/// <summary>
/// Determines whether the <see cref="GraphSet{T}" /> is cyclic.
/// </summary>
/// <typeparam name="T">type of element</typeparam>
/// <param name="set">The set.</param>
/// <returns>
/// <c>true</c> if the specified set is cyclic; otherwise, <c>false</c>.
/// </returns>
public static bool IsCyclic <T>(this GraphSet <T> set)
{
var heads = set.GetNodes().Where(x => x.Parents.Count == 0).ToList();
if (heads.Count == 0)
{
return(true);
}
var markedHeads = heads.Select(x => new MarkedNode <T>(x, new HashSet <GraphNode <T> >().ToIHashSet()));
var stack = new Stack <MarkedNode <T> >(markedHeads);
while (stack.Any())
{
var node = stack.Pop();
if (node.MarkingSet.Contains(node.Node))
{
return(true);
}
node.MarkingSet.Add(node.Node);
foreach (var child in node.Node.Children)
{
stack.Push(new MarkedNode <T>(child, node.MarkingSet.Clone()));
}
}
return(false);
}
/// <summary>
/// Gets the when all task on a GraphSet of TaskPair
/// </summary>
/// <typeparam name="T">type of elements</typeparam>
/// <param name="set">The set.</param>
/// <returns>task</returns>
public static Task GetWhenAllTask <T>(this GraphSet <TaskPair <T> > set)
{
var list = new List <Task>();
foreach (var x in set.GetNodes())
{
list.Add(x.Value.Task);
}
var array = list.ToArray();
return(Task.Factory.ContinueWhenAll(array, tasks => { }));
}
/// <summary>
/// Get a <see cref="GraphSet{T}" /> with only elements
/// satisfying the <see cref="Predicate{T}" />
/// </summary>
/// <typeparam name="T">the type of elements</typeparam>
/// <param name="set">The set.</param>
/// <param name="predicate">The predicate.</param>
/// <returns>new filtered <see cref="GraphSet{T}" /></returns>
public static GraphSet <T> Filter <T>(this GraphSet <T> set, Predicate <T> predicate)
{
return(new GraphSet <T>(set.GetNodes().Where(x => predicate(x.Value)), predicate));
}
