/src/icu/icu4c/source/common/unicode/rep.h

Source
// © 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.
     * @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

Coverage Report

Created: 2026-10-31 06:17

Line	Count	Source
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		* @stable ICU 2.1
124		*/
125		virtual void extractBetween(int32_t start,
126		int32_t limit,
127		UnicodeString& target) const = 0;
128
129		/**
130		* Replaces a substring of this object with the given text. If the
131		* characters being replaced have metadata, the new characters
132		* that replace them should be given the same metadata.
133		*
134		* <p>Subclasses must ensure that if the text between start and
135		* limit is equal to the replacement text, that replace has no
136		* effect. That is, any metadata
137		* should be unaffected. In addition, subclasses are encouraged to
138		* check for initial and trailing identical characters, and make a
139		* smaller replacement if possible. This will preserve as much
140		* metadata as possible.
141		* @param start the beginning index, inclusive; <code>0 <= start
142		* <= limit</code>.
143		* @param limit the ending index, exclusive; <code>start <= limit
144		* <= length()</code>.
145		* @param text the text to replace characters <code>start</code>
146		* to <code>limit - 1</code>
147		* @stable ICU 2.0
148		*/
149		virtual void handleReplaceBetween(int32_t start,
150		int32_t limit,
151		const UnicodeString& text) = 0;
152		// Note: All other methods in this class take the names of
153		// existing UnicodeString methods. This method is the exception.
154		// It is named differently because all replace methods of
155		// UnicodeString return a UnicodeString&. The 'between' is
156		// required in order to conform to the UnicodeString naming
157		// convention; API taking start/length are named <operation>, and
158		// those taking start/limit are named <operationBetween>. The
159		// 'handle' is added because 'replaceBetween' and
160		// 'doReplaceBetween' are already taken.
161
162		/**
163		* Copies a substring of this object, retaining metadata.
164		* This method is used to duplicate or reorder substrings.
165		* The destination index must not overlap the source range.
166		*
167		* @param start the beginning index, inclusive; <code>0 <= start <=
168		* limit</code>.
169		* @param limit the ending index, exclusive; <code>start <= limit <=
170		* length()</code>.
171		* @param dest the destination index. The characters from
172		* <code>start..limit-1</code> will be copied to <code>dest</code>.
173		* Implementations of this method may assume that <code>dest <= start \|\|
174		* dest >= limit</code>.
175		* @stable ICU 2.0
176		*/
177		virtual void copy(int32_t start, int32_t limit, int32_t dest) = 0;
178
179		/**
180		* Returns true if this object contains metadata. If a
181		* Replaceable object has metadata, calls to the Replaceable API
182		* must be made so as to preserve metadata. If it does not, calls
183		* to the Replaceable API may be optimized to improve performance.
184		* The default implementation returns true.
185		* @return true if this object contains metadata
186		* @stable ICU 2.2
187		*/
188		virtual UBool hasMetaData() const;
189
190		/**
191		* Clone this object, an instance of a subclass of Replaceable.
192		* Clones can be used concurrently in multiple threads.
193		* If a subclass does not implement clone(), or if an error occurs,
194		* then nullptr is returned.
195		* The caller must delete the clone.
196		*
197		* @return a clone of this object
198		*
199		* @see getDynamicClassID
200		* @stable ICU 2.6
201		*/
202		virtual Replaceable *clone() const;
203
204		protected:
205
206		/**
207		* Default constructor.
208		* @stable ICU 2.4
209		*/
210		inline Replaceable();
211
212		/*
213		* Assignment operator not declared. The compiler will provide one
214		* which does nothing since this class does not contain any data members.
215		* API/code coverage may show the assignment operator as present and
216		* untested - ignore.
217		* Subclasses need this assignment operator if they use compiler-provided
218		* assignment operators of their own. An alternative to not declaring one
219		* here would be to declare and empty-implement a protected or public one.
220		Replaceable &Replaceable::operator=(const Replaceable &);
221		*/
222
223		/**
224		* Virtual version of length().
225		* @stable ICU 2.4
226		*/
227		virtual int32_t getLength() const = 0;
228
229		/**
230		* Virtual version of charAt().
231		* @stable ICU 2.4
232		*/
233		virtual char16_t getCharAt(int32_t offset) const = 0;
234
235		/**
236		* Virtual version of char32At().
237		* @stable ICU 2.4
238		*/
239		virtual UChar32 getChar32At(int32_t offset) const = 0;
240		};
241
242	1.96G	inline Replaceable::Replaceable() {}
243
244		inline int32_t
245	0	Replaceable::length() const {
246	0	return getLength();
247	0	}
248
249		inline char16_t
250	0	Replaceable::charAt(int32_t offset) const {
251	0	return getCharAt(offset);
252	0	}
253
254		inline UChar32
255	0	Replaceable::char32At(int32_t offset) const {
256	0	return getChar32At(offset);
257	0	}
258
259		// There is no rep.cpp, see unistr.cpp for Replaceable function implementations.
260
261		U_NAMESPACE_END
262
263		#endif /* U_SHOW_CPLUSPLUS_API */
264
265		#endif