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# TeXLive::TLUtils.pm
# common functions for TeX Live Infrastructure
#
# Copyright 2007 Norbert Preining
# This file is licensed under the GNU General Public Licence version 2
# or any later version
#
# based on Fabrice Popineau's FileUtils.pm

package TeXLive::TLUtils;

=pod
=head1 NAME

TeXLive::TLUtils - utilities used in the TeX Live Infrastructure Modules

=head1 SYNOPSIS

  use TeXLive::TLUtils;

  TeXLive::TLUtils::sort_uniq(@list);
  TeXLive::TLUtils::push_uniq(\@list, @items);
  TeXLive::TLUtils::member($item, @list);
  TeXLive::TLUtils::debug($string);

=head1 DESCRIPTION

=cut

use File::Basename;

BEGIN {
  use Exporter ();
  use Cwd;
  use File::Path;
  use vars qw( @ISA @EXPORT_OK );
  @ISA = qw(Exporter);
  @EXPORT_OK = qw(
    &sort_uniq
    &push_uniq
  );
}

=pod

The C<sort_uniq> function sorts the given array and throws away multiple
occurrences of elements. It returns a sorted and unified array.

=cut

sub sort_uniq {
  my (@l) = @_;
  my ($e, $f, @r);
  $f = "";
  @l = sort(@l);
  foreach $e (@l) {
    if ($e ne $f) {
      $f = $e;
      push @r, $e;
    }
  }
  return @r;
}

=pod

The C<push_uniq> function pushes the last elements on the list referenced
by the first argument.

=cut

sub push_uniq {
  # can't we use $l as a reference, and then use my?  later ...
  local (*l, @le) = @_;
  foreach my $e (@le) {
    if (! &member($e, @l)) {
      push @l, $e;
    }
  }
}

=pod

The C<member> function returns true if the the first argument is contained
in the list of the remaining arguments.

=cut

sub member {
  my ($e, @l) = @_;
  my ($f);
  foreach $f (@l) {
    if ($e eq $f) {
      return 1;
    }
  }
  return 0;
}

=pod

The C<debug> function echos the argument string to STDERR in case that
the global varialbe C<opt_debug> is set.

=cut

sub debug {
  print STDERR @_ if ($::opt_debug);
}

1;

=pod

=head1 AUTHORS AND COPYRIGHT

This module and its documentation was written by 
Norbert Preining <F<preining@logic.at>> for the TeX Live distribution and both
are licensed under the GNU General Public License Version 2 or later.

=head1 SEE ALSO

The modules L<TeXLive::TLPSRC>, L<TeXLive::TLPOBJ>, 
L<TeXLive::TLPDB>, L<TeXLive::TLTREE>, and the
document L<Perl-API.txt> and the specification in the TeX Live
repository trunk/Master/tlpkg/doc/.

=cut

### Local Variables:
### perl-indent-level: 2
### tab-width: 2
### indent-tabs-mode: nil
### End:
# vim:set tabstop=2: #