[GHC] #9990: Top level module identifiers shadow imported identifiers

[GHC]

#9990: Top level module identifiers shadow imported identifiers
-------------------------------------+-------------------------------------
              Reporter:  drb226      |             Owner:
                  Type:  feature     |            Status:  new
  request                            |         Milestone:
              Priority:  normal      |           Version:
             Component:  Compiler    |  Operating System:  Unknown/Multiple
              Keywords:              |   Type of failure:  None/Unknown
          Architecture:              |        Blocked By:
  Unknown/Multiple                   |   Related Tickets:
             Test Case:              |
              Blocking:              |
Differential Revisions:              |
-------------------------------------+-------------------------------------
 Let's try this out as a language pragma and see if we like it?

 Artificial example:

 {{{#!hs
 {-# LANGUAGE TopLevelShadowsImports #-}
 import Data.Monoid
 (<>) = mappend
 main = putStrLn ("Hello" <> " " <> "World")
 }}}

 Current behavior: error: ambiguous occurrence of (<>)
 Desired behavior: uses top-level definition of (<>), prints "hello world"

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9990>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler