Haskell: Is it possible to create a list of Show types? List[Show]? -
is possible create list holds values belong show
type ?
this similar list[showable]
in scala, showable
trait.
in way 1 put, example, int
, string
same list.
is possible? if yes, how ?
you can using existential types
data showbox = forall s. show s => sb s heterolist :: [showbox] heterolist = [sb "hello world", sb 5, sb 1]
the thing can items in list show
them:
let strings = fmap (\(sb b) -> show b) heterolist
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