You can use the Interpreter.ParseAsExpression<TDelegate> method to directly parse an expression into a .NET lambda expression (Expression<TDelegate>).
The following example generates a Expression<Func<Customer, bool>> expression that can be used in a Queryable LINQ where expression or in any other place where an expression is required like Entity Framework or other similar libraries.
public static void Example1() { var persons = new List<Person> { new Person() { Name = "David", Age = 31, Gender = 'M', Country = "US" }, new Person() { Name = "Mary", Age = 29, Gender = 'F', Country = "UK" }, new Person() { Name = "Jack", Age = 12, Gender = 'M', Country = "Germany" }, new Person() { Name = "Marta", Age = 1, Gender = 'F', Country = "Japan" }, new Person() { Name = "Moses", Age = 23, Gender = 'M', Country = "US" }, }; string whereExpression = "person.Age > 18 && person.Gender == 'F'"; var interpreter = new Interpreter(); Expression<Func<Person, bool>> expression = interpreter.ParseAsExpression<Func<Person, bool>>(whereExpression, "person"); var result = persons.AsQueryable().Where(expression); foreach (var person in result) { Console.WriteLine("Name: {0}\nGender: {1}\nAge: {2}\nCountry: {3}", person.Name, person.Gender, person.Age, person.Country); } } public class Person { public string Name { get; set; } public char Gender { get; set; } public int Age { get; set; } public string Country { get; set; } } Let's execute the above code, and you will see the following output.
Name: Mary Gender: F Age: 29 Country: UK