public StackSymbolSequenceSet <S> ApplySymbolToStackSymbolSequenceSet(StackSymbolSequenceSet <S> stackSequenceSet, A symbol)
{
var res = stackSequenceSet.StackSequenceSet.Select(stackSequence =>
{
if (stackSequence.IsEpsilon())
{
return(new StackSymbolSequenceSet <S>());
}
var first = stackSequence.StackSequence.First();
var enterableTransitions = transitions.Where(t => t.CanBeEntered(symbol, first));
Assertion.Assert(enterableTransitions.Count() <= 1, "in a determinised SDA, only one transition can be entered for a specific configuration");
if (enterableTransitions.Count() == 0)
{
return(new StackSymbolSequenceSet <S>());
}
var stackSymbolsSetWritten = enterableTransitions.First().StackSymbolsSetWritten;
var remainingStackSequence = new StackSymbolSequence <S>(stackSequence.StackSequence.Skip(1).ToList());
return(stackSymbolsSetWritten.Multiply(remainingStackSequence));
});
return(StackSymbolSequenceSet <S> .Flatten(res));
}
public DeterminisedSDATransition(A symbolIn, S stackSymbolIn, StackSymbolSequenceSet <S> stackSymbolsSetWritten)
{
Assertion.Assert(stackSymbolsSetWritten.StackSequenceSet.All(s => s.StackSequence.Length <= 2), "as a determinised SDA is in normal form, a transition may only push at most two symbols");
SymbolIn = symbolIn;
StackSymbolIn = stackSymbolIn;
StackSymbolsSetWritten = stackSymbolsSetWritten;
}
public void AddTransition(A symbolIn, S stackSymbolIn, StackSymbolSequenceSet <S> stackSymbolsSetWritten)
{
Assertion.Assert(AllStackSymbols.Any(s => s.Equals(stackSymbolIn)), InvalidStackSymbolError);
Assertion.Assert(stackSymbolsSetWritten.StackSequenceSet.All(s => s.StackSequence.All(symbol => AllStackSymbols.Any(t => t.Equals(symbol)))), InvalidStackSymbolError);
Assertion.Assert(stackSymbolsSetWritten.StackSequenceSet.All(s => s.StackSequence.Length <= 2), "as a determinised SDA is in normal form, only two stack symbols can be pushed");
Assertion.Assert(!transitions.Any(t => t.SymbolIn.Equals(symbolIn) && t.StackSymbolIn.Equals(stackSymbolIn)), "the new transition violates the determinism property of the determinised SDA");
transitions.Add(new DeterminisedSDATransition <A, S>(symbolIn, stackSymbolIn, stackSymbolsSetWritten));
}
public StackSymbolSequenceSet <S> ApplyWordToStackSymbolSequenceSet(StackSymbolSequenceSet <S> stackSymbolSequenceSet, IEnumerable <A> word)
{
return(word.Aggregate(stackSymbolSequenceSet, (acc, symbol) => ApplySymbolToStackSymbolSequenceSet(acc, symbol)));
}
