Re: How do you write input methods?

[Filipp Gunbin <fgunbin@fastmail.fm>]

On 01/09/2021 20:57 +0300, Eli Zaretskii wrote:

>> From: Filipp Gunbin <fgunbin@fastmail.fm>
>> Cc: Eli Zaretskii <eliz@gnu.org>,  perry@piermont.com,  emacs-devel@gnu.org
>> Date: Wed, 01 Sep 2021 20:50:04 +0300
>>
>> FWIW, I use this (hack?) to employ available input methods for
>> transliteration.
>
> Out of curiosity: why do you need something like that? what's the use
> case?

It's because our LDAP server at work is a bit messy, attributes like
"cn" and "displayname" sometimes contain first then last name, sometimes
vice versa, sometimes in Russian, sometimes in English.  I use email
expansion in message-mode:

--8<---------------cut here---------------start------------->8---
(eval-after-load 'message
  (lambda ()
    (define-key message-mode-map (kbd "C-c TAB") #'eudc-expand-inline)))
--8<---------------cut here---------------end--------------->8---

I want to type first letters of surname in English, press C-c TAB and
get email autocompleted.  But the only "stable", predictable attribute
seems to be "sn", which is unfortunately in Russian.  So I do:

--8<---------------cut here---------------start------------->8---
(eudc-protocol-set 'eudc-inline-query-format '((sn) (email)) 'ldap)
(advice-add #'eudc-ldap-simple-query-internal
            :filter-args #'fg-dotemacs-ldap-advice)

(defun fg-dotemacs-ldap-advice (args)
  (cons (mapcar (lambda (attr)
                  (if (and (eq (car attr) 'sn)
                           (stringp (cdr attr))
                           (seq-every-p (lambda (c)
                                          (eq (aref char-script-table c) 'latin))
                                        (cdr attr)))
                      (cons (car attr)
                            (fg-dotemacs-translit (cdr attr) "cyrillic-translit"))
                    attr))
                (car args))
        (cdr args)))
--8<---------------cut here---------------end--------------->8---

As ugly as it is, but it works.

Filipp