private ITerminalToken?LexCommon(Dfa dfa)
{
DfaState?state = dfa.Start;
var start = index;
while (!Source.IsEnd(index))
{
Debug.Assert(state != null);
var next = state.Match(Source[index]);
if (next == null)
{
if (state.Final)
{
return(MakeResult(state.Payload, start, index));
}
var msg = Errors.GetExpectedMessage(Location.From(Source, index), Errors.GetSymbols(dfa).ToArray());
throw new ParserException(msg);
}
state = next;
index += 1;
}
if (state != null && state.Final)
{
return(MakeResult(state.Payload, start, index));
}
return(null);
}
public DfaSet(IReadOnlyList <Dfa> dfas, IReadOnlyList <int> stateMap, Dfa spacing)
{
Dfas = dfas;
StateMap = stateMap;
Spacing = spacing;
}