how to change C-mode syntax so that the token @' is ignored?

Question

I edit some files that are mostly C code but include a few special extension tokens. The tokens that give c-mode a problem are @' and @".

I essentially want c-mode to ignore these two bigrams. The current behavior is that the quote (single or double) is interpreted as the beginning of a quoted string.

I reckon this is childs play for anyone well versed in elisp syntax tables but I am not hence my appeal for your help.

I don't really care how @' and @" are colorized by font-lock, as long as they do not make c-mode think the quote is the beginning of a string — Jonathan Cano, Jul 28 '16 at 22:05
Also, perhaps this is more of a font-lock issue than a c-mode issue. I'm not sure. — Jonathan Cano, Jul 28 '16 at 22:09
Is `@` used anywhere else? I wonder if `@` set to be “escape” in the syntax table would work: `(modify-syntax-entry ?@ "/")` — amitp, Jul 28 '16 at 23:15
no, @ is not used anywhere else. I'll investigate this option — Jonathan Cano, Aug 02 '16 at 16:31

score 1 · Answer 1 · answered Jul 31 '16 at 22:54

You have to put a syntax-table property on the ' and " characters, e.g.:

(defun c-propertize-@ ()
  (interactive)
  (save-excursion
    (goto-char (point-min))
    (while (re-search-forward "@\\(\"\\|'\\)" nil t)
      (put-text-property (match-beginning 1)
                         (match-end 1)
                         'syntax-table
                         '(1))))) ;;= punctuation

Take a look at syntax-propertize-function, if you also want to edit these tokens.

how to change C-mode syntax so that the token @' is ignored?

1 Answers1