public void DeadStatesTest()
{
var dfa = new Dfa <string>();
dfa.AddEdge(0, "A", 3);
dfa.AddEdge(1, "B", 3);
dfa.AddEdge(2, "C", 3);
dfa.AddEdge(0, "E", 1);
dfa.AddEdge(1, "E", 2);
dfa.AddBadState(3);
var emptyDfa = new Dfa <string>();
var rules = new Dictionary <string, IDfa <Optional <Rule <string> >, string> >
{
["A"] = dfa,
["E"] = emptyDfa
};
var grammar = new CompiledGrammar <string> {
Rules = rules
};
var nullables = new List <DfaAndState <string> >
{
new DfaAndState <string> {
Dfa = emptyDfa, State = new ValueState <int>(0)
}
};
var firstSymbols = FirstHelper <string> .GetFirstSymbols(grammar, nullables);
var expected = new[]
{
"E",
"E",
string.Empty,
string.Empty
};
for (int i = 0; i < 4; ++i)
{
var stateEntity = new DfaAndState <string> {
Dfa = dfa, State = new ValueState <int>(i)
};
string output = string.Join(',', firstSymbols[stateEntity].OrderBy(x => x));
Assert.AreEqual(expected[i], output, $"Unexpected output on test {i}: expected is [{expected[i]}], but found [{output}]");
}
}
public void ThreeDfasTest()
{
var firstDfa = new Dfa <string>();
firstDfa.AddEdge(0, "D", 1);
firstDfa.AddEdge(0, "F", 4);
firstDfa.AddEdge(0, "C", 3);
firstDfa.AddEdge(0, "B", 2);
firstDfa.AddEdge(2, "B", 7);
firstDfa.AddEdge(3, "A", 5);
firstDfa.AddEdge(4, "G", 6);
firstDfa.AddEdge(6, "A", 5);
var secondDfa = new Dfa <string>();
secondDfa.AddEdge(0, "B", 1);
secondDfa.AddEdge(0, "C", 2);
secondDfa.AddEdge(2, "A", 3);
secondDfa.AddEdge(1, "E", 4);
var thirdDfa = new Dfa <string>();
var rules = new Dictionary <string, IDfa <Optional <Rule <string> >, string> >
{
["A"] = firstDfa,
["B"] = secondDfa,
["C"] = thirdDfa
};
var grammar = new CompiledGrammar <string> {
Rules = rules
};
var nullables = new List <DfaAndState <string> >
{
new DfaAndState <string> {
Dfa = thirdDfa, State = new ValueState <int>(0)
}
};
var firstSymbols = FirstHelper <string> .GetFirstSymbols(grammar, nullables);
var expected = new[]
{
new[] { "A,B,C,D,F", string.Empty, "A,B,C,D,F", "A,B,C,D,F", "G", string.Empty, "A,B,C,D,F", string.Empty },
new[] { "A,B,C,D,F", "E", "A,B,C,D,F", string.Empty, string.Empty },
new[] { string.Empty }
};
var size = new int[] { 8, 5, 1 };
var dfas = new ConcreteDfa <Optional <Rule <string> >, string>[] { firstDfa, secondDfa, thirdDfa };
for (int test = 0; test < 3; ++test)
{
for (int i = 0; i < size[test]; ++i)
{
var stateEntity = new DfaAndState <string> {
Dfa = dfas[test], State = new ValueState <int>(i)
};
string output = string.Join(',', firstSymbols[stateEntity].OrderBy(x => x));
Assert.AreEqual(expected[test][i], output, $"Unexpected output on test ({test}, {i}): expected is [{expected[test][i]}], but found [{output}]");
}
}
}
public void Test1()
{
// Z –> d | XYZ
// Y –> c | a
// X –> Y | ε
var rules = new Dictionary <char, IDfa <Optional <Rule <char> >, char> >();
var zdfa = new ConcreteDfa <Optional <Rule <char> >, char>();
zdfa.Magic = 0;
zdfa.AddEdge(0, 'X', 1);
zdfa.AddEdge(1, 'Y', 2);
zdfa.AddEdge(2, 'Z', 3);
zdfa.AddEdge(0, 'd', 3);
zdfa.Labels.Add(0, REJECT);
zdfa.Labels.Add(1, REJECT);
zdfa.Labels.Add(2, REJECT);
zdfa.Labels.Add(3, this.ACCEPT('Z'));
rules.Add('Z', zdfa);
var ydfa = new ConcreteDfa <Optional <Rule <char> >, char>();
ydfa.Magic = 1;
ydfa.AddEdge(0, 'c', 1);
ydfa.AddEdge(0, 'a', 1);
ydfa.Labels.Add(0, REJECT);
ydfa.Labels.Add(1, this.ACCEPT('Y'));
rules.Add('Y', ydfa);
var xdfa = new ConcreteDfa <Optional <Rule <char> >, char>();
xdfa.Magic = 2;
xdfa.AddEdge(0, 'Y', 1);
xdfa.Labels.Add(0, this.ACCEPT('X'));
xdfa.Labels.Add(1, this.ACCEPT('X'));
rules.Add('X', xdfa);
var grammar = new CompiledGrammar <char> {
Rules = rules, StartSymbol = 'Z'
};
var nullables = NullablesHelper <char> .GetNullableSymbols(grammar);
{
var output = nullables.OrderBy(x => (x.Dfa as ConcreteDfa <Optional <Rule <char> >, char>).Magic).ThenBy(x => (x.State as ValueState <int>).Value).ToList();
Assert.AreEqual(4, output.Count);
Assert.AreEqual(0, (output[0].Dfa as ConcreteDfa <Optional <Rule <char> >, char>).Magic);
Assert.AreEqual(3, (output[0].State as ValueState <int>).Value);
Assert.AreEqual(1, (output[1].Dfa as ConcreteDfa <Optional <Rule <char> >, char>).Magic);
Assert.AreEqual(1, (output[1].State as ValueState <int>).Value);
Assert.AreEqual(2, (output[2].Dfa as ConcreteDfa <Optional <Rule <char> >, char>).Magic);
Assert.AreEqual(0, (output[2].State as ValueState <int>).Value);
Assert.AreEqual(2, (output[3].Dfa as ConcreteDfa <Optional <Rule <char> >, char>).Magic);
Assert.AreEqual(1, (output[3].State as ValueState <int>).Value);
}
var first = FirstHelper <char> .GetFirstSymbols(grammar, nullables);
{
var output = first.OrderBy(x => (x.Key.Dfa as ConcreteDfa <Optional <Rule <char> >, char>).Magic).ThenBy(x => (x.Key.State as ValueState <int>).Value).ToList();
var symbols = output[0].Value.ToList(); // Z0
symbols.Sort();
Assert.AreEqual(5, symbols.Count);
Assert.AreEqual('X', symbols[0]);
Assert.AreEqual('Y', symbols[1]);
Assert.AreEqual('a', symbols[2]);
Assert.AreEqual('c', symbols[3]);
Assert.AreEqual('d', symbols[4]);
symbols = output[1].Value.ToList(); // Z1
symbols.Sort();
Assert.AreEqual(3, symbols.Count);
Assert.AreEqual('Y', symbols[0]);
Assert.AreEqual('a', symbols[1]);
Assert.AreEqual('c', symbols[2]);
symbols = output[2].Value.ToList(); // Z2
symbols.Sort();
Assert.AreEqual(6, symbols.Count);
Assert.AreEqual('X', symbols[0]);
Assert.AreEqual('Y', symbols[1]);
Assert.AreEqual('Z', symbols[2]);
Assert.AreEqual('a', symbols[3]);
Assert.AreEqual('c', symbols[4]);
Assert.AreEqual('d', symbols[5]);
symbols = output[3].Value.ToList(); // Z3
Assert.AreEqual(0, symbols.Count);
symbols = output[4].Value.ToList(); // Y0
symbols.Sort();
Assert.AreEqual(2, symbols.Count);
Assert.AreEqual('a', symbols[0]);
Assert.AreEqual('c', symbols[1]);
symbols = output[5].Value.ToList(); // Y1
Assert.AreEqual(0, symbols.Count);
symbols = output[6].Value.ToList(); // X0
symbols.Sort();
Assert.AreEqual(3, symbols.Count);
Assert.AreEqual('Y', symbols[0]);
Assert.AreEqual('a', symbols[1]);
Assert.AreEqual('c', symbols[2]);
symbols = output[7].Value.ToList(); // X1
Assert.AreEqual(0, symbols.Count);
}
var follow = FollowHelper <char> .GetFollowSymbols(grammar, nullables, first.InverseRelation(), '\uffff');
{
var output = follow.OrderBy(x => (x.Key.Dfa as ConcreteDfa <Optional <Rule <char> >, char>).Magic).ThenBy(x => (x.Key.State as ValueState <int>).Value).ToList();
var symbols = output[0].Value.ToList(); // Z3
Assert.AreEqual(1, symbols.Count);
Assert.AreEqual('\uffff', symbols[0]);
symbols = output[1].Value.ToList(); // Y1
symbols.Sort();
Assert.AreEqual(6, symbols.Count);
Assert.AreEqual('X', symbols[0]);
Assert.AreEqual('Y', symbols[1]);
Assert.AreEqual('Z', symbols[2]);
Assert.AreEqual('a', symbols[3]);
Assert.AreEqual('c', symbols[4]);
Assert.AreEqual('d', symbols[5]);
symbols = output[2].Value.ToList(); // X0
symbols.Sort();
Assert.AreEqual(3, symbols.Count);
Assert.AreEqual('Y', symbols[0]);
Assert.AreEqual('a', symbols[1]);
Assert.AreEqual('c', symbols[2]);
symbols = output[3].Value.ToList(); // X1
symbols.Sort();
Assert.AreEqual(3, symbols.Count);
Assert.AreEqual('Y', symbols[0]);
Assert.AreEqual('a', symbols[1]);
Assert.AreEqual('c', symbols[2]);
}
}
public void Test0SimpleParens()
{
var rules = new Dictionary <char, IDfa <Optional <Rule <char> >, char> >();
var dfa = new ConcreteDfa <Optional <Rule <char> >, char>();
dfa.AddEdge(0, '(', 1);
dfa.AddEdge(1, 'S', 2);
dfa.AddEdge(2, ')', 3);
dfa.Labels.Add(0, this.ACCEPT('S'));
dfa.Labels.Add(1, REJECT);
dfa.Labels.Add(2, REJECT);
dfa.Labels.Add(3, this.ACCEPT('S'));
rules.Add('S', dfa);
var grammar = new CompiledGrammar <char> {
Rules = rules, StartSymbol = 'S'
};
var nullables = NullablesHelper <char> .GetNullableSymbols(grammar);
{
Assert.AreEqual(2, nullables.Count);
var states = nullables.Select(x => ((ValueState <int>)x.State).Value).ToList();
states.Sort();
Assert.AreEqual(0, states[0]);
Assert.AreEqual(3, states[1]);
}
var first = FirstHelper <char> .GetFirstSymbols(grammar, nullables);
{
var output = first.OrderBy(x => (x.Key.State as ValueState <int>).Value).ToList();
var symbols = output[0].Value.ToList();
Assert.AreEqual(1, symbols.Count);
Assert.AreEqual('(', symbols[0]);
symbols = output[1].Value.ToList();
symbols.Sort();
Assert.AreEqual(3, symbols.Count);
Assert.AreEqual('(', symbols[0]);
Assert.AreEqual(')', symbols[1]);
Assert.AreEqual('S', symbols[2]);
symbols = output[2].Value.ToList();
Assert.AreEqual(1, symbols.Count);
Assert.AreEqual(')', symbols[0]);
symbols = output[3].Value.ToList();
Assert.AreEqual(0, symbols.Count);
}
var follow = FollowHelper <char> .GetFollowSymbols(grammar, nullables, first.InverseRelation(), '\uffff');
{
var output = follow.OrderBy(x => (x.Key.State as ValueState <int>).Value).ToList();
var symbols = output[0].Value.ToList(); // state 0
symbols.Sort();
Assert.AreEqual(2, symbols.Count);
Assert.AreEqual(')', symbols[0]);
Assert.AreEqual('\uffff', symbols[1]);
symbols = output[1].Value.ToList(); // state 3
symbols.Sort();
Assert.AreEqual(2, symbols.Count);
Assert.AreEqual(')', symbols[0]);
Assert.AreEqual('\uffff', symbols[1]);
}
}