Packages、symbols、exporting、using等是 Common Lisp 的一个特性,而不是特定于 ASDF。
CL-USER 1 > (defpackage "FOO" (:use "CL") (:export "BAZ"))
#<The FOO package, 0/16 internal, 1/16 external>
CL-USER 2 > (in-package "FOO")
#<The FOO package, 0/16 internal, 1/16 external>
FOO 3 > (defun baz () 'FOO)
BAZ
FOO 4 > (defpackage "BAR" (:use "CL") (:export "BAZ"))
#<The BAR package, 0/16 internal, 1/16 external>
FOO 5 > (defun bar:baz () 'bar::bar)
BAR:BAZ
FOO 6 > (in-package "CL-USER")
#<The COMMON-LISP-USER package, 54/64 internal, 0/4 external>
CL-USER 7 > (defpackage "ZIPPY"
(:use "FOO" "BAR")
(:shadowing-import-from "BAR" "BAZ"))
#<The ZIPPY package, 1/16 internal, 0/16 external>
CL-USER 8 > (in-package "ZIPPY")
#<The ZIPPY package, 1/16 internal, 0/16 external>
ZIPPY 9 > (baz)
BAR::BAR