Re: trunk r115036: * lisp/progmodes/ruby-mode.el (ruby-mode-set-encoding): Use

[Dmitry Gutov]

On 08.11.2013 20:23, Bozhidar Batsov wrote:
> I had a last minute change of heart regarding this. Based on my
> observations much more Ruby hackers use ruby-style encoding comments, so
> I thought this makes more sense as a default. AFAIK the Emacs encoding
> comments made a lot of difference in the pre-Emacs 24 era, but are not
> that important now.

I don't really know the history of this feature, but it seems to be the 
most popular/useful for the Japanese users, and they're not very visible 
on emacs-devel or the bug tracker. Maybe it's nothing.

My stance is purely based on the long-standing (and often criticized, 
sure) Emacs tradition to not change the defaults without solid reasons.

>      > +  "The style of the magic encoding comment to use."
>      > +  :type '(choice
>      > +          (const :tag "Emacs Style" emacs)
>      > +          (const :tag "Ruby Style" ruby)
>      > +          (const :tag "Custom Style" custom))
>      > +  :group 'ruby)
>      > +
>      > +(defcustom ruby-custom-encoding-magic-comment-template "#
>     coding: %s"
>
>     The way this template is duplicated below for the `ruby' case doesn't
>     look too nice.  Since you went ahead with symbol-based customization,
>     why not drop the "custom" case?
>
>
> I'm not sure what exactly the problem is with the current code. Someone
> might want to use a different encoding format, so the custom option
> seems reasonable to me. The default value of the custom template doesn't
> really matter as users interested in using a custom format will surely
> alter it.

My point is:

1) The `custom' option won't be used too often, if at all.
2) Even if that option stays, using whole two variables is an overkill, 
you can just replace the symbols inside the :type form with their 
corresponding template values and thus eliminate the `case' form below.

>      > -                     (insert "# -*- coding: " coding-system "
>     -*-\n"))))
>      > +                     (let ((encoding-magic-comment-template
>      > +                            (case ruby-encoding-magic-comment-style
>      > +                              ('ruby "# coding: %s")
>      > +                              ('emacs "# -*- coding: %s -*-")
>      > +                              ('custom

These are rather minor issues, so I'm not going to argue them further.