package org.drools.semantics.java;
/*
* $Id: JavaExprAnalyzer.java,v 1.3 2005/11/10 05:10:08 mproctor Exp $
*
* Copyright 2002 (C) The Werken Company. All Rights Reserved.
*
* Redistribution and use of this software and associated documentation
* ("Software"), with or without modification, are permitted provided that the
* following conditions are met:
*
* 1. Redistributions of source code must retain copyright statements and
* notices. Redistributions must also contain a copy of this document.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* 3. The name "drools" must not be used to endorse or promote products derived
* from this Software without prior written permission of The Werken Company.
* For written permission, please contact bob@werken.com.
*
* 4. Products derived from this Software may not be called "drools" nor may
* "drools" appear in their names without prior written permission of The Werken
* Company. "drools" is a registered trademark of The Werken Company.
*
* 5. Due credit should be given to The Werken Company.
* (http://drools.werken.com/).
*
* THIS SOFTWARE IS PROVIDED BY THE WERKEN COMPANY AND CONTRIBUTORS ``AS IS''
* AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE WERKEN COMPANY OR ITS CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
*/
import java.io.StringReader;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Set;
import org.drools.rule.Declaration;
import org.drools.semantics.java.parser.JavaLexer;
import org.drools.semantics.java.parser.JavaRecognizer;
import org.drools.semantics.java.parser.JavaTreeParser;
import antlr.RecognitionException;
import antlr.TokenStreamException;
import antlr.collections.AST;
/**
* Expression analyzer.
*
* @author <a href="mailto:bob@eng.werken.com">bob mcwhirter </a>
*/
public class JavaExprAnalyzer
{
// ------------------------------------------------------------
// Constructors
// ------------------------------------------------------------
/**
* Construct.
*/
public JavaExprAnalyzer()
{
// intentionally left blank.
}
// ------------------------------------------------------------
// Instance methods
// ------------------------------------------------------------
/**
* Analyze an expression.
*
* @param expr
* The expression to analyze.
* @param availDecls
* Total set of declarations available.
*
* @return The <code>Set</code> of declarations used by the expression.
*
* @throws TokenStreamException
* If an error occurs in the lexer.
* @throws RecognitionException
* If an error occurs in the parser.
* @throws MissingDeclarationException
* If the expression requires a declaration not present in the available declarations.
*/
public List analyze(String expr,
List availDecls) throws TokenStreamException,
RecognitionException,
MissingDeclarationException
{
JavaLexer lexer = new JavaLexer( new StringReader( expr ) );
JavaRecognizer parser = new JavaRecognizer( lexer );
parser.ruleCondition();
AST ast = parser.getAST();
return analyze( availDecls,
ast );
}
/**
* Analyze an expression.
*
* @param availDecls
* Total set of declarations available.
* @param ast
* The AST for the expression.
*
* @return The <code>Set</code> of declarations used by the expression.
*
* @throws RecognitionException
* If an error occurs in the parser.
*/
private List analyze(List availDecls,
AST ast) throws RecognitionException
{
JavaTreeParser treeParser = new JavaTreeParser();
treeParser.init();
treeParser.exprCondition( ast );
Set refs = new HashSet( treeParser.getVariableReferences() );
List decls = new ArrayList();
Iterator declIter = availDecls.iterator();
Declaration eachDecl;
while ( declIter.hasNext() )
{
eachDecl = (Declaration) declIter.next();
if ( refs.contains( eachDecl.getIdentifier() ) )
{
decls.add( eachDecl );
refs.remove( eachDecl.getIdentifier() );
}
}
/*
* if ( ! refs.isEmpty() ) { throw new MissingDeclarationException( expr, (String) refs.iterator().next() ); }
*/
return decls;
}
}