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com.hp.hpl.jena.reasoner.rulesys.impl.oldCode
Class RuleState
java.lang.Objectcom.hp.hpl.jena.reasoner.rulesys.impl.oldCode.RuleState
- public class RuleState
- extends java.lang.Object
Part of the backward chaining rule interpreter. A RuleState represents the state of a partially expanded search tree for a single Rule. The RuleStates are linked back in an OR tree to a root goal which is being satisfied. Each RuleState shares a pointer to a RuleInstance which holds references for the rule being processed and the goal which the rule is satisfying.
Encapuslation warning: this object is used in the tight inner loop of the engine so we access its field pointers directly rather than through accessor methods.
- Version:
- $Revision: 1.4 $ on $Date: 2005/02/21 12:18:05 $
| Field Summary | |
(package private) int |
clauseIndex
The clause number in the rule to be processed next. |
protected com.hp.hpl.jena.reasoner.rulesys.impl.BindingVector |
env
The binding environment for the rule so far |
protected com.hp.hpl.jena.reasoner.rulesys.Functor |
functorMatch
functor node for object binding |
protected GoalState |
goalState
The continuation point for the rule clause being processed |
protected boolean |
isScheduled
Flag to indicate that rule state is scheduled on the agenda |
(package private) int |
objectBind
binding offset for object field, -1 if none |
(package private) int |
predicateBind
binding offset for predicate field, -1 if none |
protected RuleState |
prev
the parent RuleState for backtracking |
protected RuleInstance |
ruleInstance
Reference to a package of information on the rule being processed |
(package private) int |
subjectBind
binding offset for subject field, -1 if none |
| Constructor Summary | |
private |
RuleState(RuleInstance ruleInstance,
com.hp.hpl.jena.reasoner.rulesys.impl.BindingVector env,
GoalState goalState,
int index)
Constructor used when creating the first RuleState for a rule. |
|
RuleState(RuleState parent,
com.hp.hpl.jena.reasoner.TriplePattern clause,
int index,
com.hp.hpl.jena.reasoner.rulesys.impl.BindingVector env)
Normal constructor. |
| Method Summary | |
void |
close()
Close a non-longer needed rule state. |
boolean |
couldProcess()
Return true if it seems worth scheduling this RuleState. |
static RuleState |
createInitialState(com.hp.hpl.jena.reasoner.rulesys.Rule rule,
GoalResults generator)
Create the first RuleState for using a given rule to satisfy a goal. |
com.hp.hpl.jena.graph.Triple |
getResult(com.hp.hpl.jena.reasoner.rulesys.impl.BindingVector newenv)
Return the final goal result, based on the given binding environment |
private void |
initMapping(com.hp.hpl.jena.reasoner.TriplePattern goal)
Initialize the mapping pointers that map result values to environment bindings |
com.hp.hpl.jena.reasoner.rulesys.impl.BindingVector |
newEnvironment(com.hp.hpl.jena.graph.Triple result)
Return a new binding environment based on this one but extended by the matches resulting from the given triple result for this state. |
(package private) java.lang.Object |
next()
Return the next match for this clause (or FAIL or SUSPEND) |
protected int |
nextClauseIndex()
Return the index of the next body clause to try. |
private static int |
scoreClauseBoundness(com.hp.hpl.jena.reasoner.TriplePattern clause,
com.hp.hpl.jena.reasoner.TriplePattern head,
com.hp.hpl.jena.reasoner.rulesys.impl.BindingVector env)
Score a clause in terms of groundedness using simple heurisitcs. |
private static int |
scoreNodeBoundness(com.hp.hpl.jena.graph.Node n,
com.hp.hpl.jena.reasoner.TriplePattern head,
com.hp.hpl.jena.reasoner.rulesys.impl.BindingVector env)
Score a node from a pattern as part of scoreClauseBoundedness. |
java.lang.String |
toString()
Printable string |
| Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait |
| Field Detail |
ruleInstance
protected RuleInstance ruleInstance
- Reference to a package of information on the rule being processed
prev
protected RuleState prev
- the parent RuleState for backtracking
env
protected com.hp.hpl.jena.reasoner.rulesys.impl.BindingVector env
- The binding environment for the rule so far
goalState
protected GoalState goalState
- The continuation point for the rule clause being processed
isScheduled
protected boolean isScheduled
- Flag to indicate that rule state is scheduled on the agenda
clauseIndex
int clauseIndex
- The clause number in the rule to be processed next.
subjectBind
int subjectBind
- binding offset for subject field, -1 if none
predicateBind
int predicateBind
- binding offset for predicate field, -1 if none
objectBind
int objectBind
- binding offset for object field, -1 if none
functorMatch
protected com.hp.hpl.jena.reasoner.rulesys.Functor functorMatch
- functor node for object binding
| Constructor Detail |
RuleState
public RuleState(RuleState parent, com.hp.hpl.jena.reasoner.TriplePattern clause, int index, com.hp.hpl.jena.reasoner.rulesys.impl.BindingVector env)
- Normal constructor. Creates a new RuleState as an extension to an existing one.
RuleState
private RuleState(RuleInstance ruleInstance, com.hp.hpl.jena.reasoner.rulesys.impl.BindingVector env, GoalState goalState, int index)
- Constructor used when creating the first RuleState for a rule.
The caller is responsible for initializing the mapping.
| Method Detail |
next
java.lang.Object next()
- Return the next match for this clause (or FAIL or SUSPEND)
newEnvironment
public com.hp.hpl.jena.reasoner.rulesys.impl.BindingVector newEnvironment(com.hp.hpl.jena.graph.Triple result)
- Return a new binding environment based on this one but extended
by the matches resulting from the given triple result for this state.
getResult
public com.hp.hpl.jena.graph.Triple getResult(com.hp.hpl.jena.reasoner.rulesys.impl.BindingVector newenv)
- Return the final goal result, based on the given binding environment
couldProcess
public boolean couldProcess()
- Return true if it seems worth scheduling this RuleState. This will be the case
if the RS can be immediately disposed of due to being complete or if there is a result known already.
initMapping
private void initMapping(com.hp.hpl.jena.reasoner.TriplePattern goal)
- Initialize the mapping pointers that map result values to environment bindings
nextClauseIndex
protected int nextClauseIndex()
- Return the index of the next body clause to try.
Takes clause reordering into account.
close
public void close()
- Close a non-longer needed rule state. This will decrement
the reference count of the goal table entry (this might have been
the last RuleState working on that entry) and will close any
iterators in the goal state.
createInitialState
public static RuleState createInitialState(com.hp.hpl.jena.reasoner.rulesys.Rule rule, GoalResults generator)
- Create the first RuleState for using a given rule to satisfy a goal.
scoreClauseBoundness
private static int scoreClauseBoundness(com.hp.hpl.jena.reasoner.TriplePattern clause, com.hp.hpl.jena.reasoner.TriplePattern head, com.hp.hpl.jena.reasoner.rulesys.impl.BindingVector env)
- Score a clause in terms of groundedness using simple heurisitcs.
For this case we are only considering head variables which occur
in the clause and score on boundedness of these.
scoreNodeBoundness
private static int scoreNodeBoundness(com.hp.hpl.jena.graph.Node n, com.hp.hpl.jena.reasoner.TriplePattern head, com.hp.hpl.jena.reasoner.rulesys.impl.BindingVector env)
- Score a node from a pattern as part of scoreClauseBoundedness.
toString
public java.lang.String toString()
- Printable string
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SUMMARY: JAVADOC | SOURCE | DOWNLOAD | NESTED | FIELD | CONSTR | METHOD |
DETAIL: FIELD | CONSTR | METHOD | ||||||||