On Nov 22, 2007 12:49 PM, Henning Thielemann
On Tue, 20 Nov 2007, Ross Paterson wrote:
On Mon, Nov 19, 2007 at 11:31:51PM +0100, Bjorn Bringert wrote:
On Nov 19, 2007, at 23:13 , Henning Thielemann wrote:
I like to see MTL split into a Haskell98 part and an advanced part. I mostly use functionality which would nicely fit into a Haskell98 interface and find it annoying that by importing MTL my code becomes less portable.
Yes! Please!
You mean something like http://darcs.haskell.org/packages/mtl-split ? The plan is to split Control.Monad.Identity, Control.Monad.Trans and Control.Monad.Trans.* off into a separate portable, low-level package.
I noticed that I frequently use (flip runReader, flip evalState) for point-free programming. What was the reason to choose the current order? What is the experience of other programmers?
The order of the run* functions comes from the fact that they are record selectors. This implies that they need to take the monadic computaion as their first argument. An example: newtype StateT s m a = StateT { runStateT :: s -> m (a,s) } I'm guessing that evalState and the other derived functions inherited the argument order from the run* functions. I also tend to the other order, with the monadic computation last. Cheers, Josef