linq - Parse string to C# lambda Func

Question

Is there a way to convert string representation of lambda to a lambda Func?

Func<Product, bool> func = Parse<Product, bool>("product => product.Name.Length > 0");

I tried Dynamic LINQ but it doesn't work as expected - for example it doesn't expect lambda syntax =>.

Summary of answers:

• writing my own C# compiler - very funny
• firing up external compiler (like csc.exe) - very slow
• using DLINQ - as I said I don't see how it can parse lambda expressions

Why do I need this: because there's no way to pass lambdas to custom attributes like

[Secure(role => role.CanDoThis && role.AllowedCount > 5)]

So as a workaround I'd like to pass lambda as string: "role => role.CanDoThis && role.AllowedCount > 5". But seems like I'll have to use DLINQ like this: "CanDoThis && AllowedCount > 5" - since that's the syntax it understands. But my question was about true lambdas, I've already used DLINQ at the time of asking.

Answer 1

They are many lambda expression parsers available. Some of them are Lambda-Parser, Sprache

Sample Code:

Example1 : string concat and number calculate:

string code = "2.ToString()+(4*2)"; // C# code Func<string> 
func = ExpressionParser.Compile<Func<string>>(code); // compile code 
string result = func(); // result = "28"