public Term Reduce()
{
while (currentNode.HasRedex)
{
var reductionResult = TryApply(currentNode);
if (currentStatus.NeedsSurgery)
{
currentNode = SpliceApplicationResultWithTerm(reductionResult, TreeTraversal.GetNextNodeLRP(currentNode));
currentNode = TreeTraversal.GetLowestLeftNode(currentNode.Parent);
}
else
{
currentNode = TreeTraversal.GetNextNodeLRP(currentNode);
}
}
var result = TryApply(currentNode);
if (currentStatus.NeedsSurgery)
{
var formerNode = (Term)currentStatus.CurrentApplica;
if (formerNode == TreeTraversal.GetLowestLeftNode(formerNode.Parent))
{
if (!(result.Right is VoidTerm))
{
TreeTraversal.RenewRepresentation(formerNode);
currentNode = TreeTraversal.GetLowestLeftNode(result);
currentStatus = new ReductionStatus();
return(Reduce());
}
else
{
formerNode.Parent.Left = result;
formerNode.Parent.Right = new VoidTerm();
}
}
else
{
formerNode.Parent.Right = result;
}
TreeTraversal.RenewRepresentation(formerNode);
return(formerNode.Parent);
}
var toplevel = TreeTraversal.GetToplevelTerm(currentNode);
if (toplevel.Right == null)
{
return(new Term(currentNode, new VoidTerm()));
}
else
{
return(toplevel);
}
}
public static IObservable <TAcc> Transduce <TAcc, TIn, TOut>(this IObservable <TIn> source, ITransducer <TIn, TOut> transducer, Func <TAcc, TOut, TAcc> reducer, TAcc seed)
{
var status = new ReductionStatus();
var res = seed;
var red = transducer.Transform(status, reducer);
return(new AnonymousObservable <TAcc>(observer => source.Subscribe(el => {
if (status.Complete)
{
observer.OnNext(res);
observer.OnCompleted();
return;
}
res = red(res, el);
}, observer.OnError, () => { observer.OnNext(res); observer.OnCompleted(); })));
}
public static IObservable <TOut> Transduce <TIn, TOut>(this IObservable <TIn> source, ITransducer <TIn, TOut> transducer)
{
var status = new ReductionStatus();
var reducer = transducer.Transform <Optional <TOut> >(status, Utils.Enumerator);
return(new AnonymousObservable <TOut>(observer => source.Subscribe(el => {
if (status.Complete)
{
observer.OnCompleted();
return;
}
var res = reducer(new Optional <TOut>(), el);
if (res.HasValue)
{
observer.OnNext(res.Value);
}
}, observer.OnError, observer.OnCompleted)));
}
public Reductor(Term builtTerm)
{
this.currentNode = TreeTraversal.GetLowestLeftNode(builtTerm);
this.currentStatus = new ReductionStatus();
}
