[GHC] #12403: Template Haskell boxes tuple types when reifying them

16 Jul 2016

      #12403: Template Haskell boxes tuple types when reifying them
-------------------------------------+-------------------------------------
           Reporter:  RyanGlScott    |             Owner:
               Type:  bug            |            Status:  new
           Priority:  normal         |         Milestone:  8.0.2
          Component:  Template       |           Version:  8.0.1
  Haskell                            |
           Keywords:                 |  Operating System:  Unknown/Multiple
       Architecture:                 |   Type of failure:  Incorrect result
  Unknown/Multiple                   |  at runtime
          Test Case:                 |        Blocked By:
           Blocking:                 |   Related Tickets:
Differential Rev(s):                 |         Wiki Page:
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 Example:

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

 import Language.Haskell.TH

 data T = T (# Int, Int #)

 $(return [])

 main :: IO ()
 main = putStrLn $(reify ''T >>= stringE . pprint)
 }}}

 {{{
 $ /opt/ghc/8.0.1/bin/ghc -fforce-recomp Constraints.hs
 [1 of 1] Compiling Main             ( Constraints.hs, Constraints.o )
 Linking Constraints ...
 $ ./Constraints
 data Main.T = Main.T ((,,,) GHC.Types.Int GHC.Types.Int)
 }}}

 Patch coming soon.

--
Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12403
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