#10635: -fwarn-redundant-constraints should not be part of -Wall -------------------------------------+------------------------------------- Reporter: Lemming | Owner: Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler (Type | Version: 7.11 checker) | Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Incorrect | Unknown/Multiple warning at compile-time | Test Case: Blocked By: | Blocking: Related Tickets: #9939, #9973, | Differential Rev(s): #10100, #10183 | Wiki Page: | -------------------------------------+------------------------------------- Comment (by Lemming): Replying to [comment:8 Lemming]:
If would prefer to disable the warning per constraint. E.g. I could wrap a not strictly needed constraint in a magic {{{Used :: Constraint -> Constraint}}}. However, this would not be possible in Haskell 98.
A Haskell 98 compliant pragma might look like this: {{{#!hs {-# MINIMAL_CONSTRAINTS singleton () #-} singleton :: Ord a => a -> Set a }}} The pragma means: Type check "singleton" two times, once with the constraints `()` and once with the constraint `Ord a`. Warn about redundant constraints in the pragma but not in the signature of `singleton`. If you also want to warn about not maximally general types, then the pragma should even mention the whole type signature, e.g. {{{#!hs {-# MOST_GENERAL singleton :: a -> Set a #-} singleton :: Ord a => a -> Set a {-# MOST_GENERAL asTypeOf :: a -> b -> a #-} asTypeOf :: a -> a -> a }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10635#comment:9 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler