On Wed, May 7, 2014 at 2:41 PM, Tom Ellis < tom-lists-haskell-cafe-2013@jaguarpaw.co.uk> wrote:
Btw, as I can't think of an example right now, what would be an example for code that works with transformers-0.4.0.0 but wouldn't compile anymore with transformers-0.4.1.0?
Surely just the reverse of the breaking change?
https://github.com/ibotty/streaming-commons/commit/b1137852e4f58520ad65d01b2...
No, that code is compatible with transformers 0.3, 0.4, and 0.4.1. With
On Wed, May 07, 2014 at 02:10:42PM +0300, Michael Snoyman wrote: the
syntax:
import Data.Functor.Constant (Constant (Constant), getConstant)
We're importing the data type Constrant, the data construct Constant for that data type, and the function getConstant. It doesn't matter if getConstant is a normal function or a field accessor, it can still be accessed by that syntax.
Then I don't understand why field accessors are even *allowed* to be imported beneath the type. Surely that's only necessary to disambiguate constructors from types?
In the case here, the syntax: import Control.Monad.Trans.Reader (ReaderT (..)) is very convenient. But it's true that you don't really gain much from the distinction between these two: import Control.Monad.Trans.Reader (ReaderT (ReaderT, runReaderT)) import Control.Monad.Trans.Reader (ReaderT (ReaderT), runReaderT) Perhaps the latter should be considered a better approach, since it's more resilient to changes in datatypes. Michael