From: Noam Postavsky <npostavs@gmail.com>
To: Alan Mackenzie <acm@muc.de>
Cc: 21871@debbugs.gnu.org
Subject: bug#21871: Emacs Lisp Mode (at least): spurious parens in column 0 don't get bold red highlighting.
Date: Sat, 11 Apr 2020 11:00:35 -0400 [thread overview]
Message-ID: <878sj23w4s.fsf@gmail.com> (raw)
In-Reply-To: <20151110163034.GH2626@acm.fritz.box> (Alan Mackenzie's message of "Tue, 10 Nov 2015 16:30:34 +0000")
[-- Attachment #1: Type: text/plain, Size: 647 bytes --]
Alan Mackenzie <acm@muc.de> writes:
> In the Emacs manual page "Left Margin Paren", it says that:
>
> To help you catch violations of this convention, Font Lock mode
> highlights confusing opening delimiters (those that ought to be quoted)
> in bold red.
>
> , where "this convention" is the convention of not putting opening parens
> in column 0 when they aren't at the beginning of defuns.
>
> In Emacs Lisp Mode, this highlighting isn't done. It isn't in CC Mode,
> either.
The recent thread in emacs-devel[1] reminded me I wrote a (still
half-baked) patch for this.
[1]: https://lists.gnu.org/r/emacs-devel/2020-04/msg00402.html
[-- Attachment #2: patch --]
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From b3794a2a87c6aafc2174162f72f716a5801668a4 Mon Sep 17 00:00:00 2001
From: Noam Postavsky <npostavs@gmail.com>
Date: Sat, 5 Aug 2017 12:31:02 -0400
Subject: [PATCH] [WIP] Restore highlighting of open parens in column-0
(Bug#21871)
---
lisp/emacs-lisp/lisp-mode.el | 1 +
lisp/font-lock.el | 38 ++++++++++++++++++++++++--------------
2 files changed, 25 insertions(+), 14 deletions(-)
diff --git a/lisp/emacs-lisp/lisp-mode.el b/lisp/emacs-lisp/lisp-mode.el
index 3b0f5493ee..50707fd10a 100644
--- a/lisp/emacs-lisp/lisp-mode.el
+++ b/lisp/emacs-lisp/lisp-mode.el
@@ -642,6 +642,7 @@ lisp-mode-variables
(setq-local imenu-generic-expression lisp-imenu-generic-expression)
(setq-local multibyte-syntax-as-symbol t)
;; (setq-local syntax-begin-function 'beginning-of-defun) ;;Bug#16247.
+ (setq-local font-lock-syntax-paren-check t) ;; Bug#21871.
(setq font-lock-defaults
`(,(if elisp '(lisp-el-font-lock-keywords
lisp-el-font-lock-keywords-1
diff --git a/lisp/font-lock.el b/lisp/font-lock.el
index e0955b74ab..565f4b22b4 100644
--- a/lisp/font-lock.el
+++ b/lisp/font-lock.el
@@ -1779,6 +1779,11 @@ font-lock-fontify-keywords-region
\f
;; Various functions.
+(defvar-local font-lock-syntax-paren-check nil
+ "Major modes should set this to non-nil if they rely on the
+`open-paren-in-column-0-is-defun-start' convention for movement
+or fontification.")
+
(defun font-lock-compile-keywords (keywords &optional syntactic-keywords)
"Compile KEYWORDS into the form (t KEYWORDS COMPILED...)
Here each COMPILED is of the form (MATCHER HIGHLIGHT ...) as shown in the
@@ -1798,24 +1803,29 @@ font-lock-compile-keywords
(cons t (cons keywords
(mapcar #'font-lock-compile-keyword keywords))))
(if (and (not syntactic-keywords)
- (let ((beg-function (with-no-warnings syntax-begin-function)))
- (or (eq beg-function #'beginning-of-defun)
- (if (symbolp beg-function)
- (get beg-function 'font-lock-syntax-paren-check))))
- (not beginning-of-defun-function))
+ (or (and (let ((beg-function (with-no-warnings syntax-begin-function)))
+ (or (eq beg-function #'beginning-of-defun)
+ (if (symbolp beg-function)
+ (get beg-function 'font-lock-syntax-paren-check))))
+ (not beginning-of-defun-function))
+ font-lock-syntax-paren-check))
;; Try to detect when a string or comment contains something that
;; looks like a defun and would thus confuse font-lock.
(nconc keywords
- `((,(if defun-prompt-regexp
- (concat "^\\(?:" defun-prompt-regexp "\\)?\\s(")
- "^\\s(")
- (0
- (if (memq (get-text-property (match-beginning 0) 'face)
- '(font-lock-string-face font-lock-doc-face
- font-lock-comment-face))
- (list 'face font-lock-warning-face
+ `((,(let ((regexp
+ (if defun-prompt-regexp
+ (concat "^\\(?:" defun-prompt-regexp "\\)?\\s(")
+ "^\\s(")))
+ (lambda (bound)
+ (if open-paren-in-column-0-is-defun-start
+ (re-search-forward regexp bound t))))
+ (0
+ (if (memq (get-text-property (match-beginning 0) 'face)
+ '(font-lock-string-face font-lock-doc-face
+ font-lock-comment-face))
+ (list 'face font-lock-warning-face
'help-echo "Looks like a toplevel defun: escape the parenthesis"))
- prepend)))))
+ prepend)))))
keywords))
(defun font-lock-compile-keyword (keyword)
--
2.11.0
next prev parent reply other threads:[~2020-04-11 15:00 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-11-10 16:30 bug#21871: Emacs Lisp Mode (at least): spurious parens in column 0 don't get bold red highlighting Alan Mackenzie
[not found] ` <mailman.2066.1447172952.7904.bug-gnu-emacs@gnu.org>
2015-11-12 12:44 ` Alan Mackenzie
2015-11-12 16:36 ` Glenn Morris
2015-11-12 18:12 ` Alan Mackenzie
[not found] ` <mailman.2173.1447351928.7904.bug-gnu-emacs@gnu.org>
2015-11-12 18:54 ` Alan Mackenzie
2015-11-12 19:17 ` Eli Zaretskii
2016-05-15 21:50 ` Dmitry Gutov
2016-05-16 10:20 ` Alan Mackenzie
2016-05-16 13:18 ` Dmitry Gutov
2016-05-16 15:00 ` Andreas Röhler
2016-05-17 9:02 ` Alan Mackenzie
2017-09-02 13:19 ` Eli Zaretskii
2020-04-11 15:00 ` Noam Postavsky [this message]
2021-09-19 22:14 ` Stefan Kangas
2021-09-20 17:50 ` Alan Mackenzie
2021-09-21 23:07 ` Stefan Kangas
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