lib/perl5/5.6.1/I18N/Collate.pm

   1 package I18N::Collate;
   2
   3 =head1 NAME
   4
   5 I18N::Collate - compare 8-bit scalar data according to the current locale
   6
   7   ***
   8
   9   WARNING: starting from the Perl version 5.003_06
  10   the I18N::Collate interface for comparing 8-bit scalar data
  11   according to the current locale
  12
  13         HAS BEEN DEPRECATED
  14
  15   That is, please do not use it anymore for any new applications
  16   and please migrate the old applications away from it because its
  17   functionality was integrated into the Perl core language in the
  18   release 5.003_06.
  19
  20   See the perllocale manual page for further information.
  21
  22   ***
  23
  24 =head1 SYNOPSIS
  25
  26     use I18N::Collate;
  27     setlocale(LC_COLLATE, 'locale-of-your-choice');
  28     $s1 = new I18N::Collate "scalar_data_1";
  29     $s2 = new I18N::Collate "scalar_data_2";
  30
  31 =head1 DESCRIPTION
  32
  33 This module provides you with objects that will collate
  34 according to your national character set, provided that the
  35 POSIX setlocale() function is supported on your system.
  36
  37 You can compare $s1 and $s2 above with
  38
  39     $s1 le $s2
  40
  41 to extract the data itself, you'll need a dereference: $$s1
  42
  43 This module uses POSIX::setlocale(). The basic collation conversion is
  44 done by strxfrm() which terminates at NUL characters being a decent C
  45 routine.  collate_xfrm() handles embedded NUL characters gracefully.
  46
  47 The available locales depend on your operating system; try whether
  48 C<locale -a> shows them or man pages for "locale" or "nlsinfo" or the
  49 direct approach C<ls /usr/lib/nls/loc> or C<ls /usr/lib/nls> or
  50 C<ls /usr/lib/locale>.  Not all the locales that your vendor supports
  51 are necessarily installed: please consult your operating system's
  52 documentation and possibly your local system administration.  The
  53 locale names are probably something like C<xx_XX.(ISO)?8859-N> or
  54 C<xx_XX.(ISO)?8859N>, for example C<fr_CH.ISO8859-1> is the Swiss (CH)
  55 variant of French (fr), ISO Latin (8859) 1 (-1) which is the Western
  56 European character set.
  57
  58 =cut
  59
  60 # I18N::Collate.pm
  61 #
  62 # Author:       Jarkko Hietaniemi <F<jhi@iki.fi>>
  63 #               Helsinki University of Technology, Finland
  64 #
  65 # Acks:         Guy Decoux <F<decoux@moulon.inra.fr>> understood
  66 #               overloading magic much deeper than I and told
  67 #               how to cut the size of this code by more than half.
  68 #               (my first version did overload all of lt gt eq le ge cmp)
  69 #
  70 # Purpose:      compare 8-bit scalar data according to the current locale
  71 #
  72 # Requirements: Perl5 POSIX::setlocale() and POSIX::strxfrm()
  73 #
  74 # Exports:      setlocale 1)
  75 #               collate_xfrm 2)
  76 #
  77 # Overloads:    cmp # 3)
  78 #
  79 # Usage:        use I18N::Collate;
  80 #               setlocale(LC_COLLATE, 'locale-of-your-choice'); # 4)
  81 #               $s1 = new I18N::Collate "scalar_data_1";
  82 #               $s2 = new I18N::Collate "scalar_data_2";
  83 #
  84 #               now you can compare $s1 and $s2: $s1 le $s2
  85 #               to extract the data itself, you need to deref: $$s1
  86 #
  87 # Notes:
  88 #               1) this uses POSIX::setlocale
  89 #               2) the basic collation conversion is done by strxfrm() which
  90 #                  terminates at NUL characters being a decent C routine.
  91 #                  collate_xfrm handles embedded NUL characters gracefully.
  92 #               3) due to cmp and overload magic, lt le eq ge gt work also
  93 #               4) the available locales depend on your operating system;
  94 #                  try whether "locale -a" shows them or man pages for
  95 #                  "locale" or "nlsinfo" work or the more direct
  96 #                  approach "ls /usr/lib/nls/loc" or "ls /usr/lib/nls".
  97 #                  Not all the locales that your vendor supports
  98 #                  are necessarily installed: please consult your
  99 #                  operating system's documentation.
 100 #                  The locale names are probably something like
 101 #                  'xx_XX.(ISO)?8859-N' or 'xx_XX.(ISO)?8859N',
 102 #                  for example 'fr_CH.ISO8859-1' is the Swiss (CH)
 103 #                  variant of French (fr), ISO Latin (8859) 1 (-1)
 104 #                  which is the Western European character set.
 105 #
 106 # Updated:      19961005
 107 #
 108 # ---
 109
 110 use POSIX qw(strxfrm LC_COLLATE);
 111 use warnings::register;
 112
 113 require Exporter;
 114
 115 @ISA = qw(Exporter);
 116 @EXPORT = qw(collate_xfrm setlocale LC_COLLATE);
 117 @EXPORT_OK = qw();
 118
 119 use overload qw(
 120 fallback        1
 121 cmp             collate_cmp
 122 );
 123
 124 sub new {
 125   my $new = $_[1];
 126
 127   if (warnings::enabled() && $] >= 5.003_06) {
 128     unless ($please_use_I18N_Collate_even_if_deprecated) {
 129       warnings::warn <<___EOD___;
 130 ***
 131
 132   WARNING: starting from the Perl version 5.003_06
 133   the I18N::Collate interface for comparing 8-bit scalar data
 134   according to the current locale
 135
 136         HAS BEEN DEPRECATED
 137
 138   That is, please do not use it anymore for any new applications
 139   and please migrate the old applications away from it because its
 140   functionality was integrated into the Perl core language in the
 141   release 5.003_06.
 142
 143   See the perllocale manual page for further information.
 144
 145 ***
 146 ___EOD___
 147       $please_use_I18N_Collate_even_if_deprecated++;
 148     }
 149   }
 150
 151   bless \$new;
 152 }
 153
 154 sub setlocale {
 155  my ($category, $locale) = @_[0,1];
 156
 157  POSIX::setlocale($category, $locale) if (defined $category);
 158  # the current $LOCALE
 159  $LOCALE = $locale || $ENV{'LC_COLLATE'} || $ENV{'LC_ALL'} || '';
 160 }
 161
 162 sub C {
 163   my $s = ${$_[0]};
 164
 165   $C->{$LOCALE}->{$s} = collate_xfrm($s)
 166     unless (defined $C->{$LOCALE}->{$s}); # cache when met
 167
 168   $C->{$LOCALE}->{$s};
 169 }
 170
 171 sub collate_xfrm {
 172   my $s = $_[0];
 173   my $x = '';
 174
 175   for (split(/(\000+)/, $s)) {
 176     $x .= (/^\000/) ? $_ : strxfrm("$_\000");
 177   }
 178
 179   $x;
 180 }
 181
 182 sub collate_cmp {
 183   &C($_[0]) cmp &C($_[1]);
 184 }
 185
 186 # init $LOCALE
 187
 188 &I18N::Collate::setlocale();
 189
 190 1; # keep require happy