the -*-coding: -*- stuff doesn't check for invalid codings

the -*-coding: -*- stuff doesn't check for invalid codings

[Dan Jacobson]

No error is reported to the user if he uses
;-*-coding: utf8;-*-
instead of
;-*-coding: utf-8;-*-

I.e., the -*-coding: -*- stuff doesn't check for invalid codings.

Re: the -*-coding: -*- stuff doesn't check for invalid codings

[Kevin Rodgers]

Dan Jacobson wrote:
> No error is reported to the user if he uses
> ;-*-coding: utf8;-*-
> instead of
> ;-*-coding: utf-8;-*-
> 
> I.e., the -*-coding: -*- stuff doesn't check for invalid codings.

Sure it does, it just doesn't report it (see set-auto-coding):

	      (or (coding-system-p coding-system)
		  (setq coding-system nil))

Is (error "Invalid coding system: %s" coding-system) really what
we want?

-- 
Kevin Rodgers

Re: the -*-coding: -*- stuff doesn't check for invalid codings

[Kevin Rodgers]

 >> I.e., the -*-coding: -*- stuff doesn't check for invalid codings.
 >
 > Sure it does, it just doesn't report it (see set-auto-coding):
 >
 >           (or (coding-system-p coding-system)
 >               (setq coding-system nil))
 >
 > Is (error "Invalid coding system: %s" coding-system) really what
 > we want instead of (setq coding-system nil)?

I think it would be better to signal an error there than to fall back on
the default coding system, since the author of the file clearly intends
that a specific coding system be used.

-- 
Kevin Rodgers

Re: the -*-coding: -*- stuff doesn't check for invalid codings

[Juanma Barranquero]

On 7/14/05, Kevin Rodgers <ihs_4664@yahoo.com> wrote:

> I think it would be better to signal an error there than to fall back on
> the default coding system, since the author of the file clearly intends
> that a specific coding system be used.

>From the Python docs:

"If a comment in the first or second line of the Python script matches
the regular expression coding[=:]\s*([-\w.]+), this comment is
processed as an encoding declaration; the first group of this
expression names the encoding of the source code file. The recommended
forms of this expression are

  # -*- coding: <encoding-name> -*-

which is recognized also by GNU Emacs, and 

  # vim:fileencoding=<encoding-name>

which is recognized by Bram Moolenaar's VIM."

The Python encodings are largely those of Emacs, but with some
differences. For example, coding: latin_1 is valid for Python,
unrecognized by Emacs.

Not sure whether this is an argument for throwing an error, or adding
more aliases to Emacs encodings, though.

-- 
                    /L/e/k/t/u