`sig val mk : ?attrs:Ast_helper.attrs -> ?docs:Docstrings.docs -> ?params:(Parsetree.core_type * Asttypes.variance) list -> ?priv:Asttypes.private_flag -> Ast_helper.lid -> Parsetree.extension_constructor list -> Parsetree.type_extension val constructor : ?loc:Ast_helper.loc -> ?attrs:Ast_helper.attrs -> ?docs:Docstrings.docs -> ?info:Docstrings.info -> Ast_helper.str -> Parsetree.extension_constructor_kind -> Parsetree.extension_constructor val decl : ?loc:Ast_helper.loc -> ?attrs:Ast_helper.attrs -> ?docs:Docstrings.docs -> ?info:Docstrings.info -> ?args:Parsetree.constructor_arguments -> ?res:Parsetree.core_type -> Ast_helper.str -> Parsetree.extension_constructor val rebind : ?loc:Ast_helper.loc -> ?attrs:Ast_helper.attrs -> ?docs:Docstrings.docs -> ?info:Docstrings.info -> Ast_helper.str -> Ast_helper.lid -> Parsetree.extension_constructor end`