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From-SVN: r102074

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diff --git a/libjava/classpath/gnu/regexp/REMatchEnumeration.java b/libjava/classpath/gnu/regexp/REMatchEnumeration.java
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+/* 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.regexp;
+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();
+  }
+}
+