# TWiki Enterprise Collaboration Platform, http://TWiki.org/

 #

 # Copyright (C) 1999-2007 TWiki Contributors. All Rights Reserved.

 # TWiki Contributors are listed in the AUTHORS file in the root of

 # this distribution.

 # NOTE: Please extend that file, not this notice.

 #

 # Additional copyrights apply to some or all of the code in this

 # file as follows:

 # Copyright (C) 2005 Martin Cleaver.

 #

 # This program is free software; you can redistribute it and/or

 # modify it under the terms of the GNU General Public License

 # as published by the Free Software Foundation; either version 2

 # of the License, or (at your option) any later version. For

 # more details read LICENSE in the root of this distribution.

 #

 # This program is distributed in the hope that it will be useful,

 # but WITHOUT ANY WARRANTY; without even the implied warranty of

 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

 #

 # As per the GPL, removal of this notice is prohibited.

 =pod

 ---+ package TWiki::Plurals

 Handle conversion of plural topic names to singular form.

 =cut

 package TWiki::Plurals;

 use strict;

 =pod

 ---++ StaticMethod singularForm($web, $pluralForm) -> $singularForm

 Try to singularise plural topic name.

    * =$web= - the web the topic must be in

    * =$pluralForm= - topic name

 Returns undef if no singular form exists, otherwise returns the

 singular form of the topic

 I18N - Only apply plural processing if site language is English, or

 if a built-in English-language web (Main, TWiki or Plugins).  Plurals

 apply to names ending in 's', where topic doesn't exist with plural

 name.

 SMELL: this is highly langauge specific, and shoud be overridable

 on a per-installation basis.

 =cut

 sub singularForm {

     my( $web, $pluralForm ) = @_;

     $web =~ s#\.#/#go;

     # SMELL Plural processing should be set per web

     # SMELL Lang settings should be set per web

     return undef unless( $TWiki::cfg{PluralToSingular} );

     return undef unless( $pluralForm =~ /s$/ );

     return undef unless( !defined($TWiki::cfg{Site}{Lang}) or

                            $TWiki::cfg{Site}{Lang} eq 'en'

                              or $web eq $TWiki::cfg{UsersWebName}

                                or $web eq $TWiki::cfg{SystemWebName} );

     # Topic name is plural in form

     my $singularForm = $pluralForm;

     $singularForm =~ s/ies$/y/;      # plurals like policy / policies

     $singularForm =~ s/sses$/ss/;    # plurals like address / addresses

     $singularForm =~ s/ches$/ch/;    # plurals like search / searches

     $singularForm =~ s/(oes|os)$/o/; # plurals like veto / vetoes

     $singularForm =~ s/([Xx])es$/$1/;# plurals like box / boxes

     $singularForm =~ s/([^s])s$/$1/; # others, excluding ss like address(es)

     return $singularForm

 }

 1;