Vim folding in Emacs
Vim code folding
In Vim you can mark region of text to be hidden (folded) with markers like {{{ and }}}, for example:
# Begin folded region {{{
... code ...
# }}}
I use this type of folding inside my shell init file instead of splitting it for readability; it’s easier to just copy one file around instead of multiple files when you want to use your shell configuration on a new server.
Getting it inside Emacs
In Emacs (24.3.1) this can be achieved using outline-mode, but a little bit of elisp is needed to achieve a behavior similar to vim’s. A code snippet found in the Emacs wiki let you specify a folding marker similar to vim, but it expect a level of folding, like {{{1.
I adapted the code snippet to make the level optional, defaulting to 0.
;; code folding with vim compatibility
;; https://raw.githubusercontent.com/yyetim/emacs-configuration/master/elisp/vim-fold.el
(defun set-vim-foldmarker (fmr)
"Set Vim-type foldmarkers for the current buffer"
(interactive "sSet local Vim foldmarker: ")
(if (equal fmr "")
(message "Abort")
(setq fmr (regexp-quote fmr))
(set (make-local-variable 'outline-regexp)
(concat ".*" fmr "\\([0-9]+\\)?"))
(set (make-local-variable 'outline-level)
`(lambda ()
(save-excursion
(re-search-forward
,(concat fmr "\\([0-9]+\\)") nil t)
(if (match-string 1)
(string-to-number (match-string 1))
(string-to-number "0")))))))
(global-set-key (kbd "C-<tab>") 'outline-toggle-children)