type visitor_in = {kitem : Ast_ml.item vin;ktoplevel : Ast_ml.toplevel vin;kexpr : Ast_ml.expr vin;kpattern : Ast_ml.pattern vin;kty : Ast_ml.ty vin;kfield_decl : Ast_ml.field_declaration vin;kfield_expr : Ast_ml.field_and_expr vin;kfield_pat : Ast_ml.field_pattern vin;ktype_declaration : Ast_ml.type_declaration vin;klet_def : Ast_ml.let_def vin;klet_binding : Ast_ml.let_binding vin;kqualifier : Ast_ml.qualifier vin;kmodule_expr : Ast_ml.module_expr vin;kparameter : Ast_ml.parameter vin;kargument : Ast_ml.argument vin;kinfo : Ast_ml.tok vin;}and visitor_out = Ast_ml.any -> unitand 'a vin = (('a -> unit) * visitor_out) -> 'a -> unitval default_visitor : visitor_inval mk_visitor : visitor_in -> visitor_out