata.<br> |
69 | | * <li>If the code point U+FFFF is seen, it should be interpreted as |
70 | | * a special marker having no metadata<li> |
71 | | * </li> |
72 | | * </ul> |
73 | | * If this is not the behavior, the subclass should document any differences. |
74 | | * @author Alan Liu |
75 | | * @stable ICU 2.0 |
76 | | */ |
77 | | class U_COMMON_API Replaceable : public UObject { |
78 | | |
79 | | public: |
80 | | /** |
81 | | * Destructor. |
82 | | * @stable ICU 2.0 |
83 | | */ |
84 | | virtual ~Replaceable(); |
85 | | |
86 | | /** |
87 | | * Returns the number of 16-bit code units in the text. |
88 | | * @return number of 16-bit code units in text |
89 | | * @stable ICU 1.8 |
90 | | */ |
91 | | inline int32_t length() const; |
92 | | |
93 | | /** |
94 | | * Returns the 16-bit code unit at the given offset into the text. |
95 | | * @param offset an integer between 0 and <code>length()</code>-1 |
96 | | * inclusive |
97 | | * @return 16-bit code unit of text at given offset |
98 | | * @stable ICU 1.8 |
99 | | */ |
100 | | inline char16_t charAt(int32_t offset) const; |
101 | | |
102 | | /** |
103 | | * Returns the 32-bit code point at the given 16-bit offset into |
104 | | * the text. This assumes the text is stored as 16-bit code units |
105 | | * with surrogate pairs intermixed. If the offset of a leading or |
106 | | * trailing code unit of a surrogate pair is given, return the |
107 | | * code point of the surrogate pair. |
108 | | * |
109 | | * @param offset an integer between 0 and <code>length()</code>-1 |
110 | | * inclusive |
111 | | * @return 32-bit code point of text at given offset |
112 | | * @stable ICU 1.8 |
113 | | */ |
114 | | inline UChar32 char32At(int32_t offset) const; |
115 | | |
116 | | /** |
117 | | * Copies characters in the range [<tt>start</tt>, <tt>limit</tt>) |
118 | | * into the UnicodeString <tt>target</tt>. |
119 | | * @param start offset of first character which will be copied |
120 | | * @param limit offset immediately following the last character to |
121 | | * be copied |
122 | | * @param target UnicodeString into which to copy characters. |
123 | | * @return A reference to <TT>target</TT> |
124 | | * @stable ICU 2.1 |
125 | | */ |
126 | | virtual void extractBetween(int32_t start, |
127 | | int32_t limit, |
128 | | UnicodeString& target) const = 0; |
129 | | |
130 | | /** |
131 | | * Replaces a substring of this object with the given text. If the |
132 | | * characters being replaced have metadata, the new characters |
133 | | * that replace them should be given the same metadata. |
134 | | * |
135 | | * <p>Subclasses must ensure that if the text between start and |
136 | | * limit is equal to the replacement text, that replace has no |
137 | | * effect. That is, any metadata |
138 | | * should be unaffected. In addition, subclasses are encouraged to |
139 | | * check for initial and trailing identical characters, and make a |
140 | | * smaller replacement if possible. This will preserve as much |
141 | | * metadata as possible. |
142 | | * @param start the beginning index, inclusive; <code>0 <= start |
143 | | * <= limit</code>. |
144 | | * @param limit the ending index, exclusive; <code>start <= limit |
145 | | * <= length()</code>. |
146 | | * @param text the text to replace characters <code>start</code> |
147 | | * to <code>limit - 1</code> |
148 | | * @stable ICU 2.0 |
149 | | */ |
150 | | virtual void handleReplaceBetween(int32_t start, |
151 | | int32_t limit, |
152 | | const UnicodeString& text) = 0; |
153 | | // Note: All other methods in this class take the names of |
154 | | // existing UnicodeString methods. This method is the exception. |
155 | | // It is named differently because all replace methods of |
156 | | // UnicodeString return a UnicodeString&. The 'between' is |
157 | | // required in order to conform to the UnicodeString naming |
158 | | // convention; API taking start/length are named <operation>, and |
159 | | // those taking start/limit are named <operationBetween>. The |
160 | | // 'handle' is added because 'replaceBetween' and |
161 | | // 'doReplaceBetween' are already taken. |
162 | | |
163 | | /** |
164 | | * Copies a substring of this object, retaining metadata. |
165 | | * This method is used to duplicate or reorder substrings. |
166 | | * The destination index must not overlap the source range. |
167 | | * |
168 | | * @param start the beginning index, inclusive; <code>0 <= start <= |
169 | | * limit</code>. |
170 | | * @param limit the ending index, exclusive; <code>start <= limit <= |
171 | | * length()</code>. |
172 | | * @param dest the destination index. The characters from |
173 | | * <code>start..limit-1</code> will be copied to <code>dest</code>. |
174 | | * Implementations of this method may assume that <code>dest <= start || |
175 | | * dest >= limit</code>. |
176 | | * @stable ICU 2.0 |
177 | | */ |
178 | | virtual void copy(int32_t start, int32_t limit, int32_t dest) = 0; |
179 | | |
180 | | /** |
181 | | * Returns true if this object contains metadata. If a |
182 | | * Replaceable object has metadata, calls to the Replaceable API |
183 | | * must be made so as to preserve metadata. If it does not, calls |
184 | | * to the Replaceable API may be optimized to improve performance. |
185 | | * The default implementation returns true. |
186 | | * @return true if this object contains metadata |
187 | | * @stable ICU 2.2 |
188 | | */ |
189 | | virtual UBool hasMetaData() const; |
190 | | |
191 | | /** |
192 | | * Clone this object, an instance of a subclass of Replaceable. |
193 | | * Clones can be used concurrently in multiple threads. |
194 | | * If a subclass does not implement clone(), or if an error occurs, |
195 | | * then NULL is returned. |
196 | | * The caller must delete the clone. |
197 | | * |
198 | | * @return a clone of this object |
199 | | * |
200 | | * @see getDynamicClassID |
201 | | * @stable ICU 2.6 |
202 | | */ |
203 | | virtual Replaceable *clone() const; |
204 | | |
205 | | protected: |
206 | | |
207 | | /** |
208 | | * Default constructor. |
209 | | * @stable ICU 2.4 |
210 | | */ |
211 | | inline Replaceable(); |
212 | | |
213 | | /* |
214 | | * Assignment operator not declared. The compiler will provide one |
215 | | * which does nothing since this class does not contain any data members. |
216 | | * API/code coverage may show the assignment operator as present and |
217 | | * untested - ignore. |
218 | | * Subclasses need this assignment operator if they use compiler-provided |
219 | | * assignment operators of their own. An alternative to not declaring one |
220 | | * here would be to declare and empty-implement a protected or public one. |
221 | | Replaceable &Replaceable::operator=(const Replaceable &); |
222 | | */ |
223 | | |
224 | | /** |
225 | | * Virtual version of length(). |
226 | | * @stable ICU 2.4 |
227 | | */ |
228 | | virtual int32_t getLength() const = 0; |
229 | | |
230 | | /** |
231 | | * Virtual version of charAt(). |
232 | | * @stable ICU 2.4 |
233 | | */ |
234 | | virtual char16_t getCharAt(int32_t offset) const = 0; |
235 | | |
236 | | /** |
237 | | * Virtual version of char32At(). |
238 | | * @stable ICU 2.4 |
239 | | */ |
240 | | virtual UChar32 getChar32At(int32_t offset) const = 0; |
241 | | }; |
242 | | |
243 | | inline Replaceable::Replaceable() {} |
244 | | |
245 | | inline int32_t |
246 | 0 | Replaceable::length() const { |
247 | 0 | return getLength(); |
248 | 0 | } |
249 | | |
250 | | inline char16_t |
251 | 0 | Replaceable::charAt(int32_t offset) const { |
252 | 0 | return getCharAt(offset); |
253 | 0 | } |
254 | | |
255 | | inline UChar32 |
256 | 0 | Replaceable::char32At(int32_t offset) const { |
257 | 0 | return getChar32At(offset); |
258 | 0 | } |
259 | | |
260 | | // There is no rep.cpp, see unistr.cpp for Replaceable function implementations. |
261 | | |
262 | | U_NAMESPACE_END |
263 | | |
264 | | #endif /* U_SHOW_CPLUSPLUS_API */ |
265 | | |
266 | | #endif |