internal Group(CompiledGrammar owner, int index, string name, GroupAdvanceMode advanceMode, GroupEndingMode endingMode) : base(owner, index)
{
this.name = name;
this.advanceMode = advanceMode;
this.endingMode = endingMode;
nesting = new GrammarObjectSet <Group>();
}
/// <summary>
/// Gets the DFA states which may lead to one of the given (terminal) symbols.
/// </summary>
/// <param name="filter">The filter predicate, specifying all symbols that shall be requested.</param>
public ICollection <DfaState> GetDfaStatesOfSymbols(Predicate <Symbol> filter)
{
if (filter == null)
{
throw new ArgumentNullException("filter");
}
int symbolsFound = 0;
GrammarObjectSet <Symbol> acceptSymbols = new GrammarObjectSet <Symbol>();
for (int i = 0; i < SymbolCount; i++)
{
Symbol symbol = GetSymbol(i);
if (filter(symbol))
{
acceptSymbols[symbol] = true;
symbolsFound++;
}
}
if (symbolsFound != 0)
{
Queue <DfaState> stateQueue = new Queue <DfaState>();
for (int i = 0; i < DfaStateCount; i++)
{
DfaState state = GetDfaState(i);
if (acceptSymbols[state.AcceptSymbol])
{
stateQueue.Enqueue(state);
}
}
Debug.Assert(stateQueue.Count >= symbolsFound);
Dictionary <DfaState, int> allowedStates = new Dictionary <DfaState, int>();
do
{
DfaState state = stateQueue.Dequeue();
int count;
if (!allowedStates.TryGetValue(state, out count))
{
foreach (DfaState originState in state.GetOriginStates())
{
stateQueue.Enqueue(originState);
}
}
allowedStates[state] = count + 1;
} while (stateQueue.Count > 0);
return(allowedStates.Keys);
}
return(new DfaState[0]);
}
internal void Initialize(Symbol container, Symbol start, Symbol end, Group[] nesting)
{
if (container == null)
{
throw new ArgumentNullException("container");
}
if (start == null)
{
throw new ArgumentNullException("start");
}
if (end == null)
{
throw new ArgumentNullException("end");
}
if (nesting == null)
{
throw new ArgumentNullException("nesting");
}
if (this.container != null)
{
throw new InvalidOperationException("This group has already been initialized");
}
GrammarObjectSet <Symbol> filter = new GrammarObjectSet <Symbol>();
this.container = container;
this.start = start;
this.end = end;
filter.Set(EndSymbol);
foreach (Group nested in nesting)
{
this.nesting.Set(nested);
filter.Set(nested.StartSymbol);
}
if (advanceMode == GroupAdvanceMode.Character)
{
foreach (DfaState state in Owner.GetDfaStatesOfSymbols(filter.Contains))
{
allowedDfaStates.Set(state);
}
}
}
