protected override Expression DoResolve (ResolveContext ec)
{
var results = new List<string> ();
AppendResults (results, Prefix, Evaluator.GetVarNames ());
AppendResults (results, Prefix, ec.CurrentMemberDefinition.Parent.NamespaceEntry.CompletionGetTypesStartingWith (Prefix));
AppendResults (results, Prefix, Evaluator.GetUsingList ());
throw new CompletionResult (Prefix, results.ToArray ());
}