Re: documentation bug: Mule and MSDOS

[Eli Zaretskii]

> From: dirk janssen <dirkj@br905lap.ntz.uni-leipzig.de>
> Date: Tue, 27 Mar 2001 19:03:34 +0200
> 
> Here is a backtrack of my mental states :-)
> 1. I assumed I had to convert the buffer *after* it was read in

I don't understand why did you assume this.  Codepages are just
special encoding of their supported character sets, so what led you to
think that handling a codepage-encoded file should be fundamentally
different from how you handle a file encoded in, say, Latin-1?

> 2. I could find info on disabling multibyte, but not much on enabling
> it

??? I'm probably missing something because I don't see how is this
related to the problem of visiting files encoded in IBM codepages.

> 3. the MULE docs do not mention codepages at all, one has to go to the
> emacs on dos section.

The most efficient method of finding something in the manual is by
using the Info-index command (bound to `i' in Info mode).  If you use
that, you will find the information no matter where in the manual it
is located.

> this section then lists the `dos-codepage-setup'
> command, that is not available to me.

dos-codepage-setup doesn't do anything that is useful to Unix and
GNU/Linux systems.  You need codepage-setup, which is described right
next to dos-codepage-setup.

> 4. The other command `codepage-setup' does not change the display at
> all

As expected: a codepage is just a coding system, and codepage-setup
creates it and does nothing else, as the manual explains.  (If that
explanation is not clear, please suggest how to make it more clear.)
To use that coding system, you need to visit a file while forcing
Emacs to use that codeing system.  Here's the relevant excerpt from
the manual:

    By default, Emacs defines a coding system to support the current
    codepage.  To define a coding system for some other codepage (e.g., to
    visit a file written on a DOS machine in another country), use the `M-x
    codepage-setup' command.  It prompts for the 3-digit code of the
    codepage, with completion, then creates the coding system for the
    specified codepage.  You can then use the new coding system to read and
    write files, but you must specify it explicitly for the file command
    when you want to use it (*note Specify Coding::).

> even not when I next choose this as an encoding in the
> problematic buffer.

Again, as expected: setting the coding system of a buffer doesn't
change its contents.  This is the same as with any other coding
system, such as ISO-8859-1.

> 1. Make the MULE doc more `hands-on'. Currently, it tells me a whole
> lot about various options and possibilities, but too little about how
> I put it to use. 

I don't think this is possible in general: there are too many
different combinations of the ``primitive'' operations described in
the manual; describing them all, or even a large portion of them, in a
cookbook style fashion would be impractical.

> 2. In the mule docs, insert a section on `Reading international files
> from MS-DOS or Windows (codepages)'.

This is already done for the next version, here's the excerpt:

    A special class of coding systems, collectively known as
    "codepages", is designed to support text encoded by MS-Windows and
    MS-DOS software.  To use any of these systems, you need to create it
    with `M-x codepage-setup'.  *Note MS-DOS and MULE::.

This text sits right in the middle of a section that explains what
coding systems are and how to use them.