[Haskell-cafe] Backward compatibility

[Brandon Allbery]

On Fri, May 3, 2013 at 10:54 AM, Guy <guytsalmaves-h at yahoo.com> wrote:

> http://hackage.haskell.org/**trac/ghc/wiki/**DefaultSuperclassInstances<http://hackage.haskell.org/trac/ghc/wiki/DefaultSuperclassInstances>
>
> I'm surprised that the various superclass proposals haven't got more
> attention, seeing as it would allow for this kind of class hierarchy
> clean-up without breaking lots of code.


IIRC they've been tried and found to actually cause more backward
compatibility issues than they solve because there are so many packages
which have created their own instances, and nobody's found a workaround
that doesn't either do that or lead to bizarre type errors.

-- 
brandon s allbery kf8nh                               sine nomine associates
allbery.b at gmail.com                                  ballbery at sinenomine.net
unix, openafs, kerberos, infrastructure, xmonad        http://sinenomine.net
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