public static IEnumerable <ParentedRecursiveType <TRecursiveParent, TRecursiveType> > GetSelfAndDescendentsWithParents <TRecursiveParent, TRecursiveType>(this TRecursiveParent root, TRecursiveParent parent = default(TRecursiveParent))
where TRecursiveParent : class, IRecursiveParent <TRecursiveType>
where TRecursiveType : class, IRecursiveType
{
Requires.NotNull(root, "root");
IRecursiveType rootAsRecursiveType = root;
yield return(new ParentedRecursiveType <TRecursiveParent, TRecursiveType>((TRecursiveType)rootAsRecursiveType, parent));
var rootAsParent = root as TRecursiveParent;
if (rootAsParent != null && rootAsParent.Children != null)
{
foreach (TRecursiveType child in rootAsParent.Children)
{
var childAsParent = child as TRecursiveParent;
if (childAsParent != null)
{
foreach (var descendent in childAsParent.GetSelfAndDescendentsWithParents <TRecursiveParent, TRecursiveType>(rootAsParent))
{
yield return(descendent);
}
}
else
{
yield return(new ParentedRecursiveType <TRecursiveParent, TRecursiveType>(child, rootAsParent));
}
}
}
}
/// <summary>Checks whether a given object is among this object's descendents.</summary>
public static bool HasDescendent(this IRecursiveParent parent, IRecursiveType possibleDescendent)
{
Requires.NotNull(parent, "parent");
Requires.NotNull(possibleDescendent, "possibleDescendent");
return(HasDescendent(parent, possibleDescendent.Identity));
}
/// <summary>
/// Returns a sequence starting with the given <paramref name="root"/>
/// followed by its descendents in a depth-first search.
/// </summary>
/// <param name="root">The node at which to start enumeration.</param>
/// <returns>A sequence of nodes beginning with <paramref name="root"/> and including all descendents.</returns>
public static IEnumerable <IRecursiveType> GetSelfAndDescendents(this IRecursiveType root)
{
var rootAsParent = root as IRecursiveParent <IRecursiveType>;
if (rootAsParent != null)
{
return(GetSelfAndDescendents(rootAsParent));
}
else
{
return(new[] { root });
}
}
int IRecursiveParentWithOrderedChildren.IndexOf(IRecursiveType value)
{
return(this.Children.IndexOf((TreeNode)value));
}