public void Test_State_That_ToString_Renders_A_B_C_State()
{
var state = new State(
new Production("A", new NonTerminal("B"), new NonTerminal("C")),
1,0);
Assert.AreEqual("A -> B\u25CFC\t\t(0)", state.ToString());
}
public void Test_Chart_That_Enqueue_Avoids_Duplicates()
{
var grammar = new GrammarBuilder("L")
.Production("L", r => r
.Rule("L", new RangeTerminal('a', 'z'))
.Rule(new RangeTerminal('a','z')))
.ToGrammar();
var chart = new Chart();
var firstState = new State(grammar.Productions[0], 0, 1);
var secondState = new State(grammar.Productions[0], 0, 1);
chart.Enqueue(0, firstState);
chart.Enqueue(0, secondState);
Assert.AreEqual(1, chart.EarleySets[0].Predictions.Count);
}
private void PredictProduction(IState 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 State(production, 0, j);
if (_chart.Enqueue(j, predictedState))
Log("Predict", j, predictedState);
var stateIsNullable = predictedState.Production.IsEmpty;
if (stateIsNullable)
{
var aycockHorspoolState = evidence.NextState(j);
var predictedParseNode = CreateNullParseNode(
predictedState.Production.LeftHandSide, j);
aycockHorspoolState.ParseNode
= CreateParseNode(
aycockHorspoolState,
evidence.ParseNode,
predictedParseNode,
j);
if (_chart.Enqueue(j, aycockHorspoolState))
Log("Predict", j, aycockHorspoolState);
}
}
private void LeoComplete(ITransitionState transitionState, IState completed, int k)
{
var earleySet = _chart.EarleySets[transitionState.Position];
var rootTransitionState = earleySet.FindTransitionState(
transitionState.PreDotSymbol);
if (rootTransitionState == null)
rootTransitionState = transitionState;
var virtualParseNode = new VirtualNode(k, rootTransitionState, completed.ParseNode);
var topmostItem = new State(
transitionState.Production,
transitionState.Length,
transitionState.Origin,
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 State(startProduction, 0, 0);
if (_chart.Enqueue(0, startState))
Log("Start", 0, startState);
}
ReductionPass(Location);
}
