Re: [Haskell-cafe] Need Control.Monad.State

On 28 July 2010 13:03, michael rice wrote:

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

Installed?

No; if it was installed it would specify a version.

Michael

--- On Tue, 7/27/10, Ivan Miljenovic wrote:

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

On 28 July 2010 12:39, michael rice 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

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