| /* gnu/regexp/REMatchEnumeration.java |
| Copyright (C) 1998-2001, 2004 Free Software Foundation, Inc. |
| |
| This file is part of GNU Classpath. |
| |
| GNU Classpath is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2, or (at your option) |
| any later version. |
| |
| GNU Classpath 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 for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GNU Classpath; see the file COPYING. If not, write to the |
| Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
| 02110-1301 USA. |
| |
| Linking this library statically or dynamically with other modules is |
| making a combined work based on this library. Thus, the terms and |
| conditions of the GNU General Public License cover the whole |
| combination. |
| |
| As a special exception, the copyright holders of this library give you |
| permission to link this library with independent modules to produce an |
| executable, regardless of the license terms of these independent |
| modules, and to copy and distribute the resulting executable under |
| terms of your choice, provided that you also meet, for each linked |
| independent module, the terms and conditions of the license of that |
| module. An independent module is a module which is not derived from |
| or based on this library. If you modify this library, you may extend |
| this exception to your version of the library, but you are not |
| obligated to do so. If you do not wish to do so, delete this |
| exception statement from your version. */ |
| |
| package gnu.java.util.regex; |
| import java.io.Serializable; |
| import java.util.Enumeration; |
| import java.util.NoSuchElementException; |
| |
| /** |
| * An REMatchEnumeration enumerates regular expression matches over a |
| * given input text. You obtain a reference to an enumeration using |
| * the <code>getMatchEnumeration()</code> methods on an instance of |
| * RE. |
| * |
| * <P> |
| * |
| * REMatchEnumeration does lazy computation; that is, it will not |
| * search for a match until it needs to. If you'd rather just get all |
| * the matches at once in a big array, use the |
| * <code>getAllMatches()</code> methods on RE. However, using an |
| * enumeration can help speed performance when the entire text does |
| * not need to be searched immediately. |
| * |
| * <P> |
| * |
| * The enumerated type is especially useful when searching on a Reader |
| * or InputStream, because the InputStream read position cannot be |
| * guaranteed after calling <code>getMatch()</code> (see the |
| * description of that method for an explanation of why). Enumeration |
| * also saves a lot of overhead required when calling |
| * <code>getMatch()</code> multiple times. |
| * |
| * @author <A HREF="mailto:wes@cacas.org">Wes Biggs</A> |
| */ |
| public class REMatchEnumeration implements Enumeration, Serializable { |
| private static final int YES = 1; |
| private static final int MAYBE = 0; |
| private static final int NO = -1; |
| |
| private int more; |
| private REMatch match; |
| private RE expr; |
| private CharIndexed input; |
| private int eflags; |
| private int index; |
| |
| // Package scope constructor is used by RE.getMatchEnumeration() |
| REMatchEnumeration(RE expr, CharIndexed input, int index, int eflags) { |
| more = MAYBE; |
| this.expr = expr; |
| this.input = input; |
| this.index = index; |
| this.eflags = eflags; |
| } |
| |
| /** Returns true if there are more matches in the input text. */ |
| public boolean hasMoreElements() { |
| return hasMoreMatches(null); |
| } |
| |
| /** Returns true if there are more matches in the input text. */ |
| public boolean hasMoreMatches() { |
| return hasMoreMatches(null); |
| } |
| |
| /** Returns true if there are more matches in the input text. |
| * Saves the text leading up to the match (or to the end of the input) |
| * in the specified buffer. |
| */ |
| public boolean hasMoreMatches(StringBuffer buffer) { |
| if (more == MAYBE) { |
| match = expr.getMatchImpl(input,index,eflags,buffer); |
| if (match != null) { |
| input.move((match.end[0] > 0) ? match.end[0] : 1); |
| |
| index = (match.end[0] > 0) ? match.end[0] + match.offset : index + 1; |
| more = YES; |
| } else more = NO; |
| } |
| return (more == YES); |
| } |
| |
| /** Returns the next match in the input text. */ |
| public Object nextElement() throws NoSuchElementException { |
| return nextMatch(); |
| } |
| |
| /** |
| * Returns the next match in the input text. This method is provided |
| * for convenience to avoid having to explicitly cast the return value |
| * to class REMatch. |
| */ |
| public REMatch nextMatch() throws NoSuchElementException { |
| if (hasMoreElements()) { |
| more = (input.isValid()) ? MAYBE : NO; |
| return match; |
| } |
| throw new NoSuchElementException(); |
| } |
| } |
| |