public void AddTwoIntegers()
{
AddExpression expr = new AddExpression(new ConstantExpression(1), new ConstantExpression(2));
Assert.AreEqual(3, expr.Evaluate(null));
Assert.IsFalse(expr.HasVariable());
}
public void AddVariableAndInteger()
{
Context context = new Context();
context.SetValue("One", 1);
AddExpression expr = new AddExpression(new VariableExpression(new Variable("One")), new ConstantExpression(2));
Assert.AreEqual(3, expr.Evaluate(context));
Assert.IsTrue(expr.HasVariable());
}
public void AddIntegerAndVariable()
{
Context context = new Context();
context.SetValue("Two", 2);
AddExpression expr = new AddExpression(new ConstantExpression(1), new VariableExpression(new Variable("Two")));
Assert.AreEqual(3, expr.Evaluate(context));
Assert.IsTrue(expr.HasVariable());
}
private static object Sum(Context context, IList<object> arguments)
{
if (arguments[0] is EmptyList)
return 0;
AddExpression addexpr = new AddExpression(null, null);
List list = (List)arguments[0];
object result = 0;
while (list != null)
{
result = addexpr.Apply(result, list.Head);
list = (List)list.Tail;
}
return result;
}
private IExpression ParseBinaryExpression(int level)
{
if (level >= binaryoperators.Length)
return this.ParseTerm();
IExpression expr = this.ParseBinaryExpression(level + 1);
if (expr == null)
return null;
Token token;
for (token = this.lexer.NextToken(); token != null && this.IsBinaryOperator(level, token); token = this.lexer.NextToken())
{
if (token.Value == "=:=")
expr = new StrictEqualExpression(expr, this.ParseBinaryExpression(level + 1));
else if (token.Value == "==")
expr = new EqualExpression(expr, this.ParseBinaryExpression(level + 1));
else if (token.Value == "+")
expr = new AddExpression(expr, this.ParseBinaryExpression(level + 1));
else if (token.Value == "-")
expr = new SubtractExpression(expr, this.ParseBinaryExpression(level + 1));
else if (token.Value == "*")
expr = new MultiplyExpression(expr, this.ParseBinaryExpression(level + 1));
else if (token.Value == "/")
expr = new DivideExpression(expr, this.ParseBinaryExpression(level + 1));
else if (token.Value == "div")
expr = new DivExpression(expr, this.ParseBinaryExpression(level + 1));
else if (token.Value == "rem")
expr = new RemExpression(expr, this.ParseBinaryExpression(level + 1));
}
if (token != null)
this.lexer.PushToken(token);
return expr;
}
public void AddTwoDoubles()
{
AddExpression expr = new AddExpression(new ConstantExpression(2.5), new ConstantExpression(3.7));
Assert.AreEqual(2.5 + 3.7, expr.Evaluate(null));
}
public void AddIntegerToDouble()
{
AddExpression expr = new AddExpression(new ConstantExpression(1), new ConstantExpression(2.5));
Assert.AreEqual(1 + 2.5, expr.Evaluate(null));
}
public void AddDoubleToInteger()
{
AddExpression expr = new AddExpression(new ConstantExpression(2.5), new ConstantExpression(1));
Assert.AreEqual(2.5 + 1, expr.Evaluate(null));
}