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package it.unimi.dsi.util;
/*
* DSI utilities
*
* Copyright (C) 2003-2019 Paolo Boldi and Sebastiano Vigna
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by the Free
* Software Foundation; either version 3 of the License, or (at your option)
* any later version.
*
* This library 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 Lesser General Public License
* for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, see The {@linkplain java.util.regex regular expression facilities} of the Java API
* are a powerful tool; however, when searching for a constant pattern
* many algorithms can increase of orders magnitude the speed of a search.
*
*
This class provides constant-pattern text search facilities by
* implementing Sunday's QuickSearch (a simplified but very effective variant
* of the Boyer—Moore search algorithm) using compact
* approximators, a randomised data structure that can accomodate in a
* small space (but in an approximated way) the bad-character shift table of a
* large alphabet such as Unicode.
*
*
Since a large subset of US-ASCII is used in all languages (e.g.,
* whitespace, punctuation, etc.), this class caches separately the shifts for
* the first 128 Unicode characters, resulting in very good performance even on
* text in pure US-ASCII.
*
*
Note that the {@link MutableString#indexOf(MutableString) indexOf}
* methods of {@link MutableString} use a even more simplified variant of
* QuickSearch which is less efficient, but has a smaller setup time and does
* not generate any object. The search facilities provided by this class are
* targeted at searches on very large texts, repeated searches with the same
* pattern, and case-insensitive searches.
*
*
Instances of this class are immutable and thread-safe.
*
*
This class is experimental: APIs could change with the next release.
*
* @author Sebastiano Vigna
* @author Paolo Boldi
* @since 0.6
*/
public class TextPattern implements java.io.Serializable, CharSequence {
private static final long serialVersionUID = 1L;
/** Enables case-insensitive matching.
*
*
By default, case-insensitive matching assumes that only characters in
* the ASCII charset are being matched. Unicode-aware case-insensitive
* matching can be enabled by specifying the UNICODE_CASE flag in
* conjunction with this flag.
*
*
Case-insensitivity involves a performance drop.
*/
public final static int CASE_INSENSITIVE = 1;
/** Enables Unicode-aware case folding.
*
*
When this flag is specified then case-insensitive matching, when enabled
* by the CASE_INSENSITIVE flag, is done in a manner consistent with the
* Unicode Standard. By default, case-insensitive matching assumes that
* only characters in the ASCII charset are being matched.
*
*
Unicode-aware case folding is very expensive (two method calls per
* examined non-ASCII character).
*/
public final static int UNICODE_CASE = 2;
/** The square of the golden ratio multiplied by 232. */
private final static int PHI2 = 1640531525;
/** The pattern backing array. */
protected char[] pattern;
/** The compact approximator containing the bad-character shifts; its lenght is a power of 2. */
private transient int[] badCharShift;
/** The bad-character shift for US-ASCII. */
private transient int[] asciiBadCharShift = new int[128];
/** A bit mask equal to the length of {@link #badCharShift} minus 1. */
private transient int mask;
/** A cached shift value for computing one of the hashes. It is equal to 16 minus the base 2 logarithm of the length of {@link #badCharShift}. */
private transient int hashShift;
/** Whether this pattern is case sensitive. */
private boolean caseSensitive;
/** Whether this pattern uses optimised ASCII downcasing (as opposed to the correct Unicode downcasing procedure). */
private boolean asciiCase;
/** Creates a new case-sensitive {@link TextPattern} object that can be used to search for the given pattern.
*
* @param pattern the constant pattern to search for.
*/
public TextPattern(final CharSequence pattern) {
this(pattern, 0);
}
/** Creates a new {@link TextPattern} object that can be used to search for the given pattern.
*
* @param pattern the constant pattern to search for.
* @param flags a bit mask that may include {@link #CASE_INSENSITIVE} and {@link #UNICODE_CASE}.
*/
public TextPattern(final CharSequence pattern, final int flags) {
this.pattern = new char[pattern.length()];
MutableString.getChars(pattern, 0, this.pattern.length, this.pattern, 0);
caseSensitive = (flags & CASE_INSENSITIVE) == 0;
asciiCase = (flags & UNICODE_CASE) == 0;
if (! caseSensitive) {
int i = this.pattern.length;
if (asciiCase) while(i-- != 0) this.pattern[i] = asciiToLowerCase(this.pattern[i]);
else while(i-- != 0) this.pattern[i] = unicodeToLowerCase(this.pattern[i]);
}
compile();
}
/** Returns whether this pattern is case insensitive.
*
*/
public boolean caseInsensitive() {
return ! caseSensitive;
}
/** Returns whether this pattern uses Unicode case folding.
*
*/
public boolean unicodeCase() {
return ! asciiCase;
}
/** A fast, optimised method to lower case just ASCII letters.
*
* @param c a character.
* @return the character c, downcased if it lies between A and Z.
*/
private static char asciiToLowerCase(final char c) {
return c >= 'A' && c <= 'Z' ? (char)(c + 32) : c;
}
/** A method to downcase correctly Unicode characters optimised for ASCII letters.
*
* @param c a character.
* @return the character c, downcased.
*/
private static char unicodeToLowerCase(final char c) {
if (c < 128) return c >= 'A' && c <= 'Z' ? (char)(c + 32) : c;
return Character.toLowerCase(Character.toUpperCase(c));
}
private static final int MIN_COUNT = 8;
/** Fills the search data structures using the pattern contained in {@link #pattern}. */
private void compile() {
final char[] p = pattern;
final int n = p.length;
int[] s = asciiBadCharShift;
char c;
// We make two passes on the pattern, so to approximate first the number of non-US-ASCII characters.
int h, i, j = 0, k = 0, l;
int[] max = new int[MIN_COUNT];
i = s.length;
while(i-- != 0) s[i] = n;
i = MIN_COUNT;
while(i-- != 0) max[i] = Integer.MAX_VALUE;
i = n;
while(i-- != 0) {
c = p[j++];
if (c < 128) s[c] = i;
else {
k++;
/* Bar-Yossef-Jayram-Kumar-Sivakumar-Trevisan's improvement on
Flajolet-Martin's algorithm for approximating the number of
distinct elements in a stream. We map each character with a
hash function on the unit interval, keep track of the smallest
MIN_COUNT elements, and then approximate the number of distinct
characters with MIN_COUNT divided by the largest element we
have (of course, everything is done in fixed point arithmetic
on the interval 0-2^32). If the approximation is less than the
number of characters, we use it. */
h = c * PHI2;
l = MIN_COUNT;
while(l-- != 0) if (h > max[l]) break;
if (++l < MIN_COUNT && h != max[l]) {
System.arraycopy(max, l , max, l + 1, MIN_COUNT - l - 1);
max[l] = h;
}
}
}
//System.err.println(k);
//System.err.println((int)(MIN_COUNT * 0x100000000L / (0x80000000L + M[MIN_COUNT - 1])));
k = Math.min(k, (int)(MIN_COUNT * 0x100000000L / (0x80000000L + max[MIN_COUNT - 1])));
/* We do not use less than 2^7 entries, so to compensate the setup
overhead with a more precise approximator for very small patterns. If,
however, there are no non-US-ASCII characters, we use a single-bucket
approximator (so to avoid special cases in the algorithm). In any case,
we do not use approximators with more than 2^16 entries. */
final int log2m = k == 0 ? 0 : Math.min(Math.max(Fast.mostSignificantBit(k * 3) + 1, 7), 16);
final int m = (1 << log2m) - 1;
final int hs = 16 - log2m;
/* For the characters outside Unicode, we build a compact approximator
with two hash functions h_0 and h_1. The approximator stores a function
f from the character set to integers in a table s. The value of the
function on c can be obtained by maximising the values s[h_0(c)] and
s[h_1(c)]. When storing a value, instead, we minimise s[h_0(c)] and
s[h_1(c)] with f(c). As a result, the value stored is smaller than or
equal to the actual value f(c). By tuning the size of s and the number
of hash functions one can get a desired error precision. */
s = new int[m + 1];
i = m + 1;
while(i-- != 0) s[i] = n;
i = n;
j = 0;
while(i-- != 0) {
c = p[j++];
if (c >= 128) {
s[c * c & m] = i;
s[(c * PHI2) >> hs & m] = i;
}
}
this.badCharShift = s;
this.mask = m;
this.hashShift = hs;
/*
for(i = 0; i <= m; i++) System.err.print("" + s[i] + ", ");
System.err.println();
for(c = 'a'; c <= 'z'; c++) System.err.print(c + ":" + Math.max(s[c * c & m], s[(c * PHI2) >> hs & m]) + ", ");
System.err.println();
for(c = 'A'; c <= 'Z'; c++) System.err.print(c + ":" + Math.max(s[c * c & m], s[(c * PHI2) >> hs & m]) + ", ");
System.err.println();
MutableString msp = new MutableString(pattern);
for(c = 'a'; c <= 'z'; c++) if (msp.indexOf(c) == -1 && Math.max(s[c * c & m], s[(c * PHI2) >> hs & m]) != n)
System.err.println(c + ":" + Math.max(s[c * c & m], s[(c * PHI2) >> hs & m]) + ", ");
for(c = 'A'; c <= 'Z'; c++) if (msp.indexOf(c) == -1 && Math.max(s[c * c & m], s[(c * PHI2) >> hs & m]) != n)
System.err.println(c + ":" + Math.max(s[c * c & m], s[(c * PHI2) >> hs & m]) + ", ");
*/
}
@Override
public int length() {
return pattern.length;
}
@Override
public char charAt(final int i) {
return pattern[i];
}
@Override
public CharSequence subSequence(final int from, final int to) {
return new MutableString(pattern, from, to - from + 1);
}
/** Returns the index of the first occurrence of this one-character pattern
* in the specified character array, starting at the specified index.
*
*
This method is a fallback for searches on one-character patterns.
*
* @param array the character array to look in.
* @param from the index from which the search must start.
* @param to the index at which the search must end.
* @return the index of the first occurrence of this pattern or
* -1, if this pattern never appears with index greater than
* or equal to from.
*/
private int indexOf(final char[] array, final int from, final int to) {
final char[] a = array;
final int c = pattern[0];
int i = from < 0 ? -1 : from - 1;
if (caseSensitive) {
while(++i < to) if (a[i] == c) return i;
return -1;
}
else if (asciiCase) {
while(++i < to) if (asciiToLowerCase(a[i]) == c) return i;
return -1;
}
else {
while(++i < to) if (unicodeToLowerCase(a[i]) == c) return i;
return -1;
}
}
/** Returns the index of the first occurrence of this one-character pattern
* in the specified character sequence, starting at the specified index.
*
*
This method is a fallback for searches on one-character patterns.
*
* @param s the character sequence to look in.
* @param from the index from which the search must start.
* @return the index of the first occurrence of this pattern or
* -1, if the this pattern never appears with index greater than
* or equal to from.
*/
private int indexOf(final CharSequence s, final int from, final int to) {
final int c = pattern[0];
int i = from < 0 ? -1 : from - 1;
if (caseSensitive) {
while(++i < to) if (s.charAt(i) == c) return i;
return -1;
}
else if (asciiCase) {
while(++i < to) if (asciiToLowerCase(s.charAt(i)) == c) return i;
return -1;
}
else {
while(++i < to) if (unicodeToLowerCase(s.charAt(i)) == c) return i;
return -1;
}
}
/** Returns the index of the first occurrence of this one-character pattern
* in the specified byte array, seen as an ISO-8859-1 string,
* starting at the specified index.
*
*
This method is a fallback for searches on one-character patterns.
*
* @param array the byte array to look in.
* @param from the index from which the search must start.
* @return the index of the first occurrence of this pattern or
* -1, if this pattern never appears with index greater than
* or equal to from.
*/
private int indexOf(final byte[] array, final int from, final int to) {
final byte[] a = array;
final int c = pattern[0];
int i = from < 0 ? -1 : from - 1;
if (caseSensitive) {
while(++i < to) if ((a[i] & 0xFF) == c) return i;
return -1;
}
else {
while(++i < to) if (asciiToLowerCase((char)(a[i] & 0xFF)) == c) return i;
return -1;
}
}
/** Returns the index of the first occurrence of this pattern in the given character array.
*
* @param array the character array to look in.
* @return the index of the first occurrence of this pattern contained in the
* given array, or -1, if the pattern cannot be found.
*/
public int search(final char[] array) {
return search(array, 0, array.length);
}
/** Returns the index of the first occurrence of this pattern in the given character array starting from a given index.
*
* @param array the character array to look in.
* @param from the index from which the search must start.
* @return the index of the first occurrence of this pattern contained in the
* subarray starting from from (inclusive), or
* -1, if the pattern cannot be found.
*/
public int search(char[] array, int from) {
return search(array, from, array.length);
}
/** Returns the index of the first occurrence of this pattern in the given character array between given indices.
*
* @param a the character array to look in.
* @param from the index from which the search must start.
* @param to the index at which the search must end.
* @return the index of the first occurrence of this pattern contained in the
* subarray starting from from (inclusive) up to to
* (exclusive) characters, or -1, if the pattern cannot be found.
*/
public int search(final char[] a, final int from, final int to) {
final int n = pattern.length;
if (n == 0) return from > to ? to : (from < 0 ? 0 : from);
if (n == 1) return indexOf(a, from, to);
final char[] p = pattern;
final char last = p[n - 1];
final int m1 = to - 1;
final int[] shift = badCharShift;
final int[] asciiShift = asciiBadCharShift;
final int m = mask;
final int hs = hashShift;
int i = (from < 0 ? 0 : from) + n - 1, j, k;
char c;
if (caseSensitive) {
while (i < m1) {
if (a[i] == last) {
j = n - 1;
k = i;
while(j-- != 0 && a[--k] == p[j]);
if (j < 0) return k;
}
if ((c = a[++i]) < 128) i += asciiShift[c];
else {
j = shift[c * c & m];
k = shift[(c * PHI2) >> hs & m];
i += j > k ? j : k;
}
}
if (i == m1) {
j = n;
while(j-- != 0 && a[i--] == p[j]);
if (j < 0) return i + 1;
}
return -1;
}
else if (asciiCase) {
while (i < m1) {
if (asciiToLowerCase(a[i]) == last) {
j = n - 1;
k = i;
while(j-- != 0 && asciiToLowerCase(a[--k]) == p[j]);
if (j < 0) return k;
}
if ((c = asciiToLowerCase(a[++i])) < 128) i += asciiShift[c];
else {
j = shift[c * c & m];
k = shift[(c * PHI2) >> hs & m];
i += j > k ? j : k;
}
}
if (i == m1) {
j = n;
while(j-- != 0 && asciiToLowerCase(a[i--]) == p[j]);
if (j < 0) return i + 1;
}
return -1;
}
else {
while (i < m1) {
if (unicodeToLowerCase(a[i]) == last) {
j = n - 1;
k = i;
while(j-- != 0 && unicodeToLowerCase(a[--k]) == p[j]);
if (j < 0) return k;
}
if ((c = unicodeToLowerCase(a[++i])) < 128) i += asciiShift[c];
else {
j = shift[c * c & m];
k = shift[(c * PHI2) >> hs & m];
i += j > k ? j : k;
}
}
if (i == m1) {
j = n;
while(j-- != 0 && unicodeToLowerCase(a[i--]) == p[j]);
if (j < 0) return i + 1;
}
return -1;
}
}
/** Returns the index of the first occurrence of this pattern in the given character sequence.
*
* @param s the character sequence to look in.
* @return the index of the first occurrence of this pattern contained in the
* given character sequence, or -1, if the pattern cannot be found.
*/
public int search(final CharSequence s) {
return search(s, 0, s.length());
}
/** Returns the index of the first occurrence of this pattern in the given character sequence starting from a given index.
*
* @param s the character array to look in.
* @param from the index from which the search must start.
* @return the index of the first occurrence of this pattern contained in the
* subsequence starting from from (inclusive), or
* -1, if the pattern cannot be found.
*/
public int search(final CharSequence s, final int from) {
return search(s, from, s.length());
}
/** Returns the index of the first occurrence of this pattern in the given character sequence between given indices.
*
* @param s the character array to look in.
* @param from the index from which the search must start.
* @param to the index at which the search must end.
* @return the index of the first occurrence of this pattern contained in the
* subsequence starting from from (inclusive) up to to
* (exclusive) characters, or -1, if the pattern cannot be found.
*/
public int search(final CharSequence s, final int from, final int to) {
final int n = pattern.length;
if (n == 0) return from > to ? to : (from < 0 ? 0 : from);
if (n == 1) return indexOf(s, from, to);
final char[] p = pattern;
final char last = p[n - 1];
final int m1 = to - 1;
final int[] shift = badCharShift;
final int[] asciiShift = asciiBadCharShift;
final int m = mask;
final int hs = hashShift;
int i = (from < 0 ? 0 : from) + n - 1, j, k;
char c;
if (caseSensitive) {
while (i < m1) {
if (s.charAt(i) == last) {
j = n - 1;
k = i;
while(j-- != 0 && s.charAt(--k) == p[j]);
if (j < 0) return k;
}
if ((c = s.charAt(++i)) < 128) i += asciiShift[c];
else {
j = shift[c * c & m];
k = shift[(c * PHI2) >> hs & m];
i += j > k ? j : k;
}
}
if (i == m1) {
j = n;
while(j-- != 0 && s.charAt(i--) == p[j]);
if (j < 0) return i + 1;
}
return -1;
}
else if (asciiCase) {
while (i < m1) {
if (asciiToLowerCase(s.charAt(i)) == last) {
j = n - 1;
k = i;
while(j-- != 0 && asciiToLowerCase(s.charAt(--k)) == p[j]);
if (j < 0) return k;
}
if ((c = asciiToLowerCase(s.charAt(++i))) < 128) i += asciiShift[c];
else {
j = shift[c * c & m];
k = shift[(c * PHI2) >> hs & m];
i += j > k ? j : k;
}
}
if (i == m1) {
j = n;
while(j-- != 0 && asciiToLowerCase(s.charAt(i--)) == p[j]);
if (j < 0) return i + 1;
}
return -1;
}
else {
while (i < m1) {
if (unicodeToLowerCase(s.charAt(i)) == last) {
j = n - 1;
k = i;
while(j-- != 0 && unicodeToLowerCase(s.charAt(--k)) == p[j]);
if (j < 0) return k;
}
if ((c = unicodeToLowerCase(s.charAt(++i))) < 128) i += asciiShift[c];
else {
j = shift[c * c & m];
k = shift[(c * PHI2) >> hs & m];
i += j > k ? j : k;
}
}
if (i == m1) {
j = n;
while(j-- != 0 && unicodeToLowerCase(s.charAt(i--)) == p[j]);
if (j < 0) return i + 1;
}
return -1;
}
}
/** Returns the index of the first occurrence of this pattern in the given byte array.
*
* @param a the byte array to look in.
* @return the index of the first occurrence of this pattern contained in the
* given byte array, or -1, if the pattern cannot be found.
*/
public int search(final byte[] a) {
return search(a, 0, a.length);
}
/** Returns the index of the first occurrence of this pattern in the given byte array starting from a given index.
*
* @param a the byte array to look in.
* @param from the index from which the search must start.
* @return the index of the first occurrence of this pattern contained in the
* array fragment starting from from (inclusive), or
* -1, if the pattern cannot be found.
*/
public int search(final byte[] a, final int from) {
return search(a, from, a.length);
}
/** Returns the index of the first occurrence of this pattern in the given byte array between given indices.
*
* @param a the byte array to look in.
* @param from the index from which the search must start.
* @param to the index at which the search must end.
* @return the index of the first occurrence of this pattern contained in the
* array fragment starting from from (inclusive) up to to
* (exclusive) characters, or -1, if the pattern cannot be found.
* TODO: this must be tested
*/
public int search(final byte[] a, final int from, final int to) {
final int n = pattern.length;
if (n == 0) return from > to ? to : (from < 0 ? 0 : from);
if (n == 1) return indexOf(a, from, to);
final char[] p = pattern;
final char last = p[n - 1];
final int m1 = to - 1;
final int[] shift = badCharShift;
final int[] asciiShift = asciiBadCharShift;
final int m = mask;
final int hs = hashShift;
int i = (from < 0 ? 0 : from) + n - 1, j, k;
char c;
if (caseSensitive) {
while (i < m1) {
if ((a[i] & 0xFF) == last) {
j = n - 1;
k = i;
while(j-- != 0 && (a[--k] & 0xFF)== p[j]);
if (j < 0) return k;
}
if ((c = (char)(a[++i] & 0xFF)) < 128) i += asciiShift[c];
else {
j = shift[c * c & m];
k = shift[(c * PHI2) >> hs & m];
i += j > k ? j : k;
}
}
if (i == m1) {
j = n;
while(j-- != 0 && (a[i--] & 0xFF) == p[j]);
if (j < 0) return i + 1;
}
return -1;
}
else if (asciiCase) {
while (i < m1) {
if (asciiToLowerCase((char)(a[i] & 0xFF)) == last) {
j = n - 1;
k = i;
while(j-- != 0 && asciiToLowerCase((char)(a[--k] & 0xFF)) == p[j]);
if (j < 0) return k;
}
if ((c = asciiToLowerCase((char)(a[++i] & 0xFF))) < 128) i += asciiShift[c];
else {
j = shift[c * c & m];
k = shift[(c * PHI2) >> hs & m];
i += j > k ? j : k;
}
}
if (i == m1) {
j = n;
while(j-- != 0 && asciiToLowerCase((char)(a[i--] & 0xFF)) == p[j]);
if (j < 0) return i + 1;
}
return -1;
}
else {
while (i < m1) {
if (unicodeToLowerCase((char)(a[i] & 0xFF)) == last) {
j = n - 1;
k = i;
while(j-- != 0 && unicodeToLowerCase((char)(a[--k] & 0xFF)) == p[j]);
if (j < 0) return k;
}
if ((c = unicodeToLowerCase((char)(a[++i] & 0xFF))) < 128) i += asciiShift[c];
else {
j = shift[c * c & m];
k = shift[(c * PHI2) >> hs & m];
i += j > k ? j : k;
}
}
if (i == m1) {
j = n;
while(j-- != 0 && unicodeToLowerCase((char)(a[i--] & 0xFF)) == p[j]);
if (j < 0) return i + 1;
}
return -1;
}
}
/** Returns the index of the first occurrence of this pattern in the given character list.
*
* @param list the character list to look in.
* @return the index of the first occurrence of this pattern contained in the
* given list, or -1, if the pattern cannot be found.
*/
public int search(final CharList list) {
return search(list, 0, list.size());
}
/** Returns the index of the first occurrence of this pattern in the given character list starting from a given index.
*
* @param list the character list to look in.
* @param from the index from which the search must start.
* @return the index of the first occurrence of this pattern contained in the
* sublist starting from from (inclusive), or
* -1, if the pattern cannot be found.
*/
public int search(final CharList list, int from) {
return search(list, from, list.size());
}
/** Returns the index of the first occurrence of this pattern in the given character list between given indices.
*
* @param list the character list to look in.
* @param from the index from which the search must start.
* @param to the index at which the search must end.
* @return the index of the first occurrence of this pattern contained in the
* sublist starting from from (inclusive) up to to
* (exclusive) characters, or -1, if the pattern cannot be found.
*/
public int search(final CharList list, final int from, final int to) {
final int n = pattern.length;
if (n == 0) return from > to ? to : (from < 0 ? 0 : from);
if (n == 1) return list.subList(from, to).indexOf(pattern[0]);
final char[] p = pattern;
final char last = p[n - 1];
final int m1 = to - 1;
final int[] shift = badCharShift;
final int[] asciiShift = asciiBadCharShift;
final int m = mask;
final int hs = hashShift;
int i = (from < 0 ? 0 : from) + n - 1, j, k;
char c;
if (caseSensitive) {
while (i < m1) {
if (list.getChar(i) == last) {
j = n - 1;
k = i;
while(j-- != 0 && list.getChar(--k) == p[j]);
if (j < 0) return k;
}
if ((c = list.getChar(++i)) < 128) i += asciiShift[c];
else {
j = shift[c * c & m];
k = shift[(c * PHI2) >> hs & m];
i += j > k ? j : k;
}
}
if (i == m1) {
j = n;
while(j-- != 0 && list.getChar(i--) == p[j]);
if (j < 0) return i + 1;
}
return -1;
}
else if (asciiCase) {
while (i < m1) {
if (asciiToLowerCase(list.getChar(i)) == last) {
j = n - 1;
k = i;
while(j-- != 0 && asciiToLowerCase(list.getChar(--k)) == p[j]);
if (j < 0) return k;
}
if ((c = asciiToLowerCase(list.getChar(++i))) < 128) i += asciiShift[c];
else {
j = shift[c * c & m];
k = shift[(c * PHI2) >> hs & m];
i += j > k ? j : k;
}
}
if (i == m1) {
j = n;
while(j-- != 0 && asciiToLowerCase(list.getChar(i--)) == p[j]);
if (j < 0) return i + 1;
}
return -1;
}
else {
while (i < m1) {
if (unicodeToLowerCase(list.getChar(i)) == last) {
j = n - 1;
k = i;
while(j-- != 0 && unicodeToLowerCase(list.getChar(--k)) == p[j]);
if (j < 0) return k;
}
if ((c = unicodeToLowerCase(list.getChar(++i))) < 128) i += asciiShift[c];
else {
j = shift[c * c & m];
k = shift[(c * PHI2) >> hs & m];
i += j > k ? j : k;
}
}
if (i == m1) {
j = n;
while(j-- != 0 && unicodeToLowerCase(list.getChar(i--)) == p[j]);
if (j < 0) return i + 1;
}
return -1;
}
}
/** Compares this text pattern to another object.
*
*
This method will return true iff its argument
* is a TextPattern containing the same constant pattern with the same flags set.
*
* @param o an object.
* @return true if the argument is a TextPatterns that contains the same constant pattern of this text pattern
* and has the same flags set.
*/
@Override
public final boolean equals(final Object o) {
if (o instanceof TextPattern) {
TextPattern p = (TextPattern)o;
return caseSensitive == p.caseSensitive && asciiCase == p.asciiCase && java.util.Arrays.equals(p.pattern, pattern);
}
return false;
}
/** Returns a hash code for this text pattern.
*
*
The hash code of a text pattern is the same as that of a
* String with the same content (suitably lower cased, if the pattern is case insensitive).
*
* @return a hash code array for this object.
* @see java.lang.String#hashCode()
*/
@Override
public final int hashCode() {
final char[] a = pattern;
final int l = a.length;
int h;
for (int i = h = 0; i < l; i++) h = 31 * h + a[i];
return h;
}
@Override
public final String toString() {
return new String(pattern);
}
}