Package com.bea.p13n.expression

This package provides interfaces and classes for constructing and executing runtime interpreted expression trees.

See
Description

Interface Summary

Evaluator	An interface that is implemented by the classes that can evaluate an Expression.
Executor	The Executor interface is implemented by a class that can perform the Unification-Validation-Evaluation cycle on an Expression.
Expression	An interface implemented by all simple and complex expressions.
ExpressionList	Simple wrapper interface for List for storing sub-components of an expression.
Optimizer	The Optimizer interface is implemented by the class that can optimize an Expression.
ProxyExpression	An interface implemented by the class that need to act as a proxy to the original expression.
UnificationList	An interface for a class that maps variable names to the variable values.
Unifier	An interface implemented by classes that can unify (replace occurrences of a variable with a value) an expression.
Validator	An interface that is implemented by a class that can validate various types of expressions.

Class Summary

ExpressionFactory

A factory class to create instances of the various implementation classes in the expression package.

Exception Summary

ComparisonException	An Exception class for Comparison related exceptions.
ExpressionException	Base class for all Exceptions in the expression package.
IntrospectionException	Exception class for Java reflection introspection errors.
InvalidExpressionException	Exception class to signal Expression validation errors.
MethodCallException	Exception class for MethodCall related exceptions.
UnboundVariableException	An Exception class to signal that a variable in an expression has not been unified with a value.

Package com.bea.p13n.expression Description

This package provides interfaces and classes for constructing and executing runtime interpreted expression trees. Expression trees can contain variables, common operators, Java literals and arbitrary method calls. This package also provides various services such as validation for validating an expression, unification for unifying an expression, and evaluation for evaluating an expression. These service can be constructed and used through the ExpressionFactory.

The expression package includes the following classes of operators:

• Logical
• Math
• Collection
• String
• Comparative
• Miscellaneous

Note: There is a special Expression class called ProxyExpression that acts as a proxy to an embedded expression.

See Also

ExpressionFactory, Evaluator, Validator, Unifier, Executor, Expression, ProxyExpression