Based on repeated recent experience, I expect getting rid of Rank2Types to be another substantial source of make-work for library authors. The GHC upgrade path has been very bumpy indeed recently, and this seems assured to continue that unhappy trend. I respectfully request that you silently retain Rank2Types as a synonym for RankNTypes.

Do you mean “silently and forever”? Deprecation simply means that everything continues to work, but you get a little nudge to change. Isn’t that what it’s for? If you treat deprecation as equivalent to error, then there isn’t much point in having it.

It’s possible that making Rank2Types = RankNTypes silently and forever is the right answer. It just doesn’t feel right to me. But I’m not a library author and I don’t feel terribly strongly.

Simon

From: Bryan O'Sullivan [mailto:bos@serpentine.com]
Sent: 22 October 2012 17:06
To: Simon Peyton-Jones
Cc: johan.tibell@gmail.com; Don Stewart; Duncan Coutts; Roman Leshchinskiy; ashley@semantic.org; cabal-devel@haskell.org; Ben Lippmeier; Manuel M T Chakravarty; cvs-ghc@haskell.org
Subject: Re: deprecating

On Fri, Oct 19, 2012 at 11:49 AM, Simon Peyton-Jones <simonpj@microsoft.com> wrote:

Dear maintainers of

bytestring

cabal

vector

time

dph

Hi, Simon -

How did you come up with this list? It is missing the vast majority of users of Rank2Types.

Most people embed language pragmas directly into the source files that use them, so grepping .cabal files is going to massively undercount users of any given feature.

Thanks,

Bryan.