ptolemy.actor.util

Interface Dependency

All Superinterfaces:

java.lang.Comparable<Dependency>

All Known Implementing Classes:

BooleanDependency, RealDependency, SuperdenseDependency

public interface Dependency
extends java.lang.Comparable<Dependency>

This interface provides a dependency for causality interfaces as described in the paper "Causality Interfaces for Actor Networks" by Ye Zhou and Edward A. Lee, ACM Transactions on Embedded Computing Systems (TECS), April 2008, as available as Technical Report No. UCB/EECS-2006-148, November 16, 2006.

A dependency represents a causality relationship between two ports. Implementations of this interface are required to satisfy certain algebraic properties, but as long as these are satisfied, there is considerable freedom.

Since:

Ptolemy II 8.0

Version:

$Id$

Author:

Edward A. Lee

Pt.AcceptedRating:

Red (eal)

Pt.ProposedRating:

Yellow (eal)

Field Summary

Fields

Modifier and Type	Field and Description
static int	EQUALS Return value of compareTo() if this is equal to the argument.
static int	GREATER_THAN Return value of compareTo() if this is greater than the argument.
static int	INCOMPARABLE Return value of compareTo() if this is incomparable to the argument.
static int	LESS_THAN Return value of compareTo() if this is less than the argument.

Method Summary

Modifier and Type	Method and Description
Dependency	oPlus(Dependency d) Return a dependency that results from parallel composition of this one and the specified one.
Dependency	oPlusIdentity() Return the dependency that when added to any other dependency using oPlus() yields the other dependency.
Dependency	oTimes(Dependency d) Return a dependency that results from serial composition of this one and the specified one.
Dependency	oTimesIdentity() Return the dependency that when multiplied by any other dependency using oTimes() yields the other dependency.

Methods inherited from interface java.lang.Comparable

compareTo

Field Detail

EQUALS

static final int EQUALS

Return value of compareTo() if this is equal to the argument.

See Also:

Constant Field Values

GREATER_THAN

static final int GREATER_THAN

Return value of compareTo() if this is greater than the argument.

See Also:

Constant Field Values

INCOMPARABLE

static final int INCOMPARABLE

Return value of compareTo() if this is incomparable to the argument.

See Also:

Constant Field Values

LESS_THAN

static final int LESS_THAN

Return value of compareTo() if this is less than the argument.

See Also:

Constant Field Values

Method Detail

oPlus

Dependency oPlus(Dependency d)

Return a dependency that results from parallel composition of this one and the specified one. This is required to be associative and commutative. That is, d1.oPlus(d2).oPlus(d3) should be equal to d1.oPlus(d2.oPlus(d3)), and d1.oPlus(d2) should be equal to d2.oPlus(d1). In addition, any implementation should be idempotent, meaning that d.oPlus(d) is equal to d.

Parameters:

d - The dependency to add.

Returns:

A dependency whose value is the logical OR of the two dependency values.

Throws:

java.lang.ClassCastException - if d is not a BooleanDependency.

oPlusIdentity

Dependency oPlusIdentity()

Return the dependency that when added to any other dependency using oPlus() yields the other dependency.

Returns:

The additive identity.

oTimes

Dependency oTimes(Dependency d)

Return a dependency that results from serial composition of this one and the specified one. This is required to be associative, but not necessarily commutative. That is, d1.oTimes(d2).oTimes(d3) should be equal to d1.oTimes(d2.oTimes(d3)). Moreover, it should be distributive over oPlus. That is, d1.oTimes(d2.oPlus(d3)) should be equal to (d1.oTimes(d2)).oPlus(d1.oTimes(d3)).

Parameters:

d - The dependency to multiply.

Returns:

A dependency whose value is the logical AND of the value of this one and the specified one.

Throws:

java.lang.ClassCastException - if d is not a BooleanDependency.

oTimesIdentity

Dependency oTimesIdentity()

Return the dependency that when multiplied by any other dependency using oTimes() yields the other dependency.

Returns:

The multiplicative identity.