module Ast_mapper:sig
..end
type
mapper = {
val map_opt : ('a -> 'b) -> 'a option -> 'b option
val default_mapper : mapper
val extension_of_error : Location.error -> Ast_403.Parsetree.extension
val attribute_of_warning : Location.t -> string -> string Location.loc * Ast_403.Parsetree.payload