/// <summary>
/// Continues the search started by <see cref="StartSearch"/> until either the next result is found or no result exists.
/// </summary>
/// <returns>A <see cref="SearchResult"/> indicating the result of the search.</returns>
public SearchResult ContinueSearch()
{
if (!_searchStarted)
{
return(null);
}
// as long as nodes exist in the open list
while (_openList.Any())
{
// take the first one and expand it
var node = _openList[0];
_openList.Remove(node);
_closedList.Add(node);
// check for final node
if (_searchProblem.IsFinalState(node.State))
{
return(new SearchResult(node));
}
// iterate through transitions
foreach (var transition in _searchProblem.GetTransitions(node.State))
{
// transition brings us to state on the closed list --> no need to investigate this anymore
if (_closedList.Any(n => n.State == transition.NewState))
{
continue;
}
// create child node
var newNode = CreateNodeFromTransition(node, transition);
InsertNodeIntoOpenList(newNode);
}
SortOpenList();
}
return(new SearchResult(null));
}