/// <summary>
/// When adding a production that uses an NCC, we use the build-or-share-ncc-nodes function.
/// Most of the work in this function is done by the helper function build-or-share-network-for-
/// conditions, which builds or shares the whole subnetwork for the subconditions of the NCC. The
/// rest of the build-or-share-ncc-nodes function then builds or shares the NCC and NCC partner
/// nodes.
/// </summary>
/// <param name="parent">The parent.</param>
/// <param name="c">The c.</param>
/// <param name="earlier_conds">The earlier_conds.</param>
/// <returns></returns>
private ReteNode build_or_share_ncc_nodes(JoinNode parent, Condition c, List<LeftHandSideCondition> earlier_conds)
{
ReteNode bottom_of_subnetwork = build_or_share_network_for_conditions(parent, c.SubConditions, earlier_conds);
foreach (ReteNode child in parent.Children)
{
if (child.Type == ReteNodeType.NCC && ((NCCNode) child).Partner.Parent == bottom_of_subnetwork)
{
return child;
}
}
NCCNode new_node = new NCCNode();
NCCPartnerNode new_partner = new NCCPartnerNode();
new_node.Type = ReteNodeType.NCC; // "NCC";
new_partner.Type = ReteNodeType.NCCPartner; // "NCC-partner";
parent.IsHeadOfSubNetwork = true;
new_node.Parent = parent;
parent.Children.Add(new_node);
new_partner.Parent = bottom_of_subnetwork;
bottom_of_subnetwork.Children.AddToFront(new_partner);
new_node.Partner = new_partner;
new_partner.NCCNode = new_node;
new_partner.NumberOfConjuncts = c.SubConditions.Count;
update_new_node_with_matches_from_above(new_node);
update_new_node_with_matches_from_above(new_partner);
return new_node;
}
/// <summary>
/// Ncc_node_left_activations the specified node.
/// </summary>
/// <remarks>
/// Our ncc-node-left-activation procedure is similar to the negative-node-left-activation procedure
/// (page 42). In both cases, we need to find the join results for a new token. For negative
/// nodes, we compute these join results by scanning the WMEs in an alpha memory and performing
/// the join tests on them. For NCC nodes, the join results have already been computed by the
/// subnetwork, so we simply look at the new-result-buffer in the NCC partner node to find them.
/// </remarks>
/// <param name="node">The node.</param>
/// <param name="t">The t.</param>
/// <param name="w">The w.</param>
private void ncc_node_left_activation(NCCNode node, Token t, WME w)
{
Token new_token = make_token(node, t, w);
node.Items.AddToFront(new_token);
foreach (Token result in node.Partner.NewResultBuffer)
{
node.Partner.NewResultBuffer.Remove(result);
new_token.NCCResults.AddToFront(result);
result.Owner = new_token;
}
if (new_token.NCCResults.Count == 0)
{
foreach (ReteNode child in node.Children)
{
left_activation(child, new_token, null);
}
}
}