[GHC] #11182: -XStrict doesn't imply -XStrictData

8 Dec 2015

      #11182: -XStrict doesn't imply -XStrictData
-------------------------------------+-------------------------------------
           Reporter:  RyanGlScott    |             Owner:
               Type:  bug            |            Status:  new
           Priority:  normal         |         Milestone:  8.0.1
          Component:  Compiler       |           Version:  7.11
           Keywords:                 |  Operating System:  Unknown/Multiple
       Architecture:                 |   Type of failure:  GHC rejects
  Unknown/Multiple                   |  valid program
          Test Case:                 |        Blocked By:
           Blocking:                 |   Related Tickets:  #8347
Differential Rev(s):                 |         Wiki Page:
-------------------------------------+-------------------------------------
 Compiling this code:

 {{{#!hs
 {-# LANGUAGE Strict #-}

 data Lazy a = Lazy ~a

 main :: IO ()
 main = case Lazy undefined of
             Lazy _ -> putStrLn "Lazy"
 }}}

 fails with the following error:

 {{{
 $ .\inplace\bin\ghc-stage2.exe ../Lazy.hs
 [1 of 1] Compiling Main             ( ..\Lazy.hs, ..\Lazy.o )

 ..\Lazy.hs:3:15: error:
     * Lazy annotation (~) without StrictData
         on the first argument of `Lazy'
     * In the definition of data constructor `Lazy'
       In the data type declaration for `Lazy'
 }}}

 I was under the impression that `-XStrict` implied `-XStrictData`. Is this
 not the case?

--
Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11182
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