On Thu, May 14, 2009 at 10:51 PM, Vasili I. Galchin
Hello,
When I am compiling a module, I get "Could not find module 'Control.Module.State': it is a member of package mtl-1.1.0.2, which is hidden"
1) What is the efficacy of "hiddenness"?
As I understand it, the purpose is two-fold. Firstly, if you have multiple versions a package (or multiple packages containing the same module), you can hide the ones not in use. Second, it ensures you have declared all dependencies.
2) I have forgotten what tool I run to expose a package. ??
I've only ever had this when working with Cabal, where I have missed a dependency. In this case, it looks like you have an undeclared dependency on mtl. I'm not sure whether this arises in the non-Cabal case.
3) In another vein, the code is using Data.Finitemap ... so I guess I must "darcs" install this?
I believe it was just uploaded to Hackage (it's obsolete, but useful for getting old code to run). HTH, Max