/**
 * Copyright 2014 National University of Ireland, Galway.
 *
 * This file is part of the SIREn project. Project and contact information:
 *
 *  https://github.com/rdelbru/SIREn
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.sindice.siren.qparser.keyword.nodes;

import org.apache.lucene.queryparser.flexible.core.nodes.FieldQueryNode;
import org.apache.lucene.queryparser.flexible.core.nodes.QueryNodeImpl;
import org.apache.lucene.queryparser.flexible.core.parser.EscapeQuerySyntax;

/**
 * A {@link WildcardNodeQueryNode} is used in {@link TwigQueryNode} to set no
 * constraint on the root or on the child.
 *
 * <p>
 *
 * A wildcard node is a {@link FieldQueryNode} which is equal to
 * <code>"*"</code>.
 */
public class WildcardNodeQueryNode
extends QueryNodeImpl {

  public WildcardNodeQueryNode() {
    this.setLeaf(true);
  }

  @Override
  public CharSequence toQueryString(final EscapeQuerySyntax escapeSyntaxParser) {
    return "{*}";
  }

  @Override
  public String toString() {
    return "<wildcardNode/>";
  }

}