private void Visit(TopologicalNode <T> node, ICollection <T> stack)
{
if (node.TempMarked)
{
throw new CyclicReferenceException(node.Contained);
}
if (node.Marked)
{
return;
}
node.TempMarked = true;
var children = GetChildNodes(node);
foreach (var child in children)
{
Visit(child, stack);
}
node.Marked = true;
node.TempMarked = false;
stack.Add(node.Contained);
}
private IEnumerable <TopologicalNode <T> > GetChildNodes(TopologicalNode <T> node)
{
var children = new List <TopologicalNode <T> >();
var rawChildren = _getChildren(node.Contained);
foreach (var child in rawChildren)
{
var resolved = _nodePool.FirstOrDefault(n => n.Contained.Equals(child));
if (resolved != null)
{
children.Add(resolved);
}
else
{
var newNode = new TopologicalNode <T> {
Contained = child
};
children.Add(newNode);
_nodePool.Add(newNode);
}
}
return(children);
}
public TopologicalSort(T root, Func <T, IList <T> > getChildren)
{
_getChildren = getChildren;
_root = new TopologicalNode <T> {
Contained = root
};
_nodePool = new List <TopologicalNode <T> > {
_root
};
}
public bool Equals(TopologicalNode <T> other)
{
return(Contained.Equals(other.Contained));
}