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The source code

/*
 *  gnu/regexp/RE.java
 *  Copyright (C) 1998-2001 Wes Biggs
 *
 *  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 2.1 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, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

package gnu.regexp;
import java.io.InputStream;
import java.io.Reader;
import java.io.Serializable;
import java.util.Locale;
import java.util.PropertyResourceBundle;
import java.util.ResourceBundle;
import java.util.Vector;

class IntPair implements Serializable {
  public int first, second;
}

class CharUnit implements Serializable {
  public char ch;
  public boolean bk;
}

/**
 * RE provides the user interface for compiling and matching regular
 * expressions.
 * 

* A regular expression object (class RE) is compiled by constructing it * from a String, StringBuffer or character array, with optional * compilation flags (below) * and an optional syntax specification (see RESyntax; if not specified, * RESyntax.RE_SYNTAX_PERL5 is used). *

* Various methods attempt to match input text against a compiled * regular expression. These methods are: *

  • isMatch: returns true if the input text in its entirety * matches the regular expression pattern. *
  • getMatch: returns the first match found in the input text, * or null if no match is found. *
  • getAllMatches: returns an array of all non-overlapping * matches found in the input text. If no matches are found, the array is * zero-length. *
  • substitute: substitute the first occurence of the pattern * in the input text with a replacement string (which may include * metacharacters $0-$9, see REMatch.substituteInto). *
  • substituteAll: same as above, but repeat for each match * before returning. *
  • getMatchEnumeration: returns an REMatchEnumeration object * that allows iteration over the matches (see REMatchEnumeration for some * reasons why you may want to do this instead of using getAllMatches. *

    * * These methods all have similar argument lists. The input can be a * String, a character array, a StringBuffer, a Reader or an * InputStream of some sort. Note that when using a Reader or * InputStream, the stream read position cannot be guaranteed after * attempting a match (this is not a bug, but a consequence of the way * regular expressions work). Using an REMatchEnumeration can * eliminate most positioning problems. * *

    * * The optional index argument specifies the offset from the beginning * of the text at which the search should start (see the descriptions * of some of the execution flags for how this can affect positional * pattern operators). For a Reader or InputStream, this means an * offset from the current read position, so subsequent calls with the * same index argument on a Reader or an InputStream will not * necessarily access the same position on the stream, whereas * repeated searches at a given index in a fixed string will return * consistent results. * *

    * You can optionally affect the execution environment by using a * combination of execution flags (constants listed below). * *

    * All operations on a regular expression are performed in a * thread-safe manner. * * @author Wes Biggs * @version 1.1.4-dev, to be released */ public class RE extends REToken { // This String will be returned by getVersion() private static final String VERSION = "1.1.4-dev"; // The localized strings are kept in a separate file private static ResourceBundle messages = PropertyResourceBundle.getBundle("gnu/regexp/MessagesBundle", Locale.getDefault()); // These are, respectively, the first and last tokens in our linked list // If there is only one token, firstToken == lastToken private REToken firstToken, lastToken; // This is the number of subexpressions in this regular expression, // with a minimum value of zero. Returned by getNumSubs() private int numSubs; /** Minimum length, in characters, of any possible match. */ private int minimumLength; /** * Compilation flag. Do not differentiate case. Subsequent * searches using this RE will be case insensitive. */ public static final int REG_ICASE = 2; /** * Compilation flag. The match-any-character operator (dot) * will match a newline character. When set this overrides the syntax * bit RE_DOT_NEWLINE (see RESyntax for details). This is equivalent to * the "/s" operator in Perl. */ public static final int REG_DOT_NEWLINE = 4; /** * Compilation flag. Use multiline mode. In this mode, the ^ and $ * anchors will match based on newlines within the input. This is * equivalent to the "/m" operator in Perl. */ public static final int REG_MULTILINE = 8; /** * Execution flag. * The match-beginning operator (^) will not match at the beginning * of the input string. Useful for matching on a substring when you * know the context of the input is such that position zero of the * input to the match test is not actually position zero of the text. *

    * This example demonstrates the results of various ways of matching on * a substring. *

    * * String s = "food bar fool";
    * RE exp = new RE("^foo.");
    * REMatch m0 = exp.getMatch(s);
    * REMatch m1 = exp.getMatch(s.substring(8));
    * REMatch m2 = exp.getMatch(s.substring(8),0,RE.REG_NOTBOL);
    * REMatch m3 = exp.getMatch(s,8);
    * REMatch m4 = exp.getMatch(s,8,RE.REG_ANCHORINDEX);
    *

    * // Results:
    * // m0 = "food"
    * // m1 = "fool"
    * // m2 = null
    * // m3 = null
    * // m4 = "fool"
    *
    */ public static final int REG_NOTBOL = 16; /** * Execution flag. * The match-end operator ($) does not match at the end * of the input string. Useful for matching on substrings. */ public static final int REG_NOTEOL = 32; /** * Execution flag. * When a match method is invoked that starts matching at a non-zero * index into the input, treat the input as if it begins at the index * given. The effect of this flag is that the engine does not "see" * any text in the input before the given index. This is useful so * that the match-beginning operator (^) matches not at position 0 * in the input string, but at the position the search started at * (based on the index input given to the getMatch function). See * the example under REG_NOTBOL. It also affects the use of the \< * and \b operators. */ public static final int REG_ANCHORINDEX = 64; /** * Execution flag. * The substitute and substituteAll methods will not attempt to * interpolate occurrences of $1-$9 in the replacement text with * the corresponding subexpressions. For example, you may want to * replace all matches of "one dollar" with "$1". */ public static final int REG_NO_INTERPOLATE = 128; /** Returns a string representing the version of the gnu.regexp package. */ public static final String version() { return VERSION; } // Retrieves a message from the ResourceBundle static final String getLocalizedMessage(String key) { return messages.getString(key); } /** * Constructs a regular expression pattern buffer without any compilation * flags set, and using the default syntax (RESyntax.RE_SYNTAX_PERL5). * * @param pattern A regular expression pattern, in the form of a String, * StringBuffer or char[]. Other input types will be converted to * strings using the toString() method. * @exception REException The input pattern could not be parsed. * @exception NullPointerException The pattern was null. */ public RE(Object pattern) throws REException { this(pattern,0,RESyntax.RE_SYNTAX_PERL5,0,0); } /** * Constructs a regular expression pattern buffer using the specified * compilation flags and the default syntax (RESyntax.RE_SYNTAX_PERL5). * * @param pattern A regular expression pattern, in the form of a String, * StringBuffer, or char[]. Other input types will be converted to * strings using the toString() method. * @param cflags The logical OR of any combination of the compilation flags listed above. * @exception REException The input pattern could not be parsed. * @exception NullPointerException The pattern was null. */ public RE(Object pattern, int cflags) throws REException { this(pattern,cflags,RESyntax.RE_SYNTAX_PERL5,0,0); } /** * Constructs a regular expression pattern buffer using the specified * compilation flags and regular expression syntax. * * @param pattern A regular expression pattern, in the form of a String, * StringBuffer, or char[]. Other input types will be converted to * strings using the toString() method. * @param cflags The logical OR of any combination of the compilation flags listed above. * @param syntax The type of regular expression syntax to use. * @exception REException The input pattern could not be parsed. * @exception NullPointerException The pattern was null. */ public RE(Object pattern, int cflags, RESyntax syntax) throws REException { this(pattern,cflags,syntax,0,0); } // internal constructor used for alternation private RE(REToken first, REToken last,int subs, int subIndex, int minLength) { super(subIndex); firstToken = first; lastToken = last; numSubs = subs; minimumLength = minLength; addToken(new RETokenEndSub(subIndex)); } private RE(Object patternObj, int cflags, RESyntax syntax, int myIndex, int nextSub) throws REException { super(myIndex); // Subexpression index of this token. initialize(patternObj, cflags, syntax, myIndex, nextSub); } // For use by subclasses protected RE() { super(0); } // The meat of construction protected void initialize(Object patternObj, int cflags, RESyntax syntax, int myIndex, int nextSub) throws REException { char[] pattern; if (patternObj instanceof String) { pattern = ((String) patternObj).toCharArray(); } else if (patternObj instanceof char[]) { pattern = (char[]) patternObj; } else if (patternObj instanceof StringBuffer) { pattern = new char [((StringBuffer) patternObj).length()]; ((StringBuffer) patternObj).getChars(0,pattern.length,pattern,0); } else { pattern = patternObj.toString().toCharArray(); } int pLength = pattern.length; numSubs = 0; // Number of subexpressions in this token. Vector branches = null; // linked list of tokens (sort of -- some closed loops can exist) firstToken = lastToken = null; // Precalculate these so we don't pay for the math every time we // need to access them. boolean insens = ((cflags & REG_ICASE) > 0); // Parse pattern into tokens. Does anyone know if it's more efficient // to use char[] than a String.charAt()? I'm assuming so. // index tracks the position in the char array int index = 0; // this will be the current parse character (pattern[index]) CharUnit unit = new CharUnit(); // This is used for {x,y} calculations IntPair minMax = new IntPair(); // Buffer a token so we can create a TokenRepeated, etc. REToken currentToken = null; char ch; while (index < pLength) { // read the next character unit (including backslash escapes) index = getCharUnit(pattern,index,unit); // ALTERNATION OPERATOR // \| or | (if RE_NO_BK_VBAR) or newline (if RE_NEWLINE_ALT) // not available if RE_LIMITED_OPS is set // TODO: the '\n' literal here should be a test against REToken.newline, // which unfortunately may be more than a single character. if ( ( (unit.ch == '|' && (syntax.get(RESyntax.RE_NO_BK_VBAR) ^ unit.bk)) || (syntax.get(RESyntax.RE_NEWLINE_ALT) && (unit.ch == '\n') && !unit.bk) ) && !syntax.get(RESyntax.RE_LIMITED_OPS)) { // make everything up to here be a branch. create vector if nec. addToken(currentToken); RE theBranch = new RE(firstToken, lastToken, numSubs, subIndex, minimumLength); minimumLength = 0; if (branches == null) { branches = new Vector(); } branches.addElement(theBranch); firstToken = lastToken = currentToken = null; } // INTERVAL OPERATOR: // {x} | {x,} | {x,y} (RE_INTERVALS && RE_NO_BK_BRACES) // \{x\} | \{x,\} | \{x,y\} (RE_INTERVALS && !RE_NO_BK_BRACES) // // OPEN QUESTION: // what is proper interpretation of '{' at start of string? else if ((unit.ch == '{') && syntax.get(RESyntax.RE_INTERVALS) && (syntax.get(RESyntax.RE_NO_BK_BRACES) ^ unit.bk)) { int newIndex = getMinMax(pattern,index,minMax,syntax); if (newIndex > index) { if (minMax.first > minMax.second) throw new REException(getLocalizedMessage("interval.order"),REException.REG_BADRPT,newIndex); if (currentToken == null) throw new REException(getLocalizedMessage("repeat.no.token"),REException.REG_BADRPT,newIndex); if (currentToken instanceof RETokenRepeated) throw new REException(getLocalizedMessage("repeat.chained"),REException.REG_BADRPT,newIndex); if (currentToken instanceof RETokenWordBoundary || currentToken instanceof RETokenWordBoundary) throw new REException(getLocalizedMessage("repeat.assertion"),REException.REG_BADRPT,newIndex); if ((currentToken.getMinimumLength() == 0) && (minMax.second == Integer.MAX_VALUE)) throw new REException(getLocalizedMessage("repeat.empty.token"),REException.REG_BADRPT,newIndex); index = newIndex; currentToken = setRepeated(currentToken,minMax.first,minMax.second,index); } else { addToken(currentToken); currentToken = new RETokenChar(subIndex,unit.ch,insens); } } // LIST OPERATOR: // [...] | [^...] else if ((unit.ch == '[') && !unit.bk) { Vector options = new Vector(); boolean negative = false; char lastChar = 0; if (index == pLength) throw new REException(getLocalizedMessage("unmatched.bracket"),REException.REG_EBRACK,index); // Check for initial caret, negation if ((ch = pattern[index]) == '^') { negative = true; if (++index == pLength) throw new REException(getLocalizedMessage("class.no.end"),REException.REG_EBRACK,index); ch = pattern[index]; } // Check for leading right bracket literal if (ch == ']') { lastChar = ch; if (++index == pLength) throw new REException(getLocalizedMessage("class.no.end"),REException.REG_EBRACK,index); } while ((ch = pattern[index++]) != ']') { if ((ch == '-') && (lastChar != 0)) { if (index == pLength) throw new REException(getLocalizedMessage("class.no.end"),REException.REG_EBRACK,index); if ((ch = pattern[index]) == ']') { options.addElement(new RETokenChar(subIndex,lastChar,insens)); lastChar = '-'; } else { options.addElement(new RETokenRange(subIndex,lastChar,ch,insens)); lastChar = 0; index++; } } else if ((ch == '\\') && syntax.get(RESyntax.RE_BACKSLASH_ESCAPE_IN_LISTS)) { if (index == pLength) throw new REException(getLocalizedMessage("class.no.end"),REException.REG_EBRACK,index); int posixID = -1; boolean negate = false; char asciiEsc = 0; if (("dswDSW".indexOf(pattern[index]) != -1) && syntax.get(RESyntax.RE_CHAR_CLASS_ESC_IN_LISTS)) { switch (pattern[index]) { case 'D': negate = true; case 'd': posixID = RETokenPOSIX.DIGIT; break; case 'S': negate = true; case 's': posixID = RETokenPOSIX.SPACE; break; case 'W': negate = true; case 'w': posixID = RETokenPOSIX.ALNUM; break; } } else if ("nrt".indexOf(pattern[index]) != -1) { switch (pattern[index]) { case 'n': asciiEsc = '\n'; break; case 't': asciiEsc = '\t'; break; case 'r': asciiEsc = '\r'; break; } } if (lastChar != 0) options.addElement(new RETokenChar(subIndex,lastChar,insens)); if (posixID != -1) { options.addElement(new RETokenPOSIX(subIndex,posixID,insens,negate)); } else if (asciiEsc != 0) { lastChar = asciiEsc; } else { lastChar = pattern[index]; } ++index; } else if ((ch == '[') && (syntax.get(RESyntax.RE_CHAR_CLASSES)) && (index < pLength) && (pattern[index] == ':')) { StringBuffer posixSet = new StringBuffer(); index = getPosixSet(pattern,index+1,posixSet); int posixId = RETokenPOSIX.intValue(posixSet.toString()); if (posixId != -1) options.addElement(new RETokenPOSIX(subIndex,posixId,insens,false)); } else { if (lastChar != 0) options.addElement(new RETokenChar(subIndex,lastChar,insens)); lastChar = ch; } if (index == pLength) throw new REException(getLocalizedMessage("class.no.end"),REException.REG_EBRACK,index); } // while in list // Out of list, index is one past ']' if (lastChar != 0) options.addElement(new RETokenChar(subIndex,lastChar,insens)); // Create a new RETokenOneOf addToken(currentToken); options.trimToSize(); currentToken = new RETokenOneOf(subIndex,options,negative); } // SUBEXPRESSIONS // (...) | \(...\) depending on RE_NO_BK_PARENS else if ((unit.ch == '(') && (syntax.get(RESyntax.RE_NO_BK_PARENS) ^ unit.bk)) { boolean pure = false; boolean comment = false; boolean lookAhead = false; boolean negativelh = false; if ((index+1 < pLength) && (pattern[index] == '?')) { switch (pattern[index+1]) { case '!': if (syntax.get(RESyntax.RE_LOOKAHEAD)) { pure = true; negativelh = true; lookAhead = true; index += 2; } break; case '=': if (syntax.get(RESyntax.RE_LOOKAHEAD)) { pure = true; lookAhead = true; index += 2; } break; case ':': if (syntax.get(RESyntax.RE_PURE_GROUPING)) { pure = true; index += 2; } break; case '#': if (syntax.get(RESyntax.RE_COMMENTS)) { comment = true; } break; default: throw new REException(getLocalizedMessage("repeat.no.token"), REException.REG_BADRPT, index); } } if (index >= pLength) { throw new REException(getLocalizedMessage("unmatched.paren"), REException.REG_ESUBREG,index); } // find end of subexpression int endIndex = index; int nextIndex = index; int nested = 0; while ( ((nextIndex = getCharUnit(pattern,endIndex,unit)) > 0) && !(nested == 0 && (unit.ch == ')') && (syntax.get(RESyntax.RE_NO_BK_PARENS) ^ unit.bk)) ) if ((endIndex = nextIndex) >= pLength) throw new REException(getLocalizedMessage("subexpr.no.end"),REException.REG_ESUBREG,nextIndex); else if (unit.ch == '(' && (syntax.get(RESyntax.RE_NO_BK_PARENS) ^ unit.bk)) nested++; else if (unit.ch == ')' && (syntax.get(RESyntax.RE_NO_BK_PARENS) ^ unit.bk)) nested--; // endIndex is now position at a ')','\)' // nextIndex is end of string or position after ')' or '\)' if (comment) index = nextIndex; else { // not a comment // create RE subexpression as token. addToken(currentToken); if (!pure) { numSubs++; } int useIndex = (pure || lookAhead) ? 0 : nextSub + numSubs; currentToken = new RE(String.valueOf(pattern,index,endIndex-index).toCharArray(),cflags,syntax,useIndex,nextSub + numSubs); numSubs += ((RE) currentToken).getNumSubs(); if (lookAhead) { currentToken = new RETokenLookAhead(currentToken,negativelh); } index = nextIndex; } // not a comment } // subexpression // UNMATCHED RIGHT PAREN // ) or \) throw exception if // !syntax.get(RESyntax.RE_UNMATCHED_RIGHT_PAREN_ORD) else if (!syntax.get(RESyntax.RE_UNMATCHED_RIGHT_PAREN_ORD) && ((unit.ch == ')') && (syntax.get(RESyntax.RE_NO_BK_PARENS) ^ unit.bk))) { throw new REException(getLocalizedMessage("unmatched.paren"),REException.REG_EPAREN,index); } // START OF LINE OPERATOR // ^ else if ((unit.ch == '^') && !unit.bk) { addToken(currentToken); currentToken = null; addToken(new RETokenStart(subIndex,((cflags & REG_MULTILINE) > 0) ? syntax.getLineSeparator() : null)); } // END OF LINE OPERATOR // $ else if ((unit.ch == '$') && !unit.bk) { addToken(currentToken); currentToken = null; addToken(new RETokenEnd(subIndex,((cflags & REG_MULTILINE) > 0) ? syntax.getLineSeparator() : null)); } // MATCH-ANY-CHARACTER OPERATOR (except possibly newline and null) // . else if ((unit.ch == '.') && !unit.bk) { addToken(currentToken); currentToken = new RETokenAny(subIndex,syntax.get(RESyntax.RE_DOT_NEWLINE) || ((cflags & REG_DOT_NEWLINE) > 0),syntax.get(RESyntax.RE_DOT_NOT_NULL)); } // ZERO-OR-MORE REPEAT OPERATOR // * else if ((unit.ch == '*') && !unit.bk) { if (currentToken == null) throw new REException(getLocalizedMessage("repeat.no.token"),REException.REG_BADRPT,index); if (currentToken instanceof RETokenRepeated) throw new REException(getLocalizedMessage("repeat.chained"),REException.REG_BADRPT,index); if (currentToken instanceof RETokenWordBoundary || currentToken instanceof RETokenWordBoundary) throw new REException(getLocalizedMessage("repeat.assertion"),REException.REG_BADRPT,index); if (currentToken.getMinimumLength() == 0) throw new REException(getLocalizedMessage("repeat.empty.token"),REException.REG_BADRPT,index); currentToken = setRepeated(currentToken,0,Integer.MAX_VALUE,index); } // ONE-OR-MORE REPEAT OPERATOR // + | \+ depending on RE_BK_PLUS_QM // not available if RE_LIMITED_OPS is set else if ((unit.ch == '+') && !syntax.get(RESyntax.RE_LIMITED_OPS) && (!syntax.get(RESyntax.RE_BK_PLUS_QM) ^ unit.bk)) { if (currentToken == null) throw new REException(getLocalizedMessage("repeat.no.token"),REException.REG_BADRPT,index); if (currentToken instanceof RETokenRepeated) throw new REException(getLocalizedMessage("repeat.chained"),REException.REG_BADRPT,index); if (currentToken instanceof RETokenWordBoundary || currentToken instanceof RETokenWordBoundary) throw new REException(getLocalizedMessage("repeat.assertion"),REException.REG_BADRPT,index); if (currentToken.getMinimumLength() == 0) throw new REException(getLocalizedMessage("repeat.empty.token"),REException.REG_BADRPT,index); currentToken = setRepeated(currentToken,1,Integer.MAX_VALUE,index); } // ZERO-OR-ONE REPEAT OPERATOR / STINGY MATCHING OPERATOR // ? | \? depending on RE_BK_PLUS_QM // not available if RE_LIMITED_OPS is set // stingy matching if RE_STINGY_OPS is set and it follows a quantifier else if ((unit.ch == '?') && !syntax.get(RESyntax.RE_LIMITED_OPS) && (!syntax.get(RESyntax.RE_BK_PLUS_QM) ^ unit.bk)) { if (currentToken == null) throw new REException(getLocalizedMessage("repeat.no.token"),REException.REG_BADRPT,index); // Check for stingy matching on RETokenRepeated if (currentToken instanceof RETokenRepeated) { if (syntax.get(RESyntax.RE_STINGY_OPS) && !((RETokenRepeated)currentToken).isStingy()) ((RETokenRepeated)currentToken).makeStingy(); else throw new REException(getLocalizedMessage("repeat.chained"),REException.REG_BADRPT,index); } else if (currentToken instanceof RETokenWordBoundary || currentToken instanceof RETokenWordBoundary) throw new REException(getLocalizedMessage("repeat.assertion"),REException.REG_BADRPT,index); else currentToken = setRepeated(currentToken,0,1,index); } // BACKREFERENCE OPERATOR // \1 \2 ... \9 // not available if RE_NO_BK_REFS is set else if (unit.bk && Character.isDigit(unit.ch) && !syntax.get(RESyntax.RE_NO_BK_REFS)) { addToken(currentToken); currentToken = new RETokenBackRef(subIndex,Character.digit(unit.ch,10),insens); } // START OF STRING OPERATOR // \A if RE_STRING_ANCHORS is set else if (unit.bk && (unit.ch == 'A') && syntax.get(RESyntax.RE_STRING_ANCHORS)) { addToken(currentToken); currentToken = new RETokenStart(subIndex,null); } // WORD BREAK OPERATOR // \b if ???? else if (unit.bk && (unit.ch == 'b') && syntax.get(RESyntax.RE_STRING_ANCHORS)) { addToken(currentToken); currentToken = new RETokenWordBoundary(subIndex, RETokenWordBoundary.BEGIN | RETokenWordBoundary.END, false); } // WORD BEGIN OPERATOR // \< if ???? else if (unit.bk && (unit.ch == '<')) { addToken(currentToken); currentToken = new RETokenWordBoundary(subIndex, RETokenWordBoundary.BEGIN, false); } // WORD END OPERATOR // \> if ???? else if (unit.bk && (unit.ch == '>')) { addToken(currentToken); currentToken = new RETokenWordBoundary(subIndex, RETokenWordBoundary.END, false); } // NON-WORD BREAK OPERATOR // \B if ???? else if (unit.bk && (unit.ch == 'B') && syntax.get(RESyntax.RE_STRING_ANCHORS)) { addToken(currentToken); currentToken = new RETokenWordBoundary(subIndex, RETokenWordBoundary.BEGIN | RETokenWordBoundary.END, true); } // DIGIT OPERATOR // \d if RE_CHAR_CLASS_ESCAPES is set else if (unit.bk && (unit.ch == 'd') && syntax.get(RESyntax.RE_CHAR_CLASS_ESCAPES)) { addToken(currentToken); currentToken = new RETokenPOSIX(subIndex,RETokenPOSIX.DIGIT,insens,false); } // NON-DIGIT OPERATOR // \D else if (unit.bk && (unit.ch == 'D') && syntax.get(RESyntax.RE_CHAR_CLASS_ESCAPES)) { addToken(currentToken); currentToken = new RETokenPOSIX(subIndex,RETokenPOSIX.DIGIT,insens,true); } // NEWLINE ESCAPE // \n else if (unit.bk && (unit.ch == 'n')) { addToken(currentToken); currentToken = new RETokenChar(subIndex,'\n',false); } // RETURN ESCAPE // \r else if (unit.bk && (unit.ch == 'r')) { addToken(currentToken); currentToken = new RETokenChar(subIndex,'\r',false); } // WHITESPACE OPERATOR // \s if RE_CHAR_CLASS_ESCAPES is set else if (unit.bk && (unit.ch == 's') && syntax.get(RESyntax.RE_CHAR_CLASS_ESCAPES)) { addToken(currentToken); currentToken = new RETokenPOSIX(subIndex,RETokenPOSIX.SPACE,insens,false); } // NON-WHITESPACE OPERATOR // \S else if (unit.bk && (unit.ch == 'S') && syntax.get(RESyntax.RE_CHAR_CLASS_ESCAPES)) { addToken(currentToken); currentToken = new RETokenPOSIX(subIndex,RETokenPOSIX.SPACE,insens,true); } // TAB ESCAPE // \t else if (unit.bk && (unit.ch == 't')) { addToken(currentToken); currentToken = new RETokenChar(subIndex,'\t',false); } // ALPHANUMERIC OPERATOR // \w else if (unit.bk && (unit.ch == 'w') && syntax.get(RESyntax.RE_CHAR_CLASS_ESCAPES)) { addToken(currentToken); currentToken = new RETokenPOSIX(subIndex,RETokenPOSIX.ALNUM,insens,false); } // NON-ALPHANUMERIC OPERATOR // \W else if (unit.bk && (unit.ch == 'W') && syntax.get(RESyntax.RE_CHAR_CLASS_ESCAPES)) { addToken(currentToken); currentToken = new RETokenPOSIX(subIndex,RETokenPOSIX.ALNUM,insens,true); } // END OF STRING OPERATOR // \Z else if (unit.bk && (unit.ch == 'Z') && syntax.get(RESyntax.RE_STRING_ANCHORS)) { addToken(currentToken); currentToken = new RETokenEnd(subIndex,null); } // NON-SPECIAL CHARACTER (or escape to make literal) // c | \* for example else { // not a special character addToken(currentToken); currentToken = new RETokenChar(subIndex,unit.ch,insens); } } // end while // Add final buffered token and an EndSub marker addToken(currentToken); if (branches != null) { branches.addElement(new RE(firstToken,lastToken,numSubs,subIndex,minimumLength)); branches.trimToSize(); // compact the Vector minimumLength = 0; firstToken = lastToken = null; addToken(new RETokenOneOf(subIndex,branches,false)); } else addToken(new RETokenEndSub(subIndex)); } private static int getCharUnit(char[] input, int index, CharUnit unit) throws REException { unit.ch = input[index++]; if (unit.bk = (unit.ch == '\\')) if (index < input.length) unit.ch = input[index++]; else throw new REException(getLocalizedMessage("ends.with.backslash"),REException.REG_ESCAPE,index); return index; } /** * Checks if the regular expression matches the input in its entirety. * * @param input The input text. */ public boolean isMatch(Object input) { return isMatch(input,0,0); } /** * Checks if the input string, starting from index, is an exact match of * this regular expression. * * @param input The input text. * @param index The offset index at which the search should be begin. */ public boolean isMatch(Object input,int index) { return isMatch(input,index,0); } /** * Checks if the input, starting from index and using the specified * execution flags, is an exact match of this regular expression. * * @param input The input text. * @param index The offset index at which the search should be begin. * @param eflags The logical OR of any execution flags above. */ public boolean isMatch(Object input,int index,int eflags) { return isMatchImpl(makeCharIndexed(input,index),index,eflags); } private boolean isMatchImpl(CharIndexed input, int index, int eflags) { if (firstToken == null) // Trivial case return (input.charAt(0) == CharIndexed.OUT_OF_BOUNDS); REMatch m = new REMatch(numSubs, index, eflags); if (firstToken.match(input, m)) { while (m != null) { if (input.charAt(m.index) == CharIndexed.OUT_OF_BOUNDS) { return true; } m = m.next; } } return false; } /** * Returns the maximum number of subexpressions in this regular expression. * If the expression contains branches, the value returned will be the * maximum subexpressions in any of the branches. */ public int getNumSubs() { return numSubs; } // Overrides REToken.setUncle void setUncle(REToken uncle) { if (lastToken != null) { lastToken.setUncle(uncle); } else super.setUncle(uncle); // to deal with empty subexpressions } // Overrides REToken.chain boolean chain(REToken next) { super.chain(next); setUncle(next); return true; } /** * Returns the minimum number of characters that could possibly * constitute a match of this regular expression. */ public int getMinimumLength() { return minimumLength; } /** * Returns an array of all matches found in the input. * * If the regular expression allows the empty string to match, it will * substitute matches at all positions except the end of the input. * * @param input The input text. * @return a non-null (but possibly zero-length) array of matches */ public REMatch[] getAllMatches(Object input) { return getAllMatches(input,0,0); } /** * Returns an array of all matches found in the input, * beginning at the specified index position. * * If the regular expression allows the empty string to match, it will * substitute matches at all positions except the end of the input. * * @param input The input text. * @param index The offset index at which the search should be begin. * @return a non-null (but possibly zero-length) array of matches */ public REMatch[] getAllMatches(Object input, int index) { return getAllMatches(input,index,0); } /** * Returns an array of all matches found in the input string, * beginning at the specified index position and using the specified * execution flags. * * If the regular expression allows the empty string to match, it will * substitute matches at all positions except the end of the input. * * @param input The input text. * @param index The offset index at which the search should be begin. * @param eflags The logical OR of any execution flags above. * @return a non-null (but possibly zero-length) array of matches */ public REMatch[] getAllMatches(Object input, int index, int eflags) { return getAllMatchesImpl(makeCharIndexed(input,index),index,eflags); } // this has been changed since 1.03 to be non-overlapping matches private REMatch[] getAllMatchesImpl(CharIndexed input, int index, int eflags) { Vector all = new Vector(); REMatch m = null; while ((m = getMatchImpl(input,index,eflags,null)) != null) { all.addElement(m); index = m.getEndIndex(); if (m.end[0] == 0) { // handle pathological case of zero-length match index++; input.move(1); } else { input.move(m.end[0]); } if (!input.isValid()) break; } REMatch[] mset = new REMatch[all.size()]; all.copyInto(mset); return mset; } /* Implements abstract method REToken.match() */ boolean match(CharIndexed input, REMatch mymatch) { if (firstToken == null) return next(input, mymatch); // Note the start of this subexpression mymatch.start[subIndex] = mymatch.index; return firstToken.match(input, mymatch); } /** * Returns the first match found in the input. If no match is found, * null is returned. * * @param input The input text. * @return An REMatch instance referencing the match, or null if none. */ public REMatch getMatch(Object input) { return getMatch(input,0,0); } /** * Returns the first match found in the input, beginning * the search at the specified index. If no match is found, * returns null. * * @param input The input text. * @param index The offset within the text to begin looking for a match. * @return An REMatch instance referencing the match, or null if none. */ public REMatch getMatch(Object input, int index) { return getMatch(input,index,0); } /** * Returns the first match found in the input, beginning * the search at the specified index, and using the specified * execution flags. If no match is found, returns null. * * @param input The input text. * @param index The offset index at which the search should be begin. * @param eflags The logical OR of any execution flags above. * @return An REMatch instance referencing the match, or null if none. */ public REMatch getMatch(Object input, int index, int eflags) { return getMatch(input,index,eflags,null); } /** * Returns the first match found in the input, beginning the search * at the specified index, and using the specified execution flags. * If no match is found, returns null. If a StringBuffer is * provided and is non-null, the contents of the input text from the * index to the beginning of the match (or to the end of the input, * if there is no match) are appended to the StringBuffer. * * @param input The input text. * @param index The offset index at which the search should be begin. * @param eflags The logical OR of any execution flags above. * @param buffer The StringBuffer to save pre-match text in. * @return An REMatch instance referencing the match, or null if none. */ public REMatch getMatch(Object input, int index, int eflags, StringBuffer buffer) { return getMatchImpl(makeCharIndexed(input,index),index,eflags,buffer); } REMatch getMatchImpl(CharIndexed input, int anchor, int eflags, StringBuffer buffer) { // Create a new REMatch to hold results REMatch mymatch = new REMatch(numSubs, anchor, eflags); do { // Optimization: check if anchor + minimumLength > length if (minimumLength == 0 || input.charAt(minimumLength-1) != CharIndexed.OUT_OF_BOUNDS) { if (match(input, mymatch)) { // Find longest match of them all to observe leftmost longest REMatch longest = mymatch; while ((mymatch = mymatch.next) != null) { if (mymatch.index > longest.index) { longest = mymatch; } } longest.end[0] = longest.index; longest.finish(input); return longest; } } mymatch.clear(++anchor); // Append character to buffer if needed if (buffer != null && input.charAt(0) != CharIndexed.OUT_OF_BOUNDS) { buffer.append(input.charAt(0)); } } while (input.move(1)); return null; } /** * Returns an REMatchEnumeration that can be used to iterate over the * matches found in the input text. * * @param input The input text. * @return A non-null REMatchEnumeration instance. */ public REMatchEnumeration getMatchEnumeration(Object input) { return getMatchEnumeration(input,0,0); } /** * Returns an REMatchEnumeration that can be used to iterate over the * matches found in the input text. * * @param input The input text. * @param index The offset index at which the search should be begin. * @return A non-null REMatchEnumeration instance, with its input cursor * set to the index position specified. */ public REMatchEnumeration getMatchEnumeration(Object input, int index) { return getMatchEnumeration(input,index,0); } /** * Returns an REMatchEnumeration that can be used to iterate over the * matches found in the input text. * * @param input The input text. * @param index The offset index at which the search should be begin. * @param eflags The logical OR of any execution flags above. * @return A non-null REMatchEnumeration instance, with its input cursor * set to the index position specified. */ public REMatchEnumeration getMatchEnumeration(Object input, int index, int eflags) { return new REMatchEnumeration(this,makeCharIndexed(input,index),index,eflags); } /** * Substitutes the replacement text for the first match found in the input. * * @param input The input text. * @param replace The replacement text, which may contain $x metacharacters (see REMatch.substituteInto). * @return A String interpolating the substituted text. * @see REMatch#substituteInto */ public String substitute(Object input,String replace) { return substitute(input,replace,0,0); } /** * Substitutes the replacement text for the first match found in the input * beginning at the specified index position. Specifying an index * effectively causes the regular expression engine to throw away the * specified number of characters. * * @param input The input text. * @param replace The replacement text, which may contain $x metacharacters (see REMatch.substituteInto). * @param index The offset index at which the search should be begin. * @return A String containing the substring of the input, starting * at the index position, and interpolating the substituted text. * @see REMatch#substituteInto */ public String substitute(Object input,String replace,int index) { return substitute(input,replace,index,0); } /** * Substitutes the replacement text for the first match found in the input * string, beginning at the specified index position and using the * specified execution flags. * * @param input The input text. * @param replace The replacement text, which may contain $x metacharacters (see REMatch.substituteInto). * @param index The offset index at which the search should be begin. * @param eflags The logical OR of any execution flags above. * @return A String containing the substring of the input, starting * at the index position, and interpolating the substituted text. * @see REMatch#substituteInto */ public String substitute(Object input,String replace,int index,int eflags) { return substituteImpl(makeCharIndexed(input,index),replace,index,eflags); } private String substituteImpl(CharIndexed input,String replace,int index,int eflags) { StringBuffer buffer = new StringBuffer(); REMatch m = getMatchImpl(input,index,eflags,buffer); if (m==null) return buffer.toString(); buffer.append( ((eflags & REG_NO_INTERPOLATE) > 0) ? replace : m.substituteInto(replace) ); if (input.move(m.end[0])) { do { buffer.append(input.charAt(0)); } while (input.move(1)); } return buffer.toString(); } /** * Substitutes the replacement text for each non-overlapping match found * in the input text. * * @param input The input text. * @param replace The replacement text, which may contain $x metacharacters (see REMatch.substituteInto). * @return A String interpolating the substituted text. * @see REMatch#substituteInto */ public String substituteAll(Object input,String replace) { return substituteAll(input,replace,0,0); } /** * Substitutes the replacement text for each non-overlapping match found * in the input text, starting at the specified index. * * If the regular expression allows the empty string to match, it will * substitute matches at all positions except the end of the input. * * @param input The input text. * @param replace The replacement text, which may contain $x metacharacters (see REMatch.substituteInto). * @param index The offset index at which the search should be begin. * @return A String containing the substring of the input, starting * at the index position, and interpolating the substituted text. * @see REMatch#substituteInto */ public String substituteAll(Object input,String replace,int index) { return substituteAll(input,replace,index,0); } /** * Substitutes the replacement text for each non-overlapping match found * in the input text, starting at the specified index and using the * specified execution flags. * * @param input The input text. * @param replace The replacement text, which may contain $x metacharacters (see REMatch.substituteInto). * @param index The offset index at which the search should be begin. * @param eflags The logical OR of any execution flags above. * @return A String containing the substring of the input, starting * at the index position, and interpolating the substituted text. * @see REMatch#substituteInto */ public String substituteAll(Object input,String replace,int index,int eflags) { return substituteAllImpl(makeCharIndexed(input,index),replace,index,eflags); } private String substituteAllImpl(CharIndexed input,String replace,int index,int eflags) { StringBuffer buffer = new StringBuffer(); REMatch m; while ((m = getMatchImpl(input,index,eflags,buffer)) != null) { buffer.append( ((eflags & REG_NO_INTERPOLATE) > 0) ? replace : m.substituteInto(replace) ); index = m.getEndIndex(); if (m.end[0] == 0) { char ch = input.charAt(0); if (ch != CharIndexed.OUT_OF_BOUNDS) buffer.append(ch); input.move(1); } else { input.move(m.end[0]); } if (!input.isValid()) break; } return buffer.toString(); } /* Helper function for constructor */ private void addToken(REToken next) { if (next == null) return; minimumLength += next.getMinimumLength(); if (firstToken == null) { lastToken = firstToken = next; } else { // if chain returns false, it "rejected" the token due to // an optimization, and next was combined with lastToken if (lastToken.chain(next)) { lastToken = next; } } } private static REToken setRepeated(REToken current, int min, int max, int index) throws REException { if (current == null) throw new REException(getLocalizedMessage("repeat.no.token"),REException.REG_BADRPT,index); return new RETokenRepeated(current.subIndex,current,min,max); } private static int getPosixSet(char[] pattern,int index,StringBuffer buf) { // Precondition: pattern[index-1] == ':' // we will return pos of closing ']'. int i; for (i=index; i<(pattern.length-1); i++) { if ((pattern[i] == ':') && (pattern[i+1] == ']')) return i+2; buf.append(pattern[i]); } return index; // didn't match up } private int getMinMax(char[] input,int index,IntPair minMax,RESyntax syntax) throws REException { // Precondition: input[index-1] == '{', minMax != null boolean mustMatch = !syntax.get(RESyntax.RE_NO_BK_BRACES); int startIndex = index; if (index == input.length) { if (mustMatch) throw new REException(getLocalizedMessage("unmatched.brace"),REException.REG_EBRACE,index); else return startIndex; } int min,max=0; CharUnit unit = new CharUnit(); StringBuffer buf = new StringBuffer(); // Read string of digits do { index = getCharUnit(input,index,unit); if (Character.isDigit(unit.ch)) buf.append(unit.ch); } while ((index != input.length) && Character.isDigit(unit.ch)); // Check for {} tomfoolery if (buf.length() == 0) { if (mustMatch) throw new REException(getLocalizedMessage("interval.error"),REException.REG_EBRACE,index); else return startIndex; } min = Integer.parseInt(buf.toString()); if ((unit.ch == '}') && (syntax.get(RESyntax.RE_NO_BK_BRACES) ^ unit.bk)) max = min; else if (index == input.length) if (mustMatch) throw new REException(getLocalizedMessage("interval.no.end"),REException.REG_EBRACE,index); else return startIndex; else if ((unit.ch == ',') && !unit.bk) { buf = new StringBuffer(); // Read string of digits while (((index = getCharUnit(input,index,unit)) != input.length) && Character.isDigit(unit.ch)) buf.append(unit.ch); if (!((unit.ch == '}') && (syntax.get(RESyntax.RE_NO_BK_BRACES) ^ unit.bk))) if (mustMatch) throw new REException(getLocalizedMessage("interval.error"),REException.REG_EBRACE,index); else return startIndex; // This is the case of {x,} if (buf.length() == 0) max = Integer.MAX_VALUE; else max = Integer.parseInt(buf.toString()); } else if (mustMatch) throw new REException(getLocalizedMessage("interval.error"),REException.REG_EBRACE,index); else return startIndex; // We know min and max now, and they are valid. minMax.first = min; minMax.second = max; // return the index following the '}' return index; } /** * Return a human readable form of the compiled regular expression, * useful for debugging. */ public String toString() { StringBuffer sb = new StringBuffer(); dump(sb); return sb.toString(); } void dump(StringBuffer os) { os.append('('); if (subIndex == 0) os.append("?:"); if (firstToken != null) firstToken.dumpAll(os); os.append(')'); } // Cast input appropriately or throw exception private static CharIndexed makeCharIndexed(Object input, int index) { // We could let a String fall through to final input, but since // it's the most likely input type, we check it first. if (input instanceof String) return new CharIndexedString((String) input,index); else if (input instanceof char[]) return new CharIndexedCharArray((char[]) input,index); else if (input instanceof StringBuffer) return new CharIndexedStringBuffer((StringBuffer) input,index); else if (input instanceof InputStream) return new CharIndexedInputStream((InputStream) input,index); else if (input instanceof Reader) return new CharIndexedReader((Reader) input, index); else if (input instanceof CharIndexed) return (CharIndexed) input; // do we lose index info? else return new CharIndexedString(input.toString(), index); } }

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