public void EvaluateDefinedSymbol()
{
Symbol symbol = Symbol.Create("foo");
Machine machine = new Machine();
machine.Environment.SetValue(symbol.FullName, "bar");
IExpression expression = new SymbolExpression(symbol);
Assert.AreEqual("bar", expression.Evaluate(machine, machine.Environment));
Assert.AreEqual(symbol, expression.Value);
}
public void EvaluateUnqualifiedSymbolAsDefinedVariableInCurrentNamespace()
{
Symbol symbol = Symbol.Create("foo");
Machine machine = new Machine();
Variable variable = Variable.Intern(machine, (string) machine.Environment.GetValue(Machine.CurrentNamespaceKey), "foo");
machine.SetVariableValue(variable, "bar");
IExpression expression = new SymbolExpression(symbol);
Assert.AreEqual("bar", expression.Evaluate(machine, machine.Environment));
Assert.AreEqual(symbol, expression.Value);
}
public void UndefinedSymbolEvaluateToNull()
{
Symbol symbol = Symbol.Create("foo");
Machine machine = new Machine();
IExpression expression = new SymbolExpression(symbol);
Assert.IsNull(expression.Evaluate(machine, machine.Environment));
Assert.AreEqual(symbol, expression.Value);
}
