private void StartCapture(ref RxContext cxt, int group)
{
for (int i = cxt.LastOpenCapture + 1; i < group; ++i)
cxt.Captures[i].Start = cxt.Captures[i].End = -1;
cxt.Captures[group].Start = cxt.Pos;
cxt.Captures[group].End = -1;
if (cxt.LastOpenCapture < group)
cxt.LastOpenCapture = group;
}
private void SaveGroups(ref RxContext cxt, int start, int end,
bool clear, out RxSavedGroups groups)
{
groups.Start = start;
groups.LastOpenCapture = cxt.LastOpenCapture;
groups.LastClosedCapture = cxt.LastClosedCapture;
groups.Data = new RxCapture[end - start];
for (int i = start; i < end; ++i)
{
if (clear || cxt.Captures.Length <= i)
groups.Data[i - start].Start = groups.Data[i - start].End = -1;
else
{
groups.Data[i - start] = cxt.Captures[i];
}
}
}
private void EndCapture(ref RxContext cxt, int group)
{
cxt.Captures[group].End = cxt.Pos;
cxt.LastClosedCapture = group;
}
private void RestoreGroups(ref RxContext cxt, ref RxSavedGroups groups)
{
if (groups.Data == null)
return;
for (int i = 0; i < groups.Data.Length; ++i)
cxt.Captures[i + groups.Start] = groups.Data[i];
cxt.LastOpenCapture = groups.LastOpenCapture;
cxt.LastClosedCapture = groups.LastClosedCapture;
}
private int Backtrack(ref RxContext cxt)
{
if (cxt.States.Count > 0)
{
var btState = cxt.States[cxt.States.Count - 1];
cxt.States.RemoveAt(cxt.States.Count - 1);
cxt.Pos = btState.Pos;
int index = btState.Target;
if (index >= 0)
{
if (btState.Group >= 0)
cxt.Groups.RemoveRange(btState.Group, cxt.Groups.Count - btState.Group);
RestoreGroups(ref cxt, ref btState.Groups);
return index;
}
}
if (cxt.StateBacktrack.Count > 0)
{
int btIdx = cxt.StateBacktrack[cxt.StateBacktrack.Count - 1];
cxt.StateBacktrack.RemoveAt(cxt.StateBacktrack.Count - 1);
cxt.States.RemoveRange(btIdx, cxt.States.Count - btIdx);
if (cxt.Groups.Count > 0)
cxt.Groups.RemoveAt(cxt.Groups.Count - 1);
return Backtrack(ref cxt);
}
else
{
return -1;
}
}