/// <summary>
/// Determinizes the specified automaton.
/// </summary>
/// <remarks>
/// Complexity: exponential in number of states.
/// </remarks>
/// <param name="a">The automaton.</param>
internal static void Determinize(Automaton a)
{
if (a.IsDeterministic || a.IsSingleton)
{
return;
}
var initialset = new HashSet <State>();
initialset.Add(a.Initial);
BasicOperations.Determinize(a, initialset.ToList());
}
/// <summary>
/// Accepts <code>min</code> or more concatenated repetitions of the language of the given
/// automaton.
/// </summary>
/// <param name="a">The automaton.</param>
/// <param name="min">The minimum concatenated repetitions of the language of the given
/// automaton.</param>
/// <returns>Returns an automaton that accepts <code>min</code> or more concatenated
/// repetitions of the language of the given automaton.
/// </returns>
/// <remarks>
/// Complexity: linear in number of states and in <code>min</code>.
/// </remarks>
internal static Automaton Repeat(Automaton a, int min)
{
if (min == 0)
{
return(BasicOperations.Repeat(a));
}
var @as = new List <Automaton>();
while (min-- > 0)
{
@as.Add(a);
}
@as.Add(BasicOperations.Repeat(a));
return(BasicOperations.Concatenate(@as));
}
internal static Automaton Concatenate(Automaton a1, Automaton a2)
{
if (a1.IsSingleton && a2.IsSingleton)
{
return(BasicAutomata.MakeString(a1.Singleton + a2.Singleton));
}
if (BasicOperations.IsEmpty(a1) || BasicOperations.IsEmpty(a2))
{
return(BasicAutomata.MakeEmpty());
}
bool deterministic = a1.IsSingleton && a2.IsDeterministic;
if (a1 == a2)
{
a1 = a1.CloneExpanded();
a2 = a2.CloneExpanded();
}
else
{
a1 = a1.CloneExpandedIfRequired();
a2 = a2.CloneExpandedIfRequired();
}
foreach (State s in a1.GetAcceptStates())
{
s.Accept = false;
s.AddEpsilon(a2.Initial);
}
a1.IsDeterministic = deterministic;
a1.ClearHashCode();
a1.CheckMinimizeAlways();
return(a1);
}
private Automaton ToAutomaton(
IDictionary <string, Automaton> automata,
IAutomatonProvider automatonProvider,
bool minimize)
{
IList <Automaton> list;
Automaton a = null;
switch (kind)
{
case Kind.RegexpUnion:
list = new List <Automaton>();
this.FindLeaves(exp1, Kind.RegexpUnion, list, automata, automatonProvider, minimize);
this.FindLeaves(exp2, Kind.RegexpUnion, list, automata, automatonProvider, minimize);
a = BasicOperations.Union(list);
a.Minimize();
break;
case Kind.RegexpConcatenation:
list = new List <Automaton>();
this.FindLeaves(exp1, Kind.RegexpConcatenation, list, automata, automatonProvider, minimize);
this.FindLeaves(exp2, Kind.RegexpConcatenation, list, automata, automatonProvider, minimize);
a = BasicOperations.Concatenate(list);
a.Minimize();
break;
case Kind.RegexpIntersection:
a = exp1.ToAutomaton(automata, automatonProvider, minimize)
.Intersection(exp2.ToAutomaton(automata, automatonProvider, minimize));
a.Minimize();
break;
case Kind.RegexpOptional:
a = exp1.ToAutomaton(automata, automatonProvider, minimize).Optional();
a.Minimize();
break;
case Kind.RegexpRepeat:
a = exp1.ToAutomaton(automata, automatonProvider, minimize).Repeat();
a.Minimize();
break;
case Kind.RegexpRepeatMin:
a = exp1.ToAutomaton(automata, automatonProvider, minimize).Repeat(min);
a.Minimize();
break;
case Kind.RegexpRepeatMinMax:
a = exp1.ToAutomaton(automata, automatonProvider, minimize).Repeat(min, max);
a.Minimize();
break;
case Kind.RegexpComplement:
a = exp1.ToAutomaton(automata, automatonProvider, minimize).Complement();
a.Minimize();
break;
case Kind.RegexpChar:
a = BasicAutomata.MakeChar(c);
break;
case Kind.RegexpCharRange:
a = BasicAutomata.MakeCharRange(from, to);
break;
case Kind.RegexpAnyChar:
a = BasicAutomata.MakeAnyChar();
break;
case Kind.RegexpEmpty:
a = BasicAutomata.MakeEmpty();
break;
case Kind.RegexpString:
a = BasicAutomata.MakeString(s);
break;
case Kind.RegexpAnyString:
a = BasicAutomata.MakeAnyString();
break;
case Kind.RegexpAutomaton:
Automaton aa = null;
if (automata != null)
{
automata.TryGetValue(s, out aa);
}
if (aa == null && automatonProvider != null)
{
try
{
aa = automatonProvider.GetAutomaton(s);
}
catch (IOException e)
{
throw new ArgumentException(string.Empty, e);
}
}
if (aa == null)
{
throw new ArgumentException("'" + s + "' not found");
}
a = aa.Clone(); // Always clone here (ignore allowMutate).
break;
case Kind.RegexpInterval:
a = BasicAutomata.MakeInterval(min, max, digits);
break;
}
return(a);
}
internal bool Run(string s)
{
return(BasicOperations.Run(this, s));
}
internal Automaton Repeat(int min)
{
return(BasicOperations.Repeat(this, min));
}
internal Automaton Repeat()
{
return(BasicOperations.Repeat(this));
}
internal Automaton Optional()
{
return(BasicOperations.Optional(this));
}
internal bool IsEmptyString()
{
return(BasicOperations.IsEmptyString(this));
}
internal Automaton Intersection(Automaton a)
{
return(BasicOperations.Intersection(this, a));
}
internal void Determinize()
{
BasicOperations.Determinize(this);
}
internal Automaton Concatenate(Automaton a)
{
return(BasicOperations.Concatenate(this, a));
}
internal Automaton Complement()
{
return(BasicOperations.Complement(this));
}
internal void AddEpsilons(ICollection <StatePair> pairs)
{
BasicOperations.AddEpsilons(this, pairs);
}