scalaz
OptionT monad transformer.
Apply a function in the environment of both options, containing both Fs.
F
Apply a function in the environment of both options, containing both Fs. It is not compatible with Monad#bind.
Monad#bind
7.0.3
(Since version 7.0.5) Monad[F] will be required, and this fixed, in 7.1; use a different Apply combinator in 7.0.x
Apply
app
OptionT monad transformer.