/// <summary>
/// Accepts between <code>min</code> and <code>max</code> (including both) 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>
/// <param name="max">The maximum concatenated repetitions of the language of the given
/// automaton.</param>
/// <returns>
/// Returns an automaton that accepts between <code>min</code> and <code>max</code>
/// (including both) concatenated repetitions of the language of the given automaton.
/// </returns>
/// <remarks>
/// Complexity: linear in number of states and in <code>min</code> and <code>max</code>.
/// </remarks>
internal static Automaton Repeat(Automaton a, int min, int max)
{
if (min > max)
{
return(BasicAutomata.MakeEmpty());
}
max -= min;
a.ExpandSingleton();
Automaton b;
if (min == 0)
{
b = BasicAutomata.MakeEmptyString();
}
else if (min == 1)
{
b = a.Clone();
}
else
{
var @as = new List <Automaton>();
while (min-- > 0)
{
@as.Add(a);
}
b = BasicOperations.Concatenate(@as);
}
if (max > 0)
{
Automaton d = a.Clone();
while (--max > 0)
{
Automaton c = a.Clone();
foreach (State p in c.GetAcceptStates())
{
p.AddEpsilon(d.Initial);
}
d = c;
}
foreach (State p in b.GetAcceptStates())
{
p.AddEpsilon(d.Initial);
}
b.IsDeterministic = false;
b.ClearHashCode();
b.CheckMinimizeAlways();
}
return(b);
}
private Automaton ToAutomaton(
IDictionary <string, Automaton> automata,
IAutomatonProvider automatonProvider,
bool minimize)
{
IList <Automaton> list;
Automaton a = null;
switch (this.kind)
{
case Kind.RegexpUnion:
list = new List <Automaton>();
this.FindLeaves(this.exp1, Kind.RegexpUnion, list, automata, automatonProvider, minimize);
this.FindLeaves(this.exp2, Kind.RegexpUnion, list, automata, automatonProvider, minimize);
a = BasicOperations.Union(list);
a.Minimize();
break;
case Kind.RegexpConcatenation:
list = new List <Automaton>();
this.FindLeaves(this.exp1, Kind.RegexpConcatenation, list, automata, automatonProvider, minimize);
this.FindLeaves(this.exp2, Kind.RegexpConcatenation, list, automata, automatonProvider, minimize);
a = BasicOperations.Concatenate(list);
a.Minimize();
break;
case Kind.RegexpIntersection:
a = this.exp1.ToAutomaton(automata, automatonProvider, minimize)
.Intersection(this.exp2.ToAutomaton(automata, automatonProvider, minimize));
a.Minimize();
break;
case Kind.RegexpOptional:
a = this.exp1.ToAutomaton(automata, automatonProvider, minimize).Optional();
a.Minimize();
break;
case Kind.RegexpRepeat:
a = this.exp1.ToAutomaton(automata, automatonProvider, minimize).Repeat();
a.Minimize();
break;
case Kind.RegexpRepeatMin:
a = this.exp1.ToAutomaton(automata, automatonProvider, minimize).Repeat(this.min);
a.Minimize();
break;
case Kind.RegexpRepeatMinMax:
a = this.exp1.ToAutomaton(automata, automatonProvider, minimize).Repeat(this.min, this.max);
a.Minimize();
break;
case Kind.RegexpComplement:
a = this.exp1.ToAutomaton(automata, automatonProvider, minimize).Complement();
a.Minimize();
break;
case Kind.RegexpChar:
a = BasicAutomata.MakeChar(this.c);
break;
case Kind.RegexpCharRange:
a = BasicAutomata.MakeCharRange(this.@from, this.to);
break;
case Kind.RegexpAnyChar:
a = BasicAutomata.MakeAnyChar();
break;
case Kind.RegexpEmpty:
a = BasicAutomata.MakeEmpty();
break;
case Kind.RegexpString:
a = BasicAutomata.MakeString(this.s);
break;
case Kind.RegexpAnyString:
a = BasicAutomata.MakeAnyString();
break;
case Kind.RegexpAutomaton:
Automaton aa = null;
if (automata != null)
{
automata.TryGetValue(this.s, out aa);
}
if (aa == null && automatonProvider != null)
{
try
{
aa = automatonProvider.GetAutomaton(this.s);
}
catch (IOException e)
{
throw new ArgumentException(string.Empty, e);
}
}
if (aa == null)
{
throw new ArgumentException("'" + this.s + "' not found");
}
a = aa.Clone(); // Always clone here (ignore allowMutate).
break;
case Kind.RegexpInterval:
a = BasicAutomata.MakeInterval(this.min, this.max, this.digits);
break;
}
return(a);
}