/// <summary>
/// foamliu, 2009/01/22, 得到规划.
///
/// </summary>
/// <returns></returns>
public List <string> GetPlan()
{
List <string> plan = new List <string>();
ActionLayer aLayer = this.m_firstProp.NextLayer;
while (aLayer != null)
{
plan.AddRange(aLayer.GetSelectedActions());
aLayer = aLayer.NextLayer.NextLayer;
}
List <string> temp = new List <string>();
temp.AddRange(plan);
plan.Clear();
foreach (string step in temp)
{
if (step.StartsWith("NOOP") == false && plan.Contains(step) == false)
{
plan.Add(step);
}
}
return(plan);
}
public PropositionLayer(ActionLayer prev)
{
this.m_prev = prev;
this.m_props = new List <Proposition>();
this.m_dict = new Dictionary <string, Proposition>();
this.m_conj = new Conjunction();
}
/// <summary>
/// foamliu, 2009/01/19, 扩展规划图.
///
/// Expand the planning graph, one action layer and one proposition layer at a time.
///
/// </summary>
private bool ExpandGraph()
{
for (int i = 1; i <= MaxLevel; i++)
{
// 创建 Ai 和 Pi+1
List <Action> actions = this.m_operators.GenActions(this.m_lastProp.Conjunction);
ActionLayer aLayer = new ActionLayer(this.m_lastProp, actions);
aLayer.Number = this.m_lastProp.Number;
this.m_lastProp.NextLayer = aLayer;
this.m_lastProp = aLayer.NextLayer;
this.m_lastProp.Number = aLayer.Number + 1;
if (GoalsReachable())
{
return(true);
}
// 测试是否 Level Off
if (LevelOff())
{
System.Console.WriteLine("Graph Levels Off at level" + m_lastProp.Number);
return(false);
}
}
System.Console.WriteLine("到达了预设的最大 Level:" + MaxLevel);
return(false);
}
/// <summary>
/// foamliu, 2009/01/19.
///
/// 从后往前一层层的搜索, 比如假设 Pj 层包含目标中的所有命题, 首先在 Aj-1 层找到以这些目标命题为正效果的行为,
/// 然后在 Pj-1 找这些行为的前提.
/// </summary>
public bool SearchPlan(Conjunction theGoals)
{
GenGoalSet(theGoals);
if (SearchTheLayer(0))
{
Conjunction newGoals = new Conjunction();
foreach (Action theAct in m_selectedActions)
{
newGoals.AddConjunction(theAct.PreCondition);
}
ActionLayer aLayer = m_prev.PrevLayer;
if (aLayer == null) // no more layers we reached the init state
{
return(true);
}
return(aLayer.SearchPlan(newGoals));
}
else
{
return(false);
}
}
/// <summary>
/// foamliu, 2009/01/19.
///
/// 如果一直找不到有效的规划, 则最后会到达一个命题层 P, 之后所有的命题层都与它完全相同.
/// 原因: 由于 No-Op actions 的存在, 一个命题出现在某个命题层中, 则它也必然出现在后续的命题层中.
/// 也就是命题层中命题数量是单调递增的, 而在命题有限的情况下又是有界的, 所以必然会有最大值.
///
/// 这个条件可以作为图扩展的结束测试.
/// </summary>
/// <returns></returns>
private bool LevelOff()
{
PropositionLayer p = this.m_lastProp;
ActionLayer act = p.PrevLayer;
if (!p.Equals(act.PrevLayer))
{
return(false);
}
return(true);
}
