Re: [GHC] #14670: -XRebindableSyntax needs return?

15 Jan 2019

      #14670: -XRebindableSyntax needs return?
-------------------------------------+-------------------------------------
        Reporter:  jackkelly         |                Owner:  simonmar
            Type:  bug               |               Status:  closed
        Priority:  normal            |            Milestone:  8.10.1
       Component:  Compiler          |              Version:  8.2.2
      Resolution:  worksforme        |             Keywords:
                                     |  RebindableSyntax,ApplicativeDo
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  GHC rejects       |            Test Case:
  valid program                      |  rebindable/T14670
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by jackkelly):

 This still fails for me on GHC 8.6.3, which is the latest I see on
 https://www.haskell.org/ghc . If I've missed a later version, or you've
 confirmed a fix on GHC HEAD, then please re-close:

 {{{
 $ ghci Test.hs
 GHCi, version 8.6.3: http://www.haskell.org/ghc/  :? for help
 [1 of 1] Compiling Test             ( Test.hs, interpreted )

 Test.hs:7:3: error:
     Not in scope: ‘return’
     Perhaps you want to add ‘return’ to the import list
     in the import of ‘Prelude’ (Test.hs:4:1-19).

 7 |   pure ()
   |   ^^^^^^^
 Failed, no modules loaded.
 Prelude>
 }}}

 {{{
 $ cat Test.hs
 {-# LANGUAGE RebindableSyntax #-}

 module Test where
 import Prelude (IO)
 foo :: IO ()
 foo = do
   pure ()
 }}}

-- 
Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14670#comment:9
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