/src/node/deps/icu-small/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 nullptr 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  |