/// <summary>
/// Gets the symbol at the i-th index
/// </summary>
/// <param name="index">Index of the symbol</param>
/// <returns>The symbol at the given index</returns>
public SemanticElement this[int index]
{
get
{
SPPFNodeRef reference = cacheChildren[handleIndices[index]];
SPPFNode sppfNode = sppf.GetNode(reference.NodeId);
TableElemRef label = (sppfNode as SPPFNodeNormal).GetVersion(reference.Version).Label;
return(result.GetSemanticElementForLabel(label));
}
}
/// <summary>
/// Builds the final AST for the specified SPPF node reference
/// </summary>
/// <param name="reference">A reference to an SPPF node in a specific version</param>
/// <returns>The AST node for the SPPF reference</returns>
public AST.Node BuildFinalAST(SPPFNodeRef reference)
{
SPPFNode sppfNode = sppf.GetNode(reference.NodeId);
SPPFNodeVersion version = (sppfNode as SPPFNodeNormal).GetVersion(reference.Version);
if (version.ChildrenCount == 0)
{
return(new AST.Node(version.Label));
}
AST.Node[] buffer = new AST.Node[version.ChildrenCount];
for (int i = 0; i != version.ChildrenCount; i++)
{
buffer[i] = BuildFinalAST(version.Children[i]);
}
int first = result.Store(buffer, 0, version.ChildrenCount);
return(new AST.Node(version.Label, version.ChildrenCount, first));
}
/// <summary>
/// Adds the specified GSS label to the reduction cache with the given tree action
/// </summary>
/// <param name="gssLabel">The label to add to the cache</param>
/// <param name="action">The tree action to apply</param>
private void AddToCache(int gssLabel, TreeAction action)
{
if (action == TreeAction.Drop)
{
return;
}
SPPFNode node = sppf.GetNode(gssLabel);
if (node.IsReplaceable)
{
SPPFNodeReplaceable replaceable = node as SPPFNodeReplaceable;
// this is replaceable sub-tree
for (int i = 0; i != replaceable.ChildrenCount; i++)
{
AddToCache(sppf.GetNode(replaceable.Children[i].NodeId) as SPPFNodeNormal, replaceable.Actions[i]);
}
}
else
{
// this is a simple reference to an existing SPPF node
AddToCache(node as SPPFNodeNormal, action);
}
}