public void DefineAndEvaluateFunction()
{
FunExpression expr = new FunExpression(new IExpression[] { new VariableExpression(new Variable("X")), new VariableExpression(new Variable("Y")) }, new AddExpression(new VariableExpression(new Variable("X")), new VariableExpression(new Variable("Y"))));
Context context = new Context();
Assert.IsFalse(expr.HasVariable());
var result = expr.Evaluate(context);
Assert.IsNotNull(result);
Assert.IsInstanceOfType(result, typeof(Function));
var func = (Function)result;
var newcontext = func.MakeContext(new object[] { 1, 2 });
Assert.IsNotNull(newcontext);
Assert.AreEqual(1, newcontext.GetValue("X"));
Assert.AreEqual(2, newcontext.GetValue("Y"));
Assert.AreEqual(3, func.Evaluate(newcontext));
}