// Get the future State i which is ahead of current State n. If the State i does not
// exist, create it. Otherwise return it as-is.
public State GetAhead(int consumed, ISequenceCheckpoint checkpoint)
{
if (consumed <= 0)
{
return(_current.State);
}
var i = _current.State.Number + consumed;
if (_lookup.ContainsKey(i))
{
return(_lookup[i].State);
}
var state = new State(i, checkpoint);
var current = _current;
Debug.Assert(i > current.State.Number, "We shouldn't be going backwards");
while (current.Next != null && current.Next.State.Number < i)
{
current = current.Next;
}
var newNode = new StateNode(state)
{
State = state,
Next = current.Next
};
current.Next = newNode;
_lookup.Add(i, newNode);
return(state);
}
public SuccessResultAlternative(TOutput value, int consumed, ISequenceCheckpoint continuation)
{
Assert.ArgumentNotNull(continuation, nameof(continuation));
Value = value;
Consumed = consumed;
Continuation = continuation;
}
public StateCollection(ISequenceCheckpoint cp)
{
InitialState = new State(0, cp);
_current = new StateNode(InitialState);
_lookup = new Dictionary <int, StateNode> {
{ 0, _current }
};
}
public MultiResult(IParser parser, Location location, ISequenceCheckpoint startCheckpoint, IEnumerable <IResultAlternative <TOutput> > results, IReadOnlyList <object>?data = null)
{
Parser = parser;
Results = results.ToList();
Success = Results.Any(r => r.Success);
Location = location;
StartCheckpoint = startCheckpoint;
_data = data;
}
public static IResultAlternative <TOutput> FactoryMethod(TOutput value, int consumed, ISequenceCheckpoint continuation) => new SuccessResultAlternative <TOutput>(value, consumed, continuation);
public FailureResultAlternative(string errorMessage, ISequenceCheckpoint continuation)
{
ErrorMessage = errorMessage;
Continuation = continuation;
}
private static IResultAlternative <TOutput> ParseOne(IParser <TInput, TOutput> parser, IParseState <TInput> state, ISequenceCheckpoint startCheckpoint)
{
var result = parser.Parse(state);
if (result.Success)
{
var endCheckpoint = state.Input.Checkpoint();
return(new SuccessResultAlternative <TOutput>(result.Value, result.Consumed, endCheckpoint));
}
return(new FailureResultAlternative <TOutput>(result.ErrorMessage, startCheckpoint));
}
public State(int number, ISequenceCheckpoint cp)
{
Items = new List <Item>();
Number = number;
Checkpoint = cp;
}
