Re: message-remove-duplicates and gnus-remove-duplicates

[Reiner Steib <reinersteib+gmane@imap.cc>]

On Thu, Sep 29 2005, Simon Josefsson wrote:

> Reiner Steib <reinersteib+gmane@imap.cc> writes:
>> Shouldn't we drop (or defalias) `gnus-remove-duplicates' in favor of
>> `message-remove-duplicates'?  (We can safely require `message.el' in
>> Gnus code but not the other way round.)
[...]
> There is also mm-delete-duplicates, I'm not sure how it relates.

Unless someone can see a reason that we actually need the different
implementations, I'd suggest to replace the defun in `mm-util.el' with
this code:

--8<---------------cut here---------------start------------->8---
(if (fboundp 'delete-dups)
    (defalias 'mm-delete-duplicates 'delete-dups)
  (defun mm-delete-duplicates (list)
    "Destructively remove `equal' duplicates from LIST.
Store the result in LIST and return it.  LIST must be a proper list.
Of several `equal' occurrences of an element in LIST, the first
one is kept.

This is a compatibility function for Emacsen without `delete-dups'."
    ;; Code from `subr.el' in Emacs 22:
    (let ((tail list))
      (while tail
	(setcdr tail (delete (car tail) (cdr tail)))
	(setq tail (cdr tail))))
    list))
--8<---------------cut here---------------end--------------->8---

As `message.el' and `nnmail.el' already require `mm-util.el' we can
use `mm-delete-duplicates' there.

> Let's defalias it, in case external packages use g-r-d.

I doubt that there's any external use.  At least no package in XEmacs
Sumo uses it.  And in Gnus, it's only used once.  But I won't mind
something like this in `gnus-util.el':

--8<---------------cut here---------------start------------->8---
;; In case external packages use `gnus-remove-duplicates', we provide an
;; alias.  In new code, `mm-delete-duplicates' or `delete-dups' should be
;; used.
(defalias 'gnus-remove-duplicates 'mm-delete-duplicates)
--8<---------------cut here---------------end--------------->8---

Bye, Reiner.
-- 
       ,,,
      (o o)
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