Data.Singletons
data family Sing a
class SingI a
class SingKind kparam
type KindOf a
type Demote a
data SingInstance a
data SomeSing kproxy
singInstance
withSingI
withSomeSing
singByProxy
singByProxy#
withSing
singThat
bugInGHC
type family Error str :: k
sError
data KProxy t
data Proxy t