Either (loko.Loko.Either)

val map : 
  ('SL, 'FL, 'GL, 'TL) optic ->
  ('SR, 'FR, 'GR, 'TR) optic ->
  (('SL, 'SR) Stdlib.Either.t,
    ('FL, 'FR) Stdlib.Either.t,
    ('GL, 'GR) Stdlib.Either.t,
    ('TL, 'TR) Stdlib.Either.t)
    optic

An isomorphism between eithers.

val on_left : 
  (('F, 'S) Stdlib.Either.t, 'F, 'G, ('G, 'S) Stdlib.Either.t) optic

A prism that focuses on Left.

val on_right : 
  (('S, 'F) Stdlib.Either.t, 'F, 'G, ('S, 'G) Stdlib.Either.t) optic

A prism that focuses on Right.