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Raku programming language uses some unicode characters as operators, quotation marks, etc. In this post I'm going to explain how to type those characters in Emacs using input methods.

First, you might want to see a list of those characters and their ASCII equivalents here. There is also a doc for entering unicode characters. You may specifically want to look at XCompose for a system-wide solution.

There are at least two input methods you can use to enter the unicode characters used in Raku. rfc1345 and TeX.

To select an input method type C-x RET C-\ and to switch to an input method use C-u C-\. C-\ can be used to toggle input method.

After you select an input method, You have to use the prefix character it provides for typing special characters. & is the prefix used for rfc1345 and \, ^ and some other characters are used for TeX.

Example for typing λ:

rfc1345: &l*

TeX: \lambda

To see a list of character sequences for an input method, type C-h I.

You can change the default input method by setting the default-input-method variable:

(setq default-input-method 'TeX)

To add characters which are not available in an input method:

(eval-after-load "quail/latin-ltx"
  `(let ((quail-current-package (assoc "TeX" quail-package-alist)))
     (quail-define-rules ((append . t))
                         ("\\lcb" ?｢)
                         ("\\rcb" ?｣))))

Now with TeX method enabled, \lcb types '｢' and \rcb types '｣'.

Same thing for the rfc1345 input method:

(eval-after-load "quail/rfc1345"
  `(let ((quail-current-package (assoc "rfc1345" quail-package-alist)))
    (quail-define-rules ((append . t))
                        ("&[" "｢")
                        ("&]" "｣"))))

Now with the rfc1345 method you can type '｢' with &[ and type '｣' with &].

Another way of entering unicode characters is using C-x 8 RET which runs insert-char command. C-x 8 prefix key has shortcuts for some characters. For example, C-x 8 / / inserts ÷. To add your own characters:

(global-set-key (kbd "C-x 8 l") "λ")

or:

(global-set-key (kbd "C-x 8 l") (lambda () (interactive) (insert "λ")))

Now C-x 8 l inserts λ.

Below is a list of unicode characters used in Raku and their character sequences in rfc1345 and TeX.

Note: rfc1345 character mnemonics work in Vim too. You only need to replace & with Ctrl-K.