[GHC] #8004: Applicative/Monad proposal related warnings (AMP phase 1)

[GHC]

#8004: Applicative/Monad proposal related warnings (AMP phase 1)
-------------------------------------+------------------------------------
        Reporter:  quchen            |            Owner:
            Type:  feature request   |           Status:  new
        Priority:  high              |        Milestone:  7.8.1
       Component:  Compiler          |          Version:  7.6.3
      Resolution:                    |         Keywords:
Operating System:  Unknown/Multiple  |     Architecture:  Unknown/Multiple
 Type of failure:  None/Unknown      |       Difficulty:  Unknown
       Test Case:                    |       Blocked By:
        Blocking:                    |  Related Tickets:
-------------------------------------+------------------------------------

Comment (by simonpj):

 David says: Hey everyone,

 I'm having trouble finding a good middle ground between the global and
 local environments in the typechecker. I would like to get an
 environment of things that are defined in the current module, but

  * `TcGblEnv` includes everything in scope, which is too general.
  * `TcLclEnv` is (if I'm right) meant to handle scoping, which is too
 narrow.

 The reason for this is that the AMP warnings should be restricted to a
 single module. In the current implementation, having a module import an
 AMP-violating module issues a warning from each module using the
 offender (including that module itself). It does the job, but it's not
 pretty.

 David

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8004#comment:6>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler