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# Copyright (C) 2003-2018 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 <https://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;