Re: [Haskell-cafe] haskell2010 and state question.

On Wed, 08 Dec 2010 10:03:40 +0100, Magicloud Magiclouds wrote:

Hi, Formerly, I had IORef and some state monad to do the task of keeping states. Now in haskell 2010, I cannot find anything about it. Do I have to use ghc base package for this function?

These are not standard Haskell '98 or Haskell 2010. You can find IORef in the base package; the state monad is in both the mtl and the transformers package (mtl is deprecated). The state monad uses the multi-parameter type class extension and is therefore not in standard Haskell '98 or Haskell 2010 code. IORef also uses non-standard code. Regards, Henk-Jan van Tuyl -- http://Van.Tuyl.eu/ http://members.chello.nl/hjgtuyl/tourdemonad.html --