列出当前在lisp中绑定的全局变量

Question

我是Lisp的新手并且想知道:有没有办法列出所有(用户定义的)全局变量？

Answer 1

一种可能性是检查包的哪个符号是boundp:

(defun user-defined-variables (&optional (package :cl-user))
  (loop with package = (find-package package)
        for symbol being the symbols of package
        when (and (eq (symbol-package symbol) package)
                  (boundp symbol))
          collect symbol))

它返回一个未从另一个包继承的绑定符号列表.

CL-USER> (user-defined-variables)     ; fresh session
NIL
CL-USER> 'foo                         ; intern a symbol
FOO
CL-USER> (defun bar () 'bar)          ; define a function
BAR
CL-USER> (defparameter *baz* 'baz)    ; define a global variable
*BAZ*
CL-USER> (user-defined-variables)
(*BAZ*)                               ; only returns the global variable