/// <summary>
/// P_node_activations the specified node.
/// </summary>
/// <param name="node">The node.</param>
/// <param name="tok">The tok.</param>
/// <param name="w">The w.</param>
private void p_node_activation(ProductionNode node, Token tok, WME w)
{
Token new_token = make_token(node, tok, w);
node.Items.AddToFront(new_token);
int lhsCnt = node.Production.Lhs.Count - 1;
foreach (RightHandSideCondition rhsCondition in node.Production.Rhs)
{
WME newfact = new WME();
for (int f = 0; f < 3; f++)
{
Term term = rhsCondition.Fields[f];
if (term.TermType == TermType.Variable)
{
for (int i = lhsCnt; i >= 0; i--)
{
Condition lhsCondition = node.Production.Lhs[i];
if (lhsCondition.ConditionType == ConditionType.Positive)
{
int pos = lhsCondition.Contains(term);
if (pos >= 0)
{
Token tok2 = new_token.GetTokenUp(lhsCnt - i);
newfact.Fields[f] = tok2.WME[pos];
i = -1;
}
}
}
}
else
{
newfact.Fields[f] = term;
}
}
Activation newact = new Activation(newfact, rhsCondition.ConditionType);
if (node.Production.InferredFacts.Contains(newact) == false)
{
node.Production.InferredFacts.Add(newact);
}
}
}
/// <summary>
/// Adds a production.
/// </summary>
/// <remarks>
/// We are now ready to give the add-production procedure, which takes a production (actually,
/// just the conditions of the production | the match algorithm doesn't care what the actions are)
/// and adds it to the network. It follows the basic procedure given at the beginning of this section,
/// and uses the helper functions we have just defined. The last two lines of the procedure are a
/// bit vague, because the implementation of production nodes tends to vary from one system to
/// another. It is important to note that we build the net top-down, and each time we build a
/// new join node, we insert it at the head of its alpha memory's list of successors; these two facts
/// guarantee that descendents are on each alpha memory's list before any of their ancestors, just
/// as we required in Section 2.4.1 in order to avoid duplicate tokens.
/// </remarks>
/// <param name="prod">The Production.</param>
public void AddProduction(Production prod)
{
ProductionNode new_production = new ProductionNode();
new_production.Production = prod;
AddProduction(new_production, prod.Lhs);
prod.ProductionNode = new_production;
}