You can search for identifiers within the package.
in-package search v0.2.0
val decode : 'a -> 'a decoder
val required : string -> 'a decoder -> ('a -> 'b) decoder -> 'b decoder
val required_at : string list -> 'a decoder -> ('a -> 'b) decoder -> 'b decoder
val optional : string -> 'a decoder -> 'a -> ('a -> 'b) decoder -> 'b decoder
val optional_at : string list -> 'a decoder -> 'a -> ('a -> 'b) decoder -> 'b decoder
val custom : 'a decoder -> ('a -> 'b) decoder -> 'b decoder