public void DepthFirstTraversalIsLazy()
{
var guid = Guid.NewGuid();
var descriptor = GraphDescriptor.Create(n => n, Function(new Dictionary <int, IEnumerable <int> >
{
{ 0, A(1, 2) },
{ 1, A(3, 4) },
{ 2, EnumerableEx.Throw <int>(new Exception(guid.ToString())) }
}));
var enumerator = Graph.DepthFirstTraversal(A(0), descriptor).GetEnumerator();
Assert.IsTrue(enumerator.MoveNext());
Assert.AreEqual(0, enumerator.Current);
Assert.IsTrue(enumerator.MoveNext());
Assert.AreEqual(1, enumerator.Current);
Assert.IsTrue(enumerator.MoveNext());
Assert.AreEqual(3, enumerator.Current);
Assert.IsTrue(enumerator.MoveNext());
Assert.AreEqual(4, enumerator.Current);
Assert.IsTrue(enumerator.MoveNext());
Assert.AreEqual(2, enumerator.Current);
try
{
enumerator.MoveNext();
}
catch (Exception e)
{
Assert.AreEqual(guid.ToString(), e.Message);
return;
}
Assert.Fail();
}
public static IEnumerable <IGraphDescriptor <T, T> > AllDirectedAcyclicGraphs <T>(IList <T> nodes)
{
var E = new Combinations <T>(nodes, 2).Where(e => e.Count == 2).ToList();
foreach (var F in Enumerable.Range(0, E.Count + 1).SelectMany(k => new Combinations <IList <T> >(E, k)))
{
yield return(GraphDescriptor.Create(u => u, Function(F.GroupBy(e => e[0]).ToDictionary(g => g.Key, g => g.Select(e => e[1])))));
}
}