From 75f0ed7873a0c332cd1ba771ee8acc2217843e5a Mon Sep 17 00:00:00 2001
From: Gabor Melis <(none)>
Date: Mon, 24 Apr 2023 11:23:41 +0100
Subject: [PATCH] Add lisp-fill-string-by-source-column
With lisp-fill-string-by-source-column nil (the previous default
behaviour):
(defgeneric foo ()
(:documentation "The first line of this indented docstring is roughly as long as
the rest. Using this option makes sense to ensure that docstrings are
preformatted."))
With lisp-fill-string-by-source-column t:
(defgeneric foo ()
(:documentation "The line of this indented docstring is as
roughly as long as long as rest. Use this option to make source
code look nice."))
---
lisp/emacs-lisp/lisp-mode.el | 31 +++++++++++++++++++++++--------
1 file changed, 23 insertions(+), 8 deletions(-)
diff --git a/lisp/emacs-lisp/lisp-mode.el b/lisp/emacs-lisp/lisp-mode.el
index d44c9d6e23da..c8cc1a39de84 100644
--- a/lisp/emacs-lisp/lisp-mode.el
+++ b/lisp/emacs-lisp/lisp-mode.el
@@ -1435,6 +1435,16 @@ Any non-integer value means do not use a different value of
:safe (lambda (x) (or (eq x t) (integerp x)))
:group 'lisp)
+(defcustom lisp-fill-string-by-source-column t
+ "When true, `lisp-fill-paragraph' fills strings in `lisp-mode' in
+such a way that the resulting source code respects `fill-column'.
+Else, the lines of the string are filled as if the string started
+in column 0. For function docstrings, which are typically
+indented by 3 characters, the difference between the two is
+small."
+ :type 'boolean
+ :group 'lisp)
+
(defun lisp-fill-paragraph (&optional justify)
"Like \\[fill-paragraph], but handle Emacs Lisp comments and docstrings.
If any of the current line is a comment, fill the comment or the
@@ -1501,14 +1511,19 @@ and initial semicolons."
;; statements that follow the string.
(when (ppss-string-terminator ppss)
(goto-char (ppss-comment-or-string-start ppss))
- ;; The string may be unterminated -- in that case, don't
- ;; narrow.
- (when (ignore-errors
- (progn
- (forward-sexp 1)
- t))
- (narrow-to-region (1+ (ppss-comment-or-string-start ppss))
- (1- (point)))))
+ (let ((beginning (save-excursion
+ (if lisp-fill-string-by-source-column
+ (progn
+ (beginning-of-line)
+ (point))
+ (1+ (point))))))
+ ;; The string may be unterminated -- in that case, don't
+ ;; narrow.
+ (when (ignore-errors
+ (progn
+ (forward-sexp 1)
+ t))
+ (narrow-to-region beginning (1- (point))))))
;; Move back to where we were.
(goto-char start)
;; We should fill the first line of a string