You can search for identifiers within the package.
in-package search v0.2.0
type !'c buffer = ('a, 'b, Stdlib.Bigarray.c_layout) Stdlib.Bigarray.Array1.t constraint 'c = ('a, 'b) Stdlib.Bigarray.kind
type float32 = (float, Stdlib.Bigarray.float32_elt) Stdlib.Bigarray.kind
type int8 = (int, Stdlib.Bigarray.int8_unsigned_elt) Stdlib.Bigarray.kind
val png : string -> w:int -> h:int -> c:int -> int8 buffer -> unit
val bmp : string -> w:int -> h:int -> c:int -> int8 buffer -> unit
val tga : string -> w:int -> h:int -> c:int -> int8 buffer -> unit
val hdr : string -> w:int -> h:int -> c:int -> float32 buffer -> unit