Lee Duhem:
On Sat, May 30, 2009 at 7:35 PM, Maurí cio <[email protected]>
wrote:
Hi,
How do I include type families (used as associated
types) in a module export list? E.g.:
class MyClass a where
type T a :: *
coolFunction :: Ta -> a
(...)
If I just include MyClass and its functions in the
list, instances in other modules complain they don't
know T, but I wasn't able to find how (where) to
include T in the list.
In export list, you can treat 'type T a' as normal type declaration,
ie, write
T(..) in export list.
There is also special syntax to export associated types. You can write
MyClass (type T)
in the export list; cf,
http://haskell.org/haskellwiki/GHC/Type_families#Import_and_export
Manuel
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