public void TestFunctionsComposition()
{
var zero = new FunctionZero();
var succ = new FunctionSucc();
var res = succ.exec(zero);
var idn = new FunctionI().exec(res);
var dubl = new FunctionDbl().exec(idn);
Assert.AreEqual(1, (res as Digit).digit);
Assert.AreEqual(1, (idn as Digit).digit);
Assert.AreEqual(2, (dubl as Digit).digit);
}
public void TestFunctionsSuccAndDbl()
{
var funf = new Digit(5);
var succ = new FunctionSucc();
var res = succ.exec(funf);
Assert.AreEqual(true, res.isDigit());
Assert.AreEqual(6, (res as Digit).digit);
var dbl = new FunctionDbl();
var res2 = dbl.exec(funf);
Assert.AreEqual(true, res2.isDigit());
Assert.AreEqual(10, (res2 as Digit).digit);
}