/// <summary>
/// Gets the GSS label already in history for the given GSS generation and symbol
/// </summary>
/// <param name="generation">The index of a GSS generation</param>
/// <param name="symbol">A symbol to look for</param>
/// <returns>The existing GSS label, or the epsilon label</returns>
public int GetLabelFor(int generation, TableElemRef symbol)
{
HistoryPart hp = GetHistoryPart(generation);
if (hp == null)
{
return(SPPF.EPSILON);
}
for (int i = 0; i != hp.next; i++)
{
if (sppf.GetNode(hp.data[i]).OriginalSymbol == symbol)
{
return(hp.data[i]);
}
}
return(SPPF.EPSILON);
}
/// <summary>
/// Adds the specified GSS label to the current history
/// </summary>
/// <param name="generation">The current generation</param>
/// <param name="label">The label identifier of the SPPF node to use as a GSS label</param>
private void AddToHistory(int generation, int label)
{
HistoryPart hp = GetHistoryPart(generation);
if (hp == null)
{
hp = poolHPs.Acquire();
hp.generation = generation;
hp.next = 0;
if (history.Length == nextHP)
{
Array.Resize(ref history, history.Length + INIT_HISTORY_SIZE);
}
history[nextHP++] = hp;
}
if (hp.next == hp.data.Length)
{
Array.Resize(ref hp.data, hp.data.Length + INIT_HISTORY_PART_SIZE);
}
hp.data[hp.next++] = label;
}
