2011-07-13 emacs lisp. Is there a rassoc-default for getting ALL elements matching a VALUE?
emas lisp. Is there a rassoc-default function? i.e. similar to assoc-default but get all items of a alist of a give value.
i want to be able to properly setup cperl-mode to load instead of perl-mode. Here's detail.
easy way is just
(defalias 'perl-mode 'cperl-mode)
but the problem with that is you can't call perl-mode anymore, if you still want it on occasion.
So, i went to set the auto-mode-alist. Like this:
(setq auto-mode-alist (rassq-delete-all 'perl-mode auto-mode-alist))
(add-to-list 'auto-mode-alist '("\\.\\([pP]\\([Llm]\\|erl\\|od\\)\\|al\\)\\'" . cperl-mode))
that turns out doesn't do it, because there's also interpreter-mode-alist. So i wrote:
(rassoc 'perl-mode interpreter-mode-alist)
(let ((mykey (car (rassoc 'perl-mode interpreter-mode-alist)) ))
(setq interpreter-mode-alist (rassq-delete-all 'perl-mode interpreter-mode-alist))
(add-to-list 'interpreter-mode-alist (mykey . 'cperl-mode))
but i discovered there are actually several elements for perl in that alist:
("perl" . perl-mode)
("perl5" . perl-mode)
("miniperl" . perl-mode)
So my code above won't work.
So, the proper way is to query for the value 'perl-mode, get *ALL* results, then remove them all, then add them all back with 'cperl-mode.
Ι found the function “assoc-default”, which gets all elements by KEY, not value.
so, my question is, is there a “rassoc-default” that gets by value? Or, is there any simpler proper way to setup cperl-mode instead of perl-mode?