Re: Is there any elisp functions to tell whether the cursor is in a comment block?

[Johan Bockgård]

Joe Bloggs <who@cares.invalid> writes:

> bojohan+news@dd.chalmers.se (Johan Bockgård) writes:
>
>> sunway <sunwayforever@gmail.com> writes:
>>
>>> for example, if the cursor is in a normal c code block, I want 'if '
>>> to be expanded to 'if () {}', if it is in the comment block, I prefer
>>> 'if ' not be expanded.
>>
>> ;; Non-nil when inside comment or string
>> (nth 8 (syntax-ppss (point)))
>>
>> -- 
>> Johan Bockgård
>
> I want to do that too, how do I do a conditional abbrev?
> Currently I have:
>
> (define-abbrev c-mode-abbrev-table "for"
>   "" 'c-style-for-loop)
> (define-abbrev c++-mode-abbrev-table "for"
>   "" 'c-style-for-loop)
>
> how would I make it only expand in uncommented code?


;; Emacs 22 has `looking-back' and `syntax-ppss'.
;; Emacs 23 has much more powerful abbrevs; we could simply use the
;; `:enable-function' property.

(defmacro define-expander (name predicate expander)
  `(progn (put ',name 'no-self-insert t)
          (defun ,name ()
            (when (and ,predicate
                       (re-search-backward "\\<\\w+\\=" nil t))
              (delete-region (match-beginning 0) (match-end 0))
              ,expander
              t))))

(define-expander
  FOR-LOOP
  (not (nth 8 (parse-partial-sexp
               (save-excursion (beginning-of-defun) (point))
               (point))))
  (c-style-for-loop))


(define-abbrev c-mode-abbrev-table "for" t 'FOR-LOOP)


-- 
Johan Bockgård