public void AddRowState(RowState row)
{
if (!RowStates.Contains(row))
{
RowStates.Add(row);
}
}
public override bool Equals(object obj)
{
if (obj is State state)
{
var result = RowStates.SetEquals(state.RowStates);
return(result);
}
return(false);
}
/// <summary>
/// the order is horrible. I did this to support Recursive LL(1) Grammers
/// Error :Collection was modified.
/// </summary>
public void AddClosures()
{
bool changed;
do
{
changed = false;
foreach (RowState state in RowStates.ToList())
{
if (state.GetSymbolInPosition() is Variable variable)
{
var defaultLookAhead = state.LookAhead;
// if there is no B,
if (_isClr && state.HasSymbolAfterPosition())
{
//first (B{PreviousLookAhead})
var symbolsAfterPosition = state.GetSymbolsAfterPosition().ToList();
//symbolsAfterPosition.AddRange(defaultLookAhead);
defaultLookAhead = _preprocessor.FirstSet(new List <IEnumerable <ISymbol> > {
symbolsAfterPosition
});
if (defaultLookAhead.Contains(Terminal.Epsilon))
{
defaultLookAhead.Remove(Terminal.Epsilon);
defaultLookAhead.AddRange(state.LookAhead);
}
}
variable.RuleSet.Definitions
.ForEach(rule =>
{
RowState rowState = new RowState(variable, rule);
if (_isClr)
{
rowState = new RowState(variable, rule, defaultLookAhead);
}
if (!RowStates.Contains(rowState))
{
RowStates.Add(rowState);
changed = true;
}
});
}
}
} while (changed);
}