id -package:brittany -package:base -package:hedgehog package:invertible

Identity bijection.
Convert the Identity functor.
Invariant monoidal functors. This roughly corresponds to Control.Applicative, but exposes a non-overlapping API so can be imported unqualified. It does, however, use operators similar to those provided by contravariant.
Invariant monoidal functor. This roughly corresponds to Applicative, which, for covariant functors, is equivalent to a monoidal functor. Invariant functors, however, may admit a monoidal instance but not applicative.
Monoidal functors that allow choice.
Bidirectional transforms for Data.Monoid.
Convert bijections to and from semigroupoids Iso.