Package jess

Implements the core of the Jess rule engine.


Interface Summary
Accelerator An Accelerator generates Java versions of rule LHSs, compiles them and returns new TestBase objects to execute them.
ArgumentChecker A hook in the Jess parser that lets you perform compile-time validation of function-call arguments.
ClassResearcher The ClassResearcher is used to learn about a Java class mentioned in Jess source.
ConditionalElement A conditional element is either a Pattern or a Group of Patterns.
ErrorHandler Objects of this class are notified when an error occurs while parsing Jess code.
ErrorSink An error reporting tool for the Jess parser.
Filter An interface representing a generic boolean single-argument operation.
JessListener JessListener is a notification interface for Jess events.
Modular The Modular interface represents something that has a name and belongs to a module.
Named A Named thing has a name and a construct type.
Strategy An interface for conflict resolution strategies.
TestBase A generic Rete network test.
Tokenizer The Jess parser reads its input from a Tokenizer.
Userfunction Interface for all functions, user-defined or otherwise, callable from the Jess language.
Userpackage Interface for a collection of functions, user-defined or otherwise.
Visitable Implementation of the standard Visitor pattern.
Visitor Implementation of the standard Visitor pattern.
WatchConstants Things that can be watched by the "watch" command.
WorkingMemoryMarker A WorkingMemoryMarker is a "memento" that records the state of working memory.

Class Summary
Accumulate A special ConditionalElement used to implement "accumulate" conditional elements.
Activation A list of facts that satisfy a rule.
Batch This class implements the "batch" command, and several static methods are available that you can call to load Jess code.
BindingValue A class to represent a location within a rule LHS, used internally.
Context A Context represents a scope in which variables can be declared.
DefaultClassResearcher (C) 2013 Sandia Corporation
Deffacts A Deffacts is a list of facts that are asserted when the Rete engine is reset.
Deffunction A Deffunction is a function defined in the Jess language.
Deffunction.Argument Represents a formal parameter to a Deffunction.
Defglobal A Defglobal is a globally-accessible Jess variable.
Defmodule A named module containing rules, templates, and other constructs.
Defquery A Defquery is a way of requesting specific information in working memory from procedural code.
Defrule A Defrule is a specific action meant to be taken when certain conditions are met in working memory.
Deftemplate A Deftemplate defines a class of Jess facts.
ErrorHandler.DefaultHandler A default error handler implementation that just rethrows the parameter.
Fact A Fact is the fundamental unit of information in Jess's working memory.
FactIDValue Use this subclass of Value when you want to create a Value that represents a Fact.
Filter.ByClass A Filter implementation that passes objects that are instances of a given class.
Filter.ByModule A Filter implementation that passes Jess objects defined in a given module.
FilteringIterator A wrapper around an Iterator that applies a jess.Filter to each element, rejecting the ones that don't pass the filter.
Funcall jess.Funcall is a specialized subclass of ValueVector that represents a Jess function call.
FuncallValue A class to represent a Jess function call stored in a Value.
Group A group of patterns on the LHS of a rule, like an "and", "or", "not", "accumulate", or other special CE.
HashCodeComputer The HashCodeComputer allows hash code values for objects to be computed depending on their status as instances of "value" or "non-value" classes.
HasLHS Parent class of Defrules and Defqueries.
Help Help implements the "help" function in Jess.
Jesp The Jess language parser.
JessEvent JessEvents are used by JessEvent sources (like the Rete class) to convey information about interesting things that happen to registered event listeners.
JessEventAdapter A JessEventAdapter that lets you write JessEvent handlers in the Jess language.
JessToken A packet of info about a single token parsed from an input stream.
JessVersion (C) 2013 Sandia Corporation
$Id:,v 1.23 2008-11-11 15:34:06 ejfried Exp $
LongValue A LongValue represents a Java long in Jess.
Main An interactive interface for Jess.
Node Parent class of all nodes of the Rete network.
Pattern A Pattern represents a single conditional element on a rule LHS.
PrettyPrinter A PrettyPrinter knows how to format various Jess constructs for display.
QueryResult A ResultSet-like class to report the result of executing a Jess query.
ReaderTokenizer A simple Tokenizer implementation for the Jess language that takes its input from a Reader.
Rete The central class in the Jess library.
RU General utilities and manifest constants for Jess.
StackFrame A stack frame.
Test1 Holds a single test in a Pattern on the LHS of a Rule.
Token A Token is the fundamental unit of communication in the Rete network.
Value The class jess.Value is probably the one you'll use the most in working with Jess.
ValueFactory A ValueFactory creates and possibly caches Value instances, and instances of its subclasses.
ValueVector A self-extending array that only holds Value objects.
Variable A class to represent a Jess variable.

Exception Summary
JessException This is the base class of all exceptions thrown by any functions in the Jess library.
ParseException An error during parsing.
RuleCompilerException An error has occurred while a rule is being compiled.
TerminatedException An exception class used only by the JessDE debugger.

Package jess Description

Implements the core of the Jess rule engine. The most important class is jess.Rete, which serves as a facade for the rest of the library.

Related Documentation

For overviews, tutorials, examples, guides, and tool documentation, please see:

2013 Sandia Corporation