public static ITreePath <ITextNode> CreatePathForNodeAt(this ITextNode node, int offset)
{
if (!node.InRange(offset))
{
throw new ArgumentOutOfRangeException(nameof(offset), offset, null);
}
ITreePath <ITextNode> path = new TreePath <ITextNode>(node);
for (var idx = 0; idx < node.Count;)
{
var child = node[idx];
if (child.InRange(offset))
{
path = path.Append(child);
// restart for-loop for the new node ..
// this is a stack-friendly tail recursion.
node = child;
idx = 0;
}
else
{
idx += 1;
}
}
return(path);
}
public static int NodeIndexForOffset(this ITextNode node, int offset)
{
if (node.Leaf)
{
return(-1);
}
if (!node.InRange(offset))
{
return(-1);
}
for (var idx = 0; idx < node.Count; idx += 1)
{
var n = node[idx];
if (n.InRange(offset))
{
return(idx);
}
}
return(-1);
}
