org.deri.iris.api.graph
Interface IPredicateGraph

All Known Implementing Classes:

PredicateGraph

public interface IPredicateGraph

A graph to determine the dependencies of rules and predicates to each other.

$Id$

Version:

$Revision$

Author:

Richard P??ttler (richard dot poettler at deri dot org)

Method Summary

void	addRule(Collection<IRule> r) Adds a collection of rules to the graph.
void	addRule(IRule rule) Adds a rule to the graph.
int	countNegativesForCycle() Returns the number of negative Literals in the cycle.
boolean	detectCycles() Determines whether the rules are recursive.
Set<LabeledEdge<IPredicate,Boolean>>	findEdgesForCycle() Determines the edges contained in the cycle.
Set<IPredicate>	findVertexesForCycle() Determines the vertexes contained in the cycle.
Set<IPredicate>	getDepends(IPredicate p) Returns a set of predicates the given one depends on.
Comparator<IPredicate>	getPredicateComparator() Returns a compareator which compares two predicates depending on their dependencies of their rules.
Comparator<IRule>	getRuleComparator() Returs a comparator which compares two rules depending on their dependencies of each other.

Method Detail

addRule

void addRule(IRule rule)

Adds a rule to the graph.

Parameters:

rule - the rule to add

Throws:

NullPointerException - if the rule is null

detectCycles

boolean detectCycles()

Determines whether the rules are recursive.

Returns:

true if they are recursive, otherwise false

findVertexesForCycle

Set<IPredicate> findVertexesForCycle()

Determines the vertexes contained in the cycle.

Returns:

a Set containing all the vertexes

findEdgesForCycle

Set<LabeledEdge<IPredicate,Boolean>> findEdgesForCycle()

Determines the edges contained in the cycle.

Returns:

a Set containing all the vertexes

countNegativesForCycle

int countNegativesForCycle()

Returns the number of negative Literals in the cycle.

Returns:

the number of negative literals

addRule

void addRule(Collection<IRule> r)

Adds a collection of rules to the graph.

Parameters:

r - the collection of rules

Throws:

NullPointerException - if the collections is or contains null

getDepends

Set<IPredicate> getDepends(IPredicate p)

Returns a set of predicates the given one depends on.

Parameters:

p - predicate for which to check for dependencies

Returns:

the predicates the predicate depends on

Throws:

NullPointerException - if the predicate is null

getPredicateComparator

Comparator<IPredicate> getPredicateComparator()

Returns a compareator which compares two predicates depending on their dependencies of their rules.

If one of the compared predicate isn't in the graph, or there isn't a path from one predicate to the other 0 will be returned. If the first predicate depends on the second one, the first one will be determined to be bigger, and vice versa.

Returns:

the comparator

getRuleComparator

Comparator<IRule> getRuleComparator()

Returs a comparator which compares two rules depending on their dependencies of each other.

The rules will compared according to their headpredicates.

Returns:

the comparator

See Also:

getPredicateComparator()