package org.drools.rule.builder.dialect.java;
/*
* Copyright 2005 JBoss Inc
*
* 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.
*/
import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Set;
import org.antlr.runtime.ANTLRStringStream;
import org.antlr.runtime.CharStream;
import org.antlr.runtime.CommonTokenStream;
import org.antlr.runtime.RecognitionException;
import org.antlr.runtime.TokenStream;
import org.drools.rule.builder.dialect.java.parser.JavaLexer;
import org.drools.rule.builder.dialect.java.parser.JavaLocalDeclarationDescr;
import org.drools.rule.builder.dialect.java.parser.JavaParser;
/**
* 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 RecognitionException
* If an error occurs in the parser.
*/
public JavaAnalysisResult analyzeExpression(final String expr,
final Set[] availableIdentifiers) throws RecognitionException {
final CharStream charStream = new ANTLRStringStream( expr );
final JavaLexer lexer = new JavaLexer( charStream );
final TokenStream tokenStream = new CommonTokenStream( lexer );
final JavaParser parser = new JavaParser( tokenStream );
parser.conditionalOrExpression();
JavaAnalysisResult result = new JavaAnalysisResult();
result.setIdentifiers( parser.getIdentifiers() );
return analyze( result,
availableIdentifiers );
}
public JavaAnalysisResult analyzeBlock(final String expr,
final Set[] availableIdentifiers) throws RecognitionException {
final CharStream charStream = new ANTLRStringStream( "{" + expr + "}" );
final JavaLexer lexer = new JavaLexer( charStream );
final TokenStream tokenStream = new CommonTokenStream( lexer );
final JavaParser parser = new JavaParser( tokenStream );
parser.block();
JavaAnalysisResult result = new JavaAnalysisResult();
result.setIdentifiers( parser.getIdentifiers() );
result.setLocalVariables( new HashMap() );
for( Iterator it = parser.getLocalDeclarations().iterator(); it.hasNext(); ) {
JavaLocalDeclarationDescr descr = (JavaLocalDeclarationDescr) it.next();
for( Iterator identIt = descr.getIdentifiers().iterator(); identIt.hasNext(); ) {
JavaLocalDeclarationDescr.IdentifierDescr ident = (JavaLocalDeclarationDescr.IdentifierDescr) identIt.next();
result.addLocalVariable( ident.getIdentifier(), descr );
}
}
result.setModifyBlocks( parser.getModifyBlocks() );
return analyze( result,
availableIdentifiers );
}
/**
* 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 JavaAnalysisResult analyze(final JavaAnalysisResult result,
final Set[] availableIdentifiers) throws RecognitionException {
final List identifiers = result.getIdentifiers();
final Set notBound = new HashSet( identifiers );
final List[] used = new List[availableIdentifiers.length];
for ( int i = 0, length = used.length; i < length; i++ ) {
used[i] = new ArrayList();
}
for ( int i = 0, length = availableIdentifiers.length; i < length; i++ ) {
final Set set = availableIdentifiers[i];
for ( final Iterator it = set.iterator(); it.hasNext(); ) {
final String eachDecl = (String) it.next();
if ( identifiers.contains( eachDecl ) ) {
used[i].add( eachDecl );
notBound.remove( eachDecl );
}
}
}
result.setBoundIdentifiers( used );
result.setNotBoundedIdentifiers( new ArrayList( notBound ) );
return result;
}
}