How to build a LINQ query from text at runtime?

Question

I have a

class A {
   public int X;
   public double Y;
   public string Z;
   // and more fields/properties ...
};

and a List

Answer 1

Answering it pretty late; though, it will help someone who visits this page.

I had similar requirement and I solved it by dynamically compiling string as LINQ query, executing it over in-memory collection and collecting the result. Only catch is user input needs to be valid C# compile-able code else it returns an exception message instead of result.

Code is pretty long so here is the github link

Sample application on github shows multiple examples including projection.