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Jadex Rules is a small lightweight rule engine, which currently employs the well-known Rete algorithm for highly efficient rule matching. Jadex rules is therefore similar to other rule engines like JESS and Drools. Despite the similarities there are also important differences between these systems: * Jadex Rules is very small and intended to be used as component of other software. Even though rules can be specified in a Java dialect as well as (a small variation of) the CLIPS language its primary usage is on the API level. Jadex Rules is currently the core component of the Jadex BDI reasoning engine. * Jadex Rules cleanly separates between state and rule representation. This allows the state implementation as well as the matcher to be flexibly exchanged. Some experiments have e.g. been conducted with a Jena representation. Regarding the matcher, it is planned to support also the Treat algorithm, which has a lower memory footprint than Rete. * Jadex Rules pays close attention to rule debugging. The state as well as the rete engine can be observed at runtime. The rule debugger provides functionalities to execute a rule program stepwise and also use rule breakpoints to stop the execution at those points.

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package jadex.rules.parser.conditions.javagrammar;

import jadex.rules.rulesystem.ICondition;
import jadex.rules.rulesystem.rules.Variable;
import jadex.rules.state.OAVObjectType;
import jadex.rules.state.OAVTypeModel;

import java.util.List;

/**
 *  Basic handler for context specific parsing issues.
 */
public class DefaultParserHelper implements IParserHelper
{
	//-------- attributes --------
	
	/** The build context. */
	protected BuildContext	context;
		
	//-------- constructors --------
	
	/**
	 *  Create a BDI parser helper.
	 *  @param condition	The predefined condition.
	 *  @param state	The state.
	 *  @param returnvar	The return value variable (if return value condition).
	 */
	public DefaultParserHelper(ICondition condition, OAVTypeModel tmodel)
	{
		this.context	= new BuildContext(condition, tmodel);
	}
	
	//-------- IParserHelper interface --------
	
	/**
	 *  Get a variable with a given name.
	 *  @param	name	The variable name.
	 *  @return The variable.
	 */
	public Variable	getVariable(String name)
	{
		Variable	ret	= context.getVariable(name);

		return ret;
	}

	/**
	 *  Add a variable.
	 *  @param var The variable.
	 */
	public void	addVariable(Variable var)
	{
		context.addVariable(var);
	}

	/**
	 *  Test, if a name refers to a pseudo variable (e.g. $beliefbase).
	 *  @param	name	The variable name.
	 *  @return True, if the name is a pseudo variable.
	 */
	public boolean	isPseudoVariable(String name)
	{
		return false;
	}

	/**
	 *  Get the conditions after parsing.
	 */
	public List	getConditions()
	{
		return context.getConditions();
	}

	/**
	 *	Get the build context.
	 */
	public BuildContext	getBuildContext()
	{
		return context;
	}
	
	/**
	 *	Get the replacement type for an object type in an existential declaration
	 *	E.g. when a flyweight should be replaced by the real state type
	 *  (IGoal $g instead of goal $g)
	 *  @param type	The type to be replaced.
	 *  @return a tuple containing the replacement type and the replacement value source (e.g. a function call recreating the flyweight from the state object).
	 */
	public Object[]	getReplacementType(OAVObjectType type)
	{
		return null;
	}
}