[GHC] #8269: Suggest LANGUAGE pragmas instead of -XFoo

11 Sep 2013

      #8269: Suggest LANGUAGE pragmas instead of -XFoo
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       Reporter:  nomeata           |             Owner:
           Type:  feature request   |            Status:  new
       Priority:  normal            |         Milestone:
      Component:  Compiler          |           Version:  7.6.3
       Keywords:                    |  Operating System:  Unknown/Multiple
   Architecture:  Unknown/Multiple  |   Type of failure:  None/Unknown
     Difficulty:  Unknown           |         Test Case:
     Blocked By:                    |          Blocking:
Related Tickets:                    |
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 Minor, but still: Currently GHC says:

 {{{
 readFail037.hs:4:1:
     Too many parameters for class ‛Foo’
     (Use -XMultiParamTypeClasses to allow multi-parameter classes)
     In the class declaration for ‛Foo’
 }}}

 Maybe it is just me, but generally I find LANGUAGE pragmas are the way to
 go. So I think it should read

 {{{
 readFail037.hs:4:1:
     Too many parameters for class ‛Foo’
     (Use {-# LANGUAGE MultiParamTypeClasses #-} to allow multi-parameter
 classes)
     In the class declaration for ‛Foo’
 }}}

 Note that it is easier to copying `MultiParamTypeClasses` (by double-
 clicking), entering "-X", and pasting, than copying
 `XMultiParamTypeClasses` and removing the X again.

 If noone complains or someone says that it is a good idea I’ll fix it
 myself.

-- 
Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/8269
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