1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
|
package IO::Lines;
=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. They can be tiehandle'd 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
use Carp;
use strict;
use IO::ScalarArray;
use vars qw($VERSION @ISA);
# The package version, both in 1.23 style *and* usable by MakeMaker:
$VERSION = "2.110";
# Inheritance:
@ISA = qw(IO::ScalarArray); ### also gets us new_tie :-)
#------------------------------
#
# 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 AUTHORS
=head2 Primary Maintainer
David F. Skoll (F<dfs@roaringpenguin.com>).
=head2 Principal author
Eryq (F<eryq@zeegee.com>).
President, ZeeGee Software Inc (F<http://www.zeegee.com>).
=head2 Other contributors
Thanks to the following individuals for their invaluable contributions
(if I've forgotten or misspelled your name, please email me!):
I<Morris M. Siegel,>
for his $/ patch and the new C<getlines()>.
I<Doug Wilson,>
for the IO::Handle inheritance and automatic tie-ing.
=cut
|
