EmptyPattern.java

/*
 * Copyright 2005-2006 Sun Microsystems, Inc.  All Rights Reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Sun designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Sun in the LICENSE file that accompanied this code.
 *
 * This code 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
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
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package com.sun.xml.internal.rngom.binary;

import com.sun.xml.internal.rngom.binary.visitor.PatternFunction;
import com.sun.xml.internal.rngom.binary.visitor.PatternVisitor;

public class EmptyPattern extends Pattern {
  EmptyPattern() {
    super(true, EMPTY_CONTENT_TYPE, EMPTY_HASH_CODE);
  }
  boolean samePattern(Pattern other) {
    return other instanceof EmptyPattern;
  }
  public void accept(PatternVisitor visitor) {
    visitor.visitEmpty();
  }
  public Object apply(PatternFunction f) {
    return f.caseEmpty(this);
  }
  void checkRestrictions(int context, DuplicateAttributeDetector dad, Alphabet alpha)
    throws RestrictionViolationException {
    switch (context) {
    case DATA_EXCEPT_CONTEXT:
      throw new RestrictionViolationException("data_except_contains_empty");
    case START_CONTEXT:
      throw new RestrictionViolationException("start_contains_empty");
    }
  }
}