3

I want to write my emacs-lisp-mode modification which respects some of my preferences. In particular, I want to override indentation for vector literals.

Emacs treats vector literal as quoted list while applying indentation.

[if "emacs"
    "why do you"
  "indent things this way"]

[1 2
   3 4]

[(foo 1) ;; this one is OK without modifications
 (bar 2)
 "this"
 "is good"]

I want this result:

[if "emacs"
 "why do you"
 "indent things this way"]

[1 2
 3 4]

[(foo 1) 
 (bar 2)
 "this"
 "is good"]

How can I achieve this?

2

This is a slightly modified version of lisp-indent-function, which indents to the last indentation if

  • containing form is not a proper list (e.g. vector)
  • symbol to indent is a keyword
(defun ap/lisp-indent-function (indent-point state)
  "See `lisp-indent-function'."
  (let ((normal-indent (current-column)))
    (goto-char (1+ (elt state 1)))
    (parse-partial-sexp (point) calculate-lisp-indent-last-sexp 0 t)
    (if (or (not (eq ?\( (char-before)))
            (and (elt state 2)
                 (not (and (looking-at "\\sw\\|\\s_")
                           (not (eq ?: (char-after)))))))
        ;; indent as data
        (progn
          (if (not (> (save-excursion (forward-line 1) (point))
                      calculate-lisp-indent-last-sexp))
              (progn (goto-char calculate-lisp-indent-last-sexp)
                     (beginning-of-line)
                     (parse-partial-sexp (point)
                                         calculate-lisp-indent-last-sexp 0 t)))
          ;; Indent under the list or under the first sexp on the same
          ;; line as calculate-lisp-indent-last-sexp.  Note that first
          ;; thing on that line has to be complete sexp since we are
          ;; inside the innermost containing sexp.
          (backward-prefix-chars)
          (current-column))
      ;; indent as function
      (let ((function (buffer-substring (point)
                                        (progn (forward-sexp 1) (point))))
            method)
        (setq method (or (function-get (intern-soft function)
                                       'lisp-indent-function)
                         (get (intern-soft function) 'lisp-indent-hook)))
        (cond ((or (eq method 'defun)
                   (and (null method)
                        (> (length function) 3)
                        (string-match "\\`def" function)))
               (lisp-indent-defform state indent-point))
              ((integerp method)
               (lisp-indent-specform method state
                                     indent-point normal-indent))
              (method
               (funcall method indent-point state)))))))

(setq-default lisp-indent-function 'ap/lisp-indent-function)
  • Maybe its just me, but this seems like emacs lacks some prettier API for tasks like this. Dropping down to character/regexp level for slight modification seems too low level and error-prone. – Iskander Sharipov Feb 18 '17 at 19:18

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