/// <summary>
/// Duplicate AST Node tree rooted at specified AST node and all of it's siblings.
/// </summary>
/// <param name="t">Root of AST Node tree.</param>
/// <returns>Root node of new AST Node tree (or null if <c>t</c> is null).</returns>
public virtual AST dupList(AST t)
{
AST result = dupTree(t); // if t == null, then result==null
AST nt = result;
while (t != null)
{
// for each sibling of the root
t = t.getNextSibling();
nt.setNextSibling(dupTree(t)); // dup each subtree, building new tree
nt = nt.getNextSibling();
}
return(result);
}
/// <summary>
/// Make a tree from a list of nodes. The first element in the
/// array is the root. If the root is null, then the tree is
/// a simple list not a tree. Handles null children nodes correctly.
/// For example, build(a, b, null, c) yields tree (a b c). build(null,a,b)
/// yields tree (nil a b).
/// </summary>
/// <param name="nodes">List of Nodes.</param>
/// <returns>AST Node tree.</returns>
public virtual AST make(params AST[] nodes)
{
if (nodes == null || nodes.Length == 0)
{
return(null);
}
AST root = nodes[0];
AST tail = null;
if (root != null)
{
root.setFirstChild(null); // don't leave any old pointers set
}
// link in children;
for (int i = 1; i < nodes.Length; i++)
{
if (nodes[i] == null)
{
continue;
}
// ignore null nodes
if (root == null)
{
// Set the root and set it up for a flat list
root = (tail = nodes[i]);
}
else if (tail == null)
{
root.setFirstChild(nodes[i]);
tail = root.getFirstChild();
}
else
{
tail.setNextSibling(nodes[i]);
tail = tail.getNextSibling();
}
// Chase tail to last sibling
while (tail.getNextSibling() != null)
{
tail = tail.getNextSibling();
}
}
return(root);
}