Develop Reference

Is there a way I can parse/run C# within an application, almost like a script?

I am currently writing some code and I am wondering if it would be possible to execute some C# code from my application. I'll give you an idea, lets say I want to give the user a textbox and have them type some code and hit go, I want them to ask for a list of fruit and then go through each fruit and output it.. an example:
var fruitList = getFruit();
foreach(var fruit in fruitList)
{
print(fruit.Name);
}
I would like to be able to go through this and assign a list of Fruit objects to fruitList, the parser should be able to tie up getFruit() to a method I've written in the c# code. The same goes for print, it should equate this to a print function I've written that outputs it to a textbox.
Now I know that C# isn't a script, it is compiled, and I've done a lot of Googling but can't really find anything. My only option to me appears to be to write a little language parser myself - which sounds fun - but I've done this before and I know it's hard work. So this is just a preliminary check to see if some solution does exist before I commit to the long haul.
So, my fellow programmers, do you know of anything that may be able to assist me?
If not, no problem, I appreciate all feedback whether it's tips, advice, links to articles such as this http://blogs.msdn.com/b/ericwhite/archive/2010/06/29/writing-a-recursive-descent-parser-using-c-and-linq.aspx or a solution.
Regards,
Adam
EDIT: I have managed to get a working example. Note this code is a bit messy as I've pasted some other code in to the test app, but it works. Basically, I compile the code into a DLL, then I load the DLL, find the type, find the method, and invoke it. It's pretty damn quick too! I don't want to spam you so the full code is below:
http://imdsm.blogspot.com/2012/01/compile-c-into-assembly-then-load-it.html
Thank you to everyone who posted here. You just saved me days of confusion!

You mean like in this screenshot here?
We use this in our software, HeuristicLab, you can add a ProgrammableOperator into an operator graph which will execute the code that you typed in at the place that you typed it in a custom-built algorithm.
In the System.CodeDom namespace you've got all you need to dynamically compile code. You can create an assembly from the compilation, get the assembly's types and execute their code.

I think the new compiler project of microsoft is what you are looking for. With it you can run C# as were a script indeed.
Project "Roslyn"

Have a look if Roslyn can help , it's still in CTP status.

You can use the CSharpCodeProvider
Or you could use a scripting language and run the interpreter in your application
Ex IronRuby

using c# like script in runtime

I want to learn if there is any library in .net to write c# scripts. Let me describe you with more detail, for example I have an application. When I run it, a c# editor will be opened end user will write some c# codes and when click run, this code should be evaluated and dom should be created after interpret my run time c# code will run. this is brief description of my mind...

I put together a little app called SimpleDevelop which uses CSharpCodeProvider to do what you describe. My understanding is that this (CodeDom) is deprecated and generally discouraged; however, it seems to work just fine for simple scenarios.

Basically, you want to use something like the CSharpCodeProvider. The Razor view engine in MVC essentially uses this to compile your code into an executable to run. If you want your user to be able to write code and then have it interpreted, you would start here. Please note though, this is an incredibly complicated and time intensive feat to get right; plus, linking in and executing foreign code dynamically is a security nightmare. Just be safe.

Are you looking for a test bench sort of?
I use LinqPad for that.
It is mostly a test bench for Linq queries, but I find it very useful for C# statements and mini programs and such.

Check out the System.CodeDom namespace.
This article contains lots of useful information: http://www.developerfusion.com/article/4529/using-net-to-make-your-application-scriptable/2/

You can use the Compiler namespace and compilate the code at runtime. Take a look here for an explanation on how to do it.

I have created an application which will run c# like script without using visual studio.
It is on https://sourceforge.net/projects/csharpquickcode/

c# compile source code from database

I would like to build an application framework that is mainly interpreted.
Say that the source code would be stored in the database that could be edited by the users and always the latest version would be executed.
Can anyone give me some ideas how does one implement sth like this !
cheers,
gabor

In .Net, you can use reflection and CodeDOM to compile code on the fly. But neither approach is really very simple or practical. Mono has some ability to interpret c# on the fly as well, but I haven't looked closely at it yet.
Another alternative is to go with an interpreted .Net language like Boo or IronPython as the language for your database code.
Either way, make sure you think long and hard about the security of your platform. Allowing users to execute arbitrary code is always an exercise fraught with peril. It's often too tempting to look for a simple eval() method, and even if one exists, that is not good enough for this kind of scenario.

Try Mono ( http://www.monoproject.org ). It supports many scripting languages including JavaScript.

If you don't want to use any scripting you can use CodeDOM or Reflection (see Reflection.Emit).
Here are really useful links on the topic :
Dynamically executing code in .Net (Here you can find a tool which can be very helpul)
Late Binding and On-the-Fly Code
Generation Using Reflection in C#
Dynamic Source Code Generation and
Compilation

Usually the Program uses a scripting language for the scriptable parts, i.e. Lua or Javascript.

To answer your technical question: You don't want to write your own language and interpreter. That's too much work for you to do. So pick some other language, say Python or Lua, and look for the documentation that lets your C program hand it blocks of code to execute. Of course, the script needs to be able to do something, so you'll need to find how to expose your program's objects to the script. Also, what will happen if a client is running the program when you update its source code in the database? Should the client restart? Are you going to store the entire program as a single row in this database, or did you want to store individual functions? That affects how you structure your updates.
To address other issues with your question: Why do you want to do this? Making "interpreted language" part of your design spec for a system is not often a good sign. Is the real requirement something like this: "I update the program often and I want users to always have the latest copy?" If so, there are other, better ways to go about this (just give us your actual scenario and requirements).

How to convert vb.net coded to WORKING c# code?

Hi I want to convert the code at Webcam using DirectShow.NET to C#. It works perfectly in vb.net. I tried converting using an online converter, however I got about 30 errors,
Any suggestions to what I must do next:
This is the converter that I used :
1) Convert VB.NET to C#

The CodeProject article says the author originally converted this sample from C# to VB.NET. This may be the original C# source:
Link

Who says you even have to convert it? You could throw it in a Class Library and use the DLL in your C# project. No need for translating perfectly working .Net code into other .Net code.

Without the errors and relavent source code, we can't really help. The best bet is to use an online converter (as you did) and fix compiler errors, then test for other errors.

I've used sharpdevelop to translate between vb and c# a few times for projects. It's really pretty great, only had to make minor changes.
http://www.sharpdevelop.net

Use RedGate's reflector against the compiled assembly and the Denis Bauer's disassembler to get back code in the language of your choice.

I'd echo the npinti's suggestion; but I've never found a converter that will do everything flawlessly.
My guess is that you'll find several that do a good/great job; but you're still going to have to do a little work to get everything to play nice.

Learn C#, then convert it.

Maybe C-Sharpener For VB will work

Here is your golden ticket!!! ;) When i found this tool (which does a perfect conversion 99% of the time, it really make s a VB developers life easier and opens up all the online snippets and samples exclusively in C now available for a VB'er... Which BTW- is so overlooked on it's strengths at this point, it's just, well, crazy! ;)
Here is that 'gem' i am referring to: http://converter.telerik.com/
Hope that helps!!!

Lex/Yacc for C#?

Actually, maybe not full-blown Lex/Yacc. I'm implementing a command-interpreter front-end to administer a webapp. I'm looking for something that'll take a grammar definition and turn it into a parser that directly invokes methods on my object. Similar to how ASP.NET MVC can figure out which controller method to invoke, and how to pony up the arguments.
So, if the user types "create foo" at my command-prompt, it should transparently call a method:
private void Create(string id) { /* ... */ }
Oh, and if it could generate help text from (e.g.) attributes on those controller methods, that'd be awesome, too.

I've done a couple of small projects with GPLEX/GPPG, which are pretty straightforward reimplementations of LEX/YACC in C#. I've not used any of the other tools above, so I can't really compare them, but these worked fine.
GPPG can be found here and GPLEX here.
That being said, I agree, a full LEX/YACC solution probably is overkill for your problem. I would suggest generating a set of bindings using IronPython: it interfaces easily with .NET code, non-programmers seem to find the basic syntax fairly usable, and it gives you a lot of flexibility/power if you choose to use it.

I'm not sure Lex/Yacc will be of any help. You'll just need a basic tokenizer and an interpreter which are faster to write by hand. If you're still into parsing route see Irony.
As a sidenote: have you considered PowerShell and its commandlets?

Also look at Antlr, which has C# support.

Still early CTP so can't be used in production apps but you may be interested in Oslo/MGrammar:
http://msdn.microsoft.com/en-us/oslo/

Jison is getting a lot of traction recently. It is a Bison port to javascript. Because of it's extremely simple nature, I've ported the jison parsing/lexing template to php, and now to C#. It is still very new, but if you get a chance, take a look at it here: https://github.com/robertleeplummerjr/jison/tree/master/ports/csharp/Jison

If you don't fear alpha software and want an alternative to Lex / Yacc for creating your own languages, you might look into Oslo. I would recommend you to sit through session recordings of sessions TL27 and TL31 from last years PDC. TL31 directly addresses the creation of Domain Specific Languages using Oslo.

Coco/R is a compiler generator with a .NET implementation. You could try that out, but I'm not sure if getting such a library to work would be faster than writing your own tokenizer.
http://www.ssw.uni-linz.ac.at/Research/Projects/Coco/

I would suggest csflex - C# port of flex - most famous unix scanner generator.

I believe that lex/yacc are in one of the SDKs already (i.e. RTM). Either Windows or .NET Framework SDK.

Gardens Point Parser Generator here provides Yacc/Bison functionality for C#. It can be donwloaded here. A usefull example using GPPG is provided here

As Anton said, PowerShell is probably the way to go. If you do want a lex/ yacc implementation then Malcolm Crowe has a good set.
Edit: Direct Link to the Compiler Tools

Just for the record, implementation of lexer and LALR parser in C# for C#:
http://code.google.com/p/naive-language-tools/
It should be similar in use to Lex/Yacc, however those tools (NLT) are not generators! Thus, forget about speed.