[michael@localhost ~]$ ghc-pkg list mtl
/usr/lib/ghc-6.12.1/package.conf.d
[michael@localhost ~]$

Installed?

Michael

--- On Tue, 7/27/10, Ivan Miljenovic <ivan.miljenovic@gmail.com> wrote:

From: Ivan Miljenovic <ivan.miljenovic@gmail.com>
Subject: Re: [Haskell-cafe] Need Control.Monad.State
To: "michael rice" <nowgate@yahoo.com>
Cc: haskell-cafe@haskell.org
Date: Tuesday, July 27, 2010, 10:51 PM

On 28 July 2010 12:39, michael rice <nowgate@yahoo.com> wrote:
>
> How do I import Control.Monad.State?

Install and use the mtl library (comes with the Haskell platform),
monads-fd (almost identical API to mtl; the point of this is that mtl
uses some extension: the non-extension bits are in the transformers
library and monads-fd extends transformers by using extensions to
implement mtl functionality) or monads-tf (a different approach to
what monads-fd does using different extensions).

To check if you have mtl installed (substitute the other package names
if necessary):

ghc-pkg list mtl

If it isn't installed, you can use cabal-install to install it:

cabal install mtl

--
Ivan Lazar Miljenovic
Ivan.Miljenovic@gmail.com
IvanMiljenovic.wordpress.com