You can search for identifiers within the package.
in-package search v0.2.0
type (!'ok, !'err) t = [
| `Error of 'err
| `Ok of 'ok
]
val return : 'a -> [> `Ok of 'a ]
val bind : [< `Error of 'a | `Ok of 'b ] -> ('b -> [> `Error of 'a ] as 'c) -> 'c
val (>>=) : [< `Error of 'a | `Ok of 'b ] -> ('b -> [> `Error of 'a ] as 'c) -> 'c
val fail : 'a -> [> `Error of 'a ]