Re: defcustom :version

[Reiner Steib]

On Sat, Mar 11 2006, Bill Wohler wrote:

> We don't use any :version keywords in the MH-E package at the moment,
> although I'd like to add them. Before doing so, I hope you can help me
> answer a couple of questions about them.
>
> First, how are people using the defcustom :version keyword?

Maybe you already know this but... you don't need to add the keyword
to each variable: You can also add it to the custom group. 

> The big problem I have with them is that it seems we have to use the
> Emacs version. That makes them pretty useless for the MH-E package which
> has turned three *major* releases and a score of minor releases since
> Emacs 21 came out. In the past few years, I would have used 21.4, 21.5,
> 22.0, and 22.1 as the "next" version kept creeping up. How would I have
> documented the variables? [...]
>
> I see the Gnus folks are using the Emacs version in their
> variables. 

Admittedly, many Gnus developers weren't aware of :version, so I added
many of version numbers after Jan D. pointed it out on emacs-devel
after Gnus was updated there.

> How have you folks answered these questions?

Not really an answer to the questions you raised, but this is how I
suggest to handle it in Gnus:

,----[ (info "(gnus-coding)Gnus Maintainance Guide") ]
| For new customizable variables introduced in Oort Gnus (including the
| v5-10 branch) use `:version "22.1" ;; Oort Gnus' including the comment.
| If the variable is new in No Gnus use `:version "23.0" ;; No Gnus'.
`----

> Unless, of course, folks think is reasonable and proper that large
> independent packages that happen to be bundled with Emacs can use their
> versions with the defcustom :version keyword.

This only would make sense if `customize-changed-options' could handle
such "package versions".  Maybe extending the format to allow plists
such as...

  :version '(:emacs 22.1 :mh-e 7.0)
  :version '(:emacs 22.1 :gnus 5.10.2)

("mh-e" / "gnus" could either refer to the package or to a
customization group.  The later might be difficult for Gnus because
not everything included in Gnus is within the `gnus' customization
group)

Limiting `customize-changed-options' to certain custom groups (and
subgroups) would be useful independent of extending :version keyword.

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