// Dynamic LINQ

// Doc: https://linq-dynamic.net/parse-lambda

​

​

using System;

using System.Collections.Generic;

using System.Linq.Expressions;

using System.Linq.Dynamic.Core;

using System.Linq.Dynamic.Core.Parser;

using System.Linq.Dynamic.Core.CustomTypeProviders;

using System.ComponentModel.DataAnnotations;

using FastExpressionCompiler;

​

public class Program

{

    [DynamicLinqType]

    public class X{

        public int value = 10;

    }

    public static void Main()

    {

        ParameterExpression x = Expression.Parameter(typeof(double), "threshold");

        ParameterExpression y = Expression.Parameter(typeof(List<double>), "mylist");

​

        var symbols = new[] { x, y };

​

        Expression body = new ExpressionParser(symbols, "mylist.Where(c => c > threshold).First()", null, new ParsingConfig()).Parse(typeof(double));

​

        LambdaExpression e = Expression.Lambda(body, symbols);

​

​

        var c = e.CompileFast();

        var result = c.DynamicInvoke(new object[]{ 3.0, new List<double>{1.0,2.0,3.0,4.0 } });

​

        Console.WriteLine(result);

    }

}