CustomDelegatingParser.java

/*
 * Copyright (C) 2011 Laurent Caillette
 *
 * This program 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 3 of the License, or (at your option) any later version.
 *
 * This program 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 for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package org.novelang.parser.antlr;

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

import com.google.common.base.Throwables;
import org.antlr.runtime.RecognitionException;
import static org.junit.Assert.assertSame;

import org.novelang.common.ReflectionTools;

/**
 * Calls a pluggable method of ANTLR-generated parser.
 *
 * @author Laurent Caillette
*/
/*package*/ class CustomDelegatingParser extends AbstractDelegatingParser {

  private final Method parserMethod ;

  public CustomDelegatingParser( final Method parserMethod, final String text ) {
    super( text, new GrammarDelegate( TreeFixture.LOCATION_FACTORY ) ) ;
    // Full qualified name because IDEA gets fooled by Maven projects.
    assertSame( org.novelang.parser.antlr.NovelangParser.class, parserMethod.getDeclaringClass() );
    this.parserMethod = parserMethod ;
  }

  @Override
  public Object callParserMethod() throws RecognitionException {

    final Object parsingResult ;

    try {
      parsingResult = parserMethod.invoke( antlrParser ) ;
    } catch( IllegalAccessException e ) {
      throw new RuntimeException( e ) ;
    } catch( InvocationTargetException e ) {
      if( e.getCause() instanceof RecognitionException ) {
        throw ( RecognitionException ) e.getCause() ;
      } else {
        throw Throwables.propagate( e ) ;
      } 
    }

    final Method getTreeMethod = ReflectionTools.getMethod( parsingResult.getClass(), "getTree" ) ;
    return ReflectionTools.invoke( getTreeMethod, parsingResult ) ;
  }
}