Cannot compare 'Object' type

[justinushermawan]

Hi, does it support for 'object' data type?

public class Index
{
    public long Position { get; set; }

    public object[] Values { get; set; }
}

var indexes = new Dictionary<long, Index>();
indexes.Add(1, new Index { Position = 1000, Values = new object[3] { "Welly", "Chandra", 26 } });
indexes.Add(2, new Index { Position = 1001, Values = new object[3] { "Darma", "Angelo", 25 } });
indexes.Add(3, new Index { Position = 1002, Values = new object[3] { "Abby", "Yeremia", 28 } });
indexes.Add(4, new Index { Position = 1003, Values = new object[3] { "Yonathan", "Gunawan", 22 } });
indexes.Add(5, new Index { Position = 1004, Values = new object[3] { "Aldy", "Santoso", 24 } });
var queryable = indexes.Values.AsQueryable();
var result = queryable.Where("Values[1] = \"Yeremia\" || Values[2] = 24").ToList();

It always throw an exception: System.InvalidOperationException: The binary operator Equal is not defined for the types 'System.Object' and 'System.Int32'.

[zspitz]

@justinushermawan As a workaround, you could do the following:

var result = queryable.Where("Values[1].Equals(\"Yeremia\") || Values[2].Equals(24)").ToList();

[justinushermawan]

Thank you. Yes, I think it would be possible to call the Object.Equals() instead .

[zspitz]

@StefH @JonathanMagnan

Could this issue be fixed by checking if there is an operator overload for = between the two sides, and if not then replacing with a call to the .Equals instance method? There's already a similar check for implicit conversions between two types.

[igitur]

I bumped into this as well. Here is my use-case:

using System;
using System.Linq;
using System.Linq.Dynamic.Core;

using System.Linq.Expressions;
using System.Collections.Generic;

internal class Program
{
    private class Person
    {
        // Deliberately typing these as `object` to illustrate the issue
        public object Id { get; set; } = Guid.NewGuid();
        public object  Name { get; set; }
        public object Age => Convert.ToInt32(Math.Floor((DateTime.Today.Month - DateOfBirth.Month + 12 * DateTime.Today.Year - 12 * DateOfBirth.Year) / 12d));
        public DateTime DateOfBirth { get; set; }
    }

    private static void Main(string[] args)
    {
        var people = new List<Person>
        {
            new Person {Name = "Francois", DateOfBirth = new DateTime(1978, 07, 16)},
            new Person {Name = "Marichen", DateOfBirth = new DateTime(1982, 07, 28)},
            new Person {Name = "Wynand", DateOfBirth = new DateTime(1977, 01, 01)},
            new Person {Name = "Theron", DateOfBirth = new DateTime(1972, 06, 15)},
            new Person {Name = "Werner", DateOfBirth = new DateTime(1998, 02, 28)},
            new Person {Name = "Graeme", DateOfBirth = new DateTime(1935, 09, 03)},
        };

        var younglings = people
            .AsQueryable()
            .Where("Age < 30")
            .ToList();

        foreach (var p in younglings)
            Console.WriteLine($"{p.Name} {p.Age}");

        Console.WriteLine();
        Console.WriteLine("====================================");
        Console.WriteLine();

        Console.ReadKey(false);
    }
}

[StefH]

@igitur @justinushermawan

This will be supported in the next version by setting a config setting (ConvertObjectToSupportComparison) to true.

The next code will work:

class Person
{
    public string Name { get; set; }
    public object Age { get; set; }
}

var persons = new[]
{
    new Person { Name = "Foo", Age = 99 },
    new Person { Name = "Bar", Age = 33 }
}.AsQueryable();

var config = new ParsingConfig
{
    ConvertObjectToSupportComparison = true
};

var results = persons.Where(config, "Age > 50").ToList();

[StefH]

#805