Re: Emacs i18n

[Paul Eggert <eggert@cs.ucla.edu>]

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On 3/25/19 2:32 PM, Juri Linkov wrote:
> I don't know where to put i18n related code, so since ngettext should
> have C calls anyway, I moved it to editfns.c near the function ‘message’
> where it still just returns the correct plurals without doing any translation.

That stub had some problems:

1. It lacked documentation in the Elisp manual. Important changes like
this should be documented -- to some extent the documentation is even
more important than the code. Can you write something?

2. While you're thinking about (1) here are some other questions. How
will ngettext determine the message catalog? Is the catalog visible to
users as a global variable, or as a hidden part of the global state, or
is it something explicit? How will catalogs from multiple packages be
used? How would a multi-lingual application work in Emacs if the message
catalog is part of global state? This seems to be a crucial issue, I'd
say. For example, should Emacs export dcngettext to Lisp code, instead
of just plain ngettext? (Emacs could then define ngettext in terms of
dcngettext.)

3. User C code is not supposed to inspect the _LIBC macro; that's for
glibc internal use. In Emacs _LIBC should be used only with code shared
with glibc, and we should assume _LIBC is never defined when files are
compiled for Emacs.

4. The stub doesn't work with bignums.

5. When calling the C-level ngettext, strings are not properly recoded.

I fixed (3) and (4), and temporarily worked around (5), by installing
the attached patch. To do a better job with (2) and (5) please see the
gettext manual's instructions for package maintainers, here:

https://www.gnu.org/software/gettext/manual/gettext.html#Maintainers

To my mind (1) and (2) are the most-pressing problems.


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From a361c54b8339ad79f65e924c4a1f7bbcdb1859e2 Mon Sep 17 00:00:00 2001
From: Paul Eggert <eggert@cs.ucla.edu>
Date: Mon, 25 Mar 2019 15:20:20 -0700
Subject: [PATCH] Port recent ngettext stub to non-glibc
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

* src/editfns.c: Don’t try to call glibc ngettext;
we’re not ready for that yet.
(Fngettext): Do not restrict integer arguments to fixnums.
Improve doc string a bit.
---
 src/editfns.c | 34 +++++++++-------------------------
 1 file changed, 9 insertions(+), 25 deletions(-)

diff --git a/src/editfns.c b/src/editfns.c
index ab48cdb6fd..bfffadc733 100644
--- a/src/editfns.c
+++ b/src/editfns.c
@@ -53,12 +53,6 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
 #include "window.h"
 #include "blockinput.h"
 
-#ifdef _LIBC
-# include <libintl.h>
-#else
-# include "gettext.h"
-#endif
-
 static void update_buffer_properties (ptrdiff_t, ptrdiff_t);
 static Lisp_Object styled_format (ptrdiff_t, Lisp_Object *, bool);
 
@@ -2845,30 +2839,20 @@ usage: (save-restriction &rest BODY)  */)
 /* i18n (internationalization).  */
 
 DEFUN ("ngettext", Fngettext, Sngettext, 3, 3, 0,
-       doc: /* Return the plural form of the translation of the string.
-This function is similar to the `gettext' function as it finds the message
-catalogs in the same way.  But it takes two extra arguments.  The MSGID
-parameter must contain the singular form of the string to be converted.
-It is also used as the key for the search in the catalog.
-The MSGID_PLURAL parameter is the plural form.  The parameter N is used
-to determine the plural form.  If no message catalog is found MSGID is
-returned if N is equal to 1, otherwise MSGID_PLURAL.  */)
+       doc: /* Return the translation of MSGID (plural MSGID_PLURAL) depending on N.
+MSGID is the singular form of the string to be converted;
+use it as the key for the search in the translation catalog.
+MSGID_PLURAL is the plural form.  Use N to select the proper translation.
+If no message catalog is found, MSGID is returned if N is equal to 1,
+otherwise MSGID_PLURAL.  */)
   (Lisp_Object msgid, Lisp_Object msgid_plural, Lisp_Object n)
 {
   CHECK_STRING (msgid);
   CHECK_STRING (msgid_plural);
-  CHECK_FIXNUM (n);
+  CHECK_INTEGER (n);
 
-#ifdef _LIBGETTEXT_H
-  return build_string (ngettext (SSDATA (msgid),
-                                 SSDATA (msgid_plural),
-                                 XFIXNUM (n)));
-#else
-  if (XFIXNUM (n) == 1)
-    return msgid;
-  else
-    return msgid_plural;
-#endif
+  /* Placeholder implementation until we get our act together.  */
+  return EQ (n, make_fixnum (1)) ? msgid : msgid_plural;
 }
 \f
 DEFUN ("message", Fmessage, Smessage, 1, MANY, 0,
-- 
2.20.1