Original article: https://www.strathweb.com/2018/01/easy-way-to-create-a-c-lambda-expression-from-a-string-with-roslyn/

DynamicLambdaWithRoslyn.cs

using System;
using System.Collections.Generic;
using System.Linq;
using Microsoft.CodeAnalysis.CSharp.Scripting;
using Microsoft.CodeAnalysis.Scripting;

namespace CorePlayground
{
    public class Album
    {
        public int Quantity { get; set; }

        public string Title { get; set; }

        public string Artist { get; set; }
    }
    public class Program
    {
        /// <summary>
        /// WARN: Use this on application startup because it is kinda slow operation.
        /// </summary>
        /// <param name="args"></param>
        static void Main(string[] args)
        {
            var albums = new List<Album>
            {
                new Album { Quantity = 10, Artist = "Betontod", Title = "Revolution" },
                new Album { Quantity = 50, Artist = "The Dangerous Summer", Title = "The Dangerous Summer" },
                new Album { Quantity = 200, Artist = "Depeche Mode", Title = "Spirit" },
            };

            string discountFilter = "album => album.Quantity > 50";
            ScriptOptions options = ScriptOptions.Default.AddReferences(typeof(Album).Assembly);
            

            Func<Album, bool> discountFilterExpression = CSharpScript.EvaluateAsync<Func<Album, bool>>(discountFilter, options).Result;

            IEnumerable<Album> discountedAlbums = albums.Where(discountFilterExpression);
        }
    }
}