[GHC] #8021: Multiple constraint classes - the alternative to superclass

[GHC]

#8021: Multiple constraint classes - the alternative to superclass
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Reporter:  wvv               |          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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Comment(by wvv):

 In other worlds, classes become instances of interfaces


 {{{
 class Monoid a where ...  <<==>> class () => Monoid a where ...

 class Monad m => Monoid m where ...
 }}}
 means something like
 {{{
 interface Monoid

 class instance Monad m => Mononoid m where ...

 class instance () => Mononoid a where ...

 }}}

 Sure, interface is unwritten and compiler must create by itself and check
 class instances

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/8021#comment:1>
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