SJavaParser.java

package jadex.rules.parser.conditions.javagrammar;

import jadex.commons.SReflect;
import jadex.rules.state.OAVObjectType;
import jadex.rules.state.OAVTypeModel;

import org.antlr.runtime.TokenStream;

/**
 *  Static helper methods for Java condition parser.
 */
// Currently not used (todo: replace syntactic predicates in primaryPrefix() with semantic ones)
public class SJavaParser
{
	/**
     *  Lookahead for a type.
     *  @param input	The token stream.
     *  @param tmodel	The OAV type model.
     *  @return	The token index of the last token (identifier) or -1 if no type could be matched.
     */
    protected static int	lookaheadType(TokenStream input, OAVTypeModel tmodel, String[] imports)
    {
    	return lookaheadType(1, input, tmodel, imports);
    }

    /**
     *  Lookahead for a type.
     *  @param index	The start index (starts with 1).
     *  @param input	The token stream.
     *  @param tmodel	The OAV type model.
     *  @return	The token index of the last token (identifier) or -1 if no type could be matched.
     */
    protected static int	lookaheadType(int index, TokenStream input, OAVTypeModel tmodel, String[] imports)
    {
    	if(input.LA(index)==JavaJadexLexer.IDENTIFIER)
    	{
	    	String	typename	= input.LT(index).getText();
	    	OAVObjectType	type	= null;
	    	while(type==null && index!=-1)
	    	{
		    	try
		    	{
		        	type	= tmodel.getObjectType(typename);	        	
		    	}
		    	catch(Throwable e)
		    	{
		    		Class	clazz	= SReflect.findClass0(typename, imports, tmodel.getClassLoader());
		    		if(clazz!=null)
		    		{
		    			type	= tmodel.getJavaType(clazz);
		    		}
		    		else if(".".equals(input.LT(index+1).getText()))
		    		{
		    			index	+= 2;
		    			typename	+= "." + input.LT(index).getText();
		    		}
		    		else
		    		{
		    			index	= -1;
		    		}
		    	}
	    	}
    	}
    	else
    	{
    		index	= -1;
    	}
    	
    	return index;
    }

    /**
     *  Lookahead for an existential declaration (type var).
     *  @param input	The token stream.
     *  @param tmodel	The OAV type model.
     *  @return	True for an existential declaration.
     */
    protected static boolean	lookaheadExistential(TokenStream input, OAVTypeModel tmodel, String[] imports)
    {
    	int index	= lookaheadType(input, tmodel, imports);
    	return index!=-1 && input.LA(index+1)==JavaJadexLexer.IDENTIFIER;
    }

    /**
     *  Lookahead for a static field.
     *  @param input	The token stream.
     *  @param tmodel	The OAV type model.
     *  @return	True for a static field.
     */
    protected static boolean	lookaheadStaticField(TokenStream input, OAVTypeModel tmodel, String[] imports)
    {
    	int index	= lookaheadType(input, tmodel, imports);
    	return index!=-1 &&	".".equals(input.LT(index+1).getText()) && input.LA(index+2)==JavaJadexLexer.IDENTIFIER;
    }
    
    /**
     *  Lookahead for a static method.
     *  @param input	The token stream.
     *  @param tmodel	The OAV type model.
     *  @return	True for a static field.
     */
    protected static boolean	lookaheadStaticMethod(TokenStream input, OAVTypeModel tmodel, String[] imports)
    {
    	int index	= lookaheadType(input, tmodel, imports);
    	return index!=-1 &&	".".equals(input.LT(index+1).getText()) && input.LA(index+2)==JavaJadexLexer.IDENTIFIER  &&	"(".equals(input.LT(index+3).getText());
    }

    
    /**
     *  Lookahead for a type cast.
     *  @param input	The token stream.
     *  @param tmodel	The OAV type model.
     *  @return	True for a type cast.
     */
    protected static boolean	lookaheadCast(TokenStream input, OAVTypeModel tmodel, String[] imports)
    {
    	boolean	ret	= "(".equals(input.LT(1).getText());
    	if(ret)
    	{
    		int index	= lookaheadType(2, input, tmodel, imports);
    		ret	= index!=-1 && ")".equals(input.LT(index+1).getText());
    	}
    	return ret;
    }
}