1 /*
2 * Copyright (c) 2016, 2019, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package java.util.regex;
27
28 import java.util.Objects;
29
30 final class Grapheme {
31
32 /**
33 * Look for the next extended grapheme cluster boundary in a CharSequence. It assumes
34 * the start of the char sequence is a boundary.
35 * <p>
36 * See Unicode Standard Annex #29 Unicode Text Segmentation for the specification
37 * for the extended grapheme cluster boundary rules. The following implementation
38 * is based on version 12.0 of the annex.
39 * (http://www.unicode.org/reports/tr29/tr29-35.html)
40 *
41 * @param src the {@code CharSequence} to be scanned
42 * @param off offset to start looking for the next boundary in the src
43 * @param limit limit offset in the src (exclusive)
44 * @return the next possible boundary
45 */
46 static int nextBoundary(CharSequence src, int off, int limit) {
47 Objects.checkFromToIndex(off, limit, src.length());
48
49 int ch0 = Character.codePointAt(src, 0);
50 int ret = Character.charCount(ch0);
51 int ch1;
52 // indicates whether gb11 or gb12 is underway
53 boolean gb11 = EmojiData.isExtendedPictographic(ch0);
54 int riCount = getType(ch0) == RI ? 1 : 0;
55 while (ret < limit) {
56 ch1 = Character.codePointAt(src, ret);
57 int t0 = getType(ch0);
58 int t1 = getType(ch1);
59
60 if (gb11 && t0 == ZWJ && t1 == EXTENDED_PICTOGRAPHIC) {
61 gb11 = false;
62 } else if (riCount % 2 == 1 && t0 == RI && t1 == RI) {
63 // continue for gb12
64 } else if (rules[t0][t1]) {
65 if (ret > off) {
66 break;
67 } else {
68 gb11 = EmojiData.isExtendedPictographic(ch1);
69 riCount = 0;
70 }
71 }
72
73 riCount += getType(ch1) == RI ? 1 : 0;
74 ch0 = ch1;
75 ret += Character.charCount(ch1);
76 }
77 return ret;
78 }
79
80 // types
81 private static final int OTHER = 0;
82 private static final int CR = 1;
83 private static final int LF = 2;
84 private static final int CONTROL = 3;
85 private static final int EXTEND = 4;
86 private static final int ZWJ = 5;
87 private static final int RI = 6;
88 private static final int PREPEND = 7;
89 private static final int SPACINGMARK = 8;
90 private static final int L = 9;
91 private static final int V = 10;
92 private static final int T = 11;
93 private static final int LV = 12;
94 private static final int LVT = 13;
95 private static final int EXTENDED_PICTOGRAPHIC = 14;
96
97 private static final int FIRST_TYPE = 0;
98 private static final int LAST_TYPE = 14;
99
100 private static boolean[][] rules;
101 static {
102 rules = new boolean[LAST_TYPE + 1][LAST_TYPE + 1];
103 // GB 999 Any + Any -> default
104 for (int i = FIRST_TYPE; i <= LAST_TYPE; i++)
105 for (int j = FIRST_TYPE; j <= LAST_TYPE; j++)
106 rules[i][j] = true;
107 // GB 6 L x (L | V | LV | VT)
108 rules[L][L] = false;
109 rules[L][V] = false;
110 rules[L][LV] = false;
111 rules[L][LVT] = false;
112 // GB 7 (LV | V) x (V | T)
113 rules[LV][V] = false;
114 rules[LV][T] = false;
115 rules[V][V] = false;
116 rules[V][T] = false;
117 // GB 8 (LVT | T) x T
118 rules[LVT][T] = false;
119 rules[T][T] = false;
120 // GB 9 x (Extend|ZWJ)
121 // GB 9a x Spacing Mark
122 // GB 9b Prepend x
123 for (int i = FIRST_TYPE; i <= LAST_TYPE; i++) {
124 rules[i][EXTEND] = false;
125 rules[i][ZWJ] = false;
126 rules[i][SPACINGMARK] = false;
127 rules[PREPEND][i] = false;
128 }
129 // GB 4 (Control | CR | LF) +
130 // GB 5 + (Control | CR | LF)
131 for (int i = FIRST_TYPE; i <= LAST_TYPE; i++)
132 for (int j = CR; j <= CONTROL; j++) {
133 rules[i][j] = true;
134 rules[j][i] = true;
135 }
136 // GB 3 CR x LF
137 rules[CR][LF] = false;
138 // GB 11 Exended_Pictographic x (Extend|ZWJ)
139 rules[EXTENDED_PICTOGRAPHIC][EXTEND] = false;
140 rules[EXTENDED_PICTOGRAPHIC][ZWJ] = false;
141 }
142
143 // Hangul syllables
144 private static final int SYLLABLE_BASE = 0xAC00;
145 private static final int LCOUNT = 19;
146 private static final int VCOUNT = 21;
147 private static final int TCOUNT = 28;
148 private static final int NCOUNT = VCOUNT * TCOUNT; // 588
149 private static final int SCOUNT = LCOUNT * NCOUNT; // 11172
150
151 // #tr29: SpacingMark exceptions: The following (which have
152 // General_Category = Spacing_Mark and would otherwise be included)
153 // are specifically excluded
154 private static boolean isExcludedSpacingMark(int cp) {
155 return cp == 0x102B || cp == 0x102C || cp == 0x1038 ||
156 cp >= 0x1062 && cp <= 0x1064 ||
157 cp >= 0x1062 && cp <= 0x106D ||
158 cp == 0x1083 ||
159 cp >= 0x1087 && cp <= 0x108C ||
160 cp == 0x108F ||
161 cp >= 0x109A && cp <= 0x109C ||
162 cp == 0x1A61 || cp == 0x1A63 || cp == 0x1A64 ||
163 cp == 0xAA7B || cp == 0xAA7D;
164 }
165
166 @SuppressWarnings("fallthrough")
167 private static int getType(int cp) {
168 if (EmojiData.isExtendedPictographic(cp)) {
169 return EXTENDED_PICTOGRAPHIC;
170 }
171
172 int type = Character.getType(cp);
173 switch(type) {
174 case Character.CONTROL:
175 if (cp == 0x000D)
176 return CR;
177 if (cp == 0x000A)
178 return LF;
179 return CONTROL;
180 case Character.UNASSIGNED:
181 // NOTE: #tr29 lists "Unassigned and Default_Ignorable_Code_Point" as Control
182 // but GraphemeBreakTest.txt lists u+0378/reserved-0378 as "Other"
183 // so type it as "Other" to make the test happy
184 if (cp == 0x0378)
185 return OTHER;
186
187 case Character.LINE_SEPARATOR:
188 case Character.PARAGRAPH_SEPARATOR:
189 case Character.SURROGATE:
190 return CONTROL;
191 case Character.FORMAT:
192 if (cp == 0x200C ||
193 cp >= 0xE0020 && cp <= 0xE007F)
194 return EXTEND;
195 if (cp == 0x200D)
196 return ZWJ;
197 if (cp >= 0x0600 && cp <= 0x0605 ||
198 cp == 0x06DD || cp == 0x070F || cp == 0x08E2 ||
199 cp == 0x110BD || cp == 0x110CD)
200 return PREPEND;
201 return CONTROL;
202 case Character.NON_SPACING_MARK:
203 case Character.ENCLOSING_MARK:
204 // NOTE:
205 // #tr29 "plus a few General_Category = Spacing_Mark needed for
206 // canonical equivalence."
207 // but for "extended grapheme clusters" support, there is no
208 // need actually to diff "extend" and "spackmark" given GB9, GB9a
209 return EXTEND;
210 case Character.COMBINING_SPACING_MARK:
211 if (isExcludedSpacingMark(cp))
212 return OTHER;
213 // NOTE:
214 // 0x11720 and 0x11721 are mentioned in #tr29 as
215 // OTHER_LETTER but it appears their category has been updated to
216 // COMBING_SPACING_MARK already (verified in ver.8)
217 return SPACINGMARK;
218 case Character.OTHER_SYMBOL:
219 if (cp >= 0x1F1E6 && cp <= 0x1F1FF)
220 return RI;
221 return OTHER;
222 case Character.MODIFIER_LETTER:
223 case Character.MODIFIER_SYMBOL:
224 // WARNING:
225 // not mentioned in #tr29 but listed in GraphemeBreakProperty.txt
226 if (cp == 0xFF9E || cp == 0xFF9F ||
227 cp >= 0x1F3FB && cp <= 0x1F3FF)
228 return EXTEND;
229 return OTHER;
230 case Character.OTHER_LETTER:
231 if (cp == 0x0E33 || cp == 0x0EB3)
232 return SPACINGMARK;
233 // hangul jamo
234 if (cp >= 0x1100 && cp <= 0x11FF) {
235 if (cp <= 0x115F)
236 return L;
237 if (cp <= 0x11A7)
238 return V;
239 return T;
240 }
241 // hangul syllables
242 int sindex = cp - SYLLABLE_BASE;
243 if (sindex >= 0 && sindex < SCOUNT) {
244
245 if (sindex % TCOUNT == 0)
246 return LV;
247 return LVT;
248 }
249 // hangul jamo_extended A
250 if (cp >= 0xA960 && cp <= 0xA97C)
251 return L;
252 // hangul jamo_extended B
253 if (cp >= 0xD7B0 && cp <= 0xD7C6)
254 return V;
255 if (cp >= 0xD7CB && cp <= 0xD7FB)
256 return T;
257
258 // Prepend
259 switch (cp) {
260 case 0x0D4E:
261 case 0x111C2:
262 case 0x111C3:
263 case 0x11A3A:
264 case 0x11A84:
265 case 0x11A85:
266 case 0x11A86:
267 case 0x11A87:
268 case 0x11A88:
269 case 0x11A89:
270 case 0x11D46:
271 return PREPEND;
272 }
273 }
274 return OTHER;
275 }
276 }