cl-reexport makes a package reexport symbols which are external symbols in other packages. This functionality is intended to be used with (virtual) hierarchical packages.


Think about a (virtual) hierarchical package structure. Since Common Lisp standard has just a flat package system, the three packages are naturally at the same level, but you can regard the packages constituting a hierarchy virtually.


Here, their definitions are:

(in-package :cl-user) (defpackage (:use :cl) (:export :x)) (defpackage foo-package.baz (:use :cl) (:export :y)) (defpackage foo-package (:use :cl))

If you want reexport external symbols in FOO-PACKAGE.BAR and FOO-PACKAGE.BAZ from FOO-PACKAGE, you may just write as below:

(in-package :foo-package) (cl-reexport:reexport-from (cl-reexport:reexport-from :foo-package.baz) (in-package :cl-user) (describe 'x) >> FOO-PACKAGE.BAR:X >> [symbol] (describe 'y) >> FOO-PACKAGE.BAZ:Y >> [symbol]

:INCLUDE and :EXCLUDE options

You can also reexport the only symbols you specify or the symbols other than you specify using :INCLUDE option or :EXCLUDE option. Since they are exclusive, you cannot use :INCLUDE option and :EXCLUDE option at the same time.

(in-package :cl-user) (defpackage bar-package.a (:use :cl) (:export :x :y :z)) (defpackage bar-package.b (:use :cl) (:export :p :q :r)) (defpackage bar-package (:use :cl)) (in-package :bar-package) (cl-reexport:reexport-from :bar-package.a :include '(:x)) (cl-reexport:reexport-from :bar-package.b :include '(:p)) (in-package :cl-user) (do-external-symbols (x :bar-package) (print x)) >> BAR-PACKAGE.A:X >> BAR-PACKAGE.B:Q >> BAR-PACKAGE.B:R


You can install cl-reexport via Quicklisp:

(ql:quicklisp :cl-reexport)

Difference from ASDF 3's one-package-per-file functionality

ASDF 3 has one-package-per-file functionality and its runtime support. The structural difference between (virtual) hierarchical packages and ASDF 3's one-package-per-file functionality is:

  • (Virtual) hierarchical packages have one system definition and several packages constitute a hierarchical structure.
  • ASDF 3's one-package-per-file style has hierarchical system definitions and hierarchical packages, which are corresponding each other.
When you use former style, you can use cl-reexport.

convenience library