Earlier, we looked at .NET reflection as a way to do metaprogramming, analyzing static type information to reason about program code. Although metaprogramming using reflection can do things like load program plug-ins, if you want to reason about how that code operates, you are out of luck. The .NET reflection APIs allow you to get at the raw MSIL op codes, but you have to reverse engineer what that code does—a daunting task at best.

However, there are many applications where knowing not only the structure of program code but also how it operates can be beneficial. For example, taking a function written in F# and converting it into a form that can execute on a graphics card’s GPU (presumably to be executed much, much faster).