Emacs 如何编写一个合适的流程过滤器?

Emacs 如何编写一个合适的流程过滤器?,emacs,Emacs,我正在构建一个与Emacs通信的程序,我面临的挑战之一是编写Emacs的进程过滤器函数。它的输入字符串是一系列要求值的s表达式。以下是一个示例: (gimme-append-to-buffer "25 - William Christie dir, Les Arts Florissants - Scene 2. Prelude - Les Arts Florissants\n") (gimme-append-to-buffer "26 - William Christie dir, Les Ar

我正在构建一个与Emacs通信的程序,我面临的挑战之一是编写Emacs的进程过滤器函数。它的输入字符串是一系列要求值的s表达式。以下是一个示例:

(gimme-append-to-buffer "25 - William Christie dir, Les Arts Florissants - Scene 2. Prelude - Les Arts Florissants\n")
(gimme-append-to-buffer "26 - William Christie dir, Les Arts Florissants - Cybele: 'Je Veux Joindre' - Les Arts Florissants\n")
(gimme-append-to-buffer "27 - William Christie dir, Les Arts Florissants - Scene 3. Cybele: 'Tu T'Etonnes, Melisse' - Les Arts Florissants\n")
(gimme-append-to-buffer "28 - William Christie dir, Les Arts Florissants - Cybele: 'Que Les Plus Doux Zephyrs'. Scene 4. - Les Arts Florissants\n")
(gimme-append-to-buffer "29 - William Christie dir, Les Arts Florissants - Entree Des Nations - Les Arts Florissants\n")
(gimme-append-to-buffer "30 - William Christie dir, Les Arts Florissants - Entree Des Zephyrs - Les Arts Florissants\n")
(gimme-append-to-buffer "31 - William Christie dir, Les Arts Florissants - Choeur Des Nations' 'Que Devant Vous' - Les Arts Florissants\n")
(gimme-append-to-buffer "32 - William Christie dir, Les Arts Florissants - Atys: 'Indigne Que Je Suis' - Les Arts Florissants\n")
(gimme-append-to-buffer "33 - William Christie dir, Les Arts Florissants - Reprise Du Choeur Des Nations : 'Que Devant Nous' - Les Arts Florissants\n")
(gimme-append-to-buffer "34 - William Christie dir, Les Arts Flor*emphasized text*issants - Reprise De L'Air Des Zephyrs - Les Arts Florissants\n")
我遇到的第一个问题是,在调用函数时,字符串不知何故没有完全形成,因此编写类似于
(mapcar'eval(format“(%s)”input string))
的东西是行不通的

为了解决第一个问题,我使用了一个循环。我写的全部功能是:

 (defun eval-all-sexps (s)
   (loop for x = (ignore-errors (read-from-string s))
          then (ignore-errors (read-from-string (substring s position)))
          while x
          summing (or (cdr x) 0) into position
          doing (eval (car x))))
现在出现的第二个问题是,函数被调用了两次,每次调用的输入都比较大,首先是有效但部分的内容,然后是看起来像剩余数据的片段

为了解决这个问题,我正在考虑使用一个垃圾变量来保留循环中剩余的内容,然后将其连接到下一个调用的输入,但是我想知道你们是否有其他关于如何更优雅地处理这个问题的建议


谢谢

这就是我在使用shell模式时所做的。
我在流程输出中寻找一个特殊的记录结束字符串,以了解输出何时完成。在那之前,我一直在关注这些块

(defun my-shell-exec-filter (process result)
  (let ((end-of-result (string-match my-shell-end-of-record-string result)))
    (if (and end-of-result
             (numberp end-of-result)
             (> end-of-result 0))
        (setq my-shell-reply 
              (concat my-shell-reply
                      (substring (substring result 0 end-of-result) 0 -1)))

      (progn
        (setq my-shell-reply (concat my-shell-reply result))
        (accept-process-output process my-shell-exec-timeout 5)))))
这并不完全正确,因为记录结束字符串可以在该过滤器fn的多个调用中分割。因此,为了正确起见,它应该先确认,然后检查是否匹配。但不管怎样,你明白了

它还会递归,因此,对于非常长的输入,它可能会引发堆栈溢出异常。所以它肯定没有我想要的那么干净

这件事是由

      (setq my-shell-reply nil) 
      (set-process-filter proc my-shell-exec-filter)
      (process-send-string proc "whatever...") 
      (if (not (accept-process-output proc my-shell-exec-timeout 100))
          (error "unexpected response."))

      ;; examine my-shell-reply here ... 
我的最终解决办法是:

(defun eval-all-sexps (s)
  (let ((s (concat gimme-filter-remainder s)))
    (setq gimme-filter-remainder
          (loop for x = (ignore-errors (read-from-string s))
                then (ignore-errors (read-from-string (substring s position)))
                while x
                summing (or (cdr x) 0) into position
                doing (eval (car x))
                finally (return (substring s position))))))