尖引号(#')与符号功能有何不同? [英] How is sharp quote (#') different from symbol-function?

问题描述

在我看来，这些运算符似乎在做同样的事情.两者都带有符号并返回与其关联的函数.有什么区别吗?

To me these operators seem to do the same thing. Both take a symbol and return the function associated with it. Is there any difference?

elisp评估返回以下内容:

(defun foo(x)(+1 x))
foo
(foo 3)
4
#'foo

(defun foo (x) (+ 1 x))
foo
(foo 3)
4
#'foo

我都不明白.

此外，普通lisp和elisp之间有区别吗?我正在从任何一种资源中学习.

Furthermore is there a difference between common lisp and elisp? I'm learning from resources on either.

推荐答案

通用Lisp :

SYMBOL-FUNCTION无法从词汇绑定函数中检索函数. FUNCTION默认情况下引用词法绑定函数. #'foo只是(FUNCTION foo)的缩写.

SYMBOL-FUNCTION can't retrieve functions from lexically bound functions. FUNCTION references the lexically bound function by default. #'foo is just a shorter notation for (FUNCTION foo).

CL-USER 1 > (defun foo () 'foo)
FOO

CL-USER 2 > (flet ((foo () 'bar))
              (list (funcall (symbol-function 'foo))
                    (funcall #'foo)
                    (funcall (function foo))
                    (eq (function foo) (symbol-function 'foo))))
(FOO BAR BAR NIL)

CL-USER 3 > (eq (function foo) (symbol-function 'foo))
T

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