public void TestGreibachNormalForm()
{
Assert.IsFalse(grammar1.InGreibachNormalForm());
Assert.IsFalse(grammar2.InGreibachNormalForm());
Assert.IsFalse(grammar3.InGreibachNormalForm());
Assert.IsTrue(grammar1.ToGreibachNormalForm().InGreibachNormalForm());
Assert.IsTrue(grammar2.ToGreibachNormalForm().InGreibachNormalForm());
CFG grammar3Greibach = grammar3.ToGreibachNormalForm();
Assert.IsTrue(grammar3Greibach.InGreibachNormalForm());
Assert.IsTrue(derives(grammar3Greibach, ""));
Assert.IsTrue(derives(grammar3Greibach, "()"));
Assert.IsTrue(derives(grammar3Greibach, "()()"));
Assert.IsTrue(derives(grammar3Greibach, "(())"));
Assert.IsTrue(derives(grammar3Greibach, "(()())"));
Assert.IsTrue(derives(grammar3Greibach, "()(()(()))(())"));
Assert.IsFalse(derives(grammar3Greibach, "("));
Assert.IsFalse(derives(grammar3Greibach, ")"));
Assert.IsFalse(derives(grammar3Greibach, "())"));
Assert.IsFalse(derives(grammar3Greibach, "(()()"));
Assert.IsFalse(derives(grammar3Greibach, "((())))"));
Assert.IsFalse(derives(grammar3Greibach, "(()(())"));
Assert.IsFalse(derives(grammar3Greibach, "()(()((()))(())))"));
Assert.IsTrue(CFGBuilder.Start("A")
.Derive("A").To("a")
.Derive("A").ToEpsilon()
.Build().InGreibachNormalForm());
Assert.IsFalse(CFGBuilder.Start("A")
.Derive("A").To("a", "A")
.Derive("A").ToEpsilon()
.Build().InGreibachNormalForm());
}
public void TestReversed()
{
CFG reversed = CFGBuilder.Start("a")
.Derive("a").To("c", "b")
.Derive("a").To("f", "e", "d")
.Derive("b").To("a")
.Derive("c").ToEpsilon()
.Build();
Assert.AreEqual(reversed, grammar1.Reversed());
}
public void TestRemoveEpsilonProductions()
{
CFG grammar2Transformed = grammar2.RemoveEpsilonProductions();
CFG expectedresult = CFGBuilder.Start("a")
.Derive("a").ToEpsilon()
.Derive("a").To("c", "d")
.Derive("a").To("d")
.Derive("c").To("d")
.Build();
Assert.AreEqual(expectedresult, grammar2Transformed);
}
public void TestSimplify()
{
Assert.AreEqual(grammar1, grammar1.Simplify());
Assert.AreEqual(grammar2, grammar2.Simplify());
Assert.AreEqual(grammar3, grammar3.Simplify());
CFG expectedResult = CFGBuilder.Start("S")
.Derive("S").To("S", "A")
.Derive("A").ToEpsilon()
.Build();
Assert.AreEqual(expectedResult, grammar4.Simplify());
}
public void TestMoreGrammars()
{
CFG grammar = CFGBuilder.Start("X")
.Derive("X").To("a", "Y")
.Derive("X").ToEpsilon()
.Derive("Y").To("b", "Z")
.Derive("Z").To("c", "X")
.Build().Reversed();
Assert.IsTrue(grammar.HasLeftRecursion());
grammar.ToGreibachNormalForm();
}