private static void CheckStateStability <TLabel>(IDfa <TLabel, char> dfa)
{
foreach (var state in ReachableStates(dfa))
{
bool expectedStability = true;
foreach (var(_, nextState) in dfa.Transitions(state))
{
if (nextState != state)
{
expectedStability = false;
break;
}
}
Assert.AreEqual(expectedStability, dfa.IsStable(state), "Stability of the state is incorrect");
}
}
private static IReadOnlyCollection <ParseAction <TLabel> > GetAllParseActions(
CompiledGrammar <TLabel> grammar,
IState state,
IDfa <Optional <Rule <TLabel> >, TLabel> dfa,
TLabel label,
IReadOnlyDictionary <TLabel, IReadOnlyCollection <DfaAndState <TLabel> > > follow,
IReadOnlyDictionary <TLabel, IReadOnlyCollection <DfaAndState <TLabel> > > firstPlus)
{
var actions = new List <ParseAction <TLabel> >();
var stateLabel = dfa.Label(state);
var dfaAndState = new DfaAndState <TLabel>()
{
Dfa = dfa, State = state
};
if (stateLabel.IsSome() && follow.ContainsKey(label) && follow[label].Contains(dfaAndState))
{
actions.Add(
new ParseAction <TLabel>()
{
Kind = ParseAction <TLabel> .ActionKind.Reduce, Label = stateLabel.Get().Lhs
});
}
var transitions = dfa.Transitions(state);
if (transitions.ContainsKey(label))
{
var nextState = transitions[label];
if (!dfa.IsStable(nextState) || dfa.Label(nextState).IsSome())
{
actions.Add(
new ParseAction <TLabel>()
{
Kind = ParseAction <TLabel> .ActionKind.Shift, Label = label
});
}
}
if (firstPlus.ContainsKey(label))
{
var firstPlusStates = firstPlus[label];
foreach (var transitionLabel in transitions.Keys)
{
var nextState = transitions[transitionLabel];
if ((!dfa.IsStable(nextState) || dfa.Label(nextState).IsSome()) && grammar.Rules.ContainsKey(transitionLabel))
{
var subDfa = grammar.Rules[transitionLabel];
var subDfaAndStartState = new DfaAndState <TLabel>()
{
Dfa = subDfa, State = subDfa.StartingState()
};
if (firstPlusStates.Contains(subDfaAndStartState))
{
actions.Add(
new ParseAction <TLabel>()
{
Kind = ParseAction <TLabel> .ActionKind.Call, Label = transitionLabel
});
}
}
}
}
return(actions);
}