public static Automaton MakeInterval(int min, int max, int digits)
{
var a = new Automaton();
var x = Convert.ToString(min);
var y = Convert.ToString(max);
if (min > max || (digits > 0 && y.Length > digits))
{
throw new ArgumentException();
}
var d = digits > 0 ? digits : y.Length;
var sb1 = new StringBuilder();
for (var i = x.Length; i < d; i++)
{
_ = sb1.Append('0');
}
_ = sb1.Append(x);
x = sb1.ToString();
var sb2 = new StringBuilder();
for (var i = y.Length; i < d; i++)
{
_ = sb2.Append('0');
}
_ = sb2.Append(y);
y = sb2.ToString();
ICollection <State> initials = new List <State>();
a.Initial = Between(x, y, 0, initials, digits <= 0);
if (digits <= 0)
{
var pairs = (from p in initials
where a.Initial != p
select new StatePair(a.Initial, p)).ToList();
a.AddEpsilons(pairs);
a.Initial.AddTransition(new Transition('0', a.Initial));
a.IsDeterministic = false;
}
else
{
a.IsDeterministic = true;
}
a.CheckMinimizeAlways();
return(a);
}