Re: [GHC] #312: Poor error message for kind error

#312: Poor error message for kind error
--------------------------------------+-------------------------------------
  Reporter:  simonpj                  |          Owner:  simonpj 
      Type:  bug                      |         Status:  assigned
  Priority:  low                      |      Milestone:          
 Component:  Compiler (Type checker)  |        Version:  6.4.1   
  Severity:  normal                   |     Resolution:  None    
  Keywords:                           |             Os:  Unknown 
Difficulty:  Unknown                  |   Architecture:  Unknown 
--------------------------------------+-------------------------------------
Changes (by simonmar):

  * architecture:  => Unknown
  * difficulty:  => Unknown
  * version:  None => 6.4.1
  * os:  => Unknown

Old description:

> {{{
> A kind error can lead to the following poor error msg:
>
> tcfail132.hs:30:51:
>     Kind error: Expecting kind `k_a18s -> k_a18w ->
> k_a18A -> *',
>                 but `DUnit t' has kind `k_a18s ->
> k_a18w -> *'
>     In the type synonym declaration for `LiftObject'
>

> The source program is
>
> newtype Object f' f t o1 o2  = Object (f' t o1 -> f t o2)
> type DUnit t o1 o2       = ()
>
> type T f g t o1 o2  = Either (f t o1 o2) (g t o1 o2)
>
> type LiftObject t f' f         = T (Object f' f t) (DUnit t)
>
> }}}

New description:

 {{{
 A kind error can lead to the following poor error msg:

 tcfail132.hs:30:51:
     Kind error: Expecting kind `k_a18s -> k_a18w ->
 k_a18A -> *',
                 but `DUnit t' has kind `k_a18s ->
 k_a18w -> *'
     In the type synonym declaration for `LiftObject'


 The source program is

 newtype Object f' f t o1 o2  = Object (f' t o1 -> f t o2)
 type DUnit t o1 o2       = ()

 type T f g t o1 o2  = Either (f t o1 o2) (g t o1 o2)

 type LiftObject t f' f         = T (Object f' f t) (DUnit t)

 }}}

-- 
Ticket URL: <http://cvs.haskell.org/trac/ghc/ticket/312>
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