ExpressionsWorking_stackoverflow_Q51676887, C#

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//Rextester.Program.Main is the entry point for your code. Don't change it.
//Compiler version 4.0.30319.17929 for Microsoft (R) .NET Framework 4.5

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

namespace Rextester
{
    public class Program
    {
        public static void Main(string[] args)
        {
            var selectExpression = GetSelectionExpression.Compile();
		
		var fooRepo = new FooRepository();
		
		foreach (var result in fooRepo.Foos.Select(selectExpression))
			Console.WriteLine(result);
        }
        
        	public static Expression<Func<Foo, dynamic>> GetSelectionExpression
	{
		get { 
				Expression<Func<Foo, dynamic>> expression = foo => new 
				{
					RecordExists = foo.Bar.Exists,
                    RecordAmount = foo.Bar.Amount,
				    RecordHasPaid = foo.Bar.Exists && foo.Bar.Amount > 0
				};
			
			 	return expression;
			}
	}
    }

public class FooRepository
{
	public List<Foo> Foos = new List<Foo>(new Foo[] 
	{ 
		new Foo() { Bar = new Bar { Amount = 20, Exists = true } },
		new Foo() { Bar = new Bar { Amount = 23, Exists = false } },
		new Foo() { Bar = new Bar { Amount = 65, Exists = true } },
		new Foo() { Bar = new Bar { Amount = 2, Exists = false } },
	});
}

public static class ExpressionHelper
{
	public static Expression<Func<Bar, bool>> BarHasPaid(Bar foobar)
	{
		return b => b.Exists && b.Amount > 0;
	}
}

public class Bar
{
	public int? Amount {get;set;}
	public bool Exists {get;set;}
}

public class Foo
{
	public Bar Bar {get;set;}
}
}

Show compiler warnings [ + ] Show input
Compilation time: 0,17 sec, absolute running time: 0,59 sec, cpu time: 0,58 sec, average memory usage: 24 Mb, average nr of threads: 5