Make names of major modes shorter in the mode-line

Question

I want to make names of major modes shorter. No longer than three characters. Is there any packages that do something like that?

It's better to shorten mode names in automatic fashion, so one doesn't need to constantly manage this thing manually. I'm ready to consider any principle of shortening. Most trivial would be to use abbreviations, so emacs-lisp-mode would become el, for example. interactive-haskell-mode would become ih. Not bad at all for a start.

I also like Unicode characters like Greek letters and other stuff to be mode names, currently I use sort of hack to “rename” modes, but maybe there is full featured package to do it?

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Clarification: the question is about mode names (values of variable mode-name usually), they are displayed in mode line. I want to make major mode “lighters” shorter.

Answer 1

Cyphejor can handle this. Here is how it works (copied from README.md file):

First you need to set value of variable cyphejor-rules. This variable contains rules that the package uses to generate new names for major modes from their symbol names (values of major-mode variable).

Value of cyphejor-rules should be a list. Every element of the list must be either a list:

(string replacement &rest parameters)

where string is a “word” in major mode symbol name, replacement is another string to be used instead, parameters is a list that may be empty but may have the following keywords in it as well:

• :prefix — put it in the beginning of result string
• :postfix — put it in the end of result string

Apart from elements of the form described above the following keywords are allowed (they influence the algorithm in general):

• :downcase — replace words that are not specified explicitly with their first letter downcased

• :upcase — replace words that are not specified explicitely with their first letter upcased

If nothing is specified, use word unchanged separating it from other words with spaces if necessary.

Example of setup:

(setq
 cyphejor-rules
 '(:upcase
   ("bookmark"    "→")
   ("buffer"      "β")
   ("diff"        "Δ")
   ("dired"       "δ")
   ("emacs"       "ε")
   ("fundamental" "Ⓕ")
   ("inferior"    "i" :prefix)
   ("interaction" "i" :prefix)
   ("interactive" "i" :prefix)
   ("lisp"        "λ" :postfix)
   ("menu"        "▤" :postfix)
   ("mode"        "")
   ("package"     "↓")
   ("python"      "π")
   ("shell"       "sh" :postfix)
   ("text"        "ξ")
   ("wdired"      "↯δ")))

Next, just enable cyphejor-mode in your configuration file:

(cyphejor-mode 1)

Answer 2

If you just want to always trim the mode name to a particular length, then how about this:

(defcustom mode-name-max-length 8
  "The number of characters after which a major mode name will be
  truncated in the modeline.")

(defun truncate-mode-name ()
  (setq mode-name (truncate-string-to-width mode-name mode-name-max-length nil nil 't)))

(add-hook 'after-change-major-mode-hook #'truncate-mode-name)

(Updated to use truncate-string-to-width with ELLIPSIS argument per the comments -- thanks!)

Answer 3

You can also just get rid of the major mode lighter in the mode-line altogether.

Just take the code defining mode-line-modes from bindings.el, and comment-out or remove these lines, to try it out:

`(:propertize ("" mode-name)
              help-echo "Major mode\n\
mouse-1: Display major mode menu\n\
mouse-2: Show help for major mode\n\
mouse-3: Toggle minor modes"
              mouse-face mode-line-highlight
              local-map ,mode-line-major-mode-keymap)

Result:

(defvar mode-line-modes
  (let ((recursive-edit-help-echo "Recursive edit, type C-M-c to get out"))
    (list (propertize "%[" 'help-echo recursive-edit-help-echo)
          "("
;;;           `(:propertize ("" mode-name)
;;;                         help-echo "Major mode\n\
;;; mouse-1: Display major mode menu\n\
;;; mouse-2: Show help for major mode\n\
;;; mouse-3: Toggle minor modes"
;;;                         mouse-face mode-line-highlight
;;;                         local-map ,mode-line-major-mode-keymap)
          '("" mode-line-process)
          `(:propertize ("" minor-mode-alist)
                        mouse-face mode-line-highlight
                        help-echo "Minor mode\n\
mouse-1: Display minor mode menu\n\
mouse-2: Show help for minor mode\n\
mouse-3: Toggle minor modes"
                        local-map ,mode-line-minor-mode-keymap)
          (propertize "%n" 'help-echo "mouse-2: Remove narrowing from buffer"
                      'mouse-face 'mode-line-highlight
                      'local-map (make-mode-line-mouse-map
                                  'mouse-2 #'mode-line-widen))
          ")"
          (propertize "%]" 'help-echo recursive-edit-help-echo)
          " "))
  "Mode line construct for displaying major and minor modes.")

Answer 4

I really liked cyphejor to shorten the mode name in the mode line (I even threw in some emoji). But I missed the ability to filter by (regular) mode-name in ibuffer and other places.

So instead of activating cyphejor-mode, which actually alters mode-name, I just leave the mode off, and use its capabilities to replace the mode-name in the mode line, with caching to avoid recalculation:

  (defun my/cyphejor-with-cache ()
    (or (get major-mode 'cyphejor-cypher)
        (put major-mode 'cyphejor-cypher
         (cyphejor--cypher (symbol-name major-mode) cyphejor-rules))))
  (cl-nsubst '(:eval (my/cyphejor-with-cache)) 'mode-name
         (if minions-mode minions-mode-line-modes mode-line-modes))