/// <inheritdoc />
public bool MoveNext()
{
var next = _current.Next;
_current = next is IPredecessor <TPayload> predecessor
? predecessor
: LinkPredecessorDecorator <TPayload> .Decorate(next, new EndLink <TPayload>(next));
return(!(next is EndLink <TPayload>));
}
public PrimerLink(ILink <TPayload> firstValue)
{
var predecessor = firstValue as IPredecessor <TPayload>;
var isPredecessor = predecessor != null;
var successor = firstValue as ISuccessor <TPayload>;
var isSuccessor = successor != null;
if (isPredecessor && isSuccessor)
{
Previous = predecessor;
Next = successor;
}
else if (isSuccessor)
{
var endLink = new EndLink <TPayload>(new LazySuccessorProxy <TPayload>(() => Next));
var primer = LinkPredecessorDecorator <TPayload> .Decorate(successor, endLink);
Previous = primer;
Next = primer;
}
else if (isPredecessor)
{
var startLink = new StartLink <TPayload>(new LazyPredecessorProxy <TPayload>(() => Previous));
var primer = LinkSuccessorDecorator <TPayload> .Decorate(predecessor, startLink);
Previous = primer;
Next = primer;
}
else
{
var startLink = new StartLink <TPayload>(new LazyPredecessorProxy <TPayload>(() => Previous));
var endLink = new EndLink <TPayload>(new LazySuccessorProxy <TPayload>(() => Next));
Previous = LinkPredecessorDecorator <TPayload> .Decorate(firstValue, endLink);
Next = LinkSuccessorDecorator <TPayload> .Decorate(firstValue, startLink);
}
}
public EndLink(ISuccessor <TPayload> previous)
{
Previous = LinkPredecessorDecorator <TPayload> .Decorate(previous, this);
}