net.esper.pattern
Class EvalRootNode
java.lang.Object
net.esper.pattern.EvalNode
net.esper.pattern.EvalRootNode
- All Implemented Interfaces:
- Serializable, PatternStarter, MetaDefItem
public final class EvalRootNode
- extends EvalNode
- implements PatternStarter
This class is always the root node in the evaluation tree representing an event expression.
It hold the handle to the EPStatement implementation for notifying when matches are found.
- See Also:
- Serialized Form
EvalRootNode
public EvalRootNode()
start
public final PatternStopCallback start(PatternMatchCallback callback,
PatternContext context)
- Description copied from interface:
PatternStarter
- An event expression was started and supplies the callback to use when matching events appear.
Returns the callback to use to stop the event expression.
- Specified by:
start
in interface PatternStarter
- Parameters:
callback
- must be supplied to indicate what to call when the expression turns truecontext
- is the context for handles to services required for evaluation.
- Returns:
- a callback to stop the expression again
newState
public final EvalStateNode newState(Evaluator parentNode,
MatchedEventMap beginState,
PatternContext context,
Object stateNodeId)
- Description copied from class:
EvalNode
- Create the evaluation state node containing the truth value state for each operator in an
event expression.
- Specified by:
newState
in class EvalNode
- Parameters:
parentNode
- is the parent evaluator node that this node indicates a change in truth value tobeginState
- is the container for events that makes up the start statecontext
- is the handle to services required for evaluationstateNodeId
- is the new state object's identifier
- Returns:
- state node containing the truth value state for the operator
toString
public final String toString()
- Overrides:
toString
in class Object