public void ExpressionParserTest()
{
var p = Expression.Parameter(typeof(Employee));
var methodInfo = typeof(Employee).GetMethod("get_Item");
var body = Expression.Call(p, methodInfo, new[] { Expression.Constant("ReportsTo") });
var p_ReportsTo = Expression.Lambda(body, p);
var source = (IQueryable)db.Employees;
var q1 = source.Provider.CreateQuery(Expression.Call(typeof(Queryable), "Select",
new[] { source.ElementType, typeof(object) },
source.Expression, Expression.Quote(p_ReportsTo)));
Console.WriteLine(db.GetCommand(q1).CommandText);
Console.WriteLine();
Expression <Func <Employee, object> > exp0 = o => o["ReportsTo"];
var q = db.Employees.Select(exp0);
Console.WriteLine(db.GetCommand(q).CommandText);
Console.WriteLine();
Expression <Func <Employee, object> > exp5 = o => new { o.FirstName, ReportsTo = o["ReportsTo"] };
q = db.Employees.Select(exp5);
Console.WriteLine(db.GetCommand(q).CommandText);
Console.WriteLine();
var items = db.Employees.Select("FirstName").Cast <string>()
.ToArray();
//var parser = new ExpressionParser(new[] { Expression.Parameter(typeof(Employee)) },
// "FirstName", new object[] { });
//var exp = parser.Parse();
//Expression<Func<Employee, string>> exp1 = o => o.FirstName;
//var exp2 = ExpressionParser.Parse<Employee>("FirstName");
//var exp3 = ExpressionParser.Parse<Employee>("new (FirstName + LastName as Name)");
//var exp4 = ExpressionParser.Parse<Employee>("FirstName + LastName");
}