oh ... yes .. my .cabal file is incomplete! Thanks, Max. Vasili On Thu, May 14, 2009 at 3:56 PM, Max Rabkin wrote:

On Thu, May 14, 2009 at 10:51 PM, Vasili I. Galchin wrote:

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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.

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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.

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3) In another vein, the code is using Data.Finitemap ... so I guess

I

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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