How to exclude {{{ ... }}} in flyspell-mode and flyspell-buffer?

Question

I edit a lot of MoinMoinWiki pages in my emacs and love the flyspell-mode. Preformatted stuff in {{{...}}} (in multiple lines) as well as "backtick text backtick" usually contains snippets of programming code which make no sense to spellcheck.

Can I configure ispell/flyspell not to include the programming code?

Example:

Bla bla lorem ipsum die Standardcontainer wie `vector` eine
''Methode'' haben, die ein einzelnes Argument nimmt, also
`vector<T>::swap(vector<T)>&)`. Bla bla und diese `swap`-Methoden sind
von dieser Sorte. Warum das so ist, sehen wir gleich. Bla bla
was '''kanonisch''' ist bla bla Template-Funktion<<tlitref(stdswap)>>

{{{#!highlight c++ title="Man könnte 'std::swap@LT@@GT@' spezialisieren"
namespace std {
  template<> // wir können durchaus im namespace std spezialisieren
  void swap<Thing>(Thing&, Thing&) {
    // ...hier swappen...
  }
}
}}}

Nun, das würde sicherlich in diesem Fall helfen, doch es bleibt ein
größeres Problem: Eine teilweise Spezialisierung lorem ipsum bla bla

Answer 1

The variable ispell-skip-region-alist does what you want when spell checking the buffer, but not for flyspell. Just add an entry like

(add-to-list 'ispell-skip-region-alist
             '("^{{{" . "^}}}"))

Unfortunately, it's not as easy to get flyspell to ignore certain regions. You have to use flyspell-generic-check-word-predicate which is a function. Several modes already define this so you would have to add the following as advice to those functions. I'll assume for simplicity though that you are using a mode (I used text-mode below) which doesn't have it defined. Then you can add the following to your .emacs:

(defun flyspell-ignore-verbatim ()
  "Function used for `flyspell-generic-check-word-predicate' to ignore {{{ }}} blocks."
  (save-excursion
    (widen)
    (let ((p (point))
          (count 0))
      (not (or (and (re-search-backward "^{{{" nil t)
                    (> p (point))
                    ;; If there is no closing }}} then assume we're still in it
                    (or (not (re-search-forward "^}}}" nil t))
                        (< p (point))))
               (eq 1 (progn (while (re-search-backward "`" (line-beginning-position) t)
                              (setq count (1+ count)))
                            (- count (* 2 (/ count 2))))))))))
(put 'text-mode 'flyspell-mode-predicate 'flyspell-ignore-verbatim)