/// <summary>
/// Gets the token at the specified index.
/// </summary>
/// <param name="index">The zero-based index of the token to get.</param>
/// <returns>The token at the specified index.</returns>
/// <exception cref="System.ArgumentOutOfRangeException">
/// <paramref name="index" /> is less than 0.-or-<paramref name="index" /> is equal to or greater than <see cref="SyntaxTokenList.Count" />. </exception>
public SyntaxToken this[int index]
{
get
{
if (node != null)
{
if (node.IsList)
{
if (unchecked ((uint)index < (uint)node.SlotCount))
{
return(new SyntaxToken(this.parent, node.GetSlot(index), this.position + node.GetSlotOffset(index), this.index + index));
}
}
else if (index == 0)
{
return(new SyntaxToken(this.parent, this.node, this.position, this.index));
}
}
throw new ArgumentOutOfRangeException("index");
}
}
/// <summary>
/// Gets the trivia at the specified index.
/// </summary>
/// <param name="index">The zero-based index of the trivia to get.</param>
/// <returns>The token at the specified index.</returns>
/// <exception cref="System.ArgumentOutOfRangeException">
/// <paramref name="index" /> is less than 0.-or-<paramref name="index" /> is equal to or greater than <see cref="SyntaxTriviaList.Count" />. </exception>
public SyntaxTrivia this[int index]
{
get
{
if (_node != null)
{
if (_node.IsList)
{
if (unchecked ((uint)index < (uint)_node.SlotCount))
{
return(new SyntaxTrivia(_token, _node.GetSlot(index), _position + _node.GetSlotOffset(index), _index + index));
}
}
else if (index == 0)
{
return(new SyntaxTrivia(_token, _node, _position, _index));
}
}
throw new ArgumentOutOfRangeException("index");
}
}
/// <summary>
/// Locate the node or token 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 or token that spans the given position.</returns>
/// <remarks>
/// Assumes that <paramref name="targetPosition"/> is within the span of <paramref name="node"/>.
/// </remarks>
internal static SyntaxNodeOrToken ChildThatContainsPosition(SyntaxNode node, int targetPosition)
{
// The targetPosition must already be within this node
Debug.Assert(node.FullSpan.Contains(targetPosition));
GreenNode green = node.Green;
int position = node.Position;
int 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
// The max possible number of slots is 11 (TypeDeclarationSyntax)
// and typically much less than that
int slot;
for (slot = 0; ; slot++)
{
GreenNode greenChild = green.GetSlot(slot);
if (greenChild != null)
{
int 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)
SyntaxNode red = node.GetNodeSlot(slot);
if (!green.IsList)
{
// This is a single node or token.
// If it is a node, we are done.
if (red != null)
{
return(red);
}
// Otherwise will have to make a token with current green and position
}
else
{
slot = green.FindSlotIndexContainingOffset(targetPosition - position);
// Realize the red node (if any)
if (red != null)
{
// It is a red list of nodes (separated or not)
red = red.GetNodeSlot(slot);
if (red != null)
{
return(red);
}
// Must be a separator
}
// Otherwise we have a token.
position += green.GetSlotOffset(slot);
green = green.GetSlot(slot);
// Since we can't have "lists of lists", the Occupancy calculation for
// child elements in a list is simple.
index += slot;
}
// Make a token with current child and position.
return(new SyntaxNodeOrToken(node, green, position, index));
}