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

[Simon Josefsson <jas@extundo.com>]

Reiner Steib <reinersteib+gmane@imap.cc> writes:

> 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.

Yes, this sounds good.

>> 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---

Yes, I think that is good.  Perhaps instead use:

(define-obsolete-function-alias 'gnus-remove-duplicates 'mm-delete-duplicates)

Thanks,
Simon