TIP #404: LET MESSAGE CATALOGS GET THE LOCALE FROM THEIR FILE NAME 
====================================================================
 Version:        $Revision: 1.9 $
 Author:         Harald Oehlmann <harald.oehlmann_at_elmicron.de>
 State:          Final
 Type:           Project
 Tcl-Version:    8.6
 Vote:           Done
 Created:        Sunday, 17 July 2011
 URL:            https://tip.tcl-lang.org404.html
 Discussions-To: Tcl Core list
 Post-History:   

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 ABSTRACT 
==========

 This TIP proposes a mechanism for coupling locales more strongly to the 
 names of the files that define them, an already-recommended practice, 
 so as to make it less error-prone to produce message catalogs. 

 RATIONALE 
===========

 Current message catalog files are as follows: 

     * Catalog file name: /<locale>/ *.msg* 

     * Catalog folder: technically any, recommended: msgs in package 
       main folder. Must be specified to the command *mcload*. 

     * Catalog file contents: one command per translated item: 

           msgcat::mcset locale ori ?translation?

 Example with <locale> equal "de": 

   -de.msg-
   ::msgcat::mcset de Open Öffnen
   ::msgcat::mcset de Close Schliessen
   -eof-

 The same locale value (de) is contained in the file name and in each 
 *mcset* command. 

 This is technically unnecessary and error-prone. I found myself often 
 copying message file contents from one language to the next and not 
 setting the right locale in each *mcset* command. 

 The scope of this TIP is a new command similar to *mcset* which 
 determines the locale from the file name. 

 IMHO it makes no sense to specify the locale of *mcset* commands and 
 the locale in the file name different and thus separately. 

 SPECIFICATION 
===============

 MC FILE LOCALE 
----------------

 The *mc file locale* is a locale specified by the file name of a 
 message file. 

 Example: 

       Message catalogue file name: *de_ch.msg* 

       mc file locale: de_ch 

 The package *msgcat* maintains one value, *mc file locale*, with the 
 following properties: 

     * Its initial value is "" (the root locale). 

     * Before a message catalog file is sourced by the procedure 
       *::msgcat::mcload*, the *mc file locale* is extracted from the 
       message file name and stored as the current value. 

     * The *mc file locale* may be querried by the command 
       *::msgcat::mcconfig -mcfilelocale*. 

     * The *mc file locale* may also be set by the command 
       *::msgcat::mcconfig -mcfilelocale value*. 

     * The original message filename may /not/ be reconstructed by: 
       *[::msgcat::mcconfig -mcfilelocale].msg*; there can be case 
       differences. 

 The command *::msgcat::mcconfig* is shared with [TIP #399]. It has a 
 new option *-mcfilelocale*. 

 NEW COMMANDS 
--------------

 There are two new commands: 

     * *::msgcat::mcflset* /source/ ?/translation/? 

     * *::msgcat::mcflmset* /list/ 

 These work as: 

      ::msgcat::mcset [::msgcat::mcconfig -mcfilelocale] source ?translation?
      ::msgcat::mcmset [::msgcat::mcconfig -mcfilelocale] list

 The command name *mcflset* is an abreviation of: "*m*essage *c'atalogue 
 with *f*ile *l*ocale *set*". 

 EXAMPLE USAGES 
================

 The example of the Rationale section above may now be written as: 

   -de.msg-
   ::msgcat::mcflset Open Öffnen
   ::msgcat::mcflset Close Schliessen
   -eof-

 The locale value *de* only appears in the file name. 

 Further examples are in the tcl wiki msgcat page: 
 [<URL:http://wiki.tcl.tk/msgcat>] 

 REFERENCE IMPLEMENTATION 
==========================

 See Tcl Feature Request 3544988. 
 [<URL:http://sourceforge.net/support/tracker.php/?aid=3544988>] 

 COPYRIGHT 
===========

 This document has been placed in the public domain. 

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