public void SubWordMatchTest()
{
var dfa = new FiniteAutomata("test", true);
var state1 = new State("1");
var state2 = new State("2");
var state3 = new State("3");
// Words: "abc", "ab"
dfa.StartState.AddTransitionTo(state1, InputChar.For(CODE_A));
state1.AddTransitionTo(state2, InputChar.For(CODE_B));
state2.AddTransitionTo(state3, InputChar.For(CODE_C));
state3.IsAccepting = true;
state2.IsAccepting = true;
state3.TokenClass = 0x0ABC;
state2.TokenClass = 0x00AB;
transitionFunction.Init(dfa);
byte[] input = Encoding.ASCII.GetBytes("abc");
int tokenClass;
int tokenLength = transitionFunction.MatchToken(input, 0, input.Length, out tokenClass);
Assert.That(tokenClass, Is.EqualTo(0x0ABC));
Assert.That(tokenLength, Is.EqualTo(3));
}
public void BackEpsilonTransitionTest()
{
// 1 2 3
// (S) ---> (A) ---> (B) ---> [T]
// \______/
// e
var stateA = new State("A");
var stateB = new State("B");
var nfa = new FiniteAutomata("nfa");
nfa.StartState.AddTransitionTo(stateA, InputChar.For(0x01));
stateA.AddTransitionTo(stateB, InputChar.For(0x02));
stateB.AddTransitionTo(nfa.Terminator, InputChar.For(0x03));
stateB.AddTransitionTo(stateA, InputChar.Epsilon());
nfa.Terminator.IsAccepting = true;
var dfa = NFAToDFAConverter.Convert(nfa);
ValidateTerminator(dfa);
Assert.That(dfa.StartState.Simulate(0, 1, 2, 3), Is.SameAs(dfa.Terminator));
Assert.That(dfa.StartState.Simulate(0, 1, 2, 2, 3), Is.SameAs(dfa.Terminator));
Assert.That(dfa.StartState.Simulate(0, 1, 2, 2, 2, 3), Is.SameAs(dfa.Terminator));
Assert.That(dfa.StartState.Simulate(0, 1, 2, 2, 2, 2, 3), Is.SameAs(dfa.Terminator));
Assert.Throws<SimulationException>(() => dfa.StartState.Simulate(0, 1, 2, 4));
Assert.Throws<SimulationException>(() => dfa.StartState.Simulate(0, 1, 2, 3, 2));
Assert.That(dfa.StartState.Simulate(0, 1, 2, 2), Is.Not.SameAs(dfa.Terminator));
}
public void CppCommentMatchTest()
{
var dfaAnyChar = new FiniteAutomata("any-char", false);
dfaAnyChar.StartState = dfaAnyChar.Terminator = new State("start") {Id = 0};
dfaAnyChar.StartState.IsAccepting = true;
for (int b = 0; b <= Byte.MaxValue; b++)
{
dfaAnyChar.StartState.AddTransitionTo(dfaAnyChar.StartState, InputChar.For((byte) b));
}
var dfaSuffix = new FiniteAutomata("suffix", true);
var stateAsterisk = new State("asterisk") {Id = 1};
dfaSuffix.StartState.Id = 0;
dfaSuffix.StartState.AddTransitionTo(stateAsterisk, InputChar.For((byte) '*'));
stateAsterisk.AddTransitionTo(dfaSuffix.Terminator, InputChar.For((byte) '/'));
dfaSuffix.Terminator.IsAccepting = true;
dfaSuffix.Terminator.Id = 2;
var crossAutomata = new CrossAutomata(dfaAnyChar, dfaSuffix);
var simulatedState = crossAutomata.StartState.Simulate("abcdefgh*/");
Assert.That(simulatedState.IsAccepting);
Assert.Throws<SimulationException>(() => crossAutomata.StartState.Simulate("abcde*/abcde"));
Assert.Throws<SimulationException>(() => crossAutomata.StartState.Simulate("abcde*/abcde*/"));
}
internal FiniteAutomata(string name, bool createMarginalStates)
{
if (createMarginalStates)
{
StartState = new State(name + "::StartState");
Terminator = new State(name + "::Terminator");
}
Name = name;
}
/// <summary>
/// Lexical action, performed when token is accepted. The return value is indicator that
/// determines whether to pass the token to parser or ignore it. The return value overrides
/// UseTerminal() and IgnoreTerminal() methods of Lexer.
/// </summary>
/// <summary>
/// Adds transition to given state on input char
/// </summary>
/// <param name="state">Target state for transition</param>
/// <param name="iChar">Input char for transition</param>
internal void AddTransitionTo(State state, InputChar iChar)
{
List<State> states;
if (state == null) return;
if (Transitions.TryGetValue(iChar, out states))
{
states.Add(state);
}
else
{
Transitions[iChar] = new List<State> {state};
}
}
public void DFAConversionTest()
{
var dfa = new FiniteAutomata("dfa");
var state1 = new State("1");
var state2 = new State("2");
var state3 = new State("3");
var state4 = new State("4");
var state5 = new State("5");
dfa.StartState.AddTransitionTo(state1, InputChar.For(0x01));
dfa.StartState.AddTransitionTo(state2, InputChar.For(0x02));
dfa.StartState.AddTransitionTo(state3, InputChar.For(0x03));
dfa.StartState.AddTransitionTo(state3, InputChar.For(0x04));
state1.AddTransitionTo(state4, InputChar.For(0x05));
state2.AddTransitionTo(state4, InputChar.For(0x05));
state3.AddTransitionTo(state4, InputChar.For(0x05));
state1.AddTransitionTo(state5, InputChar.For(0x06));
state2.AddTransitionTo(state5, InputChar.For(0x06));
state3.AddTransitionTo(state5, InputChar.For(0x06));
state4.AddTransitionTo(dfa.Terminator, InputChar.For(0x07));
state5.AddTransitionTo(dfa.Terminator, InputChar.For(0x07));
dfa.Terminator.IsAccepting = true;
var resultDfa = NFAToDFAConverter.Convert(dfa);
ValidateTerminator(resultDfa);
Assert.That(resultDfa.GetStates().Count, Is.EqualTo(7));
//var state = resultDfa.StartState.Simulate(0, 1, 5, 7);
Assert.That(resultDfa.StartState.Simulate(0, 1, 5, 7), Is.SameAs(resultDfa.Terminator));
Assert.That(resultDfa.StartState.Simulate(0, 2, 5, 7), Is.SameAs(resultDfa.Terminator));
Assert.That(resultDfa.StartState.Simulate(0, 3, 5, 7), Is.SameAs(resultDfa.Terminator));
Assert.That(resultDfa.StartState.Simulate(0, 4, 5, 7), Is.SameAs(resultDfa.Terminator));
Assert.That(resultDfa.StartState.Simulate(0, 1, 6, 7), Is.SameAs(resultDfa.Terminator));
Assert.That(resultDfa.StartState.Simulate(0, 2, 6, 7), Is.SameAs(resultDfa.Terminator));
Assert.That(resultDfa.StartState.Simulate(0, 3, 6, 7), Is.SameAs(resultDfa.Terminator));
Assert.That(resultDfa.StartState.Simulate(0, 4, 6, 7), Is.SameAs(resultDfa.Terminator));
Assert.Throws<SimulationException>(() => resultDfa.StartState.Simulate(0, 1, 5, 6));
Assert.Throws<SimulationException>(() => resultDfa.StartState.Simulate(0, 2, 5, 8));
Assert.Throws<SimulationException>(() => resultDfa.StartState.Simulate(0, 3, 5, 6));
Assert.Throws<SimulationException>(() => resultDfa.StartState.Simulate(0, 4, 6, 6));
}
public void AmbiguityQuantifierTest()
{
// This test checks the following regexp: (aa|bb)*?aab
var repeatedDfa = new FiniteAutomata("repeated", true);
var stateA = new State("A") { Id = 1 };
var stateB = new State("B") { Id = 2 };
repeatedDfa.StartState.Id = 0;
repeatedDfa.Terminator.Id = 4;
repeatedDfa.StartState.AddTransitionTo(stateA, InputChar.For((byte)'a'));
repeatedDfa.StartState.AddTransitionTo(stateB, InputChar.For((byte)'b'));
stateA.AddTransitionTo(repeatedDfa.Terminator, InputChar.For((byte)'a'));
stateB.AddTransitionTo(repeatedDfa.Terminator, InputChar.For((byte)'b'));
repeatedDfa.Terminator.IsAccepting = true;
var suffixDfa = new FiniteAutomata("suffix", true);
var midState1 = new State("mid1") { Id = 1 };
var midState2 = new State("mid2") {Id = 2};
suffixDfa.StartState.Id = 0;
suffixDfa.Terminator.Id = 3;
suffixDfa.StartState.AddTransitionTo(midState1, InputChar.For((byte)'a'));
midState1.AddTransitionTo(midState2, InputChar.For((byte)'a'));
midState2.AddTransitionTo(suffixDfa.Terminator, InputChar.For((byte)'b'));
suffixDfa.Terminator.IsAccepting = true;
var crossAutomata = new CrossAutomata(repeatedDfa, suffixDfa);
var simulatedState = crossAutomata.StartState.Simulate("aab");
Assert.That(simulatedState.IsAccepting);
simulatedState = crossAutomata.StartState.Simulate("bbaab");
Assert.That(simulatedState.IsAccepting);
Assert.Throws<SimulationException>(() => crossAutomata.StartState.Simulate("aabbaab"));
Assert.Pass("Note: Some asserts were ignored");
// In order o make these tests pass a more inteligent lazy quantifier mechanism
// should be developed. When there is a transition in repeatedDfa and no transition
// in suffixDfa you can't simply go to the begginning of suffixDfa since there could
// be some input is already consumed for suffixDfa. Hence what is needed is concurrent
// simulation of many suffixDfa automatas. This point is still to be solved.
// TODO: Solve it
simulatedState = crossAutomata.StartState.Simulate("aaaab");
Assert.That(simulatedState.IsAccepting);
simulatedState = crossAutomata.StartState.Simulate("bbaaaab");
Assert.That(simulatedState.IsAccepting);
}
public void TokenPrioritizationTest()
{
// e a-z e
// (S) ---> (1) ---> (2) ---> [T]
// \ \___e__/ /
// \___________e__________/
var state1 = new State("1");
var state2 = new State("2");
var nfa1 = new FiniteAutomata("nfa");
nfa1.StartState.AddTransitionTo(state1, InputChar.Epsilon());
for (char c = 'a'; c <= 'z'; c++ )
{
state1.AddTransitionTo(state2, InputChar.For((byte)c));
}
state2.AddTransitionTo(nfa1.Terminator, InputChar.Epsilon());
state2.AddTransitionTo(state1, InputChar.Epsilon());
nfa1.StartState.AddTransitionTo(nfa1.Terminator, InputChar.Epsilon());
nfa1.Terminator.IsAccepting = true;
nfa1.Terminator.TokenClass = 1; // least priority, if defined early gets small token class
// a b c
// (S) ---> (3) ---> (4) ---> [T]
var state3 = new State("3");
var state4 = new State("4");
var nfa2 = new FiniteAutomata("nfa");
nfa1.StartState.AddTransitionTo(state3, InputChar.For((byte)'a'));
state3.AddTransitionTo(state4, InputChar.For((byte)'b'));
state4.AddTransitionTo(nfa1.Terminator, InputChar.For((byte)'c'));
nfa1.Terminator.IsAccepting = true;
nfa1.Terminator.TokenClass = 2; // most priority
var nfa = new FiniteAutomata("CommonAutomata");
nfa.StartState.AddTransitionTo(nfa1.StartState, InputChar.Epsilon());
nfa.StartState.AddTransitionTo(nfa2.StartState, InputChar.Epsilon());
var dfa = NFAToDFAConverter.Convert(nfa);
Assert.That(dfa.StartState.Simulate("abc").IsAccepting);
Assert.That(dfa.StartState.Simulate("abc").TokenClass, Is.EqualTo(2));
}
public void PrefixedSuffixedKleeneClosureTest()
{
// 1 e e 2 e e 1
// (S) ---> (0) ---> (1) ---> (2) ---> (3) ---> (4) ---> (5) ---> [T]
// \ \___e__/ /
// \___________e__________/
var state0 = new State("0");
var state1 = new State("1");
var state2 = new State("2");
var state3 = new State("3");
var state4 = new State("4");
var state5 = new State("5");
var nfa = new FiniteAutomata("nfa");
nfa.StartState.AddTransitionTo(state0, InputChar.For(1));
state0.AddTransitionTo(state1, InputChar.Epsilon());
state1.AddTransitionTo(state2, InputChar.Epsilon());
state2.AddTransitionTo(state3, InputChar.For(2));
state3.AddTransitionTo(state4, InputChar.Epsilon());
state4.AddTransitionTo(state5, InputChar.Epsilon());
state5.AddTransitionTo(nfa.Terminator, InputChar.For(1));
state1.AddTransitionTo(state4, InputChar.Epsilon());
state3.AddTransitionTo(state2, InputChar.Epsilon());
nfa.Terminator.IsAccepting = true;
var dfa = NFAToDFAConverter.Convert(nfa);
Assert.That(dfa.StartState.Simulate(0, 1, 1).IsAccepting);
Assert.That(dfa.StartState.Simulate(0, 1, 2, 1).IsAccepting);
Assert.That(dfa.StartState.Simulate(0, 1, 2, 2, 1).IsAccepting);
Assert.That(dfa.StartState.Simulate(0, 1, 2, 2, 2, 1).IsAccepting);
Assert.That(dfa.StartState.Simulate(0, 1, 2, 2, 2, 2, 1).IsAccepting);
}
public void PrefixedKleeneClosureTest()
{
// 1 e 2 e
// (S) ---> (0) ---> (1) ---> (2) ---> [T]
// \ \___e__/ /
// \___________e__________/
var state0 = new State("0");
var stateA = new State("A");
var stateB = new State("B");
var nfa = new FiniteAutomata("nfa");
nfa.StartState.AddTransitionTo(state0, InputChar.For(1));
state0.AddTransitionTo(stateA, InputChar.Epsilon());
stateA.AddTransitionTo(stateB, InputChar.For(2));
stateB.AddTransitionTo(nfa.Terminator, InputChar.Epsilon());
stateB.AddTransitionTo(stateA, InputChar.Epsilon());
state0.AddTransitionTo(nfa.Terminator, InputChar.Epsilon());
nfa.Terminator.IsAccepting = true;
var dfa = NFAToDFAConverter.Convert(nfa);
Assert.That(dfa.StartState.Simulate(0, 1).IsAccepting);
Assert.That(dfa.StartState.Simulate(0, 1, 2).IsAccepting);
Assert.That(dfa.StartState.Simulate(0, 1, 2, 2).IsAccepting);
Assert.That(dfa.StartState.Simulate(0, 1, 2, 2, 2).IsAccepting);
Assert.That(dfa.StartState.Simulate(0, 1, 2, 2, 2, 2).IsAccepting);
}
public void KleeneClosureTest()
{
// e 2 e
// (S) ---> (1) ---> (2) ---> [T]
// \ \___e__/ /
// \___________e__________/
var stateA = new State("A");
var stateB = new State("B");
var nfa = new FiniteAutomata("nfa");
nfa.StartState.AddTransitionTo(stateA, InputChar.Epsilon());
stateA.AddTransitionTo(stateB, InputChar.For(2));
stateB.AddTransitionTo(nfa.Terminator, InputChar.Epsilon());
stateB.AddTransitionTo(stateA, InputChar.Epsilon());
nfa.StartState.AddTransitionTo(nfa.Terminator, InputChar.Epsilon());
nfa.Terminator.IsAccepting = true;
var dfa = NFAToDFAConverter.Convert(nfa);
Assert.That(dfa.StartState.Simulate().IsAccepting);
Assert.That(dfa.StartState.Simulate(0, 2).IsAccepting);
Assert.That(dfa.StartState.Simulate(0, 2, 2).IsAccepting);
Assert.That(dfa.StartState.Simulate(0, 2, 2, 2).IsAccepting);
Assert.That(dfa.StartState.Simulate(0, 2, 2, 2, 2).IsAccepting);
// The result DFA has the following form:
// ___
// 1 / \
// [S] ---> [T] | 1
// \___/
// However, generally speaking it should be single accepting state with self transition on '1'
// Note that both S and T are accepting states
}
public void EpsilonTransitionsConversionTest()
{
// 1 2 4
// (S) ---> (A) ---> (B) ---> [T]
// |
// ---> (C) ---> (D) ---> [T]
// e 3 4
var stateA = new State("A");
var stateB = new State("B");
var stateC = new State("C");
var stateD = new State("D");
var nfa = new FiniteAutomata();
nfa.StartState.AddTransitionTo(stateA, InputChar.For(1));
stateA.AddTransitionTo(stateB, InputChar.For(2));
stateA.AddTransitionTo(stateC, InputChar.Epsilon());
stateC.AddTransitionTo(stateD, InputChar.For(3));
stateB.AddTransitionTo(nfa.Terminator, InputChar.For(4));
stateD.AddTransitionTo(nfa.Terminator, InputChar.For(4));
nfa.Terminator.IsAccepting = true;
var dfa = NFAToDFAConverter.Convert(nfa);
ValidateTerminator(dfa);
Assert.That(dfa.GetStates().Count, Is.EqualTo(5));
Assert.That(dfa.StartState.Simulate(0, 1, 2, 4), Is.SameAs(dfa.Terminator));
Assert.That(dfa.StartState.Simulate(0, 1, 3, 4), Is.SameAs(dfa.Terminator));
Assert.Throws<SimulationException>(() => dfa.StartState.Simulate(0, 2, 2, 4));
Assert.Throws<SimulationException>(() => dfa.StartState.Simulate(0, 1, 2, 5));
Assert.Throws<SimulationException>(() => dfa.StartState.Simulate(0, 1, 3, 2));
}
public void GeneralLazyQuantifierTest()
{
// (aa|bb|cc)
var repeatedDfa = new FiniteAutomata("repeated", true);
var stateA = new State("A") { Id = 1 };
var stateB = new State("B") { Id = 2 };
var stateC = new State("C") { Id = 3 };
repeatedDfa.StartState.Id = 0;
repeatedDfa.Terminator.Id = 4;
repeatedDfa.StartState.AddTransitionTo(stateA, InputChar.For((byte)'a'));
repeatedDfa.StartState.AddTransitionTo(stateB, InputChar.For((byte)'b'));
repeatedDfa.StartState.AddTransitionTo(stateC, InputChar.For((byte)'c'));
stateA.AddTransitionTo(repeatedDfa.Terminator, InputChar.For((byte)'a'));
stateB.AddTransitionTo(repeatedDfa.Terminator, InputChar.For((byte)'b'));
stateC.AddTransitionTo(repeatedDfa.Terminator, InputChar.For((byte)'c'));
repeatedDfa.Terminator.IsAccepting = true;
// ab
var suffixDfa = new FiniteAutomata("suffix", true);
var midState = new State("mid") { Id = 1 };
suffixDfa.StartState.Id = 0;
suffixDfa.Terminator.Id = 2;
suffixDfa.StartState.AddTransitionTo(midState, InputChar.For((byte) 'a'));
midState.AddTransitionTo(suffixDfa.Terminator, InputChar.For((byte) 'b'));
suffixDfa.Terminator.IsAccepting = true;
// (aa|bb|cc)*?ab
var crossAutomata = new CrossAutomata(repeatedDfa, suffixDfa);
var simulatedState = crossAutomata.StartState.Simulate("aa");
Assert.That(simulatedState, Is.SameAs(crossAutomata.StartState));
simulatedState = crossAutomata.StartState.Simulate("bb");
Assert.That(simulatedState, Is.SameAs(crossAutomata.StartState));
simulatedState = crossAutomata.StartState.Simulate("cc");
Assert.That(simulatedState, Is.SameAs(crossAutomata.StartState));
simulatedState = crossAutomata.StartState.Simulate("aabbccbbaa");
Assert.That(simulatedState, Is.SameAs(crossAutomata.StartState));
simulatedState = crossAutomata.StartState.Simulate("ccaabbccaabbab");
Assert.That(simulatedState.IsAccepting);
simulatedState = crossAutomata.StartState.Simulate("ab");
Assert.That(simulatedState.IsAccepting);
simulatedState = crossAutomata.StartState.Simulate("ccaabbccaabba");
Assert.That(!simulatedState.IsAccepting);
Assert.Throws<SimulationException>(() => crossAutomata.StartState.Simulate("ccaabbccaabbabab"));
}
public void InitTests()
{
stateA = new State("A");
stateB = new State("B");
stateC = new State("C");
stateD = new State("D");
stateE = new State("E");
stateF = new State("F");
mFiniteAutomata = new FiniteAutomata("Test")
{
StartState = new State("start"),
Terminator = new State("terminator")
};
expectedSet = new HashSet<State>()
{
mFiniteAutomata.StartState,
stateA,
stateB,
stateC,
stateD,
stateE,
stateF,
mFiniteAutomata.Terminator
};
}
private static State SimulateNFA(State state, params byte[] inputChars)
{
byte?[] nullableBytes = new byte?[inputChars.Length];
for (int i = 0; i < inputChars.Length; i++)
{
nullableBytes[i] = inputChars[i];
}
return state.Simulate(0, nullableBytes);
}
