/// <summary>
/// Make an AST the root of current AST.
/// </summary>
/// <param name="currentAST"></param>
/// <param name="root"></param>
public virtual void makeASTRoot(ref ASTPair currentAST, AST root)
{
if (root != null)
{
// Add the current root as a child of new root
root.addChild(currentAST.root);
// The new current child is the last sibling of the old root
currentAST.child = currentAST.root;
currentAST.advanceChildToEnd();
// Set the new root
currentAST.root = root;
}
}