com.rabbitmq.jms.parse

Interface Evaluator

All Known Implementing Classes:

SqlEvaluator

public interface Evaluator

An Evaluator will evaluate an expression.

An evaluator takes a set of values (the environment) and evaluates an expression in it, returning a Result. For example, it might evaluate a (previously given) boolean expression given a set of values assigned to variables.

Method Summary

Modifier and Type	Method and Description
boolean	evaluate(java.util.Map<java.lang.String,java.lang.Object> env) Evaluates the (given) expression with the environment given.
boolean	evaluatorOk() This call is idempotent.
java.lang.String	getErrorMessage() This call is idempotent.

Method Detail

evaluate

boolean evaluate(java.util.Map<java.lang.String,java.lang.Object> env)

Evaluates the (given) expression with the environment given. This call should not fail, provided evaluatorOk() is true.

Parameters:

env - - the values of the variables used when evaluating the expression

Returns:

the evaluated result: true or false

evaluatorOk

boolean evaluatorOk()

This call is idempotent.

Returns:

true if the evaluator can run cleanly; false otherwise

getErrorMessage

java.lang.String getErrorMessage()

This call is idempotent.

Returns:

null if evaluatorOk() is false; otherwise an error message denoting the type of failure to initialise.