package org.apache.commons.ognl;
   
   /*
    * 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
   *
   *   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.
   */
  
  import org.apache.commons.ognl.enhance.UnsupportedCompilationException;
  
  /**
   * Base class for types that compare values.
   */
  public abstract class ComparisonExpression
      extends BooleanExpression
  {
  
      private static final long serialVersionUID = -5945855000509930682L;
  
      public ComparisonExpression( int id )
      {
          super( id );
      }
  
      public ComparisonExpression( OgnlParser p, int id )
      {
          super( p, id );
      }
  
      public abstract String getComparisonFunction();
  
      /**
       * {@inheritDoc}
       */
      @Override
      public String toGetSourceString( OgnlContext context, Object target )
      {
          if ( target == null )
          {
              throw new UnsupportedCompilationException( "Current target is null, can't compile." );
          }
  
          try
          {
  
              Object value = getValueBody( context, target );
  
              if ( value != null && Boolean.class.isAssignableFrom( value.getClass() ) )
              {
                  getterClass = Boolean.TYPE;
              }
              else if ( value != null )
              {
                  getterClass = value.getClass();
              }
              else
              {
                  getterClass = Boolean.TYPE;
              }
  
              // iterate over children to make numeric type detection work properly
  
              OgnlRuntime.getChildSource( context, target, children[0] );
              OgnlRuntime.getChildSource( context, target, children[1] );
  
              // System.out.println("comparison expression currentType: " + context.getCurrentType() + " previousType: " +
              // context.getPreviousType());
  
              boolean conversion = OgnlRuntime.shouldConvertNumericTypes( context );
  
              StringBuilder result = new StringBuilder( "(" );
              if ( conversion )
              {
                  result.append( getComparisonFunction() ).append( "( ($w) (" );
              }
  
              result.append( OgnlRuntime.getChildSource( context, target, children[0], conversion ) )
                      .append( " " );
  
              if ( conversion )
              {
                  result.append( "), ($w) " );
              }
              else
              {
                  result.append( getExpressionOperator( 0 ) );
             }
 
             result.append( "" ).append( OgnlRuntime.getChildSource( context, target, children[1], conversion ) );
 
             if ( conversion )
             {
                 result.append( ")" );
             }
 
             context.setCurrentType( Boolean.TYPE );
 
             result.append( ")" );
 
             return result.toString();
         }
         catch ( NullPointerException e )
         {
 
             // expected to happen in some instances
 
             throw new UnsupportedCompilationException( "evaluation resulted in null expression." );
         }
         catch ( Throwable t )
         {
             throw OgnlOps.castToRuntime( t );
         }
     }
 }