protected override SyntaxNode DefaultVisit(SyntaxNode node)
{
_ancestors.Insert(0, node);
try
{
for (var i = 0; i < node.SlotCount; i++)
{
var child = node.GetNodeSlot(i);
Visit(child);
}
}
finally
{
_ancestors.RemoveAt(0);
}
return(node);
}
static void AddTokens(SyntaxNode current, SyntaxListBuilder <SyntaxToken> tokens)
{
if (current.SlotCount == 0 && current is SyntaxToken token)
{
// Token
tokens.Add(token);
return;
}
for (var i = 0; i < current.SlotCount; i++)
{
var child = current.GetNodeSlot(i);
if (child != null)
{
AddTokens(child, tokens);
}
}
}
/// <summary>
/// internal indexer that does not verify index.
/// Used when caller has already ensured that index is within bounds.
/// </summary>
internal static SyntaxNode ItemInternalAsNode(SyntaxNode node, int index)
{
GreenNode greenChild;
var green = node.Green;
var idx = index;
var slotIndex = 0;
// find a slot that contains the node or its parent list (if node is in a list)
// we will be skipping whole slots here so we will not loop for long
//
// at the end of this loop we will have
// 1) slot index - slotIdx
// 2) if the slot is a list, node index in the list - idx
while (true)
{
greenChild = green.GetSlot(slotIndex);
if (greenChild != null)
{
var currentOccupancy = Occupancy(greenChild);
if (idx < currentOccupancy)
{
break;
}
idx -= currentOccupancy;
}
slotIndex++;
}
// get node that represents this slot
var red = node.GetNodeSlot(slotIndex);
if (greenChild.IsList && red != null)
{
// it is a red list of nodes, most common case
return(red.GetNodeSlot(idx));
}
// this is a single node
return(red);
}
private static SyntaxNode GetNodeAt(SyntaxNode node, int i)
{
Debug.Assert(node.IsList || (i == 0 && !node.IsList));
return(node.IsList ? node.GetNodeSlot(i) : node);
}
/// <summary>
/// Locate the node that is a child of the given <see cref="SyntaxNode"/> and contains the given position.
/// </summary>
/// <param name="node">The <see cref="SyntaxNode"/> to search.</param>
/// <param name="targetPosition">The position.</param>
/// <returns>The node that spans the given position.</returns>
/// <remarks>
/// Assumes that <paramref name="targetPosition"/> is within the span of <paramref name="node"/>.
/// </remarks>
internal static SyntaxNode ChildThatContainsPosition(SyntaxNode node, int targetPosition)
{
// The targetPosition must already be within this node
Debug.Assert(node.FullSpan.Contains(targetPosition));
var green = node.Green;
var position = node.Position;
var index = 0;
Debug.Assert(!green.IsList);
// Find the green node that spans the target position.
// We will be skipping whole slots here so we will not loop for long
int slot;
for (slot = 0; ; slot++)
{
var greenChild = green.GetSlot(slot);
if (greenChild != null)
{
var endPosition = position + greenChild.FullWidth;
if (targetPosition < endPosition)
{
// Descend into the child element
green = greenChild;
break;
}
position = endPosition;
index += Occupancy(greenChild);
}
}
// Realize the red node (if any)
var red = node.GetNodeSlot(slot);
if (!green.IsList)
{
// This is a single node.
// If it is a node, we are done.
if (red != null)
{
return(red);
}
}
else
{
slot = green.FindSlotIndexContainingOffset(targetPosition - position);
// Realize the red node (if any)
if (red != null)
{
// It is a red list of nodes
red = red.GetNodeSlot(slot);
if (red != null)
{
return(red);
}
}
// Since we can't have "lists of lists", the Occupancy calculation for
// child elements in a list is simple.
index += slot;
}
return(node);
}
