content: /*****************************************************************
   *   Licensed to the Apache Software Foundation (ASF) under one
   *  or more contributor license agreements.  See the NOTICE file
   *  distributed with this work for additional information
   *  regarding copyright ownership.  The ASF licenses this file
   *  to you 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
   *
   *    https://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.apache.cayenne.exp.parser;
  
  import java.io.IOException;
  import java.math.BigDecimal;
  import java.util.List;
  
  import org.apache.cayenne.exp.Expression;
  import org.apache.cayenne.util.ConversionUtil;
  
  /**
   * "Negate" expression.
   * 
   * @since 1.1
   */
  public class ASTNegate extends SimpleNode {
  
  	private static final long serialVersionUID = -9161722951926428414L;
  
  	ASTNegate(int id) {
  		super(id);
  	}
  
  	public ASTNegate() {
  		super(ExpressionParserTreeConstants.JJTNEGATE);
  	}
  
  	public ASTNegate(Object node) {
  		super(ExpressionParserTreeConstants.JJTNEGATE);
  		jjtAddChild(wrapChild(node), 0);
  		connectChildren();
  	}
  
  	/**
  	 * Creates a copy of this expression node, without copying children.
  	 */
  	@Override
  	public Expression shallowCopy() {
  		return new ASTNegate(id);
  	}
  
  	@Override
  	protected Object evaluateNode(Object o) throws Exception {
  		int len = jjtGetNumChildren();
  		if (len == 0) {
  			return null;
  		}
  
  		BigDecimal result = ConversionUtil.toBigDecimal(evaluateChild(0, o));
  		return result != null ? result.negate() : null;
  	}
  
  	/**
  	 * @since 4.0
  	 */
  	@Override
  	public void appendAsString(Appendable out) throws IOException {
  
  		if ((children != null) && (children.length > 0)) {
  			out.append("-");
  
  			SimpleNode child = (SimpleNode) children[0];
  
  			// don't call super - we have our own parenthesis policy
  			boolean useParen = parent != null && !((child instanceof ASTScalar) || (child instanceof ASTPath));
  			if (useParen) {
  				out.append("(");
  			}
  
  			child.appendAsString(out);
  
  			if (useParen) {
  				out.append(')');
  			}
  		}
  	}
  
  	/**
  	 * @since 4.0
  	 */
  	@Override
  	public void appendAsEJBQL(List<Object> parameterAccumulator, Appendable out, String rootId) throws IOException {
  
  		if ((children != null) && (children.length > 0)) {
  			out.append("-");
  
  			SimpleNode child = (SimpleNode) children[0];
  
  			// don't call super - we have our own parenthesis policy
  			boolean useParen = parent != null && !((child instanceof ASTScalar) || (child instanceof ASTPath));
  			if (useParen) {
  				out.append("(");
  			}
  
  			child.appendAsEJBQL(parameterAccumulator, out, rootId);
  
  			if (useParen) {
  				out.append(')');
  			}
  		}
  	}
  
  	@Override
  	protected String getExpressionOperator(int index) {
  		throw new UnsupportedOperationException("No operator for '" + ExpressionParserTreeConstants.jjtNodeName[id]
  				+ "'");
  	}
  
  	@Override
  	public int getType() {
  		return Expression.NEGATIVE;
  	}
  
  	@Override
  	public int getOperandCount() {
  		return 1;
  	}
  }
  