Subject: Re: bug#37452: 26.3; skip-syntax-forward doesn't work in python-mode

From: Noam Postavsky <[email-masked]>
Date: Wed, 18 Sep 2019 18:37:39 -0400

Amai Kinono <[email-masked]> writes:

>   (defun skip-syntax ()
>     (interactive)
>     (skip-syntax-forward (char-to-string (char-syntax (char-after)))))

If you look at char-syntax's docstring, you should see

    If you’re trying to determine the syntax of characters in the buffer,
    this is probably the wrong function to use, because it can’t take
    ‘syntax-table’ text properties into account.  Consider using
    ‘syntax-after’ instead.

Which is exactly the situation you've encountered here: python-mode sets
the syntax of the quote to string fence ("|") using a text property.
This version of skip-syntax should work:

(defun syntax-class-to-char (syntax-class)
  (aref " .w_()'\"$\\/<>@!|" syntax-class))

(defun skip-syntax ()
  (interactive)
  (skip-syntax-forward (char-to-string
                        (syntax-class-to-char
                         (syntax-class (syntax-after (point)))))))

Although I'd say that the function syntax-class-to-char should be added
to Emacs (in syntax.c, so that it can reuse syntax_code_spec).