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File Content: `Lines.pm`

package IO::Lines;

use strict;
use Carp;
use IO::ScalarArray;

# The package version, both in 1.23 style *and* usable by MakeMaker:
our $VERSION = '2.113';

# Inheritance:
our @ISA = qw(IO::ScalarArray);     ### also gets us new_tie  :-)


=head1 NAME

IO::Lines - IO:: interface for reading/writing an array of lines


=head1 SYNOPSIS

    use IO::Lines;

    ### See IO::ScalarArray for details


=head1 DESCRIPTION

This class implements objects which behave just like FileHandle
(or IO::Handle) objects, except that you may use them to write to
(or read from) an array of lines.  C<tiehandle> capable as well.

This is a subclass of L<IO::ScalarArray|IO::ScalarArray>
in which the underlying
array has its data stored in a line-oriented-format: that is,
every element ends in a C<"\n">, with the possible exception of the
final element.  This makes C<getline()> I<much> more efficient;
if you plan to do line-oriented reading/printing, you want this class.

The C<print()> method will enforce this rule, so you can print
arbitrary data to the line-array: it will break the data at
newlines appropriately.

See L<IO::ScalarArray> for full usage and warnings.

=cut


#------------------------------
#
# getline
#
# Instance method, override.
# Return the next line, or undef on end of data.
# Can safely be called in an array context.
# Currently, lines are delimited by "\n".
#
sub getline {
    my $self = shift;

    if (!defined $/) {
	return join( '', $self->_getlines_for_newlines );
    }
    elsif ($/ eq "\n") {
	if (!*$self->{Pos}) {      ### full line...
	    return *$self->{AR}[*$self->{Str}++];
	}
	else {                     ### partial line...
	    my $partial = substr(*$self->{AR}[*$self->{Str}++], *$self->{Pos});
	    *$self->{Pos} = 0;
	    return $partial;
	}
    }
    else {
	croak 'unsupported $/: must be "\n" or undef';
    }
}

#------------------------------
#
# getlines
#
# Instance method, override.
# Return an array comprised of the remaining lines, or () on end of data.
# Must be called in an array context.
# Currently, lines are delimited by "\n".
#
sub getlines {
    my $self = shift;
    wantarray or croak("can't call getlines in scalar context!");

    if ((defined $/) and ($/ eq "\n")) {
	return $self->_getlines_for_newlines(@_);
    }
    else {         ### slow but steady
	return $self->SUPER::getlines(@_);
    }
}

#------------------------------
#
# _getlines_for_newlines
#
# Instance method, private.
# If $/ is newline, do fast getlines.
# This CAN NOT invoke getline!
#
sub _getlines_for_newlines {
    my $self = shift;
    my ($rArray, $Str, $Pos) = @{*$self}{ qw( AR Str Pos ) };
    my @partial = ();

    if ($Pos) {				### partial line...
	@partial = (substr( $rArray->[ $Str++ ], $Pos ));
	*$self->{Pos} = 0;
    }
    *$self->{Str} = scalar @$rArray;	### about to exhaust @$rArray
    return (@partial,
	    @$rArray[ $Str .. $#$rArray ]);	### remaining full lines...
}

#------------------------------
#
# print ARGS...
#
# Instance method, override.
# Print ARGS to the underlying line array.
#
sub print {
    if (defined $\ && $\ ne "\n") {
	croak 'unsupported $\: must be "\n" or undef';
    }

    my $self = shift;
    ### print STDERR "\n[[ARRAY WAS...\n", @{*$self->{AR}}, "<<EOF>>\n";
    my @lines = split /^/, join('', @_); @lines or return 1;

    ### Did the previous print not end with a newline?
    ### If so, append first line:
    if (@{*$self->{AR}} and (*$self->{AR}[-1] !~ /\n\Z/)) {
	*$self->{AR}[-1] .= shift @lines;
    }
    push @{*$self->{AR}}, @lines;       ### add the remainder
    ### print STDERR "\n[[ARRAY IS NOW...\n", @{*$self->{AR}}, "<<EOF>>\n";
    1;
}

#------------------------------
1;

__END__


=head1 VERSION

$Id: Lines.pm,v 1.3 2005/02/10 21:21:53 dfs Exp $


=head1 AUTHOR

Eryq (F<eryq@zeegee.com>).
President, ZeeGee Software Inc (F<http://www.zeegee.com>).

=head1 CONTRIBUTORS

Dianne Skoll (F<dfs@roaringpenguin.com>).

=head1 COPYRIGHT & LICENSE

Copyright (c) 1997 Erik (Eryq) Dorfman, ZeeGee Software, Inc. All rights reserved.

This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.

=cut
Name	Size	Permission
AtomicFile.pm	5370 bytes	0444
InnerFile.pm	7041 bytes	0444
Lines.pm	4170 bytes	0444
Scalar.pm	15028 bytes	0444
ScalarArray.pm	16447 bytes	0444
Stringy.pm	1821 bytes	0444
Wrap.pm	8789 bytes	0444
WrapTie.pm	14716 bytes	0444
File Content: Lines.pm

File Content: `Lines.pm`
