static void PrettyPrintTreeWorker <T>([NotNull] T node, [NotNull] GetChildrenAction <T> getChildren,
[NotNull] Func <T, string> toStringFunc, StringBuilder builder, bool last, string indent)
{
builder.Append(indent);
if (last)
{
builder.Append("\\-");
indent += " ";
}
else
{
builder.Append("|-");
indent += "| ";
}
builder.AppendLine(toStringFunc(node));
var lst = getChildren(node).MakeSafe().ToList();
for (int i = 0; i < lst.Count; i++)
{
var child = lst[i];
PrettyPrintTreeWorker <T>(child, getChildren, toStringFunc, builder, i == lst.Count - 1, indent);
}
}
private static void PostorderWorker <T>([NotNull] T node, [NotNull] GetChildrenAction <T> getChildren,
[NotNull] List <T> outList)
{
foreach (T child in getChildren(node).MakeSafe())
{
PostorderWorker(child, getChildren, outList);
}
outList.Add(node);
}
/// <summary>
/// traverse a tree using the postorder traversal
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="root">The root.</param>
/// <param name="getChildren">The get children.</param>
/// <returns></returns>
/// <exception cref="ArgumentNullException">
/// root
/// or
/// getChildren
/// </exception>
public static List <T> Postorder <T>([NotNull] T root, [NotNull] GetChildrenAction <T> getChildren)
{
if (root == null)
{
throw new ArgumentNullException(nameof(root));
}
if (getChildren == null)
{
throw new ArgumentNullException(nameof(getChildren));
}
var outList = new List <T>();
PostorderWorker(root, getChildren, outList);
return(outList);
}
/// <summary>
/// prints a pretty tree
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="root">The root.</param>
/// <param name="getChildren">The get children.</param>
/// <param name="toStringFunc">To string function.</param>
/// <returns></returns>
/// <exception cref="ArgumentNullException">
/// root
/// or
/// getChildren
/// </exception>
public static string PrettyPrintTree <T>([NotNull] T root, [NotNull] GetChildrenAction <T> getChildren,
Func <T, string> toStringFunc = null)
{
if (root == null)
{
throw new ArgumentNullException(nameof(root));
}
if (getChildren == null)
{
throw new ArgumentNullException(nameof(getChildren));
}
toStringFunc = toStringFunc ?? ((T f) => f.ToString());
StringBuilder builder = new StringBuilder();
string indent = "";
PrettyPrintTreeWorker(root, getChildren, toStringFunc, builder, true, indent);
return(builder.ToString());
}
public static IEnumerable <T> Preorder <T>([NotNull] T root, [NotNull] GetChildrenAction <T> getChildrenAction)
{
if (root == null)
{
throw new ArgumentNullException(nameof(root));
}
if (getChildrenAction == null)
{
throw new ArgumentNullException(nameof(getChildrenAction));
}
var stack = new Stack <T>();
stack.Push(root);
while (stack.Count > 0)
{
T node = stack.Pop();
yield return(node);
foreach (T child in getChildrenAction(node).MakeSafe())
{
stack.Push(child);
}
}
}
