// Draws trabasso dependencies between steps in the plan.
private void CreateTrabassos()
{
// Reset the causal links.
trabassos = new List <CausalLink>();
// Create an empty list of flaws.
List <Flaw> flaws = new List <Flaw>();
// Create a list of steps that includes the initial and goal steps.
List <Operator> allSteps = new List <Operator>();
// Add the initial step to the new list.
allSteps.Add(InitialStep);
// Loop through the plan's steps.
foreach (Operator step in steps)
{
// Add the current step to the new list.
allSteps.Add(step);
// Add every precondition to the flaw list.
foreach (Predicate precon in step.Preconditions)
{
flaws.Add(new Flaw(precon, step));
}
}
// Add the goal step to the new list.
allSteps.Add(GoalStep);
// Add every goal precondition to the flaw list.
foreach (Predicate precon in GoalStep.Preconditions)
{
flaws.Add(new Flaw(precon, GoalStep));
}
// Resolve every flaw.
while (flaws.Count > 0)
{
List <IOperator> span = new List <IOperator>();
span.Add(flaws.First().step.Clone() as Operator);
Operator found = null;
Predicate literal = flaws.First().precondition.Clone() as Predicate;
// Loop through the steps:
// Start at the flaw's step,
// Loop backward to the initial step.
for (int i = allSteps.IndexOf(flaws.First().step) - 1; i >= 0; i--)
{
// Loop through each step's effects.
foreach (Predicate effect in allSteps[i].Effects)
{
if (literal.Equals(effect))
{
found = allSteps.ElementAt(i).Clone() as Operator;
}
if (found != null)
{
// Check to see if the effect matches the flaw's predicate.
if (literal.IsInverse(effect))
{
// Create a new causal link object.
CausalLink link = new CausalLink();
// Set the link's predicate to the flaw's precondition.
link.Predicate = flaws[0].precondition;
// Set the link's head to the flaw's step.
link.Head = flaws[0].step;
// Set the link's tail to the effect step.
link.Tail = found;
// Set the link's span.
link.Span = span;
// Add the causal link to the list of links.
trabassos.Add(link);
// Exit the loop.
i = 0;
found = null;
}
}
}
span.Add(allSteps.ElementAt(i).Clone() as Operator);
}
// If a step was not found with an effect of the reverse literal...
// Check to see if the reverse exists in the initial state.
if (found != null)
{
// A boolean that tracks whether the reversed literal was found in the initial state.
bool inInitial = false;
if (literal.Sign)
{
// Loop through the initial state literals and check to see if the reversed literal exists.
foreach (Predicate init in initial.Predicates)
{
if (literal.Equals(init))
{
inInitial = true;
}
}
}
else
{
inInitial = true;
// Loop through the initial state literals and check to see if the reversed literal exists.
foreach (Predicate init in initial.Predicates)
{
if (literal.IsInverse(init))
{
inInitial = false;
}
}
}
// If the literal was not enabled in the initial state, add it.
if (!inInitial)
{
trabassos.Add(new CausalLink(flaws.First().precondition, flaws.First().step, found, span));
}
}
// Remove the current flaw from the list.
flaws.RemoveAt(0);
}
}
// Draws dependencies between steps in the plan.
private void CreateDependencies()
{
// Reset the causal links.
dependencies = new List <CausalLink>();
// Create an empty list of flaws.
List <Flaw> flaws = new List <Flaw>();
// Create a list of steps that includes the initial and goal steps.
List <Operator> allSteps = new List <Operator>();
// Add the initial step to the new list.
allSteps.Add(InitialStep);
// Loop through the plan's steps.
foreach (Operator step in steps)
{
// Add the current step to the new list.
allSteps.Add(step);
// Add every precondition to the flaw list.
foreach (Predicate precon in step.Preconditions)
{
flaws.Add(new Flaw(precon, step));
}
}
// Add the goal step to the new list.
allSteps.Add(GoalStep);
// Add every goal precondition to the flaw list.
foreach (Predicate precon in GoalStep.Preconditions)
{
flaws.Add(new Flaw(precon, GoalStep));
}
// Resolve every flaw.
while (flaws.Count > 0)
{
bool found = false;
List <IOperator> span = new List <IOperator>();
span.Add(flaws.First().step.Clone() as Operator);
// Loop through the steps:
// Start at the flaw's step,
// Loop backward to the initial step.
for (int i = allSteps.IndexOf(flaws.First().step) - 1; i >= 0; i--)
{
// Loop through each step's effects.
foreach (Predicate effect in allSteps[i].Effects)
{
// Check to see if the effect matches the flaw's predicate.
if (flaws.First().precondition.Equals(effect))
{
// Record that the flaw has been fixed.
found = true;
// Create a new causal link object.
CausalLink link = new CausalLink();
// Set the link's predicate to the flaw's precondition.
link.Predicate = flaws[0].precondition;
// Set the link's head to the flaw's step.
link.Head = flaws[0].step;
// Set the link's tail to the effect step.
link.Tail = allSteps[i];
// Set the link's span.
link.Span = span;
// Add the causal link to the list of links.
dependencies.Add(link);
// Exit the loop.
i = 0;
}
}
span.Add(allSteps.ElementAt(i).Clone() as Operator);
}
// If the flaw wasn't fixed, add it to the initial state.
if (!found)
{
dependencies.Add(new CausalLink(flaws.First().precondition, flaws.First().step, allSteps.First(), span));
}
// Remove the current flaw from the list.
flaws.RemoveAt(0);
}
}
