- * In addition, this class provides several methods for determining - * a character's category (lowercase letter, digit, etc.) and for converting - * characters from uppercase to lowercase and vice versa. - *
- * Character information is based on the Unicode Standard, version 6.0.0. - *
- * The methods and data of class {@code Character} are defined by - * the information in the UnicodeData file that is part of the - * Unicode Character Database maintained by the Unicode - * Consortium. This file specifies various properties including name - * and general category for every defined Unicode code point or - * character range. - *
- * The file and its description are available from the Unicode Consortium at: - *
The {@code char} data type (and therefore the value that a - * {@code Character} object encapsulates) are based on the - * original Unicode specification, which defined characters as - * fixed-width 16-bit entities. The Unicode Standard has since been - * changed to allow for characters whose representation requires more - * than 16 bits. The range of legal code points is now - * U+0000 to U+10FFFF, known as Unicode scalar value. - * (Refer to the - * definition of the U+n notation in the Unicode - * Standard.) - * - *
The set of characters from U+0000 to U+FFFF is - * sometimes referred to as the Basic Multilingual Plane (BMP). - * Characters whose code points are greater - * than U+FFFF are called supplementary characters. The Java - * platform uses the UTF-16 representation in {@code char} arrays and - * in the {@code String} and {@code StringBuffer} classes. In - * this representation, supplementary characters are represented as a pair - * of {@code char} values, the first from the high-surrogates - * range, (\uD800-\uDBFF), the second from the - * low-surrogates range (\uDC00-\uDFFF). - * - *
A {@code char} value, therefore, represents Basic - * Multilingual Plane (BMP) code points, including the surrogate - * code points, or code units of the UTF-16 encoding. An - * {@code int} value represents all Unicode code points, - * including supplementary code points. The lower (least significant) - * 21 bits of {@code int} are used to represent Unicode code - * points and the upper (most significant) 11 bits must be zero. - * Unless otherwise specified, the behavior with respect to - * supplementary characters and surrogate {@code char} values is - * as follows: - * - *
In the Java SE API documentation, Unicode code point is
- * used for character values in the range between U+0000 and U+10FFFF,
- * and Unicode code unit is used for 16-bit
- * {@code char} values that are code units of the UTF-16
- * encoding. For more information on Unicode terminology, refer to the
- * Unicode Glossary.
- *
- * @author Lee Boynton
- * @author Guy Steele
- * @author Akira Tanaka
- * @author Martin Buchholz
- * @author Ulf Zibis
- * @since 1.0
- */
-public final
-class Character implements java.io.Serializable, Comparable Such values do not represent characters by themselves,
- * but are used in the representation of
- * supplementary characters
- * in the UTF-16 encoding.
- *
- * @param ch the {@code char} value to be tested.
- * @return {@code true} if the {@code char} value is between
- * {@link #MIN_HIGH_SURROGATE} and
- * {@link #MAX_HIGH_SURROGATE} inclusive;
- * {@code false} otherwise.
- * @see Character#isLowSurrogate(char)
- * @see Character.UnicodeBlock#of(int)
- * @since 1.5
- */
- public static boolean isHighSurrogate(char ch) {
- // Help VM constant-fold; MAX_HIGH_SURROGATE + 1 == MIN_LOW_SURROGATE
- return ch >= MIN_HIGH_SURROGATE && ch < (MAX_HIGH_SURROGATE + 1);
- }
-
- /**
- * Determines if the given {@code char} value is a
- *
- * Unicode low-surrogate code unit
- * (also known as trailing-surrogate code unit).
- *
- * Such values do not represent characters by themselves,
- * but are used in the representation of
- * supplementary characters
- * in the UTF-16 encoding.
- *
- * @param ch the {@code char} value to be tested.
- * @return {@code true} if the {@code char} value is between
- * {@link #MIN_LOW_SURROGATE} and
- * {@link #MAX_LOW_SURROGATE} inclusive;
- * {@code false} otherwise.
- * @see Character#isHighSurrogate(char)
- * @since 1.5
- */
- public static boolean isLowSurrogate(char ch) {
- return ch >= MIN_LOW_SURROGATE && ch < (MAX_LOW_SURROGATE + 1);
- }
-
- /**
- * Determines if the given {@code char} value is a Unicode
- * surrogate code unit.
- *
- * Such values do not represent characters by themselves,
- * but are used in the representation of
- * supplementary characters
- * in the UTF-16 encoding.
- *
- * A char value is a surrogate code unit if and only if it is either
- * a {@linkplain #isLowSurrogate(char) low-surrogate code unit} or
- * a {@linkplain #isHighSurrogate(char) high-surrogate code unit}.
- *
- * @param ch the {@code char} value to be tested.
- * @return {@code true} if the {@code char} value is between
- * {@link #MIN_SURROGATE} and
- * {@link #MAX_SURROGATE} inclusive;
- * {@code false} otherwise.
- * @since 1.7
- */
- public static boolean isSurrogate(char ch) {
- return ch >= MIN_SURROGATE && ch < (MAX_SURROGATE + 1);
- }
-
- /**
- * Determines whether the specified pair of {@code char}
- * values is a valid
- *
- * Unicode surrogate pair.
-
- * This method is equivalent to the expression:
- * This method doesn't validate the specified character to be a
- * valid Unicode code point. The caller must validate the
- * character value using {@link #isValidCodePoint(int) isValidCodePoint}
- * if necessary.
- *
- * @param codePoint the character (Unicode code point) to be tested.
- * @return 2 if the character is a valid supplementary character; 1 otherwise.
- * @see Character#isSupplementaryCodePoint(int)
- * @since 1.5
- */
- public static int charCount(int codePoint) {
- return codePoint >= MIN_SUPPLEMENTARY_CODE_POINT ? 2 : 1;
- }
-
- /**
- * Converts the specified surrogate pair to its supplementary code
- * point value. This method does not validate the specified
- * surrogate pair. The caller must validate it using {@link
- * #isSurrogatePair(char, char) isSurrogatePair} if necessary.
- *
- * @param high the high-surrogate code unit
- * @param low the low-surrogate code unit
- * @return the supplementary code point composed from the
- * specified surrogate pair.
- * @since 1.5
- */
- public static int toCodePoint(char high, char low) {
- // Optimized form of:
- // return ((high - MIN_HIGH_SURROGATE) << 10)
- // + (low - MIN_LOW_SURROGATE)
- // + MIN_SUPPLEMENTARY_CODE_POINT;
- return ((high << 10) + low) + (MIN_SUPPLEMENTARY_CODE_POINT
- - (MIN_HIGH_SURROGATE << 10)
- - MIN_LOW_SURROGATE);
- }
-
- /**
- * Returns the code point at the given index of the
- * {@code CharSequence}. If the {@code char} value at
- * the given index in the {@code CharSequence} is in the
- * high-surrogate range, the following index is less than the
- * length of the {@code CharSequence}, and the
- * {@code char} value at the following index is in the
- * low-surrogate range, then the supplementary code point
- * corresponding to this surrogate pair is returned. Otherwise,
- * the {@code char} value at the given index is returned.
- *
- * @param seq a sequence of {@code char} values (Unicode code
- * units)
- * @param index the index to the {@code char} values (Unicode
- * code units) in {@code seq} to be converted
- * @return the Unicode code point at the given index
- * @exception NullPointerException if {@code seq} is null.
- * @exception IndexOutOfBoundsException if the value
- * {@code index} is negative or not less than
- * {@link CharSequence#length() seq.length()}.
- * @since 1.5
- */
- public static int codePointAt(CharSequence seq, int index) {
- char c1 = seq.charAt(index++);
- if (isHighSurrogate(c1)) {
- if (index < seq.length()) {
- char c2 = seq.charAt(index);
- if (isLowSurrogate(c2)) {
- return toCodePoint(c1, c2);
- }
- }
- }
- return c1;
- }
-
- /**
- * Returns the code point at the given index of the
- * {@code char} array. If the {@code char} value at
- * the given index in the {@code char} array is in the
- * high-surrogate range, the following index is less than the
- * length of the {@code char} array, and the
- * {@code char} value at the following index is in the
- * low-surrogate range, then the supplementary code point
- * corresponding to this surrogate pair is returned. Otherwise,
- * the {@code char} value at the given index is returned.
- *
- * @param a the {@code char} array
- * @param index the index to the {@code char} values (Unicode
- * code units) in the {@code char} array to be converted
- * @return the Unicode code point at the given index
- * @exception NullPointerException if {@code a} is null.
- * @exception IndexOutOfBoundsException if the value
- * {@code index} is negative or not less than
- * the length of the {@code char} array.
- * @since 1.5
- */
- public static int codePointAt(char[] a, int index) {
- return codePointAtImpl(a, index, a.length);
- }
-
- /**
- * Returns the code point at the given index of the
- * {@code char} array, where only array elements with
- * {@code index} less than {@code limit} can be used. If
- * the {@code char} value at the given index in the
- * {@code char} array is in the high-surrogate range, the
- * following index is less than the {@code limit}, and the
- * {@code char} value at the following index is in the
- * low-surrogate range, then the supplementary code point
- * corresponding to this surrogate pair is returned. Otherwise,
- * the {@code char} value at the given index is returned.
- *
- * @param a the {@code char} array
- * @param index the index to the {@code char} values (Unicode
- * code units) in the {@code char} array to be converted
- * @param limit the index after the last array element that
- * can be used in the {@code char} array
- * @return the Unicode code point at the given index
- * @exception NullPointerException if {@code a} is null.
- * @exception IndexOutOfBoundsException if the {@code index}
- * argument is negative or not less than the {@code limit}
- * argument, or if the {@code limit} argument is negative or
- * greater than the length of the {@code char} array.
- * @since 1.5
- */
- public static int codePointAt(char[] a, int index, int limit) {
- if (index >= limit || limit < 0 || limit > a.length) {
- throw new IndexOutOfBoundsException();
- }
- return codePointAtImpl(a, index, limit);
- }
-
- // throws ArrayIndexOutofBoundsException if index out of bounds
- static int codePointAtImpl(char[] a, int index, int limit) {
- char c1 = a[index++];
- if (isHighSurrogate(c1)) {
- if (index < limit) {
- char c2 = a[index];
- if (isLowSurrogate(c2)) {
- return toCodePoint(c1, c2);
- }
- }
- }
- return c1;
- }
-
- /**
- * Returns the code point preceding the given index of the
- * {@code CharSequence}. If the {@code char} value at
- * {@code (index - 1)} in the {@code CharSequence} is in
- * the low-surrogate range, {@code (index - 2)} is not
- * negative, and the {@code char} value at {@code (index - 2)}
- * in the {@code CharSequence} is in the
- * high-surrogate range, then the supplementary code point
- * corresponding to this surrogate pair is returned. Otherwise,
- * the {@code char} value at {@code (index - 1)} is
- * returned.
- *
- * @param seq the {@code CharSequence} instance
- * @param index the index following the code point that should be returned
- * @return the Unicode code point value before the given index.
- * @exception NullPointerException if {@code seq} is null.
- * @exception IndexOutOfBoundsException if the {@code index}
- * argument is less than 1 or greater than {@link
- * CharSequence#length() seq.length()}.
- * @since 1.5
- */
- public static int codePointBefore(CharSequence seq, int index) {
- char c2 = seq.charAt(--index);
- if (isLowSurrogate(c2)) {
- if (index > 0) {
- char c1 = seq.charAt(--index);
- if (isHighSurrogate(c1)) {
- return toCodePoint(c1, c2);
- }
- }
- }
- return c2;
- }
-
- /**
- * Returns the code point preceding the given index of the
- * {@code char} array. If the {@code char} value at
- * {@code (index - 1)} in the {@code char} array is in
- * the low-surrogate range, {@code (index - 2)} is not
- * negative, and the {@code char} value at {@code (index - 2)}
- * in the {@code char} array is in the
- * high-surrogate range, then the supplementary code point
- * corresponding to this surrogate pair is returned. Otherwise,
- * the {@code char} value at {@code (index - 1)} is
- * returned.
- *
- * @param a the {@code char} array
- * @param index the index following the code point that should be returned
- * @return the Unicode code point value before the given index.
- * @exception NullPointerException if {@code a} is null.
- * @exception IndexOutOfBoundsException if the {@code index}
- * argument is less than 1 or greater than the length of the
- * {@code char} array
- * @since 1.5
- */
- public static int codePointBefore(char[] a, int index) {
- return codePointBeforeImpl(a, index, 0);
- }
-
- /**
- * Returns the code point preceding the given index of the
- * {@code char} array, where only array elements with
- * {@code index} greater than or equal to {@code start}
- * can be used. If the {@code char} value at {@code (index - 1)}
- * in the {@code char} array is in the
- * low-surrogate range, {@code (index - 2)} is not less than
- * {@code start}, and the {@code char} value at
- * {@code (index - 2)} in the {@code char} array is in
- * the high-surrogate range, then the supplementary code point
- * corresponding to this surrogate pair is returned. Otherwise,
- * the {@code char} value at {@code (index - 1)} is
- * returned.
- *
- * @param a the {@code char} array
- * @param index the index following the code point that should be returned
- * @param start the index of the first array element in the
- * {@code char} array
- * @return the Unicode code point value before the given index.
- * @exception NullPointerException if {@code a} is null.
- * @exception IndexOutOfBoundsException if the {@code index}
- * argument is not greater than the {@code start} argument or
- * is greater than the length of the {@code char} array, or
- * if the {@code start} argument is negative or not less than
- * the length of the {@code char} array.
- * @since 1.5
- */
- public static int codePointBefore(char[] a, int index, int start) {
- if (index <= start || start < 0 || start >= a.length) {
- throw new IndexOutOfBoundsException();
- }
- return codePointBeforeImpl(a, index, start);
- }
-
- // throws ArrayIndexOutofBoundsException if index-1 out of bounds
- static int codePointBeforeImpl(char[] a, int index, int start) {
- char c2 = a[--index];
- if (isLowSurrogate(c2)) {
- if (index > start) {
- char c1 = a[--index];
- if (isHighSurrogate(c1)) {
- return toCodePoint(c1, c2);
- }
- }
- }
- return c2;
- }
-
- /**
- * Returns the leading surrogate (a
- *
- * high surrogate code unit) of the
- *
- * surrogate pair
- * representing the specified supplementary character (Unicode
- * code point) in the UTF-16 encoding. If the specified character
- * is not a
- * supplementary character,
- * an unspecified {@code char} is returned.
- *
- * If
- * {@link #isSupplementaryCodePoint isSupplementaryCodePoint(x)}
- * is {@code true}, then
- * {@link #isHighSurrogate isHighSurrogate}{@code (highSurrogate(x))} and
- * {@link #toCodePoint toCodePoint}{@code (highSurrogate(x), }{@link #lowSurrogate lowSurrogate}{@code (x)) == x}
- * are also always {@code true}.
- *
- * @param codePoint a supplementary character (Unicode code point)
- * @return the leading surrogate code unit used to represent the
- * character in the UTF-16 encoding
- * @since 1.7
- */
- public static char highSurrogate(int codePoint) {
- return (char) ((codePoint >>> 10)
- + (MIN_HIGH_SURROGATE - (MIN_SUPPLEMENTARY_CODE_POINT >>> 10)));
- }
-
- /**
- * Returns the trailing surrogate (a
- *
- * low surrogate code unit) of the
- *
- * surrogate pair
- * representing the specified supplementary character (Unicode
- * code point) in the UTF-16 encoding. If the specified character
- * is not a
- * supplementary character,
- * an unspecified {@code char} is returned.
- *
- * If
- * {@link #isSupplementaryCodePoint isSupplementaryCodePoint(x)}
- * is {@code true}, then
- * {@link #isLowSurrogate isLowSurrogate}{@code (lowSurrogate(x))} and
- * {@link #toCodePoint toCodePoint}{@code (}{@link #highSurrogate highSurrogate}{@code (x), lowSurrogate(x)) == x}
- * are also always {@code true}.
- *
- * @param codePoint a supplementary character (Unicode code point)
- * @return the trailing surrogate code unit used to represent the
- * character in the UTF-16 encoding
- * @since 1.7
- */
- public static char lowSurrogate(int codePoint) {
- return (char) ((codePoint & 0x3ff) + MIN_LOW_SURROGATE);
- }
-
- /**
- * Converts the specified character (Unicode code point) to its
- * UTF-16 representation. If the specified code point is a BMP
- * (Basic Multilingual Plane or Plane 0) value, the same value is
- * stored in {@code dst[dstIndex]}, and 1 is returned. If the
- * specified code point is a supplementary character, its
- * surrogate values are stored in {@code dst[dstIndex]}
- * (high-surrogate) and {@code dst[dstIndex+1]}
- * (low-surrogate), and 2 is returned.
- *
- * @param codePoint the character (Unicode code point) to be converted.
- * @param dst an array of {@code char} in which the
- * {@code codePoint}'s UTF-16 value is stored.
- * @param dstIndex the start index into the {@code dst}
- * array where the converted value is stored.
- * @return 1 if the code point is a BMP code point, 2 if the
- * code point is a supplementary code point.
- * @exception IllegalArgumentException if the specified
- * {@code codePoint} is not a valid Unicode code point.
- * @exception NullPointerException if the specified {@code dst} is null.
- * @exception IndexOutOfBoundsException if {@code dstIndex}
- * is negative or not less than {@code dst.length}, or if
- * {@code dst} at {@code dstIndex} doesn't have enough
- * array element(s) to store the resulting {@code char}
- * value(s). (If {@code dstIndex} is equal to
- * {@code dst.length-1} and the specified
- * {@code codePoint} is a supplementary character, the
- * high-surrogate value is not stored in
- * {@code dst[dstIndex]}.)
- * @since 1.5
- */
- public static int toChars(int codePoint, char[] dst, int dstIndex) {
- if (isBmpCodePoint(codePoint)) {
- dst[dstIndex] = (char) codePoint;
- return 1;
- } else if (isValidCodePoint(codePoint)) {
- toSurrogates(codePoint, dst, dstIndex);
- return 2;
- } else {
- throw new IllegalArgumentException();
- }
- }
-
- /**
- * Converts the specified character (Unicode code point) to its
- * UTF-16 representation stored in a {@code char} array. If
- * the specified code point is a BMP (Basic Multilingual Plane or
- * Plane 0) value, the resulting {@code char} array has
- * the same value as {@code codePoint}. If the specified code
- * point is a supplementary code point, the resulting
- * {@code char} array has the corresponding surrogate pair.
- *
- * @param codePoint a Unicode code point
- * @return a {@code char} array having
- * {@code codePoint}'s UTF-16 representation.
- * @exception IllegalArgumentException if the specified
- * {@code codePoint} is not a valid Unicode code point.
- * @since 1.5
- */
- public static char[] toChars(int codePoint) {
- if (isBmpCodePoint(codePoint)) {
- return new char[] { (char) codePoint };
- } else if (isValidCodePoint(codePoint)) {
- char[] result = new char[2];
- toSurrogates(codePoint, result, 0);
- return result;
- } else {
- throw new IllegalArgumentException();
- }
- }
-
- static void toSurrogates(int codePoint, char[] dst, int index) {
- // We write elements "backwards" to guarantee all-or-nothing
- dst[index+1] = lowSurrogate(codePoint);
- dst[index] = highSurrogate(codePoint);
- }
-
- /**
- * Returns the number of Unicode code points in the text range of
- * the specified char sequence. The text range begins at the
- * specified {@code beginIndex} and extends to the
- * {@code char} at index {@code endIndex - 1}. Thus the
- * length (in {@code char}s) of the text range is
- * {@code endIndex-beginIndex}. Unpaired surrogates within
- * the text range count as one code point each.
- *
- * @param seq the char sequence
- * @param beginIndex the index to the first {@code char} of
- * the text range.
- * @param endIndex the index after the last {@code char} of
- * the text range.
- * @return the number of Unicode code points in the specified text
- * range
- * @exception NullPointerException if {@code seq} is null.
- * @exception IndexOutOfBoundsException if the
- * {@code beginIndex} is negative, or {@code endIndex}
- * is larger than the length of the given sequence, or
- * {@code beginIndex} is larger than {@code endIndex}.
- * @since 1.5
- */
- public static int codePointCount(CharSequence seq, int beginIndex, int endIndex) {
- int length = seq.length();
- if (beginIndex < 0 || endIndex > length || beginIndex > endIndex) {
- throw new IndexOutOfBoundsException();
- }
- int n = endIndex - beginIndex;
- for (int i = beginIndex; i < endIndex; ) {
- if (isHighSurrogate(seq.charAt(i++)) && i < endIndex &&
- isLowSurrogate(seq.charAt(i))) {
- n--;
- i++;
- }
- }
- return n;
- }
-
- /**
- * Returns the number of Unicode code points in a subarray of the
- * {@code char} array argument. The {@code offset}
- * argument is the index of the first {@code char} of the
- * subarray and the {@code count} argument specifies the
- * length of the subarray in {@code char}s. Unpaired
- * surrogates within the subarray count as one code point each.
- *
- * @param a the {@code char} array
- * @param offset the index of the first {@code char} in the
- * given {@code char} array
- * @param count the length of the subarray in {@code char}s
- * @return the number of Unicode code points in the specified subarray
- * @exception NullPointerException if {@code a} is null.
- * @exception IndexOutOfBoundsException if {@code offset} or
- * {@code count} is negative, or if {@code offset +
- * count} is larger than the length of the given array.
- * @since 1.5
- */
- public static int codePointCount(char[] a, int offset, int count) {
- if (count > a.length - offset || offset < 0 || count < 0) {
- throw new IndexOutOfBoundsException();
- }
- return codePointCountImpl(a, offset, count);
- }
-
- static int codePointCountImpl(char[] a, int offset, int count) {
- int endIndex = offset + count;
- int n = count;
- for (int i = offset; i < endIndex; ) {
- if (isHighSurrogate(a[i++]) && i < endIndex &&
- isLowSurrogate(a[i])) {
- n--;
- i++;
- }
- }
- return n;
- }
-
- /**
- * Returns the index within the given char sequence that is offset
- * from the given {@code index} by {@code codePointOffset}
- * code points. Unpaired surrogates within the text range given by
- * {@code index} and {@code codePointOffset} count as
- * one code point each.
- *
- * @param seq the char sequence
- * @param index the index to be offset
- * @param codePointOffset the offset in code points
- * @return the index within the char sequence
- * @exception NullPointerException if {@code seq} is null.
- * @exception IndexOutOfBoundsException if {@code index}
- * is negative or larger then the length of the char sequence,
- * or if {@code codePointOffset} is positive and the
- * subsequence starting with {@code index} has fewer than
- * {@code codePointOffset} code points, or if
- * {@code codePointOffset} is negative and the subsequence
- * before {@code index} has fewer than the absolute value
- * of {@code codePointOffset} code points.
- * @since 1.5
- */
- public static int offsetByCodePoints(CharSequence seq, int index,
- int codePointOffset) {
- int length = seq.length();
- if (index < 0 || index > length) {
- throw new IndexOutOfBoundsException();
- }
-
- int x = index;
- if (codePointOffset >= 0) {
- int i;
- for (i = 0; x < length && i < codePointOffset; i++) {
- if (isHighSurrogate(seq.charAt(x++)) && x < length &&
- isLowSurrogate(seq.charAt(x))) {
- x++;
- }
- }
- if (i < codePointOffset) {
- throw new IndexOutOfBoundsException();
- }
- } else {
- int i;
- for (i = codePointOffset; x > 0 && i < 0; i++) {
- if (isLowSurrogate(seq.charAt(--x)) && x > 0 &&
- isHighSurrogate(seq.charAt(x-1))) {
- x--;
- }
- }
- if (i < 0) {
- throw new IndexOutOfBoundsException();
- }
- }
- return x;
- }
-
- /**
- * Returns the index within the given {@code char} subarray
- * that is offset from the given {@code index} by
- * {@code codePointOffset} code points. The
- * {@code start} and {@code count} arguments specify a
- * subarray of the {@code char} array. Unpaired surrogates
- * within the text range given by {@code index} and
- * {@code codePointOffset} count as one code point each.
- *
- * @param a the {@code char} array
- * @param start the index of the first {@code char} of the
- * subarray
- * @param count the length of the subarray in {@code char}s
- * @param index the index to be offset
- * @param codePointOffset the offset in code points
- * @return the index within the subarray
- * @exception NullPointerException if {@code a} is null.
- * @exception IndexOutOfBoundsException
- * if {@code start} or {@code count} is negative,
- * or if {@code start + count} is larger than the length of
- * the given array,
- * or if {@code index} is less than {@code start} or
- * larger then {@code start + count},
- * or if {@code codePointOffset} is positive and the text range
- * starting with {@code index} and ending with {@code start + count - 1}
- * has fewer than {@code codePointOffset} code
- * points,
- * or if {@code codePointOffset} is negative and the text range
- * starting with {@code start} and ending with {@code index - 1}
- * has fewer than the absolute value of
- * {@code codePointOffset} code points.
- * @since 1.5
- */
- public static int offsetByCodePoints(char[] a, int start, int count,
- int index, int codePointOffset) {
- if (count > a.length-start || start < 0 || count < 0
- || index < start || index > start+count) {
- throw new IndexOutOfBoundsException();
- }
- return offsetByCodePointsImpl(a, start, count, index, codePointOffset);
- }
-
- static int offsetByCodePointsImpl(char[]a, int start, int count,
- int index, int codePointOffset) {
- int x = index;
- if (codePointOffset >= 0) {
- int limit = start + count;
- int i;
- for (i = 0; x < limit && i < codePointOffset; i++) {
- if (isHighSurrogate(a[x++]) && x < limit &&
- isLowSurrogate(a[x])) {
- x++;
- }
- }
- if (i < codePointOffset) {
- throw new IndexOutOfBoundsException();
- }
- } else {
- int i;
- for (i = codePointOffset; x > start && i < 0; i++) {
- if (isLowSurrogate(a[--x]) && x > start &&
- isHighSurrogate(a[x-1])) {
- x--;
- }
- }
- if (i < 0) {
- throw new IndexOutOfBoundsException();
- }
- }
- return x;
- }
-
- /**
- * Determines if the specified character is a lowercase character.
- *
- * A character is lowercase if its general category type, provided
- * by {@code Character.getType(ch)}, is
- * {@code LOWERCASE_LETTER}, or it has contributory property
- * Other_Lowercase as defined by the Unicode Standard.
- *
- * The following are examples of lowercase characters:
- * Many other Unicode characters are lowercase too.
- *
- * Note: This method cannot handle supplementary characters. To support
- * all Unicode characters, including supplementary characters, use
- * the {@link #isLowerCase(int)} method.
- *
- * @param ch the character to be tested.
- * @return {@code true} if the character is lowercase;
- * {@code false} otherwise.
- * @see Character#isLowerCase(char)
- * @see Character#isTitleCase(char)
- * @see Character#toLowerCase(char)
- * @see Character#getType(char)
- */
- public static boolean isLowerCase(char ch) {
- return ch == toLowerCase(ch);
- }
-
- /**
- * Determines if the specified character is an uppercase character.
- *
- * A character is uppercase if its general category type, provided by
- * {@code Character.getType(ch)}, is {@code UPPERCASE_LETTER}.
- * or it has contributory property Other_Uppercase as defined by the Unicode Standard.
- *
- * The following are examples of uppercase characters:
- * Many other Unicode characters are uppercase too.
- *
- * Note: This method cannot handle supplementary characters. To support
- * all Unicode characters, including supplementary characters, use
- * the {@link #isUpperCase(int)} method.
- *
- * @param ch the character to be tested.
- * @return {@code true} if the character is uppercase;
- * {@code false} otherwise.
- * @see Character#isLowerCase(char)
- * @see Character#isTitleCase(char)
- * @see Character#toUpperCase(char)
- * @see Character#getType(char)
- * @since 1.0
- */
- public static boolean isUpperCase(char ch) {
- return ch == toUpperCase(ch);
- }
-
- /**
- * Determines if the specified character is a titlecase character.
- *
- * A character is a titlecase character if its general
- * category type, provided by {@code Character.getType(ch)},
- * is {@code TITLECASE_LETTER}.
- *
- * Some characters look like pairs of Latin letters. For example, there
- * is an uppercase letter that looks like "LJ" and has a corresponding
- * lowercase letter that looks like "lj". A third form, which looks like "Lj",
- * is the appropriate form to use when rendering a word in lowercase
- * with initial capitals, as for a book title.
- *
- * These are some of the Unicode characters for which this method returns
- * {@code true}:
- * Many other Unicode characters are titlecase too.
- *
- * Note: This method cannot handle supplementary characters. To support
- * all Unicode characters, including supplementary characters, use
- * the {@link #isTitleCase(int)} method.
- *
- * @param ch the character to be tested.
- * @return {@code true} if the character is titlecase;
- * {@code false} otherwise.
- * @see Character#isLowerCase(char)
- * @see Character#isUpperCase(char)
- * @see Character#toTitleCase(char)
- * @see Character#getType(char)
- * @since 1.0.2
- */
- public static boolean isTitleCase(char ch) {
- return isTitleCase((int)ch);
- }
-
- /**
- * Determines if the specified character (Unicode code point) is a titlecase character.
- *
- * A character is a titlecase character if its general
- * category type, provided by {@link Character#getType(int) getType(codePoint)},
- * is {@code TITLECASE_LETTER}.
- *
- * Some characters look like pairs of Latin letters. For example, there
- * is an uppercase letter that looks like "LJ" and has a corresponding
- * lowercase letter that looks like "lj". A third form, which looks like "Lj",
- * is the appropriate form to use when rendering a word in lowercase
- * with initial capitals, as for a book title.
- *
- * These are some of the Unicode characters for which this method returns
- * {@code true}:
- * Many other Unicode characters are titlecase too.
- *
- * @param codePoint the character (Unicode code point) to be tested.
- * @return {@code true} if the character is titlecase;
- * {@code false} otherwise.
- * @see Character#isLowerCase(int)
- * @see Character#isUpperCase(int)
- * @see Character#toTitleCase(int)
- * @see Character#getType(int)
- * @since 1.5
- */
- public static boolean isTitleCase(int codePoint) {
- return getType(codePoint) == Character.TITLECASE_LETTER;
- }
-
- /**
- * Determines if the specified character is a digit.
- *
- * A character is a digit if its general category type, provided
- * by {@code Character.getType(ch)}, is
- * {@code DECIMAL_DIGIT_NUMBER}.
- *
- * Some Unicode character ranges that contain digits:
- * Note: This method cannot handle supplementary characters. To support
- * all Unicode characters, including supplementary characters, use
- * the {@link #isDigit(int)} method.
- *
- * @param ch the character to be tested.
- * @return {@code true} if the character is a digit;
- * {@code false} otherwise.
- * @see Character#digit(char, int)
- * @see Character#forDigit(int, int)
- * @see Character#getType(char)
- */
- public static boolean isDigit(char ch) {
- return String.valueOf(ch).matches("\\d");
- }
-
- /**
- * Determines if the specified character (Unicode code point) is a digit.
- *
- * A character is a digit if its general category type, provided
- * by {@link Character#getType(int) getType(codePoint)}, is
- * {@code DECIMAL_DIGIT_NUMBER}.
- *
- * Some Unicode character ranges that contain digits:
- *
- * A character is defined if at least one of the following is true:
- * Note: This method cannot handle supplementary characters. To support
- * all Unicode characters, including supplementary characters, use
- * the {@link #isDefined(int)} method.
- *
- * @param ch the character to be tested
- * @return {@code true} if the character has a defined meaning
- * in Unicode; {@code false} otherwise.
- * @see Character#isDigit(char)
- * @see Character#isLetter(char)
- * @see Character#isLetterOrDigit(char)
- * @see Character#isLowerCase(char)
- * @see Character#isTitleCase(char)
- * @see Character#isUpperCase(char)
- * @since 1.0.2
- */
- public static boolean isDefined(char ch) {
- return isDefined((int)ch);
- }
-
- /**
- * Determines if a character (Unicode code point) is defined in Unicode.
- *
- * A character is defined if at least one of the following is true:
- *
- * A character is considered to be a letter if its general
- * category type, provided by {@code Character.getType(ch)},
- * is any of the following:
- * Note: This method cannot handle supplementary characters. To support
- * all Unicode characters, including supplementary characters, use
- * the {@link #isLetter(int)} method.
- *
- * @param ch the character to be tested.
- * @return {@code true} if the character is a letter;
- * {@code false} otherwise.
- * @see Character#isDigit(char)
- * @see Character#isJavaIdentifierStart(char)
- * @see Character#isJavaLetter(char)
- * @see Character#isJavaLetterOrDigit(char)
- * @see Character#isLetterOrDigit(char)
- * @see Character#isLowerCase(char)
- * @see Character#isTitleCase(char)
- * @see Character#isUnicodeIdentifierStart(char)
- * @see Character#isUpperCase(char)
- */
- public static boolean isLetter(char ch) {
- return String.valueOf(ch).matches("\\w") && !isDigit(ch);
- }
-
- /**
- * Determines if the specified character (Unicode code point) is a letter.
- *
- * A character is considered to be a letter if its general
- * category type, provided by {@link Character#getType(int) getType(codePoint)},
- * is any of the following:
- *
- * A character is considered to be a letter or digit if either
- * {@code Character.isLetter(char ch)} or
- * {@code Character.isDigit(char ch)} returns
- * {@code true} for the character.
- *
- * Note: This method cannot handle supplementary characters. To support
- * all Unicode characters, including supplementary characters, use
- * the {@link #isLetterOrDigit(int)} method.
- *
- * @param ch the character to be tested.
- * @return {@code true} if the character is a letter or digit;
- * {@code false} otherwise.
- * @see Character#isDigit(char)
- * @see Character#isJavaIdentifierPart(char)
- * @see Character#isJavaLetter(char)
- * @see Character#isJavaLetterOrDigit(char)
- * @see Character#isLetter(char)
- * @see Character#isUnicodeIdentifierPart(char)
- * @since 1.0.2
- */
- public static boolean isLetterOrDigit(char ch) {
- return String.valueOf(ch).matches("\\w");
- }
-
- /**
- * Determines if the specified character (Unicode code point) is a letter or digit.
- *
- * A character is considered to be a letter or digit if either
- * {@link #isLetter(int) isLetter(codePoint)} or
- * {@link #isDigit(int) isDigit(codePoint)} returns
- * {@code true} for the character.
- *
- * @param codePoint the character (Unicode code point) to be tested.
- * @return {@code true} if the character is a letter or digit;
- * {@code false} otherwise.
- * @see Character#isDigit(int)
- * @see Character#isJavaIdentifierPart(int)
- * @see Character#isLetter(int)
- * @see Character#isUnicodeIdentifierPart(int)
- * @since 1.5
- */
- public static boolean isLetterOrDigit(int codePoint) {
- return fromCodeChars(codePoint).matches("\\w");
- }
-
- static int getType(int x) {
- throw new UnsupportedOperationException();
- }
-
- /**
- * Determines if the specified character is
- * permissible as the first character in a Java identifier.
- *
- * A character may start a Java identifier if and only if
- * one of the following conditions is true:
- * Note: This method cannot handle supplementary characters. To support
- * all Unicode characters, including supplementary characters, use
- * the {@link #isJavaIdentifierStart(int)} method.
- *
- * @param ch the character to be tested.
- * @return {@code true} if the character may start a Java identifier;
- * {@code false} otherwise.
- * @see Character#isJavaIdentifierPart(char)
- * @see Character#isLetter(char)
- * @see Character#isUnicodeIdentifierStart(char)
- * @see javax.lang.model.SourceVersion#isIdentifier(CharSequence)
- * @since 1.1
- */
- public static boolean isJavaIdentifierStart(char ch) {
- return isJavaIdentifierStart((int)ch);
- }
-
- /**
- * Determines if the character (Unicode code point) is
- * permissible as the first character in a Java identifier.
- *
- * A character may start a Java identifier if and only if
- * one of the following conditions is true:
- *
- * A character may be part of a Java identifier if any of the following
- * are true:
- * Note: This method cannot handle supplementary characters. To support
- * all Unicode characters, including supplementary characters, use
- * the {@link #isJavaIdentifierPart(int)} method.
- *
- * @param ch the character to be tested.
- * @return {@code true} if the character may be part of a
- * Java identifier; {@code false} otherwise.
- * @see Character#isIdentifierIgnorable(char)
- * @see Character#isJavaIdentifierStart(char)
- * @see Character#isLetterOrDigit(char)
- * @see Character#isUnicodeIdentifierPart(char)
- * @see javax.lang.model.SourceVersion#isIdentifier(CharSequence)
- * @since 1.1
- */
- public static boolean isJavaIdentifierPart(char ch) {
- return isJavaIdentifierPart((int)ch);
- }
-
- /**
- * Determines if the character (Unicode code point) may be part of a Java
- * identifier as other than the first character.
- *
- * A character may be part of a Java identifier if any of the following
- * are true:
- *
- * Note that
- * {@code Character.isLowerCase(Character.toLowerCase(ch))}
- * does not always return {@code true} for some ranges of
- * characters, particularly those that are symbols or ideographs.
- *
- * In general, {@link String#toLowerCase()} should be used to map
- * characters to lowercase. {@code String} case mapping methods
- * have several benefits over {@code Character} case mapping methods.
- * {@code String} case mapping methods can perform locale-sensitive
- * mappings, context-sensitive mappings, and 1:M character mappings, whereas
- * the {@code Character} case mapping methods cannot.
- *
- * Note: This method cannot handle supplementary characters. To support
- * all Unicode characters, including supplementary characters, use
- * the {@link #toLowerCase(int)} method.
- *
- * @param ch the character to be converted.
- * @return the lowercase equivalent of the character, if any;
- * otherwise, the character itself.
- * @see Character#isLowerCase(char)
- * @see String#toLowerCase()
- */
- public static char toLowerCase(char ch) {
- return String.valueOf(ch).toLowerCase().charAt(0);
- }
-
- /**
- * Converts the character argument to uppercase using case mapping
- * information from the UnicodeData file.
- *
- * Note that
- * {@code Character.isUpperCase(Character.toUpperCase(ch))}
- * does not always return {@code true} for some ranges of
- * characters, particularly those that are symbols or ideographs.
- *
- * In general, {@link String#toUpperCase()} should be used to map
- * characters to uppercase. {@code String} case mapping methods
- * have several benefits over {@code Character} case mapping methods.
- * {@code String} case mapping methods can perform locale-sensitive
- * mappings, context-sensitive mappings, and 1:M character mappings, whereas
- * the {@code Character} case mapping methods cannot.
- *
- * Note: This method cannot handle supplementary characters. To support
- * all Unicode characters, including supplementary characters, use
- * the {@link #toUpperCase(int)} method.
- *
- * @param ch the character to be converted.
- * @return the uppercase equivalent of the character, if any;
- * otherwise, the character itself.
- * @see Character#isUpperCase(char)
- * @see String#toUpperCase()
- */
- public static char toUpperCase(char ch) {
- return String.valueOf(ch).toUpperCase().charAt(0);
- }
-
- /**
- * Returns the numeric value of the character {@code ch} in the
- * specified radix.
- *
- * If the radix is not in the range {@code MIN_RADIX} ≤
- * {@code radix} ≤ {@code MAX_RADIX} or if the
- * value of {@code ch} is not a valid digit in the specified
- * radix, {@code -1} is returned. A character is a valid digit
- * if at least one of the following is true:
- * Note: This method cannot handle supplementary characters. To support
- * all Unicode characters, including supplementary characters, use
- * the {@link #digit(int, int)} method.
- *
- * @param ch the character to be converted.
- * @param radix the radix.
- * @return the numeric value represented by the character in the
- * specified radix.
- * @see Character#forDigit(int, int)
- * @see Character#isDigit(char)
- */
- public static int digit(char ch, int radix) {
- return digit((int)ch, radix);
- }
-
- /**
- * Returns the numeric value of the specified character (Unicode
- * code point) in the specified radix.
- *
- * If the radix is not in the range {@code MIN_RADIX} ≤
- * {@code radix} ≤ {@code MAX_RADIX} or if the
- * character is not a valid digit in the specified
- * radix, {@code -1} is returned. A character is a valid digit
- * if at least one of the following is true:
- *
- * The letters A-Z in their uppercase ({@code '\u005Cu0041'} through
- * {@code '\u005Cu005A'}), lowercase
- * ({@code '\u005Cu0061'} through {@code '\u005Cu007A'}), and
- * full width variant ({@code '\u005CuFF21'} through
- * {@code '\u005CuFF3A'} and {@code '\u005CuFF41'} through
- * {@code '\u005CuFF5A'}) forms have numeric values from 10
- * through 35. This is independent of the Unicode specification,
- * which does not assign numeric values to these {@code char}
- * values.
- *
- * If the character does not have a numeric value, then -1 is returned.
- * If the character has a numeric value that cannot be represented as a
- * nonnegative integer (for example, a fractional value), then -2
- * is returned.
- *
- * Note: This method cannot handle supplementary characters. To support
- * all Unicode characters, including supplementary characters, use
- * the {@link #getNumericValue(int)} method.
- *
- * @param ch the character to be converted.
- * @return the numeric value of the character, as a nonnegative {@code int}
- * value; -2 if the character has a numeric value that is not a
- * nonnegative integer; -1 if the character has no numeric value.
- * @see Character#forDigit(int, int)
- * @see Character#isDigit(char)
- * @since 1.1
- */
- public static int getNumericValue(char ch) {
- return getNumericValue((int)ch);
- }
-
- /**
- * Returns the {@code int} value that the specified
- * character (Unicode code point) represents. For example, the character
- * {@code '\u005Cu216C'} (the Roman numeral fifty) will return
- * an {@code int} with a value of 50.
- *
- * The letters A-Z in their uppercase ({@code '\u005Cu0041'} through
- * {@code '\u005Cu005A'}), lowercase
- * ({@code '\u005Cu0061'} through {@code '\u005Cu007A'}), and
- * full width variant ({@code '\u005CuFF21'} through
- * {@code '\u005CuFF3A'} and {@code '\u005CuFF41'} through
- * {@code '\u005CuFF5A'}) forms have numeric values from 10
- * through 35. This is independent of the Unicode specification,
- * which does not assign numeric values to these {@code char}
- * values.
- *
- * If the character does not have a numeric value, then -1 is returned.
- * If the character has a numeric value that cannot be represented as a
- * nonnegative integer (for example, a fractional value), then -2
- * is returned.
- *
- * @param codePoint the character (Unicode code point) to be converted.
- * @return the numeric value of the character, as a nonnegative {@code int}
- * value; -2 if the character has a numeric value that is not a
- * nonnegative integer; -1 if the character has no numeric value.
- * @see Character#forDigit(int, int)
- * @see Character#isDigit(int)
- * @since 1.5
- */
- public static int getNumericValue(int codePoint) {
- throw new UnsupportedOperationException();
- }
-
- /**
- * Determines if the specified character is ISO-LATIN-1 white space.
- * This method returns {@code true} for the following five
- * characters only:
- * Note: This method cannot handle supplementary characters. To support
- * all Unicode characters, including supplementary characters, use
- * the {@link #isWhitespace(int)} method.
- *
- * @param ch the character to be tested.
- * @return {@code true} if the character is a Java whitespace
- * character; {@code false} otherwise.
- * @see Character#isSpaceChar(char)
- * @since 1.1
- */
- public static boolean isWhitespace(char ch) {
- return isWhitespace((int)ch);
- }
-
- /**
- * Determines if the specified character (Unicode code point) is
- * white space according to Java. A character is a Java
- * whitespace character if and only if it satisfies one of the
- * following criteria:
- *
- *
- * @param codePoint the character (Unicode code point) to be tested.
- * @return {@code true} if the character is a Java whitespace
- * character; {@code false} otherwise.
- * @see Character#isSpaceChar(int)
- * @since 1.5
- */
- public static boolean isWhitespace(int codePoint) {
- throw new UnsupportedOperationException();
- }
-
- /**
- * Determines if the specified character is an ISO control
- * character. A character is considered to be an ISO control
- * character if its code is in the range {@code '\u005Cu0000'}
- * through {@code '\u005Cu001F'} or in the range
- * {@code '\u005Cu007F'} through {@code '\u005Cu009F'}.
- *
- * Note: This method cannot handle supplementary characters. To support
- * all Unicode characters, including supplementary characters, use
- * the {@link #isISOControl(int)} method.
- *
- * @param ch the character to be tested.
- * @return {@code true} if the character is an ISO control character;
- * {@code false} otherwise.
- *
- * @see Character#isSpaceChar(char)
- * @see Character#isWhitespace(char)
- * @since 1.1
- */
- public static boolean isISOControl(char ch) {
- return isISOControl((int)ch);
- }
-
- /**
- * Determines if the referenced character (Unicode code point) is an ISO control
- * character. A character is considered to be an ISO control
- * character if its code is in the range {@code '\u005Cu0000'}
- * through {@code '\u005Cu001F'} or in the range
- * {@code '\u005Cu007F'} through {@code '\u005Cu009F'}.
- *
- * @param codePoint the character (Unicode code point) to be tested.
- * @return {@code true} if the character is an ISO control character;
- * {@code false} otherwise.
- * @see Character#isSpaceChar(int)
- * @see Character#isWhitespace(int)
- * @since 1.5
- */
- public static boolean isISOControl(int codePoint) {
- // Optimized form of:
- // (codePoint >= 0x00 && codePoint <= 0x1F) ||
- // (codePoint >= 0x7F && codePoint <= 0x9F);
- return codePoint <= 0x9F &&
- (codePoint >= 0x7F || (codePoint >>> 5 == 0));
- }
-
- /**
- * Determines the character representation for a specific digit in
- * the specified radix. If the value of {@code radix} is not a
- * valid radix, or the value of {@code digit} is not a valid
- * digit in the specified radix, the null character
- * ({@code '\u005Cu0000'}) is returned.
- *
- * The {@code radix} argument is valid if it is greater than or
- * equal to {@code MIN_RADIX} and less than or equal to
- * {@code MAX_RADIX}. The {@code digit} argument is valid if
- * {@code 0 <= digit < radix}.
- *
- * If the digit is less than 10, then
- * {@code '0' + digit} is returned. Otherwise, the value
- * {@code 'a' + digit - 10} is returned.
- *
- * @param digit the number to convert to a character.
- * @param radix the radix.
- * @return the {@code char} representation of the specified digit
- * in the specified radix.
- * @see Character#MIN_RADIX
- * @see Character#MAX_RADIX
- * @see Character#digit(char, int)
- */
- public static char forDigit(int digit, int radix) {
- if ((digit >= radix) || (digit < 0)) {
- return '\0';
- }
- if ((radix < Character.MIN_RADIX) || (radix > Character.MAX_RADIX)) {
- return '\0';
- }
- if (digit < 10) {
- return (char)('0' + digit);
- }
- return (char)('a' - 10 + digit);
- }
-
- /**
- * Compares two {@code Character} objects numerically.
- *
- * @param anotherCharacter the {@code Character} to be compared.
-
- * @return the value {@code 0} if the argument {@code Character}
- * is equal to this {@code Character}; a value less than
- * {@code 0} if this {@code Character} is numerically less
- * than the {@code Character} argument; and a value greater than
- * {@code 0} if this {@code Character} is numerically greater
- * than the {@code Character} argument (unsigned comparison).
- * Note that this is strictly a numerical comparison; it is not
- * locale-dependent.
- * @since 1.2
- */
- public int compareTo(Character anotherCharacter) {
- return compare(this.value, anotherCharacter.value);
- }
-
- /**
- * Compares two {@code char} values numerically.
- * The value returned is identical to what would be returned by:
- *
- *
- * @param high the high-surrogate code value to be tested
- * @param low the low-surrogate code value to be tested
- * @return {@code true} if the specified high and
- * low-surrogate code values represent a valid surrogate pair;
- * {@code false} otherwise.
- * @since 1.5
- */
- public static boolean isSurrogatePair(char high, char low) {
- return isHighSurrogate(high) && isLowSurrogate(low);
- }
-
- /**
- * Determines the number of {@code char} values needed to
- * represent the specified character (Unicode code point). If the
- * specified character is equal to or greater than 0x10000, then
- * the method returns 2. Otherwise, the method returns 1.
- *
- *
- * isHighSurrogate(high) && isLowSurrogate(low)
- *
- *
- * a b c d e f g h i j k l m n o p q r s t u v w x y z
- * '\u00DF' '\u00E0' '\u00E1' '\u00E2' '\u00E3' '\u00E4' '\u00E5' '\u00E6'
- * '\u00E7' '\u00E8' '\u00E9' '\u00EA' '\u00EB' '\u00EC' '\u00ED' '\u00EE'
- * '\u00EF' '\u00F0' '\u00F1' '\u00F2' '\u00F3' '\u00F4' '\u00F5' '\u00F6'
- * '\u00F8' '\u00F9' '\u00FA' '\u00FB' '\u00FC' '\u00FD' '\u00FE' '\u00FF'
- *
- *
- * A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
- * '\u00C0' '\u00C1' '\u00C2' '\u00C3' '\u00C4' '\u00C5' '\u00C6' '\u00C7'
- * '\u00C8' '\u00C9' '\u00CA' '\u00CB' '\u00CC' '\u00CD' '\u00CE' '\u00CF'
- * '\u00D0' '\u00D1' '\u00D2' '\u00D3' '\u00D4' '\u00D5' '\u00D6' '\u00D8'
- * '\u00D9' '\u00DA' '\u00DB' '\u00DC' '\u00DD' '\u00DE'
- *
- *
- *
- *
- *
- *
- *
- * Many other character ranges contain digits as well.
- *
- *
- *
- *
- * Many other character ranges contain digits as well.
- *
- * @param codePoint the character (Unicode code point) to be tested.
- * @return {@code true} if the character is a digit;
- * {@code false} otherwise.
- * @see Character#forDigit(int, int)
- * @see Character#getType(int)
- * @since 1.5
- */
- public static boolean isDigit(int codePoint) {
- return fromCodeChars(codePoint).matches("\\d");
- }
-
- @JavaScriptBody(args = "c", body = "return String.fromCharCode(c);")
- private native static String fromCodeChars(int codePoint);
-
- /**
- * Determines if a character is defined in Unicode.
- *
- *
- *
- *
- *
- *
- * @param codePoint the character (Unicode code point) to be tested.
- * @return {@code true} if the character has a defined meaning
- * in Unicode; {@code false} otherwise.
- * @see Character#isDigit(int)
- * @see Character#isLetter(int)
- * @see Character#isLetterOrDigit(int)
- * @see Character#isLowerCase(int)
- * @see Character#isTitleCase(int)
- * @see Character#isUpperCase(int)
- * @since 1.5
- */
- public static boolean isDefined(int codePoint) {
- return getType(codePoint) != Character.UNASSIGNED;
- }
-
- /**
- * Determines if the specified character is a letter.
- *
- *
- *
- * Not all letters have case. Many characters are
- * letters but are neither uppercase nor lowercase nor titlecase.
- *
- *
- *
- *
- * Not all letters have case. Many characters are
- * letters but are neither uppercase nor lowercase nor titlecase.
- *
- * @param codePoint the character (Unicode code point) to be tested.
- * @return {@code true} if the character is a letter;
- * {@code false} otherwise.
- * @see Character#isDigit(int)
- * @see Character#isJavaIdentifierStart(int)
- * @see Character#isLetterOrDigit(int)
- * @see Character#isLowerCase(int)
- * @see Character#isTitleCase(int)
- * @see Character#isUnicodeIdentifierStart(int)
- * @see Character#isUpperCase(int)
- * @since 1.5
- */
- public static boolean isLetter(int codePoint) {
- return fromCodeChars(codePoint).matches("\\w") && !isDigit(codePoint);
- }
-
- /**
- * Determines if the specified character is a letter or digit.
- *
- *
- *
- *
- *
- *
- * @param codePoint the character (Unicode code point) to be tested.
- * @return {@code true} if the character may start a Java identifier;
- * {@code false} otherwise.
- * @see Character#isJavaIdentifierPart(int)
- * @see Character#isLetter(int)
- * @see Character#isUnicodeIdentifierStart(int)
- * @see javax.lang.model.SourceVersion#isIdentifier(CharSequence)
- * @since 1.5
- */
- public static boolean isJavaIdentifierStart(int codePoint) {
- return
- ('A' <= codePoint && codePoint <= 'Z') ||
- ('a' <= codePoint && codePoint <= 'z');
- }
-
- /**
- * Determines if the specified character may be part of a Java
- * identifier as other than the first character.
- *
- *
- *
- *
- *
- *
- * @param codePoint the character (Unicode code point) to be tested.
- * @return {@code true} if the character may be part of a
- * Java identifier; {@code false} otherwise.
- * @see Character#isIdentifierIgnorable(int)
- * @see Character#isJavaIdentifierStart(int)
- * @see Character#isLetterOrDigit(int)
- * @see Character#isUnicodeIdentifierPart(int)
- * @see javax.lang.model.SourceVersion#isIdentifier(CharSequence)
- * @since 1.5
- */
- public static boolean isJavaIdentifierPart(int codePoint) {
- return isJavaIdentifierStart(codePoint) ||
- ('0' <= codePoint && codePoint <= '9') || codePoint == '$';
- }
-
- /**
- * Converts the character argument to lowercase using case
- * mapping information from the UnicodeData file.
- *
- *
- *
- *
- *
- *
- * @param codePoint the character (Unicode code point) to be converted.
- * @param radix the radix.
- * @return the numeric value represented by the character in the
- * specified radix.
- * @see Character#forDigit(int, int)
- * @see Character#isDigit(int)
- * @since 1.5
- */
- @JavaScriptBody(args = { "codePoint", "radix" }, body=
- "var x = parseInt(String.fromCharCode(codePoint), radix);\n"
- + "return isNaN(x) ? -1 : x;"
- )
- public static int digit(int codePoint, int radix) {
- throw new UnsupportedOperationException();
- }
-
- /**
- * Returns the {@code int} value that the specified Unicode
- * character represents. For example, the character
- * {@code '\u005Cu216C'} (the roman numeral fifty) will return
- * an int with a value of 50.
- *
- *
- *
- * @param ch the character to be tested.
- * @return {@code true} if the character is ISO-LATIN-1 white
- * space; {@code false} otherwise.
- * @see Character#isSpaceChar(char)
- * @see Character#isWhitespace(char)
- * @deprecated Replaced by isWhitespace(char).
- */
- @Deprecated
- public static boolean isSpace(char ch) {
- return (ch <= 0x0020) &&
- (((((1L << 0x0009) |
- (1L << 0x000A) |
- (1L << 0x000C) |
- (1L << 0x000D) |
- (1L << 0x0020)) >> ch) & 1L) != 0);
- }
-
-
-
- /**
- * Determines if the specified character is white space according to Java.
- * A character is a Java whitespace character if and only if it satisfies
- * one of the following criteria:
- * {@code '\t'} {@code U+0009}
- * {@code HORIZONTAL TABULATION} {@code '\n'} {@code U+000A}
- * {@code NEW LINE} {@code '\f'} {@code U+000C}
- * {@code FORM FEED} {@code '\r'} {@code U+000D}
- * {@code CARRIAGE RETURN} {@code ' '} {@code U+0020}
- * {@code SPACE}
- *
- *
- *
- *
- *
- * Character.valueOf(x).compareTo(Character.valueOf(y))
- *
- *
- * @param x the first {@code char} to compare
- * @param y the second {@code char} to compare
- * @return the value {@code 0} if {@code x == y};
- * a value less than {@code 0} if {@code x < y}; and
- * a value greater than {@code 0} if {@code x > y}
- * @since 1.7
- */
- public static int compare(char x, char y) {
- return x - y;
- }
-
-
- /**
- * The number of bits used to represent a char value in unsigned
- * binary form, constant {@code 16}.
- *
- * @since 1.5
- */
- public static final int SIZE = 16;
-
- /**
- * Returns the value obtained by reversing the order of the bytes in the
- * specified char value.
- *
- * @return the value obtained by reversing (or, equivalently, swapping)
- * the bytes in the specified char value.
- * @since 1.5
- */
- public static char reverseBytes(char ch) {
- return (char) (((ch & 0xFF00) >> 8) | (ch << 8));
- }
-
-}