[haddock] #85: show kind signatures for (gadt) type constructors

haddock haddock at projects.haskell.org
Mon Feb 9 00:41:29 EST 2009

#85: show kind signatures for (gadt) type constructors
 Reporter:  rwbarton at alum.mit.edu  |       Type:  enhancement
   Status:  new                    |   Priority:  minor      
Milestone:                         |    Version:  2.5.0      
 Keywords:                         |  
 I like to write GADT declarations in the following style:
 {-# LANGUAGE GADTs, KindSignatures #-}
 data Foo :: (* -> *) -> * -> * where
   Bar :: f x -> Foo f (f x)
 so I don't give (necessarily unused) names to the type parameters of the
 type constructor `Foo`.  If I don't export the data constructors of `Foo`
 but only `Foo` itself then the documentation generated by Haddock consists
 solely of
 data Foo

 This is uninformative and potentially misleading (it seems to suggest that
 `Foo` has kind `*`).  It would be better to produce
 data Foo :: (* -> *) -> * -> *

 This is a particularly bad set of circumstances (no constructors for the
 reader to infer the kind from) but in general I think it would be nice to
 preserve any kind signatures written in the program source.

Ticket URL: <http://trac.haskell.org/haddock/ticket/85>
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