Re: customizing mm-charset-synonym-alist

[Katsumi Yamaoka <yamaoka@jpl.org>]

>>>>> In <v98xce2a54.fsf_-_@marauder.physik.uni-ulm.de>
>>>>>	Reiner Steib wrote:

> On Thu, Apr 26 2007, Katsumi Yamaoka wrote:

>> I've also made it use defcustom, so you can now customize the alist
>> easily.

> I think this is not a good idea.

> 1. `mm-charset-synonym-alist' is modified by mm-setup-codepage-*, so a
>    user will see "CHANGED outside Customize; operating on it here may be
>    unreliable."

Oops.  I fully agree to not making it a user option.

> ,----
>| ;; Initialize:
>| (mm-setup-codepage-iso-8859)
>| (mm-setup-codepage-ibm)
> `----

> 2. The initial value depends on the availability of charsets (lots of
>    `mm-coding-system-p's).  So it will change when using different
>    Emacs versions and flavors.  But if the user has customized it,
>    this conditionals are eliminated.

> IMHO, if we want a customizable variable, we should create a new
> variable (default: nil) and construct `mm-charset-synonym-alist' from
> the new one, `mm-codepage-iso-8859-list' and `mm-codepage-ibm-list'
> (using mm-setup-codepage-*).  A new setup function should check if the
> cdr of each element is a valid charset and add it to
> `mm-charset-synonym-alist'.

I see.  Otherwise, it might not be necessary that a variable has
ones like `(iso8859-1 . iso-8859-1)' since such ones are able to
be corrected easily by a hard-wired program.

> BTW, if former defvars are changed to defcustoms, the :version is the
> one when it's made customizable, not when the defvar was introduced.
> So ":version "21.1" is not correct.

I must keep it in mind.  Thank you.  Anyway, I've made
`mm-charset-synonym-alist' revert to using `defvar'.

Regards,