//return all the nodes in a given expression tree
public static IEnumerable <EditableExpression> Nodes(this EditableExpression source)
{
//i.e. left, right, body, etc.
foreach (EditableExpression linkNode in source.LinkNodes())
{
//recursive call to get the nodes from the tree, until you hit terminals
foreach (EditableExpression subNode in linkNode.Nodes())
{
yield return(subNode);
}
}
yield return(source); //return the root of this most recent call
}