Re: Proposal: merge either into transformers

On Sat, Apr 26, 2014 at 09:16:57AM +0300, Roman Cheplyaka wrote:

* Ross Paterson [2014-04-26 01:21:09+0100]

...

Instead of EitherT, the next version will deprecate ErrorT in favour of a transformer ExceptT with base monad Except. The idea is to have analogous transformers and monads

ExceptT : Except : Either WriterT : Writer : (,) ReaderT : Reader : (->)

Great! When do you plan to make a release?

Let's say Wednesday, if no-one notices a major problem.

...

Pre-release docs are here:

http://code.haskell.org/~ross/transformers/dist/doc/html/transformers/

The docs for Control.Monad.Trans.Writer.Strict say:

...

Although the output is built strictly, it is not possible to achieve linear space behaviour with this transformer: for that, use Control.Monad.Trans.State.Strict instead.

I think it should be "constant", not "linear".

Indeed -- thanks for catching that. I wonder whether the strict writer is of any use at all.