如何设置 describe-symbol 变量值显示省略号？

闲聊灌水
1

刚才不知动了哪个设置，describe-symbol 变量值剩余部分显示省略号：

image

甚至 format 输出也同样被截短：

(substring (format "%S" helm-completing-read-handlers-alist) -10)
;; => "er-1) ...)"
2

应该是 print-length

3

好像不是：

(let ((print-length 100))
  (let ((s (format "%S" helm-completing-read-handlers-alist)))
    (cl-assert (< 100 (length s)))
    (substring (format "%S" helm-completing-read-handlers-alist) -10)))
;; => "andler-1))"
4

你这 (substring (format "%S" helm-completing-read-handlers-alist) -10) 就是返回后10个字符组成的字符串啊

5

print-length 设成 nil 应该就好了

6

就是要看能否重现末尾截短成 ...) 的效果，显然并没有。字符串长度远超100.

7 
(let ((print-length 1)) 
     (format "%S" find-function-regexp-alist)) 
;; => "((flycheck-checker . flycheck-find-checker-regexp) ...)"

(let ((print-length nil)) 
     (format "%S" find-function-regexp-alist))
;; => "((flycheck-checker . flycheck-find-checker-regexp) (define-type . cl--typedef-regexp) (leaf . leaf-find-regexp) (cl-defgeneric . cl--generic-find-defgeneric-regexp) (cl-defmethod . cl--generic-search-method) (nil . find-function-regexp) (defvar . find-variable-regexp) (defface . find-face-regexp) (feature . find-feature-regexp) (defalias . find-alias-regexp))"
8

我明白了，print-length 是指 list 长度（即元素个数），而不是转换成字符串后的长度。

9

是的

Maximum length of list to print before abbreviating.