public void StateToStringShouldCreateCorrectFormat()
{
var state = new NormalState(
new Production(new NonTerminal("A"), new NonTerminal("B"), new NonTerminal("C")),
1, 0);
Assert.AreEqual("A -> B\u25CFC\t\t(0)", state.ToString());
}
public IState NextState()
{
if (IsComplete)
return null;
var state = new NormalState(
Production,
Position + 1,
Origin);
return state;
}
public void ChartEnqueShouldAvoidDuplication()
{
ProductionExpression L = "L";
var aToZ = new RangeTerminal('a', 'z');
L.Rule = L + aToZ | aToZ;
var grammar = new GrammarExpression(L, new[] { L }).ToGrammar();
var chart = new Chart();
var firstState = new NormalState(grammar.Productions[0], 0, 1);
var secondState = new NormalState(grammar.Productions[0], 0, 1);
chart.Enqueue(0, firstState);
chart.Enqueue(0, secondState);
Assert.AreEqual(1, chart.EarleySets[0].Predictions.Count);
}
private void PredictProduction(INormalState evidence, int j, IProduction production)
{
// TODO: Pre-Compute Leo Items. If item is 1 step from being complete, add a transition item
var predictedState = new NormalState(production, 0, j);
if (_chart.Enqueue(j, predictedState))
Log("Predict", j, predictedState);
var isNullable = Grammar.IsNullable(evidence.PostDotSymbol as INonTerminal);
if (isNullable)
{
var nullParseNode = CreateNullParseNode(evidence.PostDotSymbol, j);
var aycockHorspoolState = evidence.NextState();
var evidenceParseNode = evidence.ParseNode as IInternalForestNode;
if (evidenceParseNode == null)
aycockHorspoolState.ParseNode = CreateParseNode(aycockHorspoolState, null, nullParseNode, j);
else if (evidenceParseNode.Children.Count > 0
&& evidenceParseNode.Children[0].Children.Count > 0)
{
var firstChildNode = evidenceParseNode;
var parseNode = CreateParseNode(aycockHorspoolState, firstChildNode, nullParseNode, j);
aycockHorspoolState.ParseNode = parseNode;
}
if (_chart.Enqueue(j, aycockHorspoolState))
Log("Predict", j, aycockHorspoolState);
}
}
private void LeoComplete(ITransitionState transitionState, IState completed, int k)
{
var earleySet = _chart.EarleySets[transitionState.Index];
var rootTransitionState = earleySet.FindTransitionState(
transitionState.PreDotSymbol);
if (rootTransitionState == null)
rootTransitionState = transitionState;
var virtualParseNode = CreateVirtualParseNode(completed, k, rootTransitionState);
var topmostItem = new NormalState(
transitionState.Production,
transitionState.Position,
transitionState.Origin);
topmostItem.ParseNode = virtualParseNode;
if (_chart.Enqueue(k, topmostItem))
Log("Complete", k, topmostItem);
}
private void Initialize()
{
Location = 0;
_chart = new Chart();
foreach (var startProduction in Grammar.StartProductions())
{
var startState = new NormalState(startProduction, 0, 0);
if (_chart.Enqueue(0, startState))
Log("Start", 0, startState);
}
ReductionPass(Location);
}
