No support for restricted type synonyms

[nibro]

Hugs has an extension that lets a programmer restrict the scope of a defined type synonym. This is rather useless since the module system does it a lot better.

type Table a b = [(a,b)] in
    empty :: Table a b,
    isEmpty :: Table a b -> Bool,
    add :: a -> b -> Table a b -> Table a b,
    search :: a -> Table a b -> Maybe b

empty = []
isEmpty = null
add a b t = (a,b):t
search = lookup

Still, it's a registered extension and HSE should be able to support it without too much hassle.

http://cvs.haskell.org/Hugs/pages/users_guide/restricted-synonyms.html

[nibro]

Some day...