如何查看defparameter,defconstant或defvar的doc字符串?

时间:2016-10-18 15:31:56

标签: common-lisp sbcl

使用常见的lisp,你可以添加许多文档字符串,例如:

CL-USER> (defun foo ()
           "doc string for foo"
           nil)
FOO
CL-USER> (documentation 'foo 'function)
"doc string for foo"

CL-USER> (describe 'foo)
COMMON-LISP-USER::FOO
  [symbol]

FOO names a compiled function:
  Lambda-list: ()
  Derived type: (FUNCTION NIL (VALUES NULL &OPTIONAL))
  Documentation:
    doc string for foo
  Source form:
    (SB-INT:NAMED-LAMBDA FOO
        NIL
      "doc string for foo"
      (BLOCK FOO NIL))
; No value

所以最后我可以读回文档字符串了,但是有了符号和变量,我无法用文档取回它:

CL-USER> (defparameter bar 3 "doc string for bar")
BAR
CL-USER> (describe 'bar)
COMMON-LISP-USER::BAR
  [symbol]

BAR names a special variable:
  Value: 3
  Documentation:
    doc string for bar
; No value
CL-USER> (documentation 'bar 'symbol)
WARNING: unsupported DOCUMENTATION: doc-type SYMBOL for object of type SYMBOL
NIL

所以类型'符号是错误的,或者我会使用哪种类型。我不确定到底发生了什么

我正在使用:SBCL 1.3.10

1 个答案:

答案 0 :(得分:9)

让我们看看documentation; - )

的文档
CL-USER> (documentation 'documentation 'function)
"Return the documentation string of Doc-Type for X, or NIL if none
exists. System doc-types are VARIABLE, FUNCTION, STRUCTURE, TYPE, SETF, and T.
[...]"

所以:

CL-USER> (documentation 'bar 'variable)
"doc string for bar"

有关详细信息,请参阅documentation