public void CreateSimpleList()
{
Context context = new Context();
var expr = new ListExpression(new IExpression[] { new ConstantExpression(1), new AtomExpression(new Atom("x")), new AtomExpression(new Atom("y")) });
Assert.IsFalse(expr.HasVariable());
var result = expr.Evaluate(context, true);
Assert.IsNotNull(result);
Assert.IsInstanceOfType(result, typeof(List));
var list = (List)result;
Assert.IsNotNull(list.Head);
Assert.IsNotNull(list.Tail);
Assert.AreEqual("[1,x,y]", list.ToString());
}
public void RaiseWhenUnboundVariable()
{
Context context = new Context();
var expr = new ListExpression(new IExpression[] { new ConstantExpression(1), new VariableExpression(new Variable("X")), new AtomExpression(new Atom("y")) });
Assert.IsTrue(expr.HasVariable());
try
{
expr.Evaluate(context, false);
Assert.Fail();
}
catch (Exception ex)
{
Assert.AreEqual("variable 'X' is unbound", ex.Message);
}
}