
On Wed, Dec 8, 2010 at 6:46 PM, Henk-Jan van Tuyl
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 --
First to notice that. So standard-wise, there is no way to do state thing? -- 竹密岂妨流水过 山高哪阻野云飞