Common Lisp Package and Module Management [closed]

问题

Closed. This question needs to be more focused. It is not currently accepting answers.

---

Want to improve this question? Update the question so it focuses on one problem only by editing this post.

Closed 2 years ago.

I am currently trying to understand how Common Lisp manages its packages and modules.

Consider this code:

(in-package :cl-user)

(ql:quickload :cl-who)
(ql:quickload :hunchentoot)
(ql:quickload :parenscript)

(defpackage :retro-games
  (:use :cl :cl-who :hunchentoot :parenscript))

(in-package :retro-games)

(defclass game ()
            ((name  :initarg  :name)
             (votes :initform 0)))

When I create a Slime buffer and then run this code in another buffer that is set to Slime mode, I see some prints in the first buffer that is *slime-repl sbcl*:

Load 1 ASDF system: cl-who ; Loading "cl-who"

To load "parenscript": Load 1 ASDF system: parenscript ; Loading "parenscript" ..

To load "hunchentoot": Load 1 ASDF system: hunchentoot ; Loading "hunchentoot" ..............

That is, there seems to be some "talking" going on between the two buffers. However, if I try to run (make-instance game("Chess")), I get an error because the CL-USER package does not know about the game class.

On the other hand if I run (in-package :retro-games) in the slime repl sbcl buffer, I am able to run (make-instance game("Chess")).

The question is how does Common Lisp organize its work with packages? On related note, what is the difference between a buffer being a slime repl sbcl and a buffer being in slime-mode?

Are the packages at all similar to Python's virtual environments? That is, where are the CL-WHO, HUNCHENTOOT and PARENSCRIPT being installed in my case? Do I have any choice over this?

回答1:

First, try (make-instance 'game :name "Chess"). Note that Common Lisp uses prefixed notation between paarenthesis. So, if want to call a function like foo("bar"), it would be (foo "bar"). If you want, you can create a function like:

(defun new-game (game-name) (make-instance 'game :name game-name))

If you are using Quicklisp, the packages me be installed at where you've installed quicklisp. If it is installed at your home folder, the packages should be at /home/user/quicklisp/dists/quicklisp/software/.

来源：https://stackoverflow.com/questions/46609034/common-lisp-package-and-module-management