Emacs and Unicode Tips

Here's a table on how to type these chars:

Character	Key Press
é	【Ctrl+x 8 ' e】
à	【Ctrl+x 8 ` a】
î	【Ctrl+x 8 ^ i】
ñ	【Ctrl+x 8 ~ n】
ü	【Ctrl+x 8 " u】

To see all characters you can type this way, press 【Ctrl+x 8 Ctrl+h】. Examples: ¿ ¡ ¢ £ ¥ ¤ § ¶ ® © ª «» × ÷ ¬ ° ± µ ÀÁÂÃÄÅÆ Ç ÈÉÊË ÌÍÎÏ ÐÑ ÒÓÔÕÖ ØÙÚÛÜÝÞß àáâãäåæç èéêë ìíîï ðñòóôõö øùúûüýþÿ.

If you need to type these chars often, you can set your input method to “latin-9-prefix”. (type 【Alt+x set-input-method】). That will allow you to type these chars without typing 【Ctrl+x 8】 first.

(Emacs's “latin-9-prefix” corresponds to the char set ISO 8859-9)

If you are on a Mac, these characters can be typed by holding down the Option key or use Character Palette. On Windows, you can use Windows Alt keycodes or Charmap.

Call ucs-insert 【Ctrl+x 8 Enter】, then the name of the Unicode. For example, try insert “λ”. Its name is “GREEK SMALL LETTER LAMDA”.

You can use asterisk * to match chars. For example, call ucs-insert, then type *arrow then Tab ⇆, then emacs will show all chars with “arrow” in their names.

Call ucs-insert 【Ctrl+x 8 Enter】, then the hex of the Unicode. For example, try insert “λ”. Its hex value is “3bb”.

Call eval-expression, then type (ucs-insert 955).

You can put frequently used Unicode chars into a file and save it, and define a keystroke to open this file, so that you can copy and paste the chars you want. Here's how you can define a keystroke to open a file. Put the following in your emacs init file.

; open my Unicode template with F8 key
(global-set-key (kbd "<f8>")
  (lambda () (interactive) (find-file "~/emacs.d/my_unicode_template.txt")))

Here's a example of a template: unicode.txt.

You can also install the xub Unicode Browser mode. It lets you easily browser a file of Unicode chars.

For example, put the following code in your emacs init file.

(global-set-key (kbd "<f11>") "λ") ; make F11 key insert lambda

You can also set shortcut by key sequence. Like this:

(global-set-key (kbd "M-i a") "α")
(global-set-key (kbd "M-i b") "β")

With the above, typing 【Alt+i a】 will insert α. This way you can set a whole collection of Unicode chars.

Alternatively, you can use “key-translation-map”:

(define-key key-translation-map (kbd "M-i a") (kbd "α"))
(define-key key-translation-map (kbd "M-i b") (kbd "β"))

For the difference, see: Emacs: Remapping Keys Using key-translation-map. For OS-wide, see: How to Create a APL or Math Symbols Keyboard Layout.

Put the following in your emacs init file:

(define-abbrev-table 'global-abbrev-table '(
    ("alpha" "α" nil 0)
    ("beta" "β" nil 0)
    ("gamma" "γ" nil 0)
    ("theta" "θ" nil 0)
    ("inf" "∞" nil 0)

    ("ar1" "→" nil 0)
    ("ar2" "⇒" nil 0)
    ))

(abbrev-mode 1) ; turn on abbrev mode

Select the code above and call eval-region 【Alt+x】.

Now, type alpha , it will become “α ”.

See: Using Emacs's Abbrev Mode for Abbreviation.

Regardless what text editor you are using, you need to do two things: ① Set your editor's Character encoding to one that supports your language. ② set your Input method to a particular system suitable for your language.

Char Encoding tells your computer how to map symbols/glyphs/characters into binary code. Input Method allows you to type languages that are not based on Latin alphabet. (For example, in Chinese, you cannot just type a character by pressing a key, instead, you must use a input method to type Chinese.) For English and most European langs, you don't need to worry about input method.

To set your file encoding in emacs, use the menu 〖Options▸Mule (Multilingual Environment)▸Set Language Environment〗.

To set your input method, use the menu 〖Options▸Mule (Multilingual Environment)▸Select Input Method…〗.

After you've pulled the menu, be sure to also pull the menu command 〖Options▸Save Options〗 so that emacs remembers your settings.

For me, i type Chinese sometimes. There are several encoding systems that supports Chinese, for example GB 18030 (used in China), Big5 (popular in Taiwan), UTF-8 and UTF-16. I use the UTF-8 encoding system. Among the Chinese input methods, i use the Pinyin method. Here's how to set them in emacs without using the menu: 【Alt+x set-language-environment UTF-8】 and 【Alt+x set-input-method chinese-py】.

Here's a example of actually typing the Chinese char 美 (meaning beautiful). Type 【Alt+x set-input-method Enter chinese-py】, then type “mei”. Emacs will show you a list of characters with the pronunciation of mei. Type “2” to pick the correct character. Then, emacs will insert the character. To turn off input method, press 【Ctrl+\】.

A in-depth tutorial of using Mac with Chinese is at: http://www.yale.edu/chinesemac/. It includes comprehensive info and resources on Chinese fonts, complete tutorials on several Chinese input methods, etc.

Call describe-variable 【F1 v】 then type “current-input-method”.

You can find out a char's info by placing your cursor on the character then call describe-char.

Following is the output of describe-char on char “λ” in Emacs 23:

        character: λ (955, #o1673, #x3bb)
preferred charset: unicode-bmp (Unicode Basic Multilingual Plane (U+0000..U+FFFF))
       code point: 0x03BB
           syntax: w    which means: word
         category: .:Base, G:2-byte Greek, c:Chinese, g:Greek, h:Korean, j:Japanese
      buffer code: #xCE #xBB
        file code: #xCE #xBB (encoded by coding system utf-8-unix)
          display: by this font (glyph code)
    uniscribe:-outline-DejaVu Sans Mono-normal-normal-normal-mono-13-*-*-*-c-*-iso10646-1 (#x301)
     Unicode data:  
             Name: GREEK SMALL LETTER LAMDA
         Category: Letter, Lowercase
  Combining class: Ll
    Bidi category: Ll
         Old name: GREEK SMALL LETTER LAMBDA
        Uppercase: Λ
        Titlecase: Λ

Character code properties: customize what to show
  name: GREEK SMALL LETTER LAMDA
  old-name: GREEK SMALL LETTER LAMBDA
  general-category: Ll (Letter, Lowercase)
  canonical-combining-class: 0 (Spacing, split, enclosing, reordrant, and Tibetan subjoined)
  bidi-class: L (Left-to-Right)
  mirrored: N
  uppercase: 923 (Λ)
  titlecase: 923 (Λ)

There are text properties here:
  fontified            t

Unicode version 6 (released in 2010-10) added about 1k more symbols. Emacs 23.2 does not have info on these new symbols. (e.g. 😸 GRINNING CAT FACE WITH SMILING EYES) (➲ Unicode 6 Emoticons)

You can get these info by downloading a Unicode data file and let emacs know where it is. Download it at: http://www.unicode.org/Public/UNIDATA/UnicodeData.txt, then, place the following code in your “.emacs”.

;; set Unicode data file location. (used by what-cursor-position and describe-char)
(let ((x "~/emacs.d/UnicodeData.txt"))
  (when (file-exists-p x)
    (setq describe-char-unicodedata-file x)))

Select the above code, then call eval-region. Then, you will have full Unicode char info when calling describe-char.

See also: xub Unicode Browser mode for Emacs.