[GHC] #2986: :info printing instances often isn't wanted

[GHC]

#2986: :info printing instances often isn't wanted
---------------------------------+------------------------------------------
    Reporter:  Remi              |       Owner:  Remi            
        Type:  feature request   |      Status:  new             
    Priority:  lowest            |   Milestone:  7.6.2           
   Component:  GHCi              |     Version:  6.10.1          
    Keywords:  :info instances   |          Os:  Unknown/Multiple
Architecture:  Unknown/Multiple  |     Failure:  None/Unknown    
  Difficulty:  Unknown           |    Testcase:                  
   Blockedby:                    |    Blocking:                  
     Related:                    |  
---------------------------------+------------------------------------------

Comment(by simonpj):

 Yes, I didn't find the instances summary perspicuous either; I suggest

  * For `:info Maybe`: (a type constructor)
 {{{
 data Maybe a = Nothing | Just a -- Defined in `GHC.Types'
 -- Use :instances to see the 24 instances of `Maybe'
 }}}

  * For `:info Monad`: (a class)
 {{{
 class Monad m where
   (>>=) :: m a -> (a -> m b) -> m b
   (>>) :: m a -> m b -> m b
   return :: a -> m a
   fail :: String -> m a
         -- Defined in `GHC.Base'
 -- Use :instances to see the 8 instances of `Monad'
 }}}

 For the `:instances` can you show the module where the instance comes
 from?

 Simon

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/2986#comment:24>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler