internal virtual State.HeadPosition GetSeparator(int nodeNum)
{
if (nodeNum >= stack.Size())
{
return(null);
}
TreeShapedStack <Tree> stack = this.stack;
for (int i = 0; i < nodeNum; ++i)
{
stack = stack.Pop();
}
Tree node = stack.Peek();
int head = ShiftReduceUtils.HeadIndex(node);
if (separators[head] != null)
{
return(State.HeadPosition.Head);
}
int left = ShiftReduceUtils.LeftIndex(node);
int nextLeft = separators.FloorKey(head);
bool hasLeft = (nextLeft != null && nextLeft >= left);
int right = ShiftReduceUtils.RightIndex(node);
int nextRight = separators.CeilingKey(head);
bool hasRight = (nextRight != null && nextRight <= right);
if (hasLeft && hasRight)
{
return(State.HeadPosition.Both);
}
else
{
if (hasLeft)
{
return(State.HeadPosition.Left);
}
else
{
if (hasRight)
{
return(State.HeadPosition.Right);
}
else
{
return(State.HeadPosition.None);
}
}
}
}
internal virtual string GetSeparatorBetween(Tree right, Tree left)
{
if (right == null || left == null)
{
return(null);
}
int leftHead = ShiftReduceUtils.HeadIndex(left);
int rightHead = ShiftReduceUtils.HeadIndex(right);
KeyValuePair <int, string> nextSeparator = separators.CeilingEntry(leftHead);
if (nextSeparator == null || nextSeparator.Key > rightHead)
{
return(null);
}
return(Sharpen.Runtime.Substring(nextSeparator.Value, 0, 1));
}
internal virtual int GetSeparatorCount(Tree right, Tree left)
{
if (right == null || left == null)
{
return(0);
}
int leftHead = ShiftReduceUtils.HeadIndex(left);
int rightHead = ShiftReduceUtils.HeadIndex(right);
int nextSeparator = separators.HigherKey(leftHead);
int count = 0;
while (nextSeparator != null && nextSeparator < rightHead)
{
++count;
nextSeparator = separators.HigherKey(nextSeparator);
}
return(count);
}
