They work!

Toy lenses

module Main

import Data.Profunctor
import Data.Profunctor.Lens

-- This is an unpleasant helper function because type inference is Hard
myLens : Lensing p => Simple (Lens {p}) (String, String) String
myLens = _1

-- hello : String
-- hello = view _1 ("hello", "world")
-- -----------------------------------------------------------
-- When elaborating right hand side of hello:
-- When elaborating argument a to constructor Builtins.MkPair:
--         Can't unify
--                 String (Type of "hello")
--         with
--                 a (Expected type)

-- :(

hello : String
hello = view myLens ("hello", "world") -- "hello"

goodbyeworld : (String, String)
goodbyeworld = set myLens "goodbye" ("hello", "world") -- ("goodbye", "world")

ollehworld : (String, String)
ollehworld = over myLens reverse ("hello", "world") -- ("olleh", "world")

-- This is the same problem as with myLens
myPrism : Prisming p => Simple (Prism {p}) (Either String String) String
myPrism = _l

jhi : Maybe String
jhi = preview myPrism (Left "hi") -- Just "hi"

lhi: Either String String
lhi= review myPrism "hi" -- Left "hi"