public static NFA CreateAutomaton(string a)
{
var result = new NFA();
var start = 0;
var next = 1;
result.AddState(start, false);
for (int i = 0; i < a.Length; ++i)
{
if (a[i] == '*')
{
result.AddTransition(next - 1, next - 1, NFA.Any);
}
else
{
result.AddState(next, false);
result.AddTransition(next - 1, next, (a[i] != '?' ? CharRange.SingleChar(a[i]) : NFA.Any));
++next;
}
}
result.AddState(next, true);
result.AddTransition(next - 1, next, NFA.Epsilon);
return(result);
}
public override StateRange AddTo <T>(NFA <T> nfa, CodePointEquivalenceClasses equivalenceClasses)
{
var startState = nfa.AddState();
var endState = nfa.AddState();
foreach (var states in Expressions.Select(exp => exp.AddTo(nfa, equivalenceClasses)))
{
nfa.AddEpsilonTransition(startState, states.Start);
nfa.AddEpsilonTransition(states.End, endState);
}
return(new StateRange(startState, endState));
}
public override StateRange AddTo <T>(NFA <T> nfa, CodePointEquivalenceClasses equivalenceClasses)
{
var startState = nfa.AddState();
var endState = nfa.AddState();
foreach (var equivalenceClass in equivalenceClasses.GetClasses(CodePoints))
{
nfa.AddTransition(startState, equivalenceClass, endState);
}
return(new StateRange(startState, endState));
}
public override StateRange AddTo <T>(NFA <T> nfa, CodePointEquivalenceClasses equivalenceClasses)
{
var startState = nfa.AddState();
var endState = startState;
foreach (var codePoint in Value.GetCodePoints())
{
var lastState = endState;
endState = nfa.AddState();
nfa.AddTransition(lastState, equivalenceClasses.GetClass(codePoint), endState);
}
return(new StateRange(startState, endState));
}
public override StateRange AddTo <T>(NFA <T> nfa, CodePointEquivalenceClasses equivalenceClasses)
{
// Create a separate NFA
var tempNFA = new NFA <State?>(equivalenceClasses.Count);
var states = Expression.AddTo(tempNFA, equivalenceClasses);
tempNFA.SetStart(states.Start);
tempNFA.SetFinal(states.End);
// Convert to a DFA
var dfa = tempNFA.ToDFA(stateData => null).Item2;
dfa = dfa.Minimize().Item2;
dfa.MakeComplete(); // Can only do complement on complete DFA
// Now add the complement to this nfa
var startState = nfa.AddState();
var endState = nfa.AddState();
foreach (var dfaState in dfa.States)
{
var nfaState = GetMatchingState(nfa, dfa, dfaState);
if (dfa.IsStart(dfaState))
{
nfa.AddEpsilonTransition(startState, nfaState);
}
if (!dfa.IsFinal(dfaState))
{
nfa.AddEpsilonTransition(nfaState, endState);
}
// Copy transitions
foreach (var input in nfa.Inputs)
{
var toDFAState = dfa.GetTransition(dfaState, input);
if (toDFAState != null)
{
var toNFAState = GetMatchingState(nfa, dfa, toDFAState.Value);
nfa.AddTransition(nfaState, input, toNFAState);
}
}
}
return(new StateRange(startState, endState));
}
public virtual NFAState NewState()
{
NFAState n = new NFAState(nfa);
int state = nfa.GetNewNFAStateNumber();
n.stateNumber = state;
nfa.AddState(n);
n.enclosingRule = currentRule;
return(n);
}
private static State GetMatchingState <T>(NFA <T> nfa, DFA <State?> dfa, State dfaState)
{
var nfaState = dfa.GetData(dfaState);
if (nfaState == null)
{
nfaState = nfa.AddState();
dfa.SetData(dfaState, nfaState);
}
return(nfaState.Value);
}
public static LexerNFA ConvertToNFA(LexerSpec spec)
{
spec = spec.HasBeenSimplified ? spec : spec.Simplify();
var equivalenceClasses = MakeEquivalenceClasses(spec);
var nfa = new NFA <LexerAction>(equivalenceClasses.Count);
var modeMap = spec.Modes.ToDictionary(m => m, m => nfa.AddState(true));
for (var i = 0; i < spec.Rules.Count; i++)
{
spec.Rules[i].AddStates(modeMap, equivalenceClasses, nfa, i, spec.DefaultChannel);
}
return(new LexerNFA(spec, modeMap, equivalenceClasses, nfa));
}
public static LexerNFA ConvertToNFA(LexerSpec spec)
{
spec = spec.HasBeenSimplified ? spec : spec.Simplify();
var equivalenceClasses = MakeEquivalenceClasses(spec);
var nfa = new NFA<LexerAction>(equivalenceClasses.Count);
var modeMap = spec.Modes.ToDictionary(m => m, m => nfa.AddState(true));
for(var i = 0; i < spec.Rules.Count; i++)
spec.Rules[i].AddStates(modeMap, equivalenceClasses, nfa, i, spec.DefaultChannel);
return new LexerNFA(spec, modeMap, equivalenceClasses, nfa);
}
