For a tool I'm writing ( http://hackage.haskell.org/package/explore ) I need a way to read haskell function definitions at run-time, apply them to values from my tool and retrieve the results of their application.
Can anyone give me a very basic example using GHC (6.10.4 or 6.12.1) API?
example function definition to be read from a file at run-time:
f x = 10**(4/1102*x - 1)
expected program output
--mapM_ print $ map f [428, 410, 389]
3.577165388142748
3.077536885227335
2.5821307011665815
!!UPDATE!!
I posted a quick answer but it creates an object file in the directory of execution, any tips to avoid this and avoid all file IO is most welcome. I want to also see a version that does everything in memory: user provides the function definition in a GUI for example and the compilation / evaluation does not create any object files.
Use hint. It's a GHCi-like wrapper around the GHC API that is not very difficult to use.
If you want an example of its use, I used it in my Yogurt project.