--- /dev/null
+/*
+ * gnu/regexp/REMatchEnumeration.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.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();
+ }
+}
+
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