[GHC] #9915: GHCi has trouble with 'foreign' when it is not a keyword

20 Dec 2014


      #9915: GHCi has trouble with 'foreign' when it is not a keyword
-------------------------------------+-------------------------------------
       Reporter:  cactus             |                   Owner:
           Type:  bug                |                  Status:  new
       Priority:  normal             |               Milestone:
      Component:  Compiler (Parser)  |                 Version:  7.8.3
       Keywords:  GHCi               |        Operating System:
   Architecture:  Unknown/Multiple   |  Unknown/Multiple
     Difficulty:  Unknown            |         Type of failure:
     Blocked By:                     |  None/Unknown
Related Tickets:                     |               Test Case:
                                     |                Blocking:
                                     |  Differential Revisions:
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 In Haskell 98 mode, `foreign` is not a keyword at all. The following is an
 example of a valid Haskell 98 program:

 {{{#!hs
 {-# LANGUAGE Haskell98 #-}
 module F where

 foreign :: Int
 foreign = 42
 }}}

 However, it seems noone told GHCi about this:

 {{{
 12:42:38 [cactus@galaxy hs]$ ghci -XHaskell98
 GHCi, version 7.8.3: http://www.haskell.org/ghc/  :? for help
 Loading package ghc-prim ... linking ... done.
 Loading package integer-gmp ... linking ... done.
 Loading package base ... linking ... done.
 λ» x = 42 -- Expected to fail

 <interactive>:2:3: parse error on input ‘=’
 λ» x -- Expected to fail

 <interactive>:3:1: Not in scope: ‘x’
 λ» -- So this should fail as well, right?
 λ» foreign = 42
 λ» -- Nope
 λ» foreign
 42
 λ» -- But wait, there's more!
 λ» foreign -- boo!

 <interactive>:9:1:
     Parse error: naked expression at top level
     Perhaps you intended to use TemplateHaskell
 }}}

--
Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9915
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