LINQ on the Command-Line

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.CodeDom.Compiler;
using System.Reflection;
using System.Xml.Linq;
using System.IO;
using Microsoft.CSharp;

namespace LinqOot
{
    static class MyExtensions
    {
        public static object Dump(this object value) 
        {
            if (null == value)
                return null;
            else if (value is IEnumerable<object>)
                return (value as IEnumerable<object>).Select(v => v.Dump()).ToArray();
            else
                Console.WriteLine(value.ToString());

            return value;
        }
        public static string ToString(this IEnumerable<object> value)
        {
            return string.Join("\n", (value as IEnumerable<object>).Select(s => s.ToString()));
        }
    }

    class Program
    {
        static readonly string[] tmplApp = new string[]{
        "using System;",
        "using System.Collections.Generic;",
        "using System.Linq;",
        "using System.Xml.Linq;",
        "using System.Text;",
        "using System.IO;",
        "using System.Diagnostics;",
        "",
        "class Script{ public static object Main(string[] args){{CODE}} }",
        "",
        "public static class ScriptExtensions",
        "{",
        "    public static object Dump(this object value)",
        "    {",
        "        if (null != value)",
        "        {",
        "            if (value is IEnumerable<object>)",
        "                Console.WriteLine(string.Join(\"\\n\", (value as IEnumerable<object>).Select(s => s.Dump().ToString())));",
        "            else",
        "                Console.WriteLine(value);",
        "        }",
        "        return value;",
        "    }",
        "}"};

        static void Main(string[] args)
        {
            if (0 == args.Count())
            {
                Console.WriteLine("Expect a LINQ script file to run.");
                return;
            }

            var lins = File.ReadAllLines(args[0]);

            var isLinq = args[0].ToLower().EndsWith(".linq");
            string linqType = (isLinq) ? XDocument.Parse(lins[0]).Root.Attribute("Kind").Value : string.Empty;
            var script = string.Format(("Statements" == linqType) ? "{0}\nreturn null;" : "return {0};",
                string.Join("\n", (isLinq) ? lins.Skip(2).Where(s => !s.TrimStart().StartsWith("//")) : lins));

            Assembly asm = null;
            try
            {
                asm = CompileSource(string.Join("\n", tmplApp.Select(s => s.Replace("{CODE}", script))));
            }
            catch (Exception x)
            {
                Console.WriteLine("Failed compiling script:\n\n{0}\n\n{1}", script, x.Message);
                return;
            }

            var scrObj = asm.CreateInstance("Script");
            try
            {
                object result = scrObj.GetType().InvokeMember("Main", BindingFlags.InvokeMethod, null, scrObj, new object[] { args.Skip(1).ToArray() });
                if ("Statements" != linqType)
                    result.Dump();
            }
            catch (Exception x)
            {
                Console.WriteLine("Failed executing script:\n\n{0}\n\n{1}", script, x.Message);
            }
        }

        private static Assembly CompileSource(string sourceCode)
        {
            CodeDomProvider cpd = new CSharpCodeProvider();
            CompilerParameters cp = new CompilerParameters() { GenerateExecutable = false };
            cp.ReferencedAssemblies.AddRange(new string[] { "System.dll", "System.Xml.dll", "System.Xml.Linq.dll", "System.Core.dll", "System.Data.dll"});

            // Invoke compilation.
            CompilerResults cr = cpd.CompileAssemblyFromSource(cp, sourceCode);

            return cr.CompiledAssembly;
        }
    }
}