Wrap.pm

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Author : Stefano Lattarini
Date : 2012-03-04 15:44:46
Hash : 7df05a0b
Message : maint: require perl 5.6 throughout That version of perl is quite old already, so it should be OK to require it. More importantly, it is the older perl versions the developers can currently use for testing, thus it's safer and more honest to just require it throughout. And anyway, we were already requiring it in Automake::Getopt, which implied that both automake and aclocal wouldn't have worked in practice with an older perl version. See also the discussion related to automake bug#10925. * lib/Automake/ChannelDefs.pm: Adjusted to require perl 5.6. * lib/Automake/Channels.pm: Likewise. * lib/Automake/Condition.pm: Likewise. * lib/Automake/Configure_ac.pm: Likewise. * lib/Automake/DisjConditions.pm: Likewise. * lib/Automake/FileUtils.pm: Likewise. * lib/Automake/General.pm: Likewise. * lib/Automake/Item.pm: Likewise. * lib/Automake/ItemDef.pm: Likewise. * lib/Automake/Location.pm: Likewise. * lib/Automake/Options.pm: Likewise. * lib/Automake/Rule.pm: Likewise. * lib/Automake/RuleDef.pm: Likewise. * lib/Automake/Struct.pm: Likewise. * lib/Automake/VarDef.pm: Likewise. * lib/Automake/Variable.pm: Likewise. * lib/Automake/Version.pm: Likewise. * lib/Automake/Wrap.pm: Likewise. * lib/Automake/XFile.pm: Likewise.

lib/Automake/Wrap.pm

# Copyright (C) 2003-2012 Free Software Foundation, Inc.

# 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, or (at your option)
# any later version.

# 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.  See the
# GNU General Public License for more details.

# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

package Automake::Wrap;

use 5.006;
use strict;

require Exporter;
use vars '@ISA', '@EXPORT_OK';
@ISA = qw/Exporter/;
@EXPORT_OK = qw/wrap makefile_wrap/;

=head1 NAME

Automake::Wrap - a paragraph formatter

=head1 SYNOPSIS

  use Automake::Wrap 'wrap', 'makefile_wrap';

  print wrap ($first_ident, $next_ident, $end_of_line, $max_length,
              @values);

  print makefile_wrap ("VARIABLE = ", "    ", @values);

=head1 DESCRIPTION

This modules provide facility to format list of strings.  It is
comparable to Perl's L<Text::Wrap>, however we can't use L<Text::Wrap>
because some versions will abort when some word to print exceeds the
maximum length allowed.  (Ticket #17141, fixed in Perl 5.8.0.)

=head2 Functions

=over 4

=cut

# _tab_length ($TXT)
# ------------------
# Compute the length of TXT, counting tab characters as 8 characters.
sub _tab_length($)
{
  my ($txt) = @_;
  my $len = length ($txt);
  $len += 7 * ($txt =~ tr/\t/\t/);
  return $len;
}

=item C<wrap ($head, $fill, $eol, $max_len, @values)>

Format C<@values> as a block of text that starts with C<$head>,
followed by the strings in C<@values> separated by spaces or by
C<"$eol\n$fill"> so that the length of each line never exceeds
C<$max_len>.

The C<$max_len> constraint is ignored for C<@values> items which
are too big to fit alone one a line.

The constructed paragraph is C<"\n">-terminated.

=cut

sub wrap($$$$@)
{
  my ($head, $fill, $eol, $max_len, @values) = @_;

  my $result = $head;
  my $column = _tab_length ($head);

  my $fill_len = _tab_length ($fill);
  my $eol_len = _tab_length ($eol);

  my $not_first_word = 0;

  foreach (@values)
    {
      my $len = _tab_length ($_);

      # See if the new variable fits on this line.
      # (The + 1 is for the space we add in front of the value.).
      if ($column + $len + $eol_len + 1 > $max_len
	  # Do not break before the first word if it does not fit on
	  # the next line anyway.
	  && ($not_first_word || $fill_len + $len + $eol_len + 1 <= $max_len))
	{
	  # Start a new line.
	  $result .= "$eol\n" . $fill;
	  $column = $fill_len;
	}
      elsif ($not_first_word)
	{
	  # Add a space only if result does not already end
	  # with a space.
	  $_ = " $_" if $result =~ /\S\z/;
	  ++$len;
	}
      $result .= $_;
      $column += $len;
      $not_first_word = 1;
    }

  $result .= "\n";
  return $result;
}


=item C<makefile_wrap ($head, $fill, @values)>

Format C<@values> in a way which is suitable for F<Makefile>s.
This is comparable to C<wrap>, except C<$eol> is known to
be C<" \\">, and the maximum length has been hardcoded to C<72>.

A space is appended to C<$head> when this is not already
the case.

This can be used to format variable definitions or dependency lines.

  makefile_wrap ('VARIABLE =', "\t", @values);
  makefile_wrap ('rule:', "\t", @dependencies);

=cut

sub makefile_wrap ($$@)
{
  my ($head, $fill, @values) = @_;
  if (@values)
    {
      $head .= ' ' if $head =~ /\S\z/;
      return wrap $head, $fill, " \\", 72, @values;
    }
  return "$head\n";
}


1;

### Setup "GNU" style for perl-mode and cperl-mode.
## Local Variables:
## perl-indent-level: 2
## perl-continued-statement-offset: 2
## perl-continued-brace-offset: 0
## perl-brace-offset: 0
## perl-brace-imaginary-offset: 0
## perl-label-offset: -2
## cperl-indent-level: 2
## cperl-brace-offset: 0
## cperl-continued-brace-offset: 0
## cperl-label-offset: -2
## cperl-extra-newline-before-brace: t
## cperl-merge-trailing-else: nil
## cperl-continued-statement-offset: 2
## End:

kc3-lang/automake/lib/Automake/Wrap.pm

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kc3-lang/automake /lib/Automake/Wrap.pm