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 CompareOneWithTwo()
{
StrictEqualExpression expr = new StrictEqualExpression(new ConstantExpression(1), new ConstantExpression(2));
Assert.AreEqual(false, expr.Evaluate(null));
}
public void CompareNullWithNull()
{
StrictEqualExpression expr = new StrictEqualExpression(new ConstantExpression(null), new ConstantExpression(null));
Assert.AreEqual(true, expr.Evaluate(null));
}
public void CompareNullWithBar()
{
StrictEqualExpression expr = new StrictEqualExpression(new ConstantExpression(null), new ConstantExpression("bar"));
Assert.AreEqual(false, expr.Evaluate(null));
}
public void CompareIntegerOneWithRealOne()
{
StrictEqualExpression expr = new StrictEqualExpression(new ConstantExpression(1), new ConstantExpression(1.0));
Assert.AreEqual(false, expr.Evaluate(null));
}
public void CompareFooWithFoo()
{
StrictEqualExpression expr = new StrictEqualExpression(new ConstantExpression("foo"), new ConstantExpression("foo"));
Assert.AreEqual(true, expr.Evaluate(null));
}