aboutsummaryrefslogtreecommitdiffstats
path: root/contrib/libs/icu/i18n/strmatch.h
blob: c1e0a4dbdfd52575edfd8cc5da713b4686322eee (plain) (blame)
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
// © 2016 and later: Unicode, Inc. and others. 
// License & terms of use: http://www.unicode.org/copyright.html
/*
 * Copyright (C) 2001-2011, International Business Machines Corporation
 * and others. All Rights Reserved.
 **********************************************************************
 *   Date        Name        Description
 *   07/23/01    aliu        Creation.
 **********************************************************************
 */
#ifndef STRMATCH_H
#define STRMATCH_H

#include "unicode/utypes.h"

#if !UCONFIG_NO_TRANSLITERATION

#include "unicode/unistr.h"
#include "unicode/unifunct.h"
#include "unicode/unimatch.h"
#include "unicode/unirepl.h"

U_NAMESPACE_BEGIN

class TransliterationRuleData;

/**
 * An object that matches a fixed input string, implementing the
 * UnicodeMatcher API.  This object also implements the
 * UnicodeReplacer API, allowing it to emit the matched text as
 * output.  Since the match text may contain flexible match elements,
 * such as UnicodeSets, the emitted text is not the match pattern, but
 * instead a substring of the actual matched text.  Following
 * convention, the output text is the leftmost match seen up to this
 * point.
 *
 * A StringMatcher may represent a segment, in which case it has a
 * positive segment number.  This affects how the matcher converts
 * itself to a pattern but does not otherwise affect its function.
 *
 * A StringMatcher that is not a segment should not be used as a
 * UnicodeReplacer.
 */
class StringMatcher : public UnicodeFunctor, public UnicodeMatcher, public UnicodeReplacer {

 public:

    /**
     * Construct a matcher that matches the given pattern string.
     * @param string the pattern to be matched, possibly containing
     * stand-ins that represent nested UnicodeMatcher objects.
     * @param start inclusive start index of text to be replaced
     * @param limit exclusive end index of text to be replaced;
     * must be greater than or equal to start
     * @param segmentNum the segment number from 1..n, or 0 if this is
     * not a segment.
     * @param data context object mapping stand-ins to
     * UnicodeMatcher objects.
     */
    StringMatcher(const UnicodeString& string,
                  int32_t start,
                  int32_t limit,
                  int32_t segmentNum,
                  const TransliterationRuleData& data);

    /**
     * Copy constructor
     * @param o  the object to be copied.
     */
    StringMatcher(const StringMatcher& o);
        
    /**
     * Destructor
     */
    virtual ~StringMatcher();

    /**
     * Implement UnicodeFunctor
     * @return a copy of the object.
     */
    virtual StringMatcher* clone() const; 

    /**
     * UnicodeFunctor API.  Cast 'this' to a UnicodeMatcher* pointer
     * and return the pointer.
     * @return the UnicodeMatcher point.
     */
    virtual UnicodeMatcher* toMatcher() const;

    /**
     * UnicodeFunctor API.  Cast 'this' to a UnicodeReplacer* pointer
     * and return the pointer.
     * @return the UnicodeReplacer pointer.
     */
    virtual UnicodeReplacer* toReplacer() const;

    /**
     * Implement UnicodeMatcher
     * @param text the text to be matched
     * @param offset on input, the index into text at which to begin
     * matching.  On output, the limit of the matched text.  The
     * number of matched characters is the output value of offset
     * minus the input value.  Offset should always point to the
     * HIGH SURROGATE (leading code unit) of a pair of surrogates,
     * both on entry and upon return.
     * @param limit the limit index of text to be matched.  Greater
     * than offset for a forward direction match, less than offset for
     * a backward direction match.  The last character to be
     * considered for matching will be text.charAt(limit-1) in the
     * forward direction or text.charAt(limit+1) in the backward
     * direction.
     * @param incremental  if TRUE, then assume further characters may
     * be inserted at limit and check for partial matching.  Otherwise
     * assume the text as given is complete.
     * @return a match degree value indicating a full match, a partial
     * match, or a mismatch.  If incremental is FALSE then
     * U_PARTIAL_MATCH should never be returned.
     */
    virtual UMatchDegree matches(const Replaceable& text,
                                 int32_t& offset,
                                 int32_t limit,
                                 UBool incremental);

    /**
     * Implement UnicodeMatcher
     * @param result            Output param to receive the pattern.
     * @param escapeUnprintable if True then escape the unprintable characters.
     * @return                  A reference to 'result'.
     */
    virtual UnicodeString& toPattern(UnicodeString& result,
                                     UBool escapeUnprintable = FALSE) const;

    /**
     * Implement UnicodeMatcher
     * Returns TRUE if this matcher will match a character c, where c
     * & 0xFF == v, at offset, in the forward direction (with limit >
     * offset).  This is used by <tt>RuleBasedTransliterator</tt> for
     * indexing.
     * @param v    the given value
     * @return     TRUE if this matcher will match a character c, 
     *             where c & 0xFF == v
     */
    virtual UBool matchesIndexValue(uint8_t v) const;

    /**
     * Implement UnicodeMatcher
     */
    virtual void addMatchSetTo(UnicodeSet& toUnionTo) const;

    /**
     * Implement UnicodeFunctor
     */
    virtual void setData(const TransliterationRuleData*);

    /**
     * Replace characters in 'text' from 'start' to 'limit' with the
     * output text of this object.  Update the 'cursor' parameter to
     * give the cursor position and return the length of the
     * replacement text.
     *
     * @param text the text to be matched
     * @param start inclusive start index of text to be replaced
     * @param limit exclusive end index of text to be replaced;
     * must be greater than or equal to start
     * @param cursor output parameter for the cursor position.
     * Not all replacer objects will update this, but in a complete
     * tree of replacer objects, representing the entire output side
     * of a transliteration rule, at least one must update it.
     * @return the number of 16-bit code units in the text replacing
     * the characters at offsets start..(limit-1) in text
     */
    virtual int32_t replace(Replaceable& text,
                            int32_t start,
                            int32_t limit,
                            int32_t& cursor);

    /**
     * Returns a string representation of this replacer.  If the
     * result of calling this function is passed to the appropriate
     * parser, typically TransliteratorParser, it will produce another
     * replacer that is equal to this one.
     * @param result the string to receive the pattern.  Previous
     * contents will be deleted.
     * @param escapeUnprintable if TRUE then convert unprintable
     * character to their hex escape representations, \\uxxxx or
     * \\Uxxxxxxxx.  Unprintable characters are defined by
     * Utility.isUnprintable().
     * @return a reference to 'result'.
     */
    virtual UnicodeString& toReplacerPattern(UnicodeString& result,
                                             UBool escapeUnprintable) const;

    /**
     * Remove any match data.  This must be called before performing a
     * set of matches with this segment.
     */
    void resetMatch();

    /**
     * ICU "poor man's RTTI", returns a UClassID for the actual class.
     */
    virtual UClassID getDynamicClassID() const;

    /**
     * ICU "poor man's RTTI", returns a UClassID for this class.
     */
    static UClassID U_EXPORT2 getStaticClassID();

    /**
     * Union the set of all characters that may output by this object
     * into the given set.
     * @param toUnionTo the set into which to union the output characters
     */
    virtual void addReplacementSetTo(UnicodeSet& toUnionTo) const;

 private:

    /**
     * The text to be matched.
     */
    UnicodeString pattern;

    /**
     * Context object that maps stand-ins to matcher and replacer
     * objects.
     */
    const TransliterationRuleData* data;

    /**
     * The segment number, 1-based, or 0 if not a segment.
     */
    int32_t segmentNumber;

    /**
     * Start offset, in the match text, of the <em>rightmost</em>
     * match.
     */
    int32_t matchStart;

    /**
     * Limit offset, in the match text, of the <em>rightmost</em>
     * match.
     */
    int32_t matchLimit;

};

U_NAMESPACE_END

#endif /* #if !UCONFIG_NO_TRANSLITERATION */

#endif