Re: [GHC] #11722: No TypeRep for unboxed tuples

19 Mar 2016


      #11722: No TypeRep for unboxed tuples
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        Reporter:  goldfire          |                Owner:
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.1
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Changes (by RyanGlScott):

 * cc: bgamari (added)


Comment:

 Suspiciously similar shenanigans:

 {{{#!hs
 {-# LANGUAGE UnboxedTuples #-}
 module Main where

 import Data.Typeable

 main :: IO ()
 main = print $ typeOf (Proxy :: Proxy (# #))
 }}}

 {{{
 $ /opt/ghc/head/bin/ghc -O2 -fforce-recomp Example.hs
 [1 of 1] Compiling Main             ( Example.hs, Example.o )

 Example.hs:7:24: error:
     • Couldn't match kind ‘'GHC.Types.VoidRep’
                      with ‘'GHC.Types.UnboxedTupleRep’
       When matching the kind of ‘(# #)’
     • In the first argument of ‘typeOf’, namely
         ‘(Proxy :: Proxy (# #))’
       In the second argument of ‘($)’, namely
         ‘typeOf (Proxy :: Proxy (# #))’
       In the expression: print $ typeOf (Proxy :: Proxy (# #))
 }}}

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Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11722#comment:1
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