You can search for identifiers within the package.
in-package search v0.2.0
type input
type output
type 'a mode =
| Input : input mode
| Output : output mode
type 'a channel
type input_channel = input channel
val with_file : ?buffer: (char, Stdlib.Bigarray.int8_unsigned_elt, Stdlib.Bigarray.c_layout) Stdlib.Bigarray.Array1.t -> ?flags:Unix.open_flag list -> ?perm:int -> mode:'a mode -> string -> ('a channel -> 'b Lwt.t) -> 'b Lwt.t
val read : ?count:int -> input_channel -> string Lwt.t