public 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 = Concatenate(@as);
}
if (max > 0)
{
var d = a.Clone();
while (--max > 0)
{
var c = a.Clone();
foreach (var p in c.GetAcceptStates())
{
p.AddEpsilon(d.Initial);
}
d = c;
}
foreach (var p in b.GetAcceptStates())
{
p.AddEpsilon(d.Initial);
}
b.IsDeterministic = false;
b.ClearHashCode();
b.CheckMinimizeAlways();
}
return(b);
}
