Redundant constraints

Simon Peyton Jones simonpj at
Wed Jan 7 15:19:15 UTC 2015

I've pushed a big patch that adds -fwarn-redundant-constraints (on by default).  It tells you when a constraint in a signature is unnecessary, e.g.
     f :: Ord a => a -> a -> Bool
     f x y = True
I think I have done all the necessary library updates etc, so everything should build fine.
Four libraries which we don't maintain have such warnings (MANY of them in transformers) so I'm ccing the maintainers:

o   containers

o   haskeline

o   transformers

o   binary


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