Sourcetype t = [ | `Assoc of (string * t) list| `Bool of bool| `Float of float| `Int of int| `Intlit of string| `List of t list| `Null| `String of string| `Tuple of t list| `Variant of string * t option
] Sourceexception Of_json of string * t Sourceval error : string -> t -> 'a Sourceval field : ('a * 'b) list -> 'a -> ('b -> 'c) -> 'c option Sourceval field_exn : (string * t) list -> string -> (t -> 'a) -> 'a