[GHC] #7141: Inlining the single method of a class can shadow rules

[GHC]

#7141: Inlining the single method of a class can shadow rules
---------------------------------+------------------------------------------
    Reporter:  pcapriotti        |       Owner:  simonpj         
        Type:  bug               |      Status:  new             
    Priority:  normal            |   Milestone:  7.8.1           
   Component:  Compiler          |     Version:  7.4.2           
    Keywords:                    |          Os:  Unknown/Multiple
Architecture:  Unknown/Multiple  |     Failure:  Other           
  Difficulty:  Unknown           |    Testcase:                  
   Blockedby:                    |    Blocking:                  
     Related:                    |  
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 This shows up in `template-haskell`, module `Language.Haskell.TH.Syntax`,
 where the single method of the `Lift` class:

 {{{
 class Lift t where
   lift :: t -> Q Exp
 }}}

 has a `RULE`:

 {{{
 {-# RULES "TH:liftString" lift = \s -> return (LitE (StringL s)) #-}
 }}}

 There is currently no way of preventing `lift` from being inlined.

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7141>
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