ubc.cs.JLog.Builtins.Goals
Class jOpGoal

java.lang.Object
  ubc.cs.JLog.Foundation.jGoal
      ubc.cs.JLog.Builtins.Goals.jOpGoal

All Implemented Interfaces:

iName, iNameArity

public class jOpGoal
extends jGoal

Field Summary

protected jTerm	operation
protected jTerm	priority
protected jTerm	specifier

Fields inherited from class ubc.cs.JLog.Foundation.jGoal

next

Constructor Summary

jOpGoal(jTerm t1, jTerm t2, jTerm t3)

Method Summary

int	getArity() Returns the arity of this instance.
String	getName() Returns the name of this instance.
protected int	getPriority(jTerm t)
protected int	getSpecifier(jTerm t)
boolean	prove(iGoalStack goals, iGoalStack proved) Attempt to prove the goal represented by this jGoal.
protected void	registerOperation(jTerm t, pOperatorRegistry registry, int pri, int stype)
protected void	registerOperations(pOperatorRegistry registry, int pri, int stype)
boolean	retry(iGoalStack goals, iGoalStack proved) Attempt to prove the goal represented by this jGoal.
String	toString()

Methods inherited from class ubc.cs.JLog.Foundation.jGoal

internal_remove, internal_restore

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

priority

protected jTerm priority

specifier

protected jTerm specifier

operation

protected jTerm operation

Constructor Detail

jOpGoal

public jOpGoal(jTerm t1,
               jTerm t2,
               jTerm t3)

Method Detail

prove

public boolean prove(iGoalStack goals,
                     iGoalStack proved)

Description copied from class: jGoal

Attempt to prove the goal represented by this jGoal. Goal must not be on either stack to prove (pop off goals stack before prove call). Goal must place itself on the appropriate stack before returning. proved stack if 'proved', goals stack otherwise. Since proved doesn't pop the stack we don't need a try/catch block. Must be called at least once before calling retry.

Specified by:

prove in class jGoal

Parameters:

goals - iGoalStack containing goals yet to be proved.

proved - iGoalStack containing evaluated goals (goals that may already be proved, or awaiting their child goals to be proved).

Returns:

boolean is true if this goal ended up on proved, false otherwise.

retry

public boolean retry(iGoalStack goals,
                     iGoalStack proved)

Description copied from class: jGoal

Attempt to prove the goal represented by this jGoal. Goal must not be on either stack to retry (pop off proved stack before retry call). Goal must place itself on the goal stack, and normally need not pop either stack. Since retry doesn't pop the stack we don't need a try/catch block.

Specified by:

retry in class jGoal

Parameters:

goals - iGoalStack containing goals yet to be proved.

proved - iGoalStack containing evaluated goals (goals that may already be proved, or awaiting their child goals to be proved).

Returns:

boolean is true if the prover should attempt a prove on this goal, false otherwise.

getPriority

protected int getPriority(jTerm t)

getSpecifier

protected int getSpecifier(jTerm t)

registerOperations

protected void registerOperations(pOperatorRegistry registry,
                                  int pri,
                                  int stype)

registerOperation

protected void registerOperation(jTerm t,
                                 pOperatorRegistry registry,
                                 int pri,
                                 int stype)

getName

public String getName()

Description copied from interface: iName

Returns the name of this instance.

Returns:

String containing name of this instance.

getArity

public int getArity()

Description copied from interface: iNameArity

Returns the arity of this instance.

Returns:

int whose value is the arity of this instance.

toString

public String toString()

Overrides:

toString in class Object