| /* |
| * Copyright (c) 1999, 2010, 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 Taligent, Inc. 1996, 1997 - All Rights Reserved |
| * (C) Copyright IBM Corp. 1996 - 2002 - All Rights Reserved |
| * |
| * The original version of this source code and documentation |
| * is copyrighted and owned by Taligent, Inc., a wholly-owned |
| * subsidiary of IBM. These materials are provided under terms |
| * of a License Agreement between Taligent and Sun. This technology |
| * is protected by multiple US and International patents. |
| * |
| * This notice and attribution to Taligent may not be removed. |
| * Taligent is a registered trademark of Taligent, Inc. |
| */ |
| |
| package java.text; |
| |
| import java.io.BufferedInputStream; |
| import java.io.IOException; |
| import java.security.AccessController; |
| import java.security.PrivilegedActionException; |
| import java.security.PrivilegedExceptionAction; |
| import java.util.Vector; |
| import java.util.Stack; |
| import java.util.Hashtable; |
| import java.util.Enumeration; |
| import java.util.MissingResourceException; |
| import java.text.CharacterIterator; |
| import java.text.StringCharacterIterator; |
| import sun.text.CompactByteArray; |
| import sun.text.SupplementaryCharacterData; |
| |
| /** |
| * <p>A subclass of BreakIterator whose behavior is specified using a list of rules.</p> |
| * |
| * <p>There are two kinds of rules, which are separated by semicolons: <i>substitutions</i> |
| * and <i>regular expressions.</i></p> |
| * |
| * <p>A substitution rule defines a name that can be used in place of an expression. It |
| * consists of a name, which is a string of characters contained in angle brackets, an equals |
| * sign, and an expression. (There can be no whitespace on either side of the equals sign.) |
| * To keep its syntactic meaning intact, the expression must be enclosed in parentheses or |
| * square brackets. A substitution is visible after its definition, and is filled in using |
| * simple textual substitution. Substitution definitions can contain other substitutions, as |
| * long as those substitutions have been defined first. Substitutions are generally used to |
| * make the regular expressions (which can get quite complex) shorted and easier to read. |
| * They typically define either character categories or commonly-used subexpressions.</p> |
| * |
| * <p>There is one special substitution. If the description defines a substitution |
| * called "<ignore>", the expression must be a [] expression, and the |
| * expression defines a set of characters (the "<em>ignore characters</em>") that |
| * will be transparent to the BreakIterator. A sequence of characters will break the |
| * same way it would if any ignore characters it contains are taken out. Break |
| * positions never occur befoer ignore characters.</p> |
| * |
| * <p>A regular expression uses a subset of the normal Unix regular-expression syntax, and |
| * defines a sequence of characters to be kept together. With one significant exception, the |
| * iterator uses a longest-possible-match algorithm when matching text to regular |
| * expressions. The iterator also treats descriptions containing multiple regular expressions |
| * as if they were ORed together (i.e., as if they were separated by |).</p> |
| * |
| * <p>The special characters recognized by the regular-expression parser are as follows:</p> |
| * |
| * <blockquote> |
| * <table border="1" width="100%"> |
| * <tr> |
| * <td width="6%">*</td> |
| * <td width="94%">Specifies that the expression preceding the asterisk may occur any number |
| * of times (including not at all).</td> |
| * </tr> |
| * <tr> |
| * <td width="6%">{}</td> |
| * <td width="94%">Encloses a sequence of characters that is optional.</td> |
| * </tr> |
| * <tr> |
| * <td width="6%">()</td> |
| * <td width="94%">Encloses a sequence of characters. If followed by *, the sequence |
| * repeats. Otherwise, the parentheses are just a grouping device and a way to delimit |
| * the ends of expressions containing |.</td> |
| * </tr> |
| * <tr> |
| * <td width="6%">|</td> |
| * <td width="94%">Separates two alternative sequences of characters. Either one |
| * sequence or the other, but not both, matches this expression. The | character can |
| * only occur inside ().</td> |
| * </tr> |
| * <tr> |
| * <td width="6%">.</td> |
| * <td width="94%">Matches any character.</td> |
| * </tr> |
| * <tr> |
| * <td width="6%">*?</td> |
| * <td width="94%">Specifies a non-greedy asterisk. *? works the same way as *, except |
| * when there is overlap between the last group of characters in the expression preceding the |
| * * and the first group of characters following the *. When there is this kind of |
| * overlap, * will match the longest sequence of characters that match the expression before |
| * the *, and *? will match the shortest sequence of characters matching the expression |
| * before the *?. For example, if you have "xxyxyyyxyxyxxyxyxyy" in the text, |
| * "x[xy]*x" will match through to the last x (i.e., "<strong>xxyxyyyxyxyxxyxyx</strong>yy", |
| * but "x[xy]*?x" will only match the first two xes ("<strong>xx</strong>yxyyyxyxyxxyxyxyy").</td> |
| * </tr> |
| * <tr> |
| * <td width="6%">[]</td> |
| * <td width="94%">Specifies a group of alternative characters. A [] expression will |
| * match any single character that is specified in the [] expression. For more on the |
| * syntax of [] expressions, see below.</td> |
| * </tr> |
| * <tr> |
| * <td width="6%">/</td> |
| * <td width="94%">Specifies where the break position should go if text matches this |
| * expression. (e.g., "[a-z]*/[:Zs:]*[1-0]" will match if the iterator sees a run |
| * of letters, followed by a run of whitespace, followed by a digit, but the break position |
| * will actually go before the whitespace). Expressions that don't contain / put the |
| * break position at the end of the matching text.</td> |
| * </tr> |
| * <tr> |
| * <td width="6%">\</td> |
| * <td width="94%">Escape character. The \ itself is ignored, but causes the next |
| * character to be treated as literal character. This has no effect for many |
| * characters, but for the characters listed above, this deprives them of their special |
| * meaning. (There are no special escape sequences for Unicode characters, or tabs and |
| * newlines; these are all handled by a higher-level protocol. In a Java string, |
| * "\n" will be converted to a literal newline character by the time the |
| * regular-expression parser sees it. Of course, this means that \ sequences that are |
| * visible to the regexp parser must be written as \\ when inside a Java string.) All |
| * characters in the ASCII range except for letters, digits, and control characters are |
| * reserved characters to the parser and must be preceded by \ even if they currently don't |
| * mean anything.</td> |
| * </tr> |
| * <tr> |
| * <td width="6%">!</td> |
| * <td width="94%">If ! appears at the beginning of a regular expression, it tells the regexp |
| * parser that this expression specifies the backwards-iteration behavior of the iterator, |
| * and not its normal iteration behavior. This is generally only used in situations |
| * where the automatically-generated backwards-iteration brhavior doesn't produce |
| * satisfactory results and must be supplemented with extra client-specified rules.</td> |
| * </tr> |
| * <tr> |
| * <td width="6%"><em>(all others)</em></td> |
| * <td width="94%">All other characters are treated as literal characters, which must match |
| * the corresponding character(s) in the text exactly.</td> |
| * </tr> |
| * </table> |
| * </blockquote> |
| * |
| * <p>Within a [] expression, a number of other special characters can be used to specify |
| * groups of characters:</p> |
| * |
| * <blockquote> |
| * <table border="1" width="100%"> |
| * <tr> |
| * <td width="6%">-</td> |
| * <td width="94%">Specifies a range of matching characters. For example |
| * "[a-p]" matches all lowercase Latin letters from a to p (inclusive). The - |
| * sign specifies ranges of continuous Unicode numeric values, not ranges of characters in a |
| * language's alphabetical order: "[a-z]" doesn't include capital letters, nor does |
| * it include accented letters such as a-umlaut.</td> |
| * </tr> |
| * <tr> |
| * <td width="6%">::</td> |
| * <td width="94%">A pair of colons containing a one- or two-letter code matches all |
| * characters in the corresponding Unicode category. The two-letter codes are the same |
| * as the two-letter codes in the Unicode database (for example, "[:Sc::Sm:]" |
| * matches all currency symbols and all math symbols). Specifying a one-letter code is |
| * the same as specifying all two-letter codes that begin with that letter (for example, |
| * "[:L:]" matches all letters, and is equivalent to |
| * "[:Lu::Ll::Lo::Lm::Lt:]"). Anything other than a valid two-letter Unicode |
| * category code or a single letter that begins a Unicode category code is illegal within |
| * colons.</td> |
| * </tr> |
| * <tr> |
| * <td width="6%">[]</td> |
| * <td width="94%">[] expressions can nest. This has no effect, except when used in |
| * conjunction with the ^ token.</td> |
| * </tr> |
| * <tr> |
| * <td width="6%">^</td> |
| * <td width="94%">Excludes the character (or the characters in the [] expression) following |
| * it from the group of characters. For example, "[a-z^p]" matches all Latin |
| * lowercase letters except p. "[:L:^[\u4e00-\u9fff]]" matches all letters |
| * except the Han ideographs.</td> |
| * </tr> |
| * <tr> |
| * <td width="6%"><em>(all others)</em></td> |
| * <td width="94%">All other characters are treated as literal characters. (For |
| * example, "[aeiou]" specifies just the letters a, e, i, o, and u.)</td> |
| * </tr> |
| * </table> |
| * </blockquote> |
| * |
| * <p>For a more complete explanation, see <a |
| * href="http://www.ibm.com/java/education/boundaries/boundaries.html">http://www.ibm.com/java/education/boundaries/boundaries.html</a>. |
| * For examples, see the resource data (which is annotated).</p> |
| * |
| * @author Richard Gillam |
| */ |
| class RuleBasedBreakIterator extends BreakIterator { |
| |
| /** |
| * A token used as a character-category value to identify ignore characters |
| */ |
| protected static final byte IGNORE = -1; |
| |
| /** |
| * The state number of the starting state |
| */ |
| private static final short START_STATE = 1; |
| |
| /** |
| * The state-transition value indicating "stop" |
| */ |
| private static final short STOP_STATE = 0; |
| |
| /** |
| * Magic number for the BreakIterator data file format. |
| */ |
| static final byte[] LABEL = { |
| (byte)'B', (byte)'I', (byte)'d', (byte)'a', (byte)'t', (byte)'a', |
| (byte)'\0' |
| }; |
| static final int LABEL_LENGTH = LABEL.length; |
| |
| /** |
| * Version number of the dictionary that was read in. |
| */ |
| static final byte supportedVersion = 1; |
| |
| /** |
| * Header size in byte count |
| */ |
| private static final int HEADER_LENGTH = 36; |
| |
| /** |
| * An array length of indices for BMP characters |
| */ |
| private static final int BMP_INDICES_LENGTH = 512; |
| |
| /** |
| * Tables that indexes from character values to character category numbers |
| */ |
| private CompactByteArray charCategoryTable = null; |
| private SupplementaryCharacterData supplementaryCharCategoryTable = null; |
| |
| /** |
| * The table of state transitions used for forward iteration |
| */ |
| private short[] stateTable = null; |
| |
| /** |
| * The table of state transitions used to sync up the iterator with the |
| * text in backwards and random-access iteration |
| */ |
| private short[] backwardsStateTable = null; |
| |
| /** |
| * A list of flags indicating which states in the state table are accepting |
| * ("end") states |
| */ |
| private boolean[] endStates = null; |
| |
| /** |
| * A list of flags indicating which states in the state table are |
| * lookahead states (states which turn lookahead on and off) |
| */ |
| private boolean[] lookaheadStates = null; |
| |
| /** |
| * A table for additional data. May be used by a subclass of |
| * RuleBasedBreakIterator. |
| */ |
| private byte[] additionalData = null; |
| |
| /** |
| * The number of character categories (and, thus, the number of columns in |
| * the state tables) |
| */ |
| private int numCategories; |
| |
| /** |
| * The character iterator through which this BreakIterator accesses the text |
| */ |
| private CharacterIterator text = null; |
| |
| /** |
| * A CRC32 value of all data in datafile |
| */ |
| private long checksum; |
| |
| //======================================================================= |
| // constructors |
| //======================================================================= |
| |
| /** |
| * Constructs a RuleBasedBreakIterator according to the datafile |
| * provided. |
| */ |
| public RuleBasedBreakIterator(String datafile) |
| throws IOException, MissingResourceException { |
| readTables(datafile); |
| } |
| |
| /** |
| * Read datafile. The datafile's format is as follows: |
| * <pre> |
| * BreakIteratorData { |
| * u1 magic[7]; |
| * u1 version; |
| * u4 totalDataSize; |
| * header_info header; |
| * body value; |
| * } |
| * </pre> |
| * <code>totalDataSize</code> is the summation of the size of |
| * <code>header_info</code> and <code>body</code> in byte count. |
| * <p> |
| * In <code>header</code>, each field except for checksum implies the |
| * length of each field. Since <code>BMPdataLength</code> is a fixed-length |
| * data(512 entries), its length isn't included in <code>header</code>. |
| * <code>checksum</code> is a CRC32 value of all in <code>body</code>. |
| * <pre> |
| * header_info { |
| * u4 stateTableLength; |
| * u4 backwardsStateTableLength; |
| * u4 endStatesLength; |
| * u4 lookaheadStatesLength; |
| * u4 BMPdataLength; |
| * u4 nonBMPdataLength; |
| * u4 additionalDataLength; |
| * u8 checksum; |
| * } |
| * </pre> |
| * <p> |
| * |
| * Finally, <code>BMPindices</code> and <code>BMPdata</code> are set to |
| * <code>charCategoryTable</code>. <code>nonBMPdata</code> is set to |
| * <code>supplementaryCharCategoryTable</code>. |
| * <pre> |
| * body { |
| * u2 stateTable[stateTableLength]; |
| * u2 backwardsStateTable[backwardsStateTableLength]; |
| * u1 endStates[endStatesLength]; |
| * u1 lookaheadStates[lookaheadStatesLength]; |
| * u2 BMPindices[512]; |
| * u1 BMPdata[BMPdataLength]; |
| * u4 nonBMPdata[numNonBMPdataLength]; |
| * u1 additionalData[additionalDataLength]; |
| * } |
| * </pre> |
| */ |
| protected void readTables(String datafile) |
| throws IOException, MissingResourceException { |
| |
| byte[] buffer = readFile(datafile); |
| |
| /* Read header_info. */ |
| int stateTableLength = BreakIterator.getInt(buffer, 0); |
| int backwardsStateTableLength = BreakIterator.getInt(buffer, 4); |
| int endStatesLength = BreakIterator.getInt(buffer, 8); |
| int lookaheadStatesLength = BreakIterator.getInt(buffer, 12); |
| int BMPdataLength = BreakIterator.getInt(buffer, 16); |
| int nonBMPdataLength = BreakIterator.getInt(buffer, 20); |
| int additionalDataLength = BreakIterator.getInt(buffer, 24); |
| checksum = BreakIterator.getLong(buffer, 28); |
| |
| /* Read stateTable[numCategories * numRows] */ |
| stateTable = new short[stateTableLength]; |
| int offset = HEADER_LENGTH; |
| for (int i = 0; i < stateTableLength; i++, offset+=2) { |
| stateTable[i] = BreakIterator.getShort(buffer, offset); |
| } |
| |
| /* Read backwardsStateTable[numCategories * numRows] */ |
| backwardsStateTable = new short[backwardsStateTableLength]; |
| for (int i = 0; i < backwardsStateTableLength; i++, offset+=2) { |
| backwardsStateTable[i] = BreakIterator.getShort(buffer, offset); |
| } |
| |
| /* Read endStates[numRows] */ |
| endStates = new boolean[endStatesLength]; |
| for (int i = 0; i < endStatesLength; i++, offset++) { |
| endStates[i] = buffer[offset] == 1; |
| } |
| |
| /* Read lookaheadStates[numRows] */ |
| lookaheadStates = new boolean[lookaheadStatesLength]; |
| for (int i = 0; i < lookaheadStatesLength; i++, offset++) { |
| lookaheadStates[i] = buffer[offset] == 1; |
| } |
| |
| /* Read a category table and indices for BMP characters. */ |
| short[] temp1 = new short[BMP_INDICES_LENGTH]; // BMPindices |
| for (int i = 0; i < BMP_INDICES_LENGTH; i++, offset+=2) { |
| temp1[i] = BreakIterator.getShort(buffer, offset); |
| } |
| byte[] temp2 = new byte[BMPdataLength]; // BMPdata |
| System.arraycopy(buffer, offset, temp2, 0, BMPdataLength); |
| offset += BMPdataLength; |
| charCategoryTable = new CompactByteArray(temp1, temp2); |
| |
| /* Read a category table for non-BMP characters. */ |
| int[] temp3 = new int[nonBMPdataLength]; |
| for (int i = 0; i < nonBMPdataLength; i++, offset+=4) { |
| temp3[i] = BreakIterator.getInt(buffer, offset); |
| } |
| supplementaryCharCategoryTable = new SupplementaryCharacterData(temp3); |
| |
| /* Read additional data */ |
| if (additionalDataLength > 0) { |
| additionalData = new byte[additionalDataLength]; |
| System.arraycopy(buffer, offset, additionalData, 0, additionalDataLength); |
| } |
| |
| /* Set numCategories */ |
| numCategories = stateTable.length / endStates.length; |
| } |
| |
| protected byte[] readFile(final String datafile) |
| throws IOException, MissingResourceException { |
| |
| BufferedInputStream is; |
| try { |
| is = (BufferedInputStream)AccessController.doPrivileged( |
| new PrivilegedExceptionAction() { |
| public Object run() throws Exception { |
| return new BufferedInputStream(getClass().getResourceAsStream("/sun/text/resources/" + datafile)); |
| } |
| } |
| ); |
| } |
| catch (PrivilegedActionException e) { |
| throw new InternalError(e.toString()); |
| } |
| |
| int offset = 0; |
| |
| /* First, read magic, version, and header_info. */ |
| int len = LABEL_LENGTH + 5; |
| byte[] buf = new byte[len]; |
| if (is.read(buf) != len) { |
| throw new MissingResourceException("Wrong header length", |
| datafile, ""); |
| } |
| |
| /* Validate the magic number. */ |
| for (int i = 0; i < LABEL_LENGTH; i++, offset++) { |
| if (buf[offset] != LABEL[offset]) { |
| throw new MissingResourceException("Wrong magic number", |
| datafile, ""); |
| } |
| } |
| |
| /* Validate the version number. */ |
| if (buf[offset] != supportedVersion) { |
| throw new MissingResourceException("Unsupported version(" + buf[offset] + ")", |
| datafile, ""); |
| } |
| |
| /* Read data: totalDataSize + 8(for checksum) */ |
| len = BreakIterator.getInt(buf, ++offset); |
| buf = new byte[len]; |
| if (is.read(buf) != len) { |
| throw new MissingResourceException("Wrong data length", |
| datafile, ""); |
| } |
| |
| is.close(); |
| |
| return buf; |
| } |
| |
| byte[] getAdditionalData() { |
| return additionalData; |
| } |
| |
| void setAdditionalData(byte[] b) { |
| additionalData = b; |
| } |
| |
| //======================================================================= |
| // boilerplate |
| //======================================================================= |
| /** |
| * Clones this iterator. |
| * @return A newly-constructed RuleBasedBreakIterator with the same |
| * behavior as this one. |
| */ |
| public Object clone() { |
| RuleBasedBreakIterator result = (RuleBasedBreakIterator) super.clone(); |
| if (text != null) { |
| result.text = (CharacterIterator) text.clone(); |
| } |
| return result; |
| } |
| |
| /** |
| * Returns true if both BreakIterators are of the same class, have the same |
| * rules, and iterate over the same text. |
| */ |
| public boolean equals(Object that) { |
| try { |
| if (that == null) { |
| return false; |
| } |
| |
| RuleBasedBreakIterator other = (RuleBasedBreakIterator) that; |
| if (checksum != other.checksum) { |
| return false; |
| } |
| if (text == null) { |
| return other.text == null; |
| } else { |
| return text.equals(other.text); |
| } |
| } |
| catch(ClassCastException e) { |
| return false; |
| } |
| } |
| |
| /** |
| * Returns text |
| */ |
| public String toString() { |
| StringBuffer sb = new StringBuffer(); |
| sb.append('['); |
| sb.append("checksum=0x" + Long.toHexString(checksum)); |
| sb.append(']'); |
| return sb.toString(); |
| } |
| |
| /** |
| * Compute a hashcode for this BreakIterator |
| * @return A hash code |
| */ |
| public int hashCode() { |
| return (int)checksum; |
| } |
| |
| //======================================================================= |
| // BreakIterator overrides |
| //======================================================================= |
| |
| /** |
| * Sets the current iteration position to the beginning of the text. |
| * (i.e., the CharacterIterator's starting offset). |
| * @return The offset of the beginning of the text. |
| */ |
| public int first() { |
| CharacterIterator t = getText(); |
| |
| t.first(); |
| return t.getIndex(); |
| } |
| |
| /** |
| * Sets the current iteration position to the end of the text. |
| * (i.e., the CharacterIterator's ending offset). |
| * @return The text's past-the-end offset. |
| */ |
| public int last() { |
| CharacterIterator t = getText(); |
| |
| // I'm not sure why, but t.last() returns the offset of the last character, |
| // rather than the past-the-end offset |
| t.setIndex(t.getEndIndex()); |
| return t.getIndex(); |
| } |
| |
| /** |
| * Advances the iterator either forward or backward the specified number of steps. |
| * Negative values move backward, and positive values move forward. This is |
| * equivalent to repeatedly calling next() or previous(). |
| * @param n The number of steps to move. The sign indicates the direction |
| * (negative is backwards, and positive is forwards). |
| * @return The character offset of the boundary position n boundaries away from |
| * the current one. |
| */ |
| public int next(int n) { |
| int result = current(); |
| while (n > 0) { |
| result = handleNext(); |
| --n; |
| } |
| while (n < 0) { |
| result = previous(); |
| ++n; |
| } |
| return result; |
| } |
| |
| /** |
| * Advances the iterator to the next boundary position. |
| * @return The position of the first boundary after this one. |
| */ |
| public int next() { |
| return handleNext(); |
| } |
| |
| private int cachedLastKnownBreak = BreakIterator.DONE; |
| |
| /** |
| * Advances the iterator backwards, to the last boundary preceding this one. |
| * @return The position of the last boundary position preceding this one. |
| */ |
| public int previous() { |
| // if we're already sitting at the beginning of the text, return DONE |
| CharacterIterator text = getText(); |
| if (current() == text.getBeginIndex()) { |
| return BreakIterator.DONE; |
| } |
| |
| // set things up. handlePrevious() will back us up to some valid |
| // break position before the current position (we back our internal |
| // iterator up one step to prevent handlePrevious() from returning |
| // the current position), but not necessarily the last one before |
| // where we started |
| int start = current(); |
| int lastResult = cachedLastKnownBreak; |
| if (lastResult >= start || lastResult <= BreakIterator.DONE) { |
| getPrevious(); |
| lastResult = handlePrevious(); |
| } else { |
| //it might be better to check if handlePrevious() give us closer |
| //safe value but handlePrevious() is slow too |
| //So, this has to be done carefully |
| text.setIndex(lastResult); |
| } |
| int result = lastResult; |
| |
| // iterate forward from the known break position until we pass our |
| // starting point. The last break position before the starting |
| // point is our return value |
| while (result != BreakIterator.DONE && result < start) { |
| lastResult = result; |
| result = handleNext(); |
| } |
| |
| // set the current iteration position to be the last break position |
| // before where we started, and then return that value |
| text.setIndex(lastResult); |
| cachedLastKnownBreak = lastResult; |
| return lastResult; |
| } |
| |
| /** |
| * Returns previous character |
| */ |
| private int getPrevious() { |
| char c2 = text.previous(); |
| if (Character.isLowSurrogate(c2) && |
| text.getIndex() > text.getBeginIndex()) { |
| char c1 = text.previous(); |
| if (Character.isHighSurrogate(c1)) { |
| return Character.toCodePoint(c1, c2); |
| } else { |
| text.next(); |
| } |
| } |
| return (int)c2; |
| } |
| |
| /** |
| * Returns current character |
| */ |
| int getCurrent() { |
| char c1 = text.current(); |
| if (Character.isHighSurrogate(c1) && |
| text.getIndex() < text.getEndIndex()) { |
| char c2 = text.next(); |
| text.previous(); |
| if (Character.isLowSurrogate(c2)) { |
| return Character.toCodePoint(c1, c2); |
| } |
| } |
| return (int)c1; |
| } |
| |
| /** |
| * Returns the count of next character. |
| */ |
| private int getCurrentCodePointCount() { |
| char c1 = text.current(); |
| if (Character.isHighSurrogate(c1) && |
| text.getIndex() < text.getEndIndex()) { |
| char c2 = text.next(); |
| text.previous(); |
| if (Character.isLowSurrogate(c2)) { |
| return 2; |
| } |
| } |
| return 1; |
| } |
| |
| /** |
| * Returns next character |
| */ |
| int getNext() { |
| int index = text.getIndex(); |
| int endIndex = text.getEndIndex(); |
| if (index == endIndex || |
| (index = index + getCurrentCodePointCount()) >= endIndex) { |
| return CharacterIterator.DONE; |
| } |
| text.setIndex(index); |
| return getCurrent(); |
| } |
| |
| /** |
| * Returns the position of next character. |
| */ |
| private int getNextIndex() { |
| int index = text.getIndex() + getCurrentCodePointCount(); |
| int endIndex = text.getEndIndex(); |
| if (index > endIndex) { |
| return endIndex; |
| } else { |
| return index; |
| } |
| } |
| |
| /** |
| * Throw IllegalArgumentException unless begin <= offset < end. |
| */ |
| protected static final void checkOffset(int offset, CharacterIterator text) { |
| if (offset < text.getBeginIndex() || offset > text.getEndIndex()) { |
| throw new IllegalArgumentException("offset out of bounds"); |
| } |
| } |
| |
| /** |
| * Sets the iterator to refer to the first boundary position following |
| * the specified position. |
| * @offset The position from which to begin searching for a break position. |
| * @return The position of the first break after the current position. |
| */ |
| public int following(int offset) { |
| |
| CharacterIterator text = getText(); |
| checkOffset(offset, text); |
| |
| // Set our internal iteration position (temporarily) |
| // to the position passed in. If this is the _beginning_ position, |
| // then we can just use next() to get our return value |
| text.setIndex(offset); |
| if (offset == text.getBeginIndex()) { |
| cachedLastKnownBreak = handleNext(); |
| return cachedLastKnownBreak; |
| } |
| |
| // otherwise, we have to sync up first. Use handlePrevious() to back |
| // us up to a known break position before the specified position (if |
| // we can determine that the specified position is a break position, |
| // we don't back up at all). This may or may not be the last break |
| // position at or before our starting position. Advance forward |
| // from here until we've passed the starting position. The position |
| // we stop on will be the first break position after the specified one. |
| int result = cachedLastKnownBreak; |
| if (result >= offset || result <= BreakIterator.DONE) { |
| result = handlePrevious(); |
| } else { |
| //it might be better to check if handlePrevious() give us closer |
| //safe value but handlePrevious() is slow too |
| //So, this has to be done carefully |
| text.setIndex(result); |
| } |
| while (result != BreakIterator.DONE && result <= offset) { |
| result = handleNext(); |
| } |
| cachedLastKnownBreak = result; |
| return result; |
| } |
| |
| /** |
| * Sets the iterator to refer to the last boundary position before the |
| * specified position. |
| * @offset The position to begin searching for a break from. |
| * @return The position of the last boundary before the starting position. |
| */ |
| public int preceding(int offset) { |
| // if we start by updating the current iteration position to the |
| // position specified by the caller, we can just use previous() |
| // to carry out this operation |
| CharacterIterator text = getText(); |
| checkOffset(offset, text); |
| text.setIndex(offset); |
| return previous(); |
| } |
| |
| /** |
| * Returns true if the specfied position is a boundary position. As a side |
| * effect, leaves the iterator pointing to the first boundary position at |
| * or after "offset". |
| * @param offset the offset to check. |
| * @return True if "offset" is a boundary position. |
| */ |
| public boolean isBoundary(int offset) { |
| CharacterIterator text = getText(); |
| checkOffset(offset, text); |
| if (offset == text.getBeginIndex()) { |
| return true; |
| } |
| |
| // to check whether this is a boundary, we can use following() on the |
| // position before the specified one and return true if the position we |
| // get back is the one the user specified |
| else { |
| return following(offset - 1) == offset; |
| } |
| } |
| |
| /** |
| * Returns the current iteration position. |
| * @return The current iteration position. |
| */ |
| public int current() { |
| return getText().getIndex(); |
| } |
| |
| /** |
| * Return a CharacterIterator over the text being analyzed. This version |
| * of this method returns the actual CharacterIterator we're using internally. |
| * Changing the state of this iterator can have undefined consequences. If |
| * you need to change it, clone it first. |
| * @return An iterator over the text being analyzed. |
| */ |
| public CharacterIterator getText() { |
| // The iterator is initialized pointing to no text at all, so if this |
| // function is called while we're in that state, we have to fudge an |
| // iterator to return. |
| if (text == null) { |
| text = new StringCharacterIterator(""); |
| } |
| return text; |
| } |
| |
| /** |
| * Set the iterator to analyze a new piece of text. This function resets |
| * the current iteration position to the beginning of the text. |
| * @param newText An iterator over the text to analyze. |
| */ |
| public void setText(CharacterIterator newText) { |
| // Test iterator to see if we need to wrap it in a SafeCharIterator. |
| // The correct behavior for CharacterIterators is to allow the |
| // position to be set to the endpoint of the iterator. Many |
| // CharacterIterators do not uphold this, so this is a workaround |
| // to permit them to use this class. |
| int end = newText.getEndIndex(); |
| boolean goodIterator; |
| try { |
| newText.setIndex(end); // some buggy iterators throw an exception here |
| goodIterator = newText.getIndex() == end; |
| } |
| catch(IllegalArgumentException e) { |
| goodIterator = false; |
| } |
| |
| if (goodIterator) { |
| text = newText; |
| } |
| else { |
| text = new SafeCharIterator(newText); |
| } |
| text.first(); |
| |
| cachedLastKnownBreak = BreakIterator.DONE; |
| } |
| |
| |
| //======================================================================= |
| // implementation |
| //======================================================================= |
| |
| /** |
| * This method is the actual implementation of the next() method. All iteration |
| * vectors through here. This method initializes the state machine to state 1 |
| * and advances through the text character by character until we reach the end |
| * of the text or the state machine transitions to state 0. We update our return |
| * value every time the state machine passes through a possible end state. |
| */ |
| protected int handleNext() { |
| // if we're already at the end of the text, return DONE. |
| CharacterIterator text = getText(); |
| if (text.getIndex() == text.getEndIndex()) { |
| return BreakIterator.DONE; |
| } |
| |
| // no matter what, we always advance at least one character forward |
| int result = getNextIndex(); |
| int lookaheadResult = 0; |
| |
| // begin in state 1 |
| int state = START_STATE; |
| int category; |
| int c = getCurrent(); |
| |
| // loop until we reach the end of the text or transition to state 0 |
| while (c != CharacterIterator.DONE && state != STOP_STATE) { |
| |
| // look up the current character's character category (which tells us |
| // which column in the state table to look at) |
| category = lookupCategory(c); |
| |
| // if the character isn't an ignore character, look up a state |
| // transition in the state table |
| if (category != IGNORE) { |
| state = lookupState(state, category); |
| } |
| |
| // if the state we've just transitioned to is a lookahead state, |
| // (but not also an end state), save its position. If it's |
| // both a lookahead state and an end state, update the break position |
| // to the last saved lookup-state position |
| if (lookaheadStates[state]) { |
| if (endStates[state]) { |
| result = lookaheadResult; |
| } |
| else { |
| lookaheadResult = getNextIndex(); |
| } |
| } |
| |
| // otherwise, if the state we've just transitioned to is an accepting |
| // state, update the break position to be the current iteration position |
| else { |
| if (endStates[state]) { |
| result = getNextIndex(); |
| } |
| } |
| |
| c = getNext(); |
| } |
| |
| // if we've run off the end of the text, and the very last character took us into |
| // a lookahead state, advance the break position to the lookahead position |
| // (the theory here is that if there are no characters at all after the lookahead |
| // position, that always matches the lookahead criteria) |
| if (c == CharacterIterator.DONE && lookaheadResult == text.getEndIndex()) { |
| result = lookaheadResult; |
| } |
| |
| text.setIndex(result); |
| return result; |
| } |
| |
| /** |
| * This method backs the iterator back up to a "safe position" in the text. |
| * This is a position that we know, without any context, must be a break position. |
| * The various calling methods then iterate forward from this safe position to |
| * the appropriate position to return. (For more information, see the description |
| * of buildBackwardsStateTable() in RuleBasedBreakIterator.Builder.) |
| */ |
| protected int handlePrevious() { |
| CharacterIterator text = getText(); |
| int state = START_STATE; |
| int category = 0; |
| int lastCategory = 0; |
| int c = getCurrent(); |
| |
| // loop until we reach the beginning of the text or transition to state 0 |
| while (c != CharacterIterator.DONE && state != STOP_STATE) { |
| |
| // save the last character's category and look up the current |
| // character's category |
| lastCategory = category; |
| category = lookupCategory(c); |
| |
| // if the current character isn't an ignore character, look up a |
| // state transition in the backwards state table |
| if (category != IGNORE) { |
| state = lookupBackwardState(state, category); |
| } |
| |
| // then advance one character backwards |
| c = getPrevious(); |
| } |
| |
| // if we didn't march off the beginning of the text, we're either one or two |
| // positions away from the real break position. (One because of the call to |
| // previous() at the end of the loop above, and another because the character |
| // that takes us into the stop state will always be the character BEFORE |
| // the break position.) |
| if (c != CharacterIterator.DONE) { |
| if (lastCategory != IGNORE) { |
| getNext(); |
| getNext(); |
| } |
| else { |
| getNext(); |
| } |
| } |
| return text.getIndex(); |
| } |
| |
| /** |
| * Looks up a character's category (i.e., its category for breaking purposes, |
| * not its Unicode category) |
| */ |
| protected int lookupCategory(int c) { |
| if (c < Character.MIN_SUPPLEMENTARY_CODE_POINT) { |
| return charCategoryTable.elementAt((char)c); |
| } else { |
| return supplementaryCharCategoryTable.getValue(c); |
| } |
| } |
| |
| /** |
| * Given a current state and a character category, looks up the |
| * next state to transition to in the state table. |
| */ |
| protected int lookupState(int state, int category) { |
| return stateTable[state * numCategories + category]; |
| } |
| |
| /** |
| * Given a current state and a character category, looks up the |
| * next state to transition to in the backwards state table. |
| */ |
| protected int lookupBackwardState(int state, int category) { |
| return backwardsStateTable[state * numCategories + category]; |
| } |
| |
| /* |
| * This class exists to work around a bug in incorrect implementations |
| * of CharacterIterator, which incorrectly handle setIndex(endIndex). |
| * This iterator relies only on base.setIndex(n) where n is less than |
| * endIndex. |
| * |
| * One caveat: if the base iterator's begin and end indices change |
| * the change will not be reflected by this wrapper. Does that matter? |
| */ |
| private static final class SafeCharIterator implements CharacterIterator, |
| Cloneable { |
| |
| private CharacterIterator base; |
| private int rangeStart; |
| private int rangeLimit; |
| private int currentIndex; |
| |
| SafeCharIterator(CharacterIterator base) { |
| this.base = base; |
| this.rangeStart = base.getBeginIndex(); |
| this.rangeLimit = base.getEndIndex(); |
| this.currentIndex = base.getIndex(); |
| } |
| |
| public char first() { |
| return setIndex(rangeStart); |
| } |
| |
| public char last() { |
| return setIndex(rangeLimit - 1); |
| } |
| |
| public char current() { |
| if (currentIndex < rangeStart || currentIndex >= rangeLimit) { |
| return DONE; |
| } |
| else { |
| return base.setIndex(currentIndex); |
| } |
| } |
| |
| public char next() { |
| |
| currentIndex++; |
| if (currentIndex >= rangeLimit) { |
| currentIndex = rangeLimit; |
| return DONE; |
| } |
| else { |
| return base.setIndex(currentIndex); |
| } |
| } |
| |
| public char previous() { |
| |
| currentIndex--; |
| if (currentIndex < rangeStart) { |
| currentIndex = rangeStart; |
| return DONE; |
| } |
| else { |
| return base.setIndex(currentIndex); |
| } |
| } |
| |
| public char setIndex(int i) { |
| |
| if (i < rangeStart || i > rangeLimit) { |
| throw new IllegalArgumentException("Invalid position"); |
| } |
| currentIndex = i; |
| return current(); |
| } |
| |
| public int getBeginIndex() { |
| return rangeStart; |
| } |
| |
| public int getEndIndex() { |
| return rangeLimit; |
| } |
| |
| public int getIndex() { |
| return currentIndex; |
| } |
| |
| public Object clone() { |
| |
| SafeCharIterator copy = null; |
| try { |
| copy = (SafeCharIterator) super.clone(); |
| } |
| catch(CloneNotSupportedException e) { |
| throw new Error("Clone not supported: " + e); |
| } |
| |
| CharacterIterator copyOfBase = (CharacterIterator) base.clone(); |
| copy.base = copyOfBase; |
| return copy; |
| } |
| } |
| } |
