// LUCENENET specific - De-nested RandomAcceptedStrings
/// <summary>
/// Return a random NFA/DFA for testing. </summary>
public static Automaton RandomAutomaton(Random random)
{
// get two random Automata from regexps
Automaton a1 = (new RegExp(AutomatonTestUtil.RandomRegexp(random), RegExpSyntax.NONE)).ToAutomaton();
if (random.NextBoolean())
{
a1 = BasicOperations.Complement(a1);
}
Automaton a2 = (new RegExp(AutomatonTestUtil.RandomRegexp(random), RegExpSyntax.NONE)).ToAutomaton();
if (random.NextBoolean())
{
a2 = BasicOperations.Complement(a2);
}
// combine them in random ways
switch (random.Next(4))
{
case 0:
return(BasicOperations.Concatenate(a1, a2));
case 1:
return(BasicOperations.Union(a1, a2));
case 2:
return(BasicOperations.Intersection(a1, a2));
default:
return(BasicOperations.Minus(a1, a2));
}
}
private static void AssertAutomaton(Automaton a)
{
Automaton clone = (Automaton)a.Clone();
// complement(complement(a)) = a
Automaton equivalent = BasicOperations.Complement(BasicOperations.Complement(a));
Assert.IsTrue(BasicOperations.SameLanguage(a, equivalent));
// a union a = a
equivalent = BasicOperations.Union(a, clone);
Assert.IsTrue(BasicOperations.SameLanguage(a, equivalent));
// a intersect a = a
equivalent = BasicOperations.Intersection(a, clone);
Assert.IsTrue(BasicOperations.SameLanguage(a, equivalent));
// a minus a = empty
Automaton empty = BasicOperations.Minus(a, clone);
Assert.IsTrue(BasicOperations.IsEmpty(empty));
// as long as don't accept the empty string
// then optional(a) - empty = a
if (!BasicOperations.Run(a, ""))
{
//System.out.println("test " + a);
Automaton optional = BasicOperations.Optional(a);
//System.out.println("optional " + optional);
equivalent = BasicOperations.Minus(optional, BasicAutomata.MakeEmptyString());
//System.out.println("equiv " + equivalent);
Assert.IsTrue(BasicOperations.SameLanguage(a, equivalent));
}
}
/// <summary>
/// See <see cref="BasicOperations.Complement(Automaton)"/>.
/// </summary>
public virtual Automaton Complement()
{
return(BasicOperations.Complement(this));
}
