存储在文件中的 elisp 代码的结果值？

Question

寻找一种方法来评估存储在外部文件中的 elisp 代码并将其结果作为函数参数传递。演示我想要实现的目标的示例如下：

;; content of my_template.el
'(this is a list)

;; content of .emacs where result of my_template.el has to be used
(define-auto-insert "\.ext$"
    ;; bellow is my attempt to retrieve resulting list object
    ;; but getting nil instead
    (with-temp-buffer
      (insert-file-contents ("my_template.el"))
      (eval-buffer))))

可能正在寻找一个类似 eval 的函数，它除了副作用之外还有最后一个表达式的 returns 结果。

有什么想法吗？

Answer 1

使用变量共享数据更简单也更普遍，例如：

;; content of ~/my_template.el
(defvar my-template '(this is a list))

;; content of .emacs where result of my_template.el has to be used
(load-file "~/my_template.el")
(define-auto-insert "\.ext$"
  my-template)

更新函数eval-file应该做你想做的：

;; content of ~/my_template.el
'(this is a list)

(defun eval-file (file)
  "Execute FILE and return the result of the last expression."
  (load-file file)
  (with-temp-buffer
    (insert-file-contents file)
    (emacs-lisp-mode)
    (goto-char (point-max))
    (backward-sexp)
    (eval (sexp-at-point))))

(eval-file "~/my_template.el")
=> (this is a list)

更新两次：不对最后一个表达式求值两次

(defun eval-file (file)
  "Execute FILE and return the result of the last expression."
  (eval
   (ignore-errors
     (read-from-whole-string
      (with-temp-buffer
        (insert-file-contents file)
        (buffer-string))))))

(eval-file "~/my_template.el")
=> (this is a list)

Answer 2

不要从字符串中读取。从缓冲区读取。

(defun load&return (file &optional msgp)
  "Load FILE.  Return the value of the last sexp read."
  (interactive "fFile: \np")
  (let* ((sexp  (with-current-buffer (find-file-noselect file)
                  (goto-char (point-min))
                  (read (current-buffer))))
         (val   (ignore-errors (eval sexp))))
    (prog1 val (when msgp (message "Value: %S" val)))))

存储在文件中的 elisp 代码的结果值？

Result value of elisp code stored in a file?

emacs

elisp

emacs24

dot-emacs