/* * Copyright (c) 2005, 2009, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation.  Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. *//* ******************************************************************************* * (C) Copyright IBM Corp. and others, 1996-2009 - All Rights Reserved         * *                                                                             * * The original version of this source code and documentation is copyrighted   * * and owned by IBM, These materials are provided under terms of a License     * * Agreement between IBM and Sun. This technology is protected by multiple     * * US and International patents. This notice and attribution to IBM may not    * * to removed.                                                                 * ******************************************************************************* */ package sun.text.normalizer; public final class Utility {     /**     * Convenience utility to compare two Object[]s     * Ought to be in System.     * @param len the length to compare.     * The start indices and start+len must be valid.     */    public final static boolean arrayRegionMatches(char[] source, int sourceStart,                                            char[] target, int targetStart,                                            int len)    {        int sourceEnd = sourceStart + len;        int delta = targetStart - sourceStart;        for (int i = sourceStart; i < sourceEnd; i++) {            if (source[i]!=target[i + delta])            return false;        }        return true;    }     /**     * Convert characters outside the range U+0020 to U+007F to     * Unicode escapes, and convert backslash to a double backslash.     */    public static final String escape(String s) {        StringBuffer buf = new StringBuffer();        for (int i=0; i<s.length(); ) {            int c = UTF16.charAt(s, i);            i += UTF16.getCharCount(c);            if (c >= ' ' && c <= 0x007F) {                if (c == '\\') {                    buf.append("\\\\"); // That is, "\\"                } else {                    buf.append((char)c);                }            } else {                boolean four = c <= 0xFFFF;                buf.append(four ? "\\u" : "\\U");                hex(c, four ? 4 : 8, buf);            }        }        return buf.toString();    }     /* This map must be in ASCENDING ORDER OF THE ESCAPE CODE */    static private final char[] UNESCAPE_MAP = {        /*"   0x22, 0x22 */        /*'   0x27, 0x27 */        /*?   0x3F, 0x3F */        /*\   0x5C, 0x5C */        /*a*/ 0x61, 0x07,        /*b*/ 0x62, 0x08,        /*e*/ 0x65, 0x1b,        /*f*/ 0x66, 0x0c,        /*n*/ 0x6E, 0x0a,        /*r*/ 0x72, 0x0d,        /*t*/ 0x74, 0x09,        /*v*/ 0x76, 0x0b    };     /**     * Convert an escape to a 32-bit code point value.  We attempt     * to parallel the icu4c unescapeAt() function.     * @param offset16 an array containing offset to the character     * <em>after</em> the backslash.  Upon return offset16[0] will     * be updated to point after the escape sequence.     * @return character value from 0 to 10FFFF, or -1 on error.     */    public static int unescapeAt(String s, int[] offset16) {        int c;        int result = 0;        int n = 0;        int minDig = 0;        int maxDig = 0;        int bitsPerDigit = 4;        int dig;        int i;        boolean braces = false;         /* Check that offset is in range */        int offset = offset16[0];        int length = s.length();        if (offset < 0 || offset >= length) {            return -1;        }         /* Fetch first UChar after '\\' */        c = UTF16.charAt(s, offset);        offset += UTF16.getCharCount(c);         /* Convert hexadecimal and octal escapes */        switch (c) {        case 'u':            minDig = maxDig = 4;            break;        case 'U':            minDig = maxDig = 8;            break;        case 'x':            minDig = 1;            if (offset < length && UTF16.charAt(s, offset) == 0x7B /*{*/) {                ++offset;                braces = true;                maxDig = 8;            } else {                maxDig = 2;            }            break;        default:            dig = UCharacter.digit(c, 8);            if (dig >= 0) {                minDig = 1;                maxDig = 3;                n = 1; /* Already have first octal digit */                bitsPerDigit = 3;                result = dig;            }            break;        }        if (minDig != 0) {            while (offset < length && n < maxDig) {                c = UTF16.charAt(s, offset);                dig = UCharacter.digit(c, (bitsPerDigit == 3) ? 8 : 16);                if (dig < 0) {                    break;                }                result = (result << bitsPerDigit) | dig;                offset += UTF16.getCharCount(c);                ++n;            }            if (n < minDig) {                return -1;            }            if (braces) {                if (c != 0x7D /*}*/) {                    return -1;                }                ++offset;            }            if (result < 0 || result >= 0x110000) {                return -1;            }            // If an escape sequence specifies a lead surrogate, see            // if there is a trail surrogate after it, either as an            // escape or as a literal.  If so, join them up into a            // supplementary.            if (offset < length &&                UTF16.isLeadSurrogate((char) result)) {                int ahead = offset+1;                c = s.charAt(offset); // [sic] get 16-bit code unit                if (c == '\\' && ahead < length) {                    int o[] = new int[] { ahead };                    c = unescapeAt(s, o);                    ahead = o[0];                }                if (UTF16.isTrailSurrogate((char) c)) {                    offset = ahead;                result = UCharacterProperty.getRawSupplementary(                                  (char) result, (char) c);                }            }            offset16[0] = offset;            return result;        }         /* Convert C-style escapes in table */        for (i=0; i<UNESCAPE_MAP.length; i+=2) {            if (c == UNESCAPE_MAP[i]) {                offset16[0] = offset;                return UNESCAPE_MAP[i+1];            } else if (c < UNESCAPE_MAP[i]) {                break;            }        }         /* Map \cX to control-X: X & 0x1F */        if (c == 'c' && offset < length) {            c = UTF16.charAt(s, offset);            offset16[0] = offset + UTF16.getCharCount(c);            return 0x1F & c;        }         /* If no special forms are recognized, then consider         * the backslash to generically escape the next character. */        offset16[0] = offset;        return c;    }     /**     * Convert a integer to size width hex uppercase digits.     * E.g., hex('a', 4, str) => "0041".     * Append the output to the given StringBuffer.     * If width is too small to fit, nothing will be appended to output.     */    public static StringBuffer hex(int ch, int width, StringBuffer output) {        return appendNumber(output, ch, 16, width);    }     /**     * Convert a integer to size width (minimum) hex uppercase digits.     * E.g., hex('a', 4, str) => "0041".  If the integer requires more     * than width digits, more will be used.     */    public static String hex(int ch, int width) {        StringBuffer buf = new StringBuffer();        return appendNumber(buf, ch, 16, width).toString();    }     /**     * Skip over a sequence of zero or more white space characters     * at pos.  Return the index of the first non-white-space character     * at or after pos, or str.length(), if there is none.     */    public static int skipWhitespace(String str, int pos) {        while (pos < str.length()) {            int c = UTF16.charAt(str, pos);            if (!UCharacterProperty.isRuleWhiteSpace(c)) {                break;            }            pos += UTF16.getCharCount(c);        }        return pos;    }     static final char DIGITS[] = {        '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',        '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'    };     /**     * Append the digits of a positive integer to the given     * <code>StringBuffer</code> in the given radix. This is     * done recursively since it is easiest to generate the low-     * order digit first, but it must be appended last.     *     * @param result is the <code>StringBuffer</code> to append to     * @param n is the positive integer     * @param radix is the radix, from 2 to 36 inclusive     * @param minDigits is the minimum number of digits to append.     */    private static void recursiveAppendNumber(StringBuffer result, int n,                                                int radix, int minDigits)    {        int digit = n % radix;         if (n >= radix || minDigits > 1) {            recursiveAppendNumber(result, n / radix, radix, minDigits - 1);        }         result.append(DIGITS[digit]);    }     /**     * Append a number to the given StringBuffer in the given radix.     * Standard digits '0'-'9' are used and letters 'A'-'Z' for     * radices 11 through 36.     * @param result the digits of the number are appended here     * @param n the number to be converted to digits; may be negative.     * If negative, a '-' is prepended to the digits.     * @param radix a radix from 2 to 36 inclusive.     * @param minDigits the minimum number of digits, not including     * any '-', to produce.  Values less than 2 have no effect.  One     * digit is always emitted regardless of this parameter.     * @return a reference to result     */    public static StringBuffer appendNumber(StringBuffer result, int n,                                             int radix, int minDigits)        throws IllegalArgumentException    {        if (radix < 2 || radix > 36) {            throw new IllegalArgumentException("Illegal radix " + radix);        }          int abs = n;         if (n < 0) {            abs = -n;            result.append("-");        }         recursiveAppendNumber(result, abs, radix, minDigits);         return result;    }     /**     * Return true if the character is NOT printable ASCII.  The tab,     * newline and linefeed characters are considered unprintable.     */    public static boolean isUnprintable(int c) {        return !(c >= 0x20 && c <= 0x7E);    }     /**     * Escape unprintable characters using <backslash>uxxxx notation     * for U+0000 to U+FFFF and <backslash>Uxxxxxxxx for U+10000 and     * above.  If the character is printable ASCII, then do nothing     * and return FALSE.  Otherwise, append the escaped notation and     * return TRUE.     */    public static boolean escapeUnprintable(StringBuffer result, int c) {        if (isUnprintable(c)) {            result.append('\\');            if ((c & ~0xFFFF) != 0) {                result.append('U');                result.append(DIGITS[0xF&(c>>28)]);                result.append(DIGITS[0xF&(c>>24)]);                result.append(DIGITS[0xF&(c>>20)]);                result.append(DIGITS[0xF&(c>>16)]);            } else {                result.append('u');            }            result.append(DIGITS[0xF&(c>>12)]);            result.append(DIGITS[0xF&(c>>8)]);            result.append(DIGITS[0xF&(c>>4)]);            result.append(DIGITS[0xF&c]);            return true;        }        return false;    }     /**    * Similar to StringBuffer.getChars, version 1.3.    * Since JDK 1.2 implements StringBuffer.getChars differently, this method    * is here to provide consistent results.    * To be removed after JDK 1.2 ceased to be the reference platform.    * @param src source string buffer    * @param srcBegin offset to the start of the src to retrieve from    * @param srcEnd offset to the end of the src to retrieve from    * @param dst char array to store the retrieved chars    * @param dstBegin offset to the start of the destination char array to    *                 store the retrieved chars    */    public static void getChars(StringBuffer src, int srcBegin, int srcEnd,                                char dst[], int dstBegin)    {        if (srcBegin == srcEnd) {            return;        }        src.getChars(srcBegin, srcEnd, dst, dstBegin);    } }