#4508: DeriveFoldable should not require DeriveFunctor
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Reporter: batterseapower | Owner:
Type: bug | Status: new
Priority: normal | Component: Compiler
Version: 6.12.3 | Keywords:
Testcase: | Blockedby:
Os: Unknown/Multiple | Blocking:
Architecture: Unknown/Multiple | Failure: Incorrect warning at
compile-time
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Functor is not a superclass of Foldable, so there is no reason to require
DeriveFunctor to be on if you use the DeriveFoldable flag. However, at the
moment GHC requires you to use both flags even if you only derive
Foldable.
(Yes, surprisingly some things are Foldable but not Functor -- such as
Data.Set).
--
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/4508>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler
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