[GHC] #8004: Applicative/Monad proposal related warnings (AMP phase 1)

[GHC]

#8004: Applicative/Monad proposal related warnings (AMP phase 1)
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Reporter:  quchen            |          Owner:                  
    Type:  feature request   |         Status:  new             
Priority:  normal            |      Component:  Compiler        
 Version:  7.6.3             |       Keywords:                  
      Os:  Unknown/Multiple  |   Architecture:  Unknown/Multiple
 Failure:  None/Unknown      |      Blockedby:                  
Blocking:                    |        Related:                  
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 Add ad-hoc warnings to GHC telling the user about the following:[[BR]]
 - Instance of `Monad` without instances of `Functor`/`Applicative`[[BR]]
 - Instance of `MonadPlus` without instance of `Alternative`[[BR]]
 - Module defines functions named `(<*>)`, `pure` or `join`

 Refactoring code to remove these warnings makes sure the AMP will not
 break the module in the future. Since they are basically meta-
 deprecations, I would suggest treating them similar to ordinary
 deprecations.



 This is part of phase 1 of the Applicative/Monad proposal (AMP), as
 discussed on the mailing lists [1]; a more detailed description of the AMP
 is available on the Wiki [2].

 [1]: [http://article.gmane.org/gmane.comp.lang.haskell.libraries/19482]
 [2]: [http://www.haskell.org/haskellwiki/Functor-Applicative-
 Monad_Proposal]

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/8004>
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