/// <summary>
/// Tries to reorder patterns when the initial ordering is considered poor
/// </summary>
/// <param name="gp">Graph Pattern</param>
/// <param name="desiredVariables">Variables that are desired</param>
/// <param name="start">Point at which to start looking for better matches</param>
/// <param name="end">Point at which to move the better match to</param>
private void TryReorderPatterns(GraphPattern gp, List<String> desiredVariables, int start, int end)
{
if (end > start) return;
//Find the first pattern which does contain a pre-existing variable
for (int i = start; i < gp.TriplePatterns.Count; i++)
{
if (gp.TriplePatterns[i].Variables.Any(v => desiredVariables.Contains(v)))
{
int newEnd = i;
desiredVariables.AddRange(gp.TriplePatterns[i].Variables.Where(v => desiredVariables.Contains(v)));
while (i > end)
{
//Swap Patterns around
gp.SwapTriplePatterns(i - 1, i);
i--;
}
end = newEnd;
}
}
}
