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International Component for Unicode for Java (ICU4J) is a mature, widely used Java library
providing Unicode and Globalization support
The newest version!
// © 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
/*
*******************************************************************************
* Copyright (C) 1996-2015, International Business Machines Corporation and *
* others. All Rights Reserved. *
*******************************************************************************
*/
package com.ibm.icu.impl;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.Locale;
import java.util.regex.Pattern;
import com.ibm.icu.lang.UCharacter;
import com.ibm.icu.text.Replaceable;
import com.ibm.icu.text.UTF16;
import com.ibm.icu.text.UnicodeMatcher;
import com.ibm.icu.util.ICUUncheckedIOException;
public final class Utility {
private static final char APOSTROPHE = '\'';
private static final char BACKSLASH = '\\';
private static final int MAGIC_UNSIGNED = 0x80000000;
/**
* Convenience utility to compare two Object[]s.
* Ought to be in System
*/
public final static boolean arrayEquals(Object[] source, Object target) {
if (source == null) return (target == null);
if (!(target instanceof Object[])) return false;
Object[] targ = (Object[]) target;
return (source.length == targ.length
&& arrayRegionMatches(source, 0, targ, 0, source.length));
}
/**
* Convenience utility to compare two int[]s
* Ought to be in System
*/
public final static boolean arrayEquals(int[] source, Object target) {
if (source == null) return (target == null);
if (!(target instanceof int[])) return false;
int[] targ = (int[]) target;
return (source.length == targ.length
&& arrayRegionMatches(source, 0, targ, 0, source.length));
}
/**
* Convenience utility to compare two double[]s
* Ought to be in System
*/
public final static boolean arrayEquals(double[] source, Object target) {
if (source == null) return (target == null);
if (!(target instanceof double[])) return false;
double[] targ = (double[]) target;
return (source.length == targ.length
&& arrayRegionMatches(source, 0, targ, 0, source.length));
}
public final static boolean arrayEquals(byte[] source, Object target) {
if (source == null) return (target == null);
if (!(target instanceof byte[])) return false;
byte[] targ = (byte[]) target;
return (source.length == targ.length
&& arrayRegionMatches(source, 0, targ, 0, source.length));
}
/**
* Convenience utility to compare two Object[]s
* Ought to be in System
*/
public final static boolean arrayEquals(Object source, Object target) {
if (source == null) return (target == null);
// for some reason, the correct arrayEquals is not being called
// so do it by hand for now.
if (source instanceof Object[])
return(arrayEquals((Object[]) source,target));
if (source instanceof int[])
return(arrayEquals((int[]) source,target));
if (source instanceof double[])
return(arrayEquals((double[]) source, target));
if (source instanceof byte[])
return(arrayEquals((byte[]) source,target));
return source.equals(target);
}
/**
* 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(Object[] source, int sourceStart,
Object[] target, int targetStart,
int len)
{
int sourceEnd = sourceStart + len;
int delta = targetStart - sourceStart;
for (int i = sourceStart; i < sourceEnd; i++) {
if (!arrayEquals(source[i],target[i + delta]))
return false;
}
return true;
}
/**
* 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;
}
/**
* Convenience utility to compare two int[]s.
* @param len the length to compare.
* The start indices and start+len must be valid.
* Ought to be in System
*/
public final static boolean arrayRegionMatches(int[] source, int sourceStart,
int[] 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;
}
/**
* Convenience utility to compare two arrays of doubles.
* @param len the length to compare.
* The start indices and start+len must be valid.
* Ought to be in System
*/
public final static boolean arrayRegionMatches(double[] source, int sourceStart,
double[] 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;
}
public final static boolean arrayRegionMatches(byte[] source, int sourceStart,
byte[] 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;
}
/**
* Trivial reference equality.
* This method should help document that we really want == not equals(),
* and to have a single place to suppress warnings from static analysis tools.
*/
public static final boolean sameObjects(Object a, Object b) {
return a == b;
}
/**
* Convenience utility. Does null checks on objects, then calls compare.
*/
public static > int checkCompare(T a, T b) {
return a == null ?
b == null ? 0 : -1 :
b == null ? 1 : a.compareTo(b);
}
/**
* Convenience utility. Does null checks on object, then calls hashCode.
*/
public static int checkHash(Object a) {
return a == null ? 0 : a.hashCode();
}
/**
* The ESCAPE character is used during run-length encoding. It signals
* a run of identical chars.
*/
private static final char ESCAPE = '\uA5A5';
/**
* The ESCAPE_BYTE character is used during run-length encoding. It signals
* a run of identical bytes.
*/
static final byte ESCAPE_BYTE = (byte)0xA5;
/**
* Construct a string representing an int array. Use run-length encoding.
* A character represents itself, unless it is the ESCAPE character. Then
* the following notations are possible:
* ESCAPE ESCAPE ESCAPE literal
* ESCAPE n c n instances of character c
* Since an encoded run occupies 3 characters, we only encode runs of 4 or
* more characters. Thus we have n > 0 and n != ESCAPE and n <= 0xFFFF.
* If we encounter a run where n == ESCAPE, we represent this as:
* c ESCAPE n-1 c
* The ESCAPE value is chosen so as not to collide with commonly
* seen values.
*/
static public final String arrayToRLEString(int[] a) {
StringBuilder buffer = new StringBuilder();
appendInt(buffer, a.length);
int runValue = a[0];
int runLength = 1;
for (int i=1; i 0 and n != ESCAPE and n <= 0xFFFF.
* If we encounter a run where n == ESCAPE, we represent this as:
* c ESCAPE n-1 c
* The ESCAPE value is chosen so as not to collide with commonly
* seen values.
*/
static public final String arrayToRLEString(short[] a) {
StringBuilder buffer = new StringBuilder();
// for (int i=0; i> 16));
buffer.append((char) a.length);
short runValue = a[0];
int runLength = 1;
for (int i=1; i 0 and n != ESCAPE and n <= 0xFFFF.
* If we encounter a run where n == ESCAPE, we represent this as:
* c ESCAPE n-1 c
* The ESCAPE value is chosen so as not to collide with commonly
* seen values.
*/
static public final String arrayToRLEString(char[] a) {
StringBuilder buffer = new StringBuilder();
buffer.append((char) (a.length >> 16));
buffer.append((char) a.length);
char runValue = a[0];
int runLength = 1;
for (int i=1; i 0 and n != ESCAPE_BYTE and n <= 0xFF.
* If we encounter a run where n == ESCAPE_BYTE, we represent this as:
* b ESCAPE_BYTE n-1 b
* The ESCAPE_BYTE value is chosen so as not to collide with commonly
* seen values.
*/
static public final String arrayToRLEString(byte[] a) {
StringBuilder buffer = new StringBuilder();
buffer.append((char) (a.length >> 16));
buffer.append((char) a.length);
byte runValue = a[0];
int runLength = 1;
byte[] state = new byte[2];
for (int i=1; i 0 && <= 0xFFFF.
*/
private static final void encodeRun(T buffer, int value, int length) {
if (length < 4) {
for (int j=0; j void appendInt(T buffer, int value) {
try {
buffer.append((char)(value >>> 16));
buffer.append((char)(value & 0xFFFF));
} catch (IOException e) {
throw new IllegalIcuArgumentException(e);
}
}
/**
* Encode a run, possibly a degenerate run (of < 4 values).
* @param length The length of the run; must be > 0 && <= 0xFFFF.
*/
private static final void encodeRun(T buffer, short value, int length) {
try {
char valueChar = (char) value;
if (length < 4) {
for (int j=0; j 0 && <= 0xFF.
*/
private static final void encodeRun(T buffer, byte value, int length,
byte[] state) {
if (length < 4) {
for (int j=0; j void appendEncodedByte(T buffer, byte value,
byte[] state) {
try {
if (state[0] != 0) {
char c = (char) ((state[1] << 8) | ((value) & 0xFF));
buffer.append(c);
state[0] = 0;
}
else {
state[0] = 1;
state[1] = value;
}
} catch (IOException e) {
throw new IllegalIcuArgumentException(e);
}
}
/**
* Construct an array of ints from a run-length encoded string.
*/
static public final int[] RLEStringToIntArray(String s) {
int length = getInt(s, 0);
int[] array = new int[length];
int ai = 0, i = 1;
int maxI = s.length() / 2;
while (ai < length && i < maxI) {
int c = getInt(s, i++);
if (c == ESCAPE) {
c = getInt(s, i++);
if (c == ESCAPE) {
array[ai++] = c;
} else {
int runLength = c;
int runValue = getInt(s, i++);
for (int j=0; j> 8);
nextChar = false;
}
else {
b = (byte) (c & 0xFF);
nextChar = true;
}
// This part of the loop is a tiny state machine which handles
// the parsing of the run-length encoding. This would be simpler
// if we could look ahead, but we can't, so we use 'node' to
// move between three nodes in the state machine.
switch (node) {
case 0:
// Normal idle node
if (b == ESCAPE_BYTE) {
node = 1;
}
else {
array[ai++] = b;
}
break;
case 1:
// We have seen one ESCAPE_BYTE; we expect either a second
// one, or a run length and value.
if (b == ESCAPE_BYTE) {
array[ai++] = ESCAPE_BYTE;
node = 0;
}
else {
runLength = b;
// Interpret signed byte as unsigned
if (runLength < 0) runLength += 0x100;
node = 2;
}
break;
case 2:
// We have seen an ESCAPE_BYTE and length byte. We interpret
// the next byte as the value to be repeated.
for (int j=0; j 0) buffer.append('+').append(LINE_SEPARATOR);
buffer.append(" \"");
int count = 11;
while (i> 6]); // HEX_DIGIT works for octal
buffer.append(HEX_DIGIT[(c & 0070) >> 3]);
buffer.append(HEX_DIGIT[(c & 0007)]);
count += 4;
}
}
else if (c <= '\u007E') {
buffer.append(c);
count += 1;
}
else {
buffer.append("\\u");
buffer.append(HEX_DIGIT[(c & 0xF000) >> 12]);
buffer.append(HEX_DIGIT[(c & 0x0F00) >> 8]);
buffer.append(HEX_DIGIT[(c & 0x00F0) >> 4]);
buffer.append(HEX_DIGIT[(c & 0x000F)]);
count += 6;
}
}
buffer.append('"');
}
return buffer.toString();
}
static final char[] HEX_DIGIT = {'0','1','2','3','4','5','6','7',
'8','9','A','B','C','D','E','F'};
/**
* Format a String for representation in a source file. Like
* formatForSource but does not do line breaking.
*/
static public final String format1ForSource(String s) {
StringBuilder buffer = new StringBuilder();
buffer.append("\"");
for (int i=0; i> 6]); // HEX_DIGIT works for octal
buffer.append(HEX_DIGIT[(c & 0070) >> 3]);
buffer.append(HEX_DIGIT[(c & 0007)]);
}
}
else if (c <= '\u007E') {
buffer.append(c);
}
else {
buffer.append("\\u");
buffer.append(HEX_DIGIT[(c & 0xF000) >> 12]);
buffer.append(HEX_DIGIT[(c & 0x0F00) >> 8]);
buffer.append(HEX_DIGIT[(c & 0x00F0) >> 4]);
buffer.append(HEX_DIGIT[(c & 0x000F)]);
}
}
buffer.append('"');
return buffer.toString();
}
/**
* 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) {
StringBuilder buf = new StringBuilder();
for (int i=0; i= ' ' && c <= 0x007F) {
if (c == '\\') {
buf.append("\\\\"); // That is, "\\"
} else {
buf.append((char)c);
}
} else {
boolean four = c <= 0xFFFF;
buf.append(four ? "\\u" : "\\U");
buf.append(hex(c, four ? 4 : 8));
}
}
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 one octal digit to a numeric value 0..7, or -1 on failure */
private static final int _digit8(int c) {
if (c >= '0' && c <= '7') {
return c - '0';
}
return -1;
}
/* Convert one hex digit to a numeric value 0..F, or -1 on failure */
private static final int _digit16(int c) {
if (c >= '0' && c <= '9') {
return c - '0';
}
if (c >= 'A' && c <= 'F') {
return c - ('A' - 10);
}
if (c >= 'a' && c <= 'f') {
return c - ('a' - 10);
}
return -1;
}
/**
* Converts an escape to a code point value. We attempt
* to parallel the icu4c unescapeAt() function.
* This function returns an integer with
* both the code point (bits 28..8) and the length of the escape sequence (bits 7..0).
* offset+length is the index after the escape sequence.
*
* @param offset the offset to the character after the backslash.
* @return the code point and length, or -1 on error.
*/
public static int unescapeAndLengthAt(CharSequence s, int offset) {
return unescapeAndLengthAt(s, offset, s.length());
}
private static int unescapeAndLengthAt(CharSequence s, int offset, int length) {
int result = 0;
int n = 0;
int minDig = 0;
int maxDig = 0;
int bitsPerDigit = 4;
int dig;
boolean braces = false;
/* Check that offset is in range */
if (offset < 0 || offset >= length) {
return -1;
}
int start = offset;
/* Fetch first UChar after '\\' */
int c = s.charAt(offset++);
/* 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 && s.charAt(offset) == '{') {
++offset;
braces = true;
maxDig = 8;
} else {
maxDig = 2;
}
break;
default:
dig = _digit8(c);
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 = s.charAt(offset);
dig = (bitsPerDigit == 3) ? _digit8(c) : _digit16(c);
if (dig < 0) {
break;
}
result = (result << bitsPerDigit) | dig;
++offset;
++n;
}
if (n < minDig) {
return -1;
}
if (braces) {
if (c != '}') {
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(result)) {
int ahead = offset+1;
c = s.charAt(offset);
if (c == '\\' && ahead < length) {
// Calling ourselves recursively may cause a stack overflow if
// we have repeated escaped lead surrogates.
// Limit the length to 11 ("x{0000DFFF}") after ahead.
int tailLimit = ahead + 11;
if (tailLimit > length) {
tailLimit = length;
}
int cpAndLength = unescapeAndLengthAt(s, ahead, tailLimit);
if (cpAndLength >= 0) {
c = cpAndLength >> 8;
ahead += cpAndLength & 0xff;
}
}
if (UTF16.isTrailSurrogate(c)) {
offset = ahead;
result = UCharacter.toCodePoint(result, c);
}
}
return codePointAndLength(result, start, offset);
}
/* Convert C-style escapes in table */
for (int i=0; i= 0;
return cpAndLength >> 8;
}
public static int lengthFromCodePointAndLength(int cpAndLength) {
assert cpAndLength >= 0;
return cpAndLength & 0xff;
}
/**
* Convert all escapes in a given string using unescapeAndLengthAt().
* @exception IllegalArgumentException if an invalid escape is
* seen.
*/
public static String unescape(CharSequence s) {
StringBuilder buf = null;
for (int i=0; i> 8);
i += cpAndLength & 0xff;
} else if (buf != null) {
// We could optimize this further by appending whole substrings between escapes.
buf.append(c);
}
}
if (buf == null) {
// No escapes in s.
return s.toString();
}
return buf.toString();
}
/**
* Convert all escapes in a given string using unescapeAndLengthAt().
* Leave invalid escape sequences unchanged.
*/
public static String unescapeLeniently(CharSequence s) {
StringBuilder buf = null;
for (int i=0; i> 8);
i += cpAndLength & 0xff;
}
} else if (buf != null) {
// We could optimize this further by appending whole substrings between escapes.
buf.append(c);
}
}
if (buf == null) {
// No escapes in s.
return s.toString();
}
return buf.toString();
}
/**
* Convert a char to 4 hex uppercase digits. E.g., hex('a') =>
* "0041".
*/
public static String hex(long ch) {
return hex(ch, 4);
}
/**
* Supplies a zero-padded hex representation of an integer (without 0x)
*/
static public String hex(long i, int places) {
if (i == Long.MIN_VALUE) return "-8000000000000000";
boolean negative = i < 0;
if (negative) {
i = -i;
}
String result = Long.toString(i, 16).toUpperCase(Locale.ENGLISH);
if (result.length() < places) {
result = "0000000000000000".substring(result.length(),places) + result;
}
if (negative) {
return '-' + result;
}
return result;
}
/**
* Convert a string to comma-separated groups of 4 hex uppercase
* digits. E.g., hex('ab') => "0041,0042".
*/
public static String hex(CharSequence s) {
return hex(s, 4, ",", true, new StringBuilder()).toString();
}
/**
* Convert a string to separated groups of hex uppercase
* digits. E.g., hex('ab'...) => "0041,0042". Append the output
* to the given Appendable.
*/
public static T hex(S s, int width, U separator, boolean useCodePoints, T result) {
try {
if (useCodePoints) {
int cp;
for (int i = 0; i < s.length(); i += UTF16.getCharCount(cp)) {
cp = Character.codePointAt(s, i);
if (i != 0) {
result.append(separator);
}
result.append(hex(cp,width));
}
} else {
for (int i = 0; i < s.length(); ++i) {
if (i != 0) {
result.append(separator);
}
result.append(hex(s.charAt(i),width));
}
}
return result;
} catch (IOException e) {
throw new IllegalIcuArgumentException(e);
}
}
public static String hex(byte[] o, int start, int end, String separator) {
StringBuilder result = new StringBuilder();
//int ch;
for (int i = start; i < end; ++i) {
if (i != 0) result.append(separator);
result.append(hex(o[i]));
}
return result.toString();
}
/**
* Convert a string to comma-separated groups of 4 hex uppercase
* digits. E.g., hex('ab') => "0041,0042".
*/
public static String hex(S s, int width, S separator) {
return hex(s, width, separator, true, new StringBuilder()).toString();
}
/**
* Split a string into pieces based on the given divider character
* @param s the string to split
* @param divider the character on which to split. Occurrences of
* this character are not included in the output
* @param output an array to receive the substrings between
* instances of divider. It must be large enough on entry to
* accommodate all output. Adjacent instances of the divider
* character will place empty strings into output. Before
* returning, output is padded out with empty strings.
*/
public static void split(String s, char divider, String[] output) {
int last = 0;
int current = 0;
int i;
for (i = 0; i < s.length(); ++i) {
if (s.charAt(i) == divider) {
output[current++] = s.substring(last,i);
last = i+1;
}
}
output[current++] = s.substring(last,i);
while (current < output.length) {
output[current++] = "";
}
}
/**
* Split a string into pieces based on the given divider character
* @param s the string to split
* @param divider the character on which to split. Occurrences of
* this character are not included in the output
* @return output an array to receive the substrings between
* instances of divider. Adjacent instances of the divider
* character will place empty strings into output.
*/
public static String[] split(String s, char divider) {
int last = 0;
int i;
ArrayList output = new ArrayList<>();
for (i = 0; i < s.length(); ++i) {
if (s.charAt(i) == divider) {
output.add(s.substring(last,i));
last = i+1;
}
}
output.add( s.substring(last,i));
return output.toArray(new String[output.size()]);
}
/**
* Look up a given string in a string array. Returns the index at
* which the first occurrence of the string was found in the
* array, or -1 if it was not found.
* @param source the string to search for
* @param target the array of zero or more strings in which to
* look for source
* @return the index of target at which source first occurs, or -1
* if not found
*/
public static int lookup(String source, String[] target) {
for (int i = 0; i < target.length; ++i) {
if (source.equals(target[i])) return i;
}
return -1;
}
/**
* Parse a single non-whitespace character 'ch', optionally
* preceded by whitespace.
* @param id the string to be parsed
* @param pos INPUT-OUTPUT parameter. On input, pos[0] is the
* offset of the first character to be parsed. On output, pos[0]
* is the index after the last parsed character. If the parse
* fails, pos[0] will be unchanged.
* @param ch the non-whitespace character to be parsed.
* @return true if 'ch' is seen preceded by zero or more
* whitespace characters.
*/
public static boolean parseChar(String id, int[] pos, char ch) {
int start = pos[0];
pos[0] = PatternProps.skipWhiteSpace(id, pos[0]);
if (pos[0] == id.length() ||
id.charAt(pos[0]) != ch) {
pos[0] = start;
return false;
}
++pos[0];
return true;
}
/**
* Parse a pattern string starting at offset pos. Keywords are
* matched case-insensitively. Spaces may be skipped and may be
* optional or required. Integer values may be parsed, and if
* they are, they will be returned in the given array. If
* successful, the offset of the next non-space character is
* returned. On failure, -1 is returned.
* @param pattern must only contain lowercase characters, which
* will match their uppercase equivalents as well. A space
* character matches one or more required spaces. A '~' character
* matches zero or more optional spaces. A '#' character matches
* an integer and stores it in parsedInts, which the caller must
* ensure has enough capacity.
* @param parsedInts array to receive parsed integers. Caller
* must ensure that parsedInts.length is >= the number of '#'
* signs in 'pattern'.
* @return the position after the last character parsed, or -1 if
* the parse failed
*/
@SuppressWarnings("fallthrough")
public static int parsePattern(String rule, int pos, int limit,
String pattern, int[] parsedInts) {
// TODO Update this to handle surrogates
int[] p = new int[1];
int intCount = 0; // number of integers parsed
for (int i=0; i= limit) {
return -1;
}
c = rule.charAt(pos++);
if (!PatternProps.isWhiteSpace(c)) {
return -1;
}
// FALL THROUGH to skipWhitespace
case '~':
pos = PatternProps.skipWhiteSpace(rule, pos);
break;
case '#':
p[0] = pos;
parsedInts[intCount++] = parseInteger(rule, p, limit);
if (p[0] == pos) {
// Syntax error; failed to parse integer
return -1;
}
pos = p[0];
break;
default:
if (pos >= limit) {
return -1;
}
c = (char) UCharacter.toLowerCase(rule.charAt(pos++));
if (c != cpat) {
return -1;
}
break;
}
}
return pos;
}
/**
* Parse a pattern string within the given Replaceable and a parsing
* pattern. Characters are matched literally and case-sensitively
* except for the following special characters:
*
* ~ zero or more Pattern_White_Space chars
*
* If end of pattern is reached with all matches along the way,
* pos is advanced to the first unparsed index and returned.
* Otherwise -1 is returned.
* @param pat pattern that controls parsing
* @param text text to be parsed, starting at index
* @param index offset to first character to parse
* @param limit offset after last character to parse
* @return index after last parsed character, or -1 on parse failure.
*/
public static int parsePattern(String pat,
Replaceable text,
int index,
int limit) {
int ipat = 0;
// empty pattern matches immediately
if (ipat == pat.length()) {
return index;
}
int cpat = Character.codePointAt(pat, ipat);
while (index < limit) {
int c = text.char32At(index);
// parse \s*
if (cpat == '~') {
if (PatternProps.isWhiteSpace(c)) {
index += UTF16.getCharCount(c);
continue;
} else {
if (++ipat == pat.length()) {
return index; // success; c unparsed
}
// fall thru; process c again with next cpat
}
}
// parse literal
else if (c == cpat) {
int n = UTF16.getCharCount(c);
index += n;
ipat += n;
if (ipat == pat.length()) {
return index; // success; c parsed
}
// fall thru; get next cpat
}
// match failure of literal
else {
return -1;
}
cpat = UTF16.charAt(pat, ipat);
}
return -1; // text ended before end of pat
}
/**
* Parse an integer at pos, either of the form \d+ or of the form
* 0x[0-9A-Fa-f]+ or 0[0-7]+, that is, in standard decimal, hex,
* or octal format.
* @param pos INPUT-OUTPUT parameter. On input, the first
* character to parse. On output, the character after the last
* parsed character.
*/
public static int parseInteger(String rule, int[] pos, int limit) {
int count = 0;
int value = 0;
int p = pos[0];
int radix = 10;
if (rule.regionMatches(true, p, "0x", 0, 2)) {
p += 2;
radix = 16;
} else if (p < limit && rule.charAt(p) == '0') {
p++;
count = 1;
radix = 8;
}
while (p < limit) {
int d = UCharacter.digit(rule.charAt(p++), radix);
if (d < 0) {
--p;
break;
}
++count;
int v = (value * radix) + d;
if (v <= value) {
// If there are too many input digits, at some point
// the value will go negative, e.g., if we have seen
// "0x8000000" already and there is another '0', when
// we parse the next 0 the value will go negative.
return 0;
}
value = v;
}
if (count > 0) {
pos[0] = p;
}
return value;
}
/**
* Parse a Unicode identifier from the given string at the given
* position. Return the identifier, or null if there is no
* identifier.
* @param str the string to parse
* @param pos INPUT-OUTPUT parameter. On INPUT, pos[0] is the
* first character to examine. It must be less than str.length(),
* and it must not point to a whitespace character. That is, must
* have pos[0] < str.length(). On
* OUTPUT, the position after the last parsed character.
* @return the Unicode identifier, or null if there is no valid
* identifier at pos[0].
*/
public static String parseUnicodeIdentifier(String str, int[] pos) {
// assert(pos[0] < str.length());
StringBuilder buf = new StringBuilder();
int p = pos[0];
while (p < str.length()) {
int ch = Character.codePointAt(str, p);
if (buf.length() == 0) {
if (UCharacter.isUnicodeIdentifierStart(ch)) {
buf.appendCodePoint(ch);
} else {
return null;
}
} else {
if (UCharacter.isUnicodeIdentifierPart(ch)) {
buf.appendCodePoint(ch);
} else {
break;
}
}
p += UTF16.getCharCount(ch);
}
pos[0] = p;
return buf.toString();
}
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
* Appendable 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 Appendable 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(T result, int n,
int radix, int minDigits)
{
try {
int digit = n % radix;
if (n >= radix || minDigits > 1) {
recursiveAppendNumber(result, n / radix, radix, minDigits - 1);
}
result.append(DIGITS[digit]);
} catch (IOException e) {
throw new IllegalIcuArgumentException(e);
}
}
/**
* Append a number to the given Appendable 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 T appendNumber(T result, int n,
int radix, int minDigits)
{
try {
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;
} catch (IOException e) {
throw new IllegalIcuArgumentException(e);
}
}
/**
* Parse an unsigned 31-bit integer at the given offset. Use
* UCharacter.digit() to parse individual characters into digits.
* @param text the text to be parsed
* @param pos INPUT-OUTPUT parameter. On entry, pos[0] is the
* offset within text at which to start parsing; it should point
* to a valid digit. On exit, pos[0] is the offset after the last
* parsed character. If the parse failed, it will be unchanged on
* exit. Must be >= 0 on entry.
* @param radix the radix in which to parse; must be >= 2 and <=
* 36.
* @return a non-negative parsed number, or -1 upon parse failure.
* Parse fails if there are no digits, that is, if pos[0] does not
* point to a valid digit on entry, or if the number to be parsed
* does not fit into a 31-bit unsigned integer.
*/
public static int parseNumber(String text, int[] pos, int radix) {
// assert(pos[0] >= 0);
// assert(radix >= 2);
// assert(radix <= 36);
int n = 0;
int p = pos[0];
while (p < text.length()) {
int ch = Character.codePointAt(text, p);
int d = UCharacter.digit(ch, radix);
if (d < 0) {
break;
}
n = radix*n + d;
// ASSUME that when a 32-bit integer overflows it becomes
// negative. E.g., 214748364 * 10 + 8 => negative value.
if (n < 0) {
return -1;
}
++p;
}
if (p == pos[0]) {
return -1;
}
pos[0] = p;
return n;
}
/**
* Return true if the character is NOT printable ASCII. The tab,
* newline and linefeed characters are considered unprintable.
*/
public static boolean isUnprintable(int c) {
//0x20 = 32 and 0x7E = 126
return !(c >= 0x20 && c <= 0x7E);
}
/**
* @return true for control codes and for surrogate and noncharacter code points
*/
public static boolean shouldAlwaysBeEscaped(int c) {
if (c < 0x20) {
return true; // C0 control codes
} else if (c <= 0x7e) {
return false; // printable ASCII
} else if (c <= 0x9f) {
return true; // C1 control codes
} else if (c < 0xd800) {
return false; // most of the BMP
} else if (c <= 0xdfff || (0xfdd0 <= c && c <= 0xfdef) || (c & 0xfffe) == 0xfffe) {
return true; // surrogate or noncharacter code points
} else if (c <= 0x10ffff) {
return false; // all else
} else {
return true; // not a code point
}
}
/**
* Escapes one unprintable code point using uxxxx notation
* for U+0000 to U+FFFF and 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(T result, int c) {
if (isUnprintable(c)) {
escape(result, c);
return true;
}
return false;
}
/**
* Escapes one code point using uxxxx notation
* for U+0000 to U+FFFF and Uxxxxxxxx for U+10000 and above.
* @return result
*/
public static T escape(T result, int c) {
try {
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 result;
} catch (IOException e) {
throw new ICUUncheckedIOException(e);
}
}
/**
* Returns the index of the first character in a set, ignoring quoted text.
* For example, in the string "abc'hide'h", the 'h' in "hide" will not be
* found by a search for "h". Unlike String.indexOf(), this method searches
* not for a single character, but for any character of the string
* setOfChars.
* @param text text to be searched
* @param start the beginning index, inclusive; 0 <= start
* <= limit.
* @param limit the ending index, exclusive; start <= limit
* <= text.length().
* @param setOfChars string with one or more distinct characters
* @return Offset of the first character in setOfChars
* found, or -1 if not found.
* @see String#indexOf
*/
public static int quotedIndexOf(String text, int start, int limit,
String setOfChars) {
for (int i=start; i= 0) {
return i;
}
}
return -1;
}
/**
* Append a character to a rule that is being built up. To flush
* the quoteBuf to rule, make one final call with isLiteral == true.
* If there is no final character, pass in (int)-1 as c.
* @param rule the string to append the character to
* @param c the character to append, or (int)-1 if none.
* @param isLiteral if true, then the given character should not be
* quoted or escaped. Usually this means it is a syntactic element
* such as > or $
* @param escapeUnprintable if true, then unprintable characters
* should be escaped using escapeUnprintable(). These escapes will
* appear outside of quotes.
* @param quoteBuf a buffer which is used to build up quoted
* substrings. The caller should initially supply an empty buffer,
* and thereafter should not modify the buffer. The buffer should be
* cleared out by, at the end, calling this method with a literal
* character (which may be -1).
*/
public static void appendToRule(StringBuffer rule,
int c,
boolean isLiteral,
boolean escapeUnprintable,
StringBuffer quoteBuf) {
// If we are escaping unprintables, then escape them outside
// quotes. \\u and \\U are not recognized within quotes. The same
// logic applies to literals, but literals are never escaped.
if (isLiteral ||
(escapeUnprintable && Utility.isUnprintable(c))) {
if (quoteBuf.length() > 0) {
// We prefer backslash APOSTROPHE to double APOSTROPHE
// (more readable, less similar to ") so if there are
// double APOSTROPHEs at the ends, we pull them outside
// of the quote.
// If the first thing in the quoteBuf is APOSTROPHE
// (doubled) then pull it out.
while (quoteBuf.length() >= 2 &&
quoteBuf.charAt(0) == APOSTROPHE &&
quoteBuf.charAt(1) == APOSTROPHE) {
rule.append(BACKSLASH).append(APOSTROPHE);
quoteBuf.delete(0, 2);
}
// If the last thing in the quoteBuf is APOSTROPHE
// (doubled) then remove and count it and add it after.
int trailingCount = 0;
while (quoteBuf.length() >= 2 &&
quoteBuf.charAt(quoteBuf.length()-2) == APOSTROPHE &&
quoteBuf.charAt(quoteBuf.length()-1) == APOSTROPHE) {
quoteBuf.setLength(quoteBuf.length()-2);
++trailingCount;
}
if (quoteBuf.length() > 0) {
rule.append(APOSTROPHE);
rule.append(quoteBuf);
rule.append(APOSTROPHE);
quoteBuf.setLength(0);
}
while (trailingCount-- > 0) {
rule.append(BACKSLASH).append(APOSTROPHE);
}
}
if (c != -1) {
/* Since spaces are ignored during parsing, they are
* emitted only for readability. We emit one here
* only if there isn't already one at the end of the
* rule.
*/
if (c == ' ') {
int len = rule.length();
if (len > 0 && rule.charAt(len-1) != ' ') {
rule.append(' ');
}
} else if (!escapeUnprintable || !Utility.escapeUnprintable(rule, c)) {
rule.appendCodePoint(c);
}
}
}
// Escape ' and '\' and don't begin a quote just for them
else if (quoteBuf.length() == 0 &&
(c == APOSTROPHE || c == BACKSLASH)) {
rule.append(BACKSLASH).append((char)c);
}
// Specials (printable ascii that isn't [0-9a-zA-Z]) and
// whitespace need quoting. Also append stuff to quotes if we are
// building up a quoted substring already.
else if (quoteBuf.length() > 0 ||
(c >= 0x0021 && c <= 0x007E &&
!((c >= 0x0030/*'0'*/ && c <= 0x0039/*'9'*/) ||
(c >= 0x0041/*'A'*/ && c <= 0x005A/*'Z'*/) ||
(c >= 0x0061/*'a'*/ && c <= 0x007A/*'z'*/))) ||
PatternProps.isWhiteSpace(c)) {
quoteBuf.appendCodePoint(c);
// Double ' within a quote
if (c == APOSTROPHE) {
quoteBuf.append((char)c);
}
}
// Otherwise just append
else {
rule.appendCodePoint(c);
}
}
/**
* Append the given string to the rule. Calls the single-character
* version of appendToRule for each character.
*/
public static void appendToRule(StringBuffer rule,
String text,
boolean isLiteral,
boolean escapeUnprintable,
StringBuffer quoteBuf) {
for (int i=0; i target) {
return 1;
}
return 0;
}
/**
* Find the highest bit in a positive integer. This is done
* by doing a binary search through the bits.
*
* @param n is the integer
*
* @return the bit number of the highest bit, with 0 being
* the low order bit, or -1 if n is not positive
*/
public static final byte highBit(int n)
{
if (n <= 0) {
return -1;
}
byte bit = 0;
if (n >= 1 << 16) {
n >>= 16;
bit += 16;
}
if (n >= 1 << 8) {
n >>= 8;
bit += 8;
}
if (n >= 1 << 4) {
n >>= 4;
bit += 4;
}
if (n >= 1 << 2) {
n >>= 2;
bit += 2;
}
if (n >= 1 << 1) {
n >>= 1;
bit += 1;
}
return bit;
}
/**
* Utility method to take a int[] containing codepoints and return
* a string representation with code units.
*/
public static String valueOf(int[]source){
// TODO: Investigate why this method is not on UTF16 class
StringBuilder result = new StringBuilder(source.length);
for(int i=0; i A appendTo(CharSequence string, A appendable) {
try {
appendable.append(string);
return appendable;
} catch (IOException e) {
throw new ICUUncheckedIOException(e);
}
}
/**
* Java 8+ String#join(CharSequence, Iterable) compatible method for Java 7 env.
* @param delimiter the delimiter that separates each element
* @param elements the elements to join together.
* @return a new String that is composed of the elements separated by the delimiter
* @throws NullPointerException If delimiter or elements is null
*/
public static String joinStrings(CharSequence delimiter, Iterable elements) {
if (delimiter == null || elements == null) {
throw new NullPointerException("Delimiter or elements is null");
}
StringBuilder buf = new StringBuilder();
Iterator itr = elements.iterator();
boolean isFirstElem = true;
while (itr.hasNext()) {
CharSequence element = itr.next();
if (element != null) {
if (!isFirstElem) {
buf.append(delimiter);
} else {
isFirstElem = false;
}
buf.append(element);
}
}
return buf.toString();
}
}