`sig type iterator = { attribute : Ast_iterator.iterator -> Parsetree.attribute -> unit; attributes : Ast_iterator.iterator -> Parsetree.attribute list -> unit; case : Ast_iterator.iterator -> Parsetree.case -> unit; cases : Ast_iterator.iterator -> Parsetree.case list -> unit; class_declaration : Ast_iterator.iterator -> Parsetree.class_declaration -> unit; class_description : Ast_iterator.iterator -> Parsetree.class_description -> unit; class_expr : Ast_iterator.iterator -> Parsetree.class_expr -> unit; class_field : Ast_iterator.iterator -> Parsetree.class_field -> unit; class_signature : Ast_iterator.iterator -> Parsetree.class_signature -> unit; class_structure : Ast_iterator.iterator -> Parsetree.class_structure -> unit; class_type : Ast_iterator.iterator -> Parsetree.class_type -> unit; class_type_declaration : Ast_iterator.iterator -> Parsetree.class_type_declaration -> unit; class_type_field : Ast_iterator.iterator -> Parsetree.class_type_field -> unit; constructor_declaration : Ast_iterator.iterator -> Parsetree.constructor_declaration -> unit; expr : Ast_iterator.iterator -> Parsetree.expression -> unit; extension : Ast_iterator.iterator -> Parsetree.extension -> unit; extension_constructor : Ast_iterator.iterator -> Parsetree.extension_constructor -> unit; include_declaration : Ast_iterator.iterator -> Parsetree.include_declaration -> unit; include_description : Ast_iterator.iterator -> Parsetree.include_description -> unit; label_declaration : Ast_iterator.iterator -> Parsetree.label_declaration -> unit; location : Ast_iterator.iterator -> Location.t -> unit; module_binding : Ast_iterator.iterator -> Parsetree.module_binding -> unit; module_declaration : Ast_iterator.iterator -> Parsetree.module_declaration -> unit; module_expr : Ast_iterator.iterator -> Parsetree.module_expr -> unit; module_type : Ast_iterator.iterator -> Parsetree.module_type -> unit; module_type_declaration : Ast_iterator.iterator -> Parsetree.module_type_declaration -> unit; open_description : Ast_iterator.iterator -> Parsetree.open_description -> unit; pat : Ast_iterator.iterator -> Parsetree.pattern -> unit; payload : Ast_iterator.iterator -> Parsetree.payload -> unit; signature : Ast_iterator.iterator -> Parsetree.signature -> unit; signature_item : Ast_iterator.iterator -> Parsetree.signature_item -> unit; structure : Ast_iterator.iterator -> Parsetree.structure -> unit; structure_item : Ast_iterator.iterator -> Parsetree.structure_item -> unit; typ : Ast_iterator.iterator -> Parsetree.core_type -> unit; type_declaration : Ast_iterator.iterator -> Parsetree.type_declaration -> unit; type_extension : Ast_iterator.iterator -> Parsetree.type_extension -> unit; type_kind : Ast_iterator.iterator -> Parsetree.type_kind -> unit; value_binding : Ast_iterator.iterator -> Parsetree.value_binding -> unit; value_description : Ast_iterator.iterator -> Parsetree.value_description -> unit; with_constraint : Ast_iterator.iterator -> Parsetree.with_constraint -> unit; } val default_iterator : Ast_iterator.iterator end`