exception Error of string
val mapping : [> `O of 'a ] -> 'b
val scalar : [> `Scalar of Yaml.scalar ] -> string
val bool : [> `Scalar of Yaml.scalar ] -> bool
val sequence : [> `A of Yaml.sequence ] -> Yaml.yaml list
val find_key_opt : Yaml.mapping -> Stdlib.String.t -> Yaml.yaml option
val find_key : Yaml.mapping -> Stdlib.String.t -> Yaml.yaml
val keys : Yaml.mapping -> (string -> Yaml.yaml -> 'a) -> 'b list
val expression : [> `Scalar of Yaml.scalar ] -> Types.Ast.t
val endian : [> `Scalar of Yaml.scalar ] -> [> `BE | `LE ]