SyntaxTreeNodeCollection GetModifiedSubNodes(SyntaxTreeNode node)
{
SyntaxTreeNodeCollection modifiedSubNodes = null; //lazy
for (int i = 0; i < node.SubNodes.Count; i++)
{
var subNode = node.SubNodes[i];
var replacement = Visit(subNode);
if (replacement != subNode)
{
if (modifiedSubNodes == null) //lazy init
{
modifiedSubNodes = new SyntaxTreeNodeCollection();
for (int j = 0; j < i; j++) //copy unmodified nodes
{
modifiedSubNodes.Add(node.SubNodes[j]);
}
}
if (replacement != null) //insert replacement
{
modifiedSubNodes.Add(replacement);
}
}
else
{
if (modifiedSubNodes != null) //only insert unmodified subnode if the lazy collection has been initialized
{
modifiedSubNodes.Add(subNode);
}
}
}
return(modifiedSubNodes);
}
/// <summary>
/// Initialize an instance with the given <see cref="SyntaxTreeNodeCollection"/>.
/// </summary>
/// <param name="subNodes">Can not be null!</param>
/// <exception cref="ArgumentNullException"></exception>
public SequenceNode(SyntaxTreeNodeCollection subNodes)
: base(subNodes)
{
if (subNodes == null)
{
throw new ArgumentNullException(nameof(subNodes));
}
}
protected SyntaxTreeNode()
{
SubNodes = new SyntaxTreeNodeCollection();
}
public SequenceNode(SyntaxTreeNodeCollection subNodes) : base(subNodes)
{
}
