public void ParseSimpleBinaryExpression()
{
IExpression expression = this.ParseExpression("a + 2");
Assert.IsNotNull(expression);
Assert.IsInstanceOfType(expression, typeof(ArithmeticBinaryExpression));
ArithmeticBinaryExpression operation = (ArithmeticBinaryExpression)expression;
Assert.AreEqual(ArithmeticOperator.Add, operation.Operation);
Assert.IsNotNull(operation.LeftExpression);
Assert.IsInstanceOfType(operation.LeftExpression, typeof(VariableExpression));
Assert.IsNotNull(operation.RightExpression);
Assert.IsInstanceOfType(operation.RightExpression, typeof(ConstantExpression));
}