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+/*
+ * gnu/regexp/RETokenOneOf.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;
+
+/**
+ * @since gnu.regexp 1.1.3
+ * @author Shashank Bapat
+ */
+final class RETokenLookAhead extends REToken
+{
+ REToken re;
+ boolean negative;
+
+ RETokenLookAhead(REToken re, boolean negative) throws REException {
+ super(0);
+ this.re = re;
+ this.negative = negative;
+ }
+
+ boolean match(CharIndexed input, REMatch mymatch)
+ {
+ REMatch trymatch = (REMatch)mymatch.clone();
+ REMatch trymatch1 = (REMatch)mymatch.clone();
+ REMatch newMatch = null;
+ if (re.match(input, trymatch)) {
+ if (negative) return false;
+ if (next(input, trymatch1))
+ newMatch = trymatch1;
+ }
+
+ if (newMatch != null) {
+ if (negative) return false;
+ //else
+ mymatch.assignFrom(newMatch);
+ return true;
+ }
+ else { // no match
+ if (negative)
+ return next(input, mymatch);
+ //else
+ return false;
+ }
+ }
+
+ void dump(StringBuffer os) {
+ os.append("(?");
+ os.append(negative ? '!' : '=');
+ re.dumpAll(os);
+ os.append(')');
+ }
+}
+