Emacs instructions - tonsky/FiraCode Wiki

Installing

Make sure you install the font.

Enabling

There are a few options when it comes down to using ligatures in Emacs. They are listed in order of preferred to less-preferred. Pick one!

Using composition mode in Emacs Mac port

If you're using the latest Mac port of Emacs (by Mitsuharu Yamamoto) for macOS, you can use:

(mac-auto-operator-composition-mode)

Using ligature.el

If you're using a modern version of emacs, you might have ligature support built-in, via HARFBUZZ / Cairo. The ligature.el package adds infrastructure that uses Harfbuzz and Cairo to render ligatures from the fonts, just like in any other editor. Add the following to your init.el file:

;; Enable the www ligature in every possible major mode
(ligature-set-ligatures 't '("www"))

;; Enable ligatures in programming modes                                                           
(ligature-set-ligatures 'prog-mode '("www" "**" "***" "**/" "*>" "*/" "\\\\" "\\\\\\" "{-" "::"
                                     ":::" ":=" "!!" "!=" "!==" "-}" "----" "-->" "->" "->>"
                                     "-<" "-<<" "-~" "#{" "#[" "##" "###" "####" "#(" "#?" "#_"
                                     "#_(" ".-" ".=" ".." "..<" "..." "?=" "??" ";;" "/*" "/**"
                                     "/=" "/==" "/>" "//" "///" "&&" "||" "||=" "|=" "|>" "^=" "$>"
                                     "++" "+++" "+>" "=:=" "==" "===" "==>" "=>" "=>>" "<="
                                     "=<<" "=/=" ">-" ">=" ">=>" ">>" ">>-" ">>=" ">>>" "<*"
                                     "<*>" "<|" "<|>" "<$" "<$>" "<!--" "<-" "<--" "<->" "<+"
                                     "<+>" "<=" "<==" "<=>" "<=<" "<>" "<<" "<<-" "<<=" "<<<"
                                     "<~" "<~~" "</" "</>" "[email protected]" "~-" "~>" "~~" "~~>" "%%"))

(global-ligature-mode 't)

This is generally the easiest solution, but can only be used on macOS. Also tested on Linux, it works.

One thing to be aware of is that not all modes where you want code ligatures may derive from prog-mode, so you may also want to call ligature-set-ligatures with other modes (e.g. html-mode).

Using prettify-symbols

Note: fira-code-mode is a MELPA package implementing something similar to this solution, meaning you can implement the below by installing the Fira Code Symbol font and by using the following snippet:

(use-package fira-code-mode
  :custom (fira-code-mode-disabled-ligatures '("[]" "x"))  ; ligatures you don't want
  :hook prog-mode)                                         ; mode to enable fira-code-mode in

These instructions are pieced together by @Triavanicus, taking some pieces from: Hasklig-Mode.

This method requires you to install the Fira Code Symbol font, made by @siegebell: https://github.com/tonsky/FiraCode/issues/211#issuecomment-239058632

(defun fira-code-mode--make-alist (list)
  "Generate prettify-symbols alist from LIST."
  (let ((idx -1))
    (mapcar
     (lambda (s)
       (setq idx (1+ idx))
       (let* ((code (+ #Xe100 idx))
          (width (string-width s))
          (prefix ())
          (suffix '(?\s (Br . Br)))
          (n 1))
     (while (< n width)
       (setq prefix (append prefix '(?\s (Br . Bl))))
       (setq n (1+ n)))
     (cons s (append prefix suffix (list (decode-char 'ucs code))))))
     list)))

(defconst fira-code-mode--ligatures
  '("www" "**" "***" "**/" "*>" "*/" "\\\\" "\\\\\\"
    "{-" "[]" "::" ":::" ":=" "!!" "!=" "!==" "-}"
    "--" "---" "-->" "->" "->>" "-<" "-<<" "-~"
    "#{" "#[" "##" "###" "####" "#(" "#?" "#_" "#_("
    ".-" ".=" ".." "..<" "..." "?=" "??" ";;" "/*"
    "/**" "/=" "/==" "/>" "//" "///" "&&" "||" "||="
    "|=" "|>" "^=" "$>" "++" "+++" "+>" "=:=" "=="
    "===" "==>" "=>" "=>>" "<=" "=<<" "=/=" ">-" ">="
    ">=>" ">>" ">>-" ">>=" ">>>" "<*" "<*>" "<|" "<|>"
    "<$" "<$>" "<!--" "<-" "<--" "<->" "<+" "<+>" "<="
    "<==" "<=>" "<=<" "<>" "<<" "<<-" "<<=" "<<<" "<~"
    "<~~" "</" "</>" "[email protected]" "~-" "~=" "~>" "~~" "~~>" "%%"
    "x" ":" "+" "+" "*"))

(defvar fira-code-mode--old-prettify-alist)

(defun fira-code-mode--enable ()
  "Enable Fira Code ligatures in current buffer."
  (setq-local fira-code-mode--old-prettify-alist prettify-symbols-alist)
  (setq-local prettify-symbols-alist (append (fira-code-mode--make-alist fira-code-mode--ligatures) fira-code-mode--old-prettify-alist))
  (prettify-symbols-mode t))

(defun fira-code-mode--disable ()
  "Disable Fira Code ligatures in current buffer."
  (setq-local prettify-symbols-alist fira-code-mode--old-prettify-alist)
  (prettify-symbols-mode -1))

(define-minor-mode fira-code-mode
  "Fira Code ligatures minor mode"
  :lighter " Fira Code"
  (setq-local prettify-symbols-unprettify-at-point 'right-edge)
  (if fira-code-mode
      (fira-code-mode--enable)
    (fira-code-mode--disable)))

(defun fira-code-mode--setup ()
  "Setup Fira Code Symbols"
  (set-fontset-font t '(#Xe100 . #Xe16f) "Fira Code Symbol"))

(provide 'fira-code-mode)

Alternative instructions

https://github.com/Profpatsch/blog/blob/master/posts/ligature-emulation-in-emacs/post.md#appendix-b-update-1-firacode-integration

Using composition char table

Put this lisp in your .emacs.

Thanks to Sean Farley for putting this together; extended by Jason Blevins.

(when (window-system)
  (set-frame-font "Fira Code"))
(let ((alist '((33 . ".\\(?:\\(?:==\\|!!\\)\\|[!=]\\)")
               (35 . ".\\(?:###\\|##\\|_(\\|[#(?[_{]\\)")
               (36 . ".\\(?:>\\)")
               (37 . ".\\(?:\\(?:%%\\)\\|%\\)")
               (38 . ".\\(?:\\(?:&&\\)\\|&\\)")
               (42 . ".\\(?:\\(?:\\*\\*/\\)\\|\\(?:\\*[*/]\\)\\|[*/>]\\)")
               (43 . ".\\(?:\\(?:\\+\\+\\)\\|[+>]\\)")
               (45 . ".\\(?:\\(?:-[>-]\\|<<\\|>>\\)\\|[<>}~-]\\)")
               (46 . ".\\(?:\\(?:\\.[.<]\\)\\|[.=-]\\)")
               (47 . ".\\(?:\\(?:\\*\\*\\|//\\|==\\)\\|[*/=>]\\)")
               (48 . ".\\(?:x[a-zA-Z]\\)")
               (58 . ".\\(?:::\\|[:=]\\)")
               (59 . ".\\(?:;;\\|;\\)")
               (60 . ".\\(?:\\(?:!--\\)\\|\\(?:~~\\|->\\|\\$>\\|\\*>\\|\\+>\\|--\\|<[<=-]\\|=[<=>]\\||>\\)\\|[*$+~/<=>|-]\\)")
               (61 . ".\\(?:\\(?:/=\\|:=\\|<<\\|=[=>]\\|>>\\)\\|[<=>~]\\)")
               (62 . ".\\(?:\\(?:=>\\|>[=>-]\\)\\|[=>-]\\)")
               (63 . ".\\(?:\\(\\?\\?\\)\\|[:=?]\\)")
               (91 . ".\\(?:]\\)")
               (92 . ".\\(?:\\(?:\\\\\\\\\\)\\|\\\\\\)")
               (94 . ".\\(?:=\\)")
               (119 . ".\\(?:ww\\)")
               (123 . ".\\(?:-\\)")
               (124 . ".\\(?:\\(?:|[=|]\\)\\|[=>|]\\)")
               (126 . ".\\(?:~>\\|~~\\|[>[email protected]~-]\\)")
               )
             ))
  (dolist (char-regexp alist)
    (set-char-table-range composition-function-table (car char-regexp)
                          `([,(cdr char-regexp) 0 font-shape-gstring]))))

Note! If you get error in process filter: Attempt to shape unibyte text, check out this issue. Emacs Cider users may avoid this issue by commenting the following line from the above config:

;; (46 . ".\\(?:\\(?:\\.[.<]\\)\\|[.=-]\\)")

Char 45 is also known to have issues in macOS Mojave.

If you are having problems with helm you can disable ligatures in helm or disable char 46:

   (add-hook 'helm-major-mode-hook
          (lambda ()
            (setq auto-composition-mode nil)))

If you are having issues with ediff, you can disable char 45 or disable ligatures in ediff completely:

  (add-hook 'ediff-mode-hook
            (lambda ()
              (setq auto-composition-mode nil)))

Note! Disabling ligatures in ediff mode only removes them in the ediff buffer itself(the small buffer underneath) and not the buffers you compare. Which is probably a preferred solution

Using font-lock keywords

If none of the above worked, you can try this method.

This method requires you to install the Fira Code Symbol font, made by @siegebell: https://github.com/tonsky/FiraCode/issues/211#issuecomment-239058632

;;; Fira code
;; This works when using emacs --daemon + emacsclient
(add-hook 'after-make-frame-functions (lambda (frame) (set-fontset-font t '(#Xe100 . #Xe16f) "Fira Code Symbol")))
;; This works when using emacs without server/client
(set-fontset-font t '(#Xe100 . #Xe16f) "Fira Code Symbol")
;; I haven't found one statement that makes both of the above situations work, so I use both for now

(defconst fira-code-font-lock-keywords-alist
  (mapcar (lambda (regex-char-pair)
            `(,(car regex-char-pair)
              (0 (prog1 ()
                   (compose-region (match-beginning 1)
                                   (match-end 1)
                                   ;; The first argument to concat is a string containing a literal tab
                                   ,(concat "   " (list (decode-char 'ucs (cadr regex-char-pair)))))))))
          '(("\\(www\\)"                   #Xe100)
            ("[^/]\\(\\*\\*\\)[^/]"        #Xe101)
            ("\\(\\*\\*\\*\\)"             #Xe102)
            ("\\(\\*\\*/\\)"               #Xe103)
            ("\\(\\*>\\)"                  #Xe104)
            ("[^*]\\(\\*/\\)"              #Xe105)
            ("\\(\\\\\\\\\\)"              #Xe106)
            ("\\(\\\\\\\\\\\\\\)"          #Xe107)
            ("\\({-\\)"                    #Xe108)
            ("\\(\\[\\]\\)"                #Xe109)
            ("\\(::\\)"                    #Xe10a)
            ("\\(:::\\)"                   #Xe10b)
            ("[^=]\\(:=\\)"                #Xe10c)
            ("\\(!!\\)"                    #Xe10d)
            ("\\(!=\\)"                    #Xe10e)
            ("\\(!==\\)"                   #Xe10f)
            ("\\(-}\\)"                    #Xe110)
            ("\\(--\\)"                    #Xe111)
            ("\\(---\\)"                   #Xe112)
            ("\\(-->\\)"                   #Xe113)
            ("[^-]\\(->\\)"                #Xe114)
            ("\\(->>\\)"                   #Xe115)
            ("\\(-<\\)"                    #Xe116)
            ("\\(-<<\\)"                   #Xe117)
            ("\\(-~\\)"                    #Xe118)
            ("\\(#{\\)"                    #Xe119)
            ("\\(#\\[\\)"                  #Xe11a)
            ("\\(##\\)"                    #Xe11b)
            ("\\(###\\)"                   #Xe11c)
            ("\\(####\\)"                  #Xe11d)
            ("\\(#(\\)"                    #Xe11e)
            ("\\(#\\?\\)"                  #Xe11f)
            ("\\(#_\\)"                    #Xe120)
            ("\\(#_(\\)"                   #Xe121)
            ("\\(\\.-\\)"                  #Xe122)
            ("\\(\\.=\\)"                  #Xe123)
            ("\\(\\.\\.\\)"                #Xe124)
            ("\\(\\.\\.<\\)"               #Xe125)
            ("\\(\\.\\.\\.\\)"             #Xe126)
            ("\\(\\?=\\)"                  #Xe127)
            ("\\(\\?\\?\\)"                #Xe128)
            ("\\(;;\\)"                    #Xe129)
            ("\\(/\\*\\)"                  #Xe12a)
            ("\\(/\\*\\*\\)"               #Xe12b)
            ("\\(/=\\)"                    #Xe12c)
            ("\\(/==\\)"                   #Xe12d)
            ("\\(/>\\)"                    #Xe12e)
            ("\\(//\\)"                    #Xe12f)
            ("\\(///\\)"                   #Xe130)
            ("\\(&&\\)"                    #Xe131)
            ("\\(||\\)"                    #Xe132)
            ("\\(||=\\)"                   #Xe133)
            ("[^|]\\(|=\\)"                #Xe134)
            ("\\(|>\\)"                    #Xe135)
            ("\\(\\^=\\)"                  #Xe136)
            ("\\(\\$>\\)"                  #Xe137)
            ("\\(\\+\\+\\)"                #Xe138)
            ("\\(\\+\\+\\+\\)"             #Xe139)
            ("\\(\\+>\\)"                  #Xe13a)
            ("\\(=:=\\)"                   #Xe13b)
            ("[^!/]\\(==\\)[^>]"           #Xe13c)
            ("\\(===\\)"                   #Xe13d)
            ("\\(==>\\)"                   #Xe13e)
            ("[^=]\\(=>\\)"                #Xe13f)
            ("\\(=>>\\)"                   #Xe140)
            ("\\(<=\\)"                    #Xe141)
            ("\\(=<<\\)"                   #Xe142)
            ("\\(=/=\\)"                   #Xe143)
            ("\\(>-\\)"                    #Xe144)
            ("\\(>=\\)"                    #Xe145)
            ("\\(>=>\\)"                   #Xe146)
            ("[^-=]\\(>>\\)"               #Xe147)
            ("\\(>>-\\)"                   #Xe148)
            ("\\(>>=\\)"                   #Xe149)
            ("\\(>>>\\)"                   #Xe14a)
            ("\\(<\\*\\)"                  #Xe14b)
            ("\\(<\\*>\\)"                 #Xe14c)
            ("\\(<|\\)"                    #Xe14d)
            ("\\(<|>\\)"                   #Xe14e)
            ("\\(<\\$\\)"                  #Xe14f)
            ("\\(<\\$>\\)"                 #Xe150)
            ("\\(<!--\\)"                  #Xe151)
            ("\\(<-\\)"                    #Xe152)
            ("\\(<--\\)"                   #Xe153)
            ("\\(<->\\)"                   #Xe154)
            ("\\(<\\+\\)"                  #Xe155)
            ("\\(<\\+>\\)"                 #Xe156)
            ("\\(<=\\)"                    #Xe157)
            ("\\(<==\\)"                   #Xe158)
            ("\\(<=>\\)"                   #Xe159)
            ("\\(<=<\\)"                   #Xe15a)
            ("\\(<>\\)"                    #Xe15b)
            ("[^-=]\\(<<\\)"               #Xe15c)
            ("\\(<<-\\)"                   #Xe15d)
            ("\\(<<=\\)"                   #Xe15e)
            ("\\(<<<\\)"                   #Xe15f)
            ("\\(<~\\)"                    #Xe160)
            ("\\(<~~\\)"                   #Xe161)
            ("\\(</\\)"                    #Xe162)
            ("\\(</>\\)"                   #Xe163)
            ("\\([email protected]\\)"                    #Xe164)
            ("\\(~-\\)"                    #Xe165)
            ("\\(~=\\)"                    #Xe166)
            ("\\(~>\\)"                    #Xe167)
            ("[^<]\\(~~\\)"                #Xe168)
            ("\\(~~>\\)"                   #Xe169)
            ("\\(%%\\)"                    #Xe16a)
            ("[0\[]\\(x\\)"                #Xe16b)
            ("[^:=]\\(:\\)[^:=]"           #Xe16c)
            ("[^\\+<>]\\(\\+\\)[^\\+<>]"   #Xe16d)
            ("[^\\*/<>]\\(\\*\\)[^\\*/<>]" #Xe16f))))

(defun add-fira-code-symbol-keywords ()
  (font-lock-add-keywords nil fira-code-font-lock-keywords-alist))

(add-hook 'prog-mode-hook
          #'add-fira-code-symbol-keywords)

On some systems, == will appear incorrectly as a blank space in certain modes unless you add the following lines to your init file:

(set-language-environment "UTF-8")
(set-default-coding-systems 'utf-8)