How are etc/*.map files used?

How are etc/*.map files used?

[Eli Zaretskii]

The file etc/charsets/README says nothing about the intended usage of
the *.map files in there, it just tells how to generate those files.
Are we using these files somehow, and if so, where?

I bumped into an email today that used IBM037 charset, which I
couldn't read until I manually made a coding-system-alias for it from
EBCDIC (which isn't quite right).  But etc/charsets/IBM037.map does
exists, so it sounds like Emacs ought to support that encoding.

What am I missing?

Re: How are etc/*.map files used?

[Andreas Schwab]

Eli Zaretskii <eliz@gnu.org> writes:

> The file etc/charsets/README says nothing about the intended usage of
> the *.map files in there, it just tells how to generate those files.
> Are we using these files somehow, and if so, where?

See define-charset.

Andreas.

-- 
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
"And now for something completely different."

Re: How are etc/*.map files used?

[Eli Zaretskii]

> From: Andreas Schwab <schwab@linux-m68k.org>
> Cc: emacs-devel@gnu.org
> Date: Fri, 12 Aug 2011 15:08:11 +0200
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > The file etc/charsets/README says nothing about the intended usage of
> > the *.map files in there, it just tells how to generate those files.
> > Are we using these files somehow, and if so, where?
> 
> See define-charset.

Thanks.

Re: How are etc/*.map files used?

[Kenichi Handa]

In article <83zkjex1ru.fsf@gnu.org>, Eli Zaretskii <eliz@gnu.org> writes:

> The file etc/charsets/README says nothing about the intended usage of
> the *.map files in there, it just tells how to generate those files.
> Are we using these files somehow, and if so, where?

They are used to define a charset as a :map argument of
define-charset.

> I bumped into an email today that used IBM037 charset, which I
> couldn't read until I manually made a coding-system-alias for it from
> EBCDIC (which isn't quite right).  But etc/charsets/IBM037.map does
> exists, so it sounds like Emacs ought to support that encoding.

Perhaps I just forgot to define a charset from that map in
mule-conf.el.

You can define the charset and the corresponding
coding-system as this:

(define-charset 'ibm037 "IBM037"
  :code-space [0 255]
  :map "IBM037")
(define-coding-system 'ibm037 "IBM037"
  :coding-type 'charset
  :mnemonic ??         ;; You must find an appropriate mnemonic letter
  :charset-list '(ibm037))

Then, for instance:

(encode-coding-string "012abc" 'ibm037) => "\360\361\362\201\202\203"

---
Kenichi Handa
handa@m17n.org