1 /*
2 * Copyright (c) 2000, 2017, 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.lang;
27
28 import java.util.NoSuchElementException;
29 import java.util.PrimitiveIterator;
30 import java.util.Spliterator;
31 import java.util.Spliterators;
32 import java.util.function.IntConsumer;
33 import java.util.stream.IntStream;
34 import java.util.stream.StreamSupport;
35
36 /**
37 * A {@code CharSequence} is a readable sequence of {@code char} values. This
38 * interface provides uniform, read-only access to many different kinds of
39 * {@code char} sequences.
40 * A {@code char} value represents a character in the <i>Basic
41 * Multilingual Plane (BMP)</i> or a surrogate. Refer to <a
42 * href="Character.html#unicode">Unicode Character Representation</a> for details.
43 *
44 * <p> This interface does not refine the general contracts of the {@link
45 * java.lang.Object#equals(java.lang.Object) equals} and {@link
46 * java.lang.Object#hashCode() hashCode} methods. The result of comparing two
47 * objects that implement {@code CharSequence} is therefore, in general,
48 * undefined. Each object may be implemented by a different class, and there
49 * is no guarantee that each class will be capable of testing its instances
50 * for equality with those of the other. It is therefore inappropriate to use
51 * arbitrary {@code CharSequence} instances as elements in a set or as keys in
52 * a map. </p>
53 *
54 * @author Mike McCloskey
55 * @since 1.4
56 * @spec JSR-51
57 */
58
59 public interface CharSequence {
60
61 /**
62 * Returns the length of this character sequence. The length is the number
63 * of 16-bit {@code char}s in the sequence.
64 *
65 * @return the number of {@code char}s in this sequence
66 */
67 int length();
68
220 }
221 char c1 = charAt(cur++);
222 if (Character.isHighSurrogate(c1) && cur < length) {
223 char c2 = charAt(cur);
224 if (Character.isLowSurrogate(c2)) {
225 cur++;
226 return Character.toCodePoint(c1, c2);
227 }
228 }
229 return c1;
230 }
231 }
232
233 return StreamSupport.intStream(() ->
234 Spliterators.spliteratorUnknownSize(
235 new CodePointIterator(),
236 Spliterator.ORDERED),
237 Spliterator.ORDERED,
238 false);
239 }
240 }
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1 /*
2 * Copyright (c) 2000, 2018, 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.lang;
27
28 import java.util.NoSuchElementException;
29 import java.util.Objects;
30 import java.util.PrimitiveIterator;
31 import java.util.Spliterator;
32 import java.util.Spliterators;
33 import java.util.function.IntConsumer;
34 import java.util.stream.IntStream;
35 import java.util.stream.StreamSupport;
36
37 /**
38 * A {@code CharSequence} is a readable sequence of {@code char} values. This
39 * interface provides uniform, read-only access to many different kinds of
40 * {@code char} sequences.
41 * A {@code char} value represents a character in the <i>Basic
42 * Multilingual Plane (BMP)</i> or a surrogate. Refer to <a
43 * href="Character.html#unicode">Unicode Character Representation</a> for details.
44 *
45 * <p> This interface does not refine the general contracts of the {@link
46 * java.lang.Object#equals(java.lang.Object) equals} and {@link
47 * java.lang.Object#hashCode() hashCode} methods. The result of testing two objects
48 * that implement {@code CharSequence} for equality is therefore, in general, undefined.
49 * Each object may be implemented by a different class, and there
50 * is no guarantee that each class will be capable of testing its instances
51 * for equality with those of the other. It is therefore inappropriate to use
52 * arbitrary {@code CharSequence} instances as elements in a set or as keys in
53 * a map. </p>
54 *
55 * @author Mike McCloskey
56 * @since 1.4
57 * @spec JSR-51
58 */
59
60 public interface CharSequence {
61
62 /**
63 * Returns the length of this character sequence. The length is the number
64 * of 16-bit {@code char}s in the sequence.
65 *
66 * @return the number of {@code char}s in this sequence
67 */
68 int length();
69
221 }
222 char c1 = charAt(cur++);
223 if (Character.isHighSurrogate(c1) && cur < length) {
224 char c2 = charAt(cur);
225 if (Character.isLowSurrogate(c2)) {
226 cur++;
227 return Character.toCodePoint(c1, c2);
228 }
229 }
230 return c1;
231 }
232 }
233
234 return StreamSupport.intStream(() ->
235 Spliterators.spliteratorUnknownSize(
236 new CodePointIterator(),
237 Spliterator.ORDERED),
238 Spliterator.ORDERED,
239 false);
240 }
241
242 /**
243 * Compares two {@code CharSequence} instances lexicographically. Returns a
244 * negative value, zero, or a positive value if the first sequence is lexicographically
245 * less than, equal to, or greater than the second, respectively.
246 *
247 * <p>
248 * The lexicographical ordering of {@code CharSequence} is defined as follows.
249 * Consider a {@code CharSequence} <i>cs</i> of length <i>len</i> to be a
250 * sequence of char values, <i>cs[0]</i> to <i>cs[len-1]</i>. Suppose <i>k</i>
251 * is the lowest index at which the corresponding char values from each sequence
252 * differ. The lexicographic ordering of the sequences is determined by a numeric
253 * comparison of the char values <i>cs1[k]</i> with <i>cs2[k]</i>. If there is
254 * no such index <i>k</i>, the shorter sequence is considered lexicographically
255 * less than the other. If the sequences have the same length, the sequences are
256 * considered lexicographically equal.
257 *
258 *
259 * @param cs1 the first {@code CharSequence}
260 * @param cs2 the second {@code CharSequence}
261 *
262 * @return the value {@code 0} if the two {@code CharSequence} are equal;
263 * a negative integer if the first {@code CharSequence}
264 * is lexicographically less than the second; or a
265 * positive integer if the first {@code CharSequence} is
266 * lexicographically greater than the second.
267 *
268 * @since 11
269 */
270 @SuppressWarnings("unchecked")
271 public static int compare(CharSequence cs1, CharSequence cs2) {
272 if (Objects.requireNonNull(cs1) == Objects.requireNonNull(cs2)) {
273 return 0;
274 }
275
276 if (cs1.getClass() == cs2.getClass() && cs1 instanceof Comparable) {
277 return ((Comparable<Object>) cs1).compareTo(cs2);
278 }
279
280 for (int i = 0, len = Math.min(cs1.length(), cs2.length()); i < len; i++) {
281 char a = cs1.charAt(i);
282 char b = cs2.charAt(i);
283 if (a != b) {
284 return a - b;
285 }
286 }
287
288 return cs1.length() - cs2.length();
289 }
290
291 }
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