[GHC] #11208: GHCi doesn't qualify types anymore

[GHC]

#11208: GHCi doesn't qualify types anymore
-------------------------------------+-------------------------------------
           Reporter:  hvr            |             Owner:
               Type:  bug            |            Status:  new
           Priority:  highest        |         Milestone:  8.0.1
          Component:  GHCi           |           Version:  7.11
           Keywords:  regression     |  Operating System:  Unknown/Multiple
       Architecture:                 |   Type of failure:  Other
  Unknown/Multiple                   |
          Test Case:                 |        Blocked By:
           Blocking:                 |   Related Tickets:
Differential Rev(s):                 |         Wiki Page:
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 `M.hs` contains:

 {{{#!hs
 module M where

 import qualified Prelude as P

 f n = n P.+ 1

 g h (P.Just x) = P.Just (h x)
 g _ P.Nothing  = P.Nothing
 }}}

 GHC 7.10.3 behaves as expected:

 {{{
 $ ghci-7.10.3 -ignore-dot-ghci M.hs
 GHCi, version 7.10.3: http://www.haskell.org/ghc/  :? for help
 [1 of 1] Compiling M                ( M.hs, interpreted )
 Ok, modules loaded: M.
 *M> :browse
 f :: P.Num a => a -> a
 g :: (t -> a) -> P.Maybe t -> P.Maybe a
 *M> :t f
 f :: P.Num a => a -> a
 *M> :t g
 g :: (t -> a) -> P.Maybe t -> P.Maybe a
 }}}

 However, GHC HEAD drops the module qualifiers

 {{{
 $ ghci-7.11.20151209 -ignore-dot-ghci M.hs
 GHCi, version 7.11.20151209: http://www.haskell.org/ghc/  :? for help
 [1 of 1] Compiling M                ( M.hs, interpreted )
 Ok, modules loaded: M.
 *M> :browse
 f :: Num a => a -> a
 g :: (t -> a) -> Maybe t -> Maybe a
 *M> :t f
 f :: Num a => a -> a
 *M> :t g
 g :: (t -> a) -> Maybe t -> Maybe a
 *M> Nothing :: Maybe ()

 <interactive>:4:12: error:
     Not in scope: type constructor or class ‘Maybe’
     Perhaps you meant ‘P.Maybe’ (imported from Prelude)
 }}}

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11208>
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