> newtype Sequ a = Sequ ([a] -> [a]) > > empty = Sequ (as -> as) > > single a = Sequ (as -> a : as) > > Sequ x1 <> Sequ x2 = Sequ (as -> x1 (x2 as)) > > fromList as = Sequ (as' -> as ++ as') > > fromListT as = Sequ as > > toList (Sequ x) = x []
> instance Show a => Show (Sequ a) where > showsPrec d a = showsPrec d (toList a)
Derived function(s).
> guard :: Bool -> Sequ a -> Sequ a > guard False _as = empty > guard True as = as
