Can Roslyn used to evaluate a dynamic if in c#

Question

I asked this question in stack over flow at 

http://stackoverflow.com/questions/9844599/is-it-possible-to-creating-expression-tree-for-dynamic-if-statement 

One of the suggestion was to use Rosyln. In my case I will have a code like the following

if (15 > 10)

{

     return 45;

}

else

{

    int result = 23 + 20;

    return result;

}

all variables evaluated to a values. I would like to evaluate the expression and get the result. Is it possible to do with Rosyln?

Answer 1

If you're creating the code, then maybe producing it as a string is not the best idea. I think it would be better if the result was a Expression or Roslyn SyntaxNode. But if you're sure you want to use strings, then, yes, you can compile and execute it using Roslyn.

Probably the best option is to use the Scripting API. Although your code is in quite a weird format: it looks like a method body without the method, it's certainly not an expression. One way to work around that is to enclose your code in a lambda and execute that:

var engine = new ScriptEngine();

Func<int> func = engine.Execute<Func<int>>("() => { " + yourCode + " }");

int result = func();