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
|
package Class::MakeMethods::Template::StructBuiltin;
use Class::MakeMethods::Template::Generic '-isasubclass';
$VERSION = 1.008;
use strict;
require 5.00;
use Carp;
=head1 NAME
Class::MakeMethods::Template::StructBuiltin
=head1 SYNOPSIS
use Class::MakeMethods::Template::StructBuiltin (
-TargetClass => 'MyStat',
builtin_isa => [
'-{new_function}'=>'stat',
qw/ dev ino mode nlink /
]
);
=head1 DESCRIPTION
This class generates a wrapper around some builtin function,
storing the results in the object and providing a by-name interface.
Takes a (core) function name, and a arrayref of return position names
(we will call it pos_list). Creates:
=over 4
=item new
Calls the core func with any given arguments, stores the result in the
instance.
=item x
For each member of pos_list, creates a method of the same name which
gets/sets the nth member of the returned list, where n is the position
of x in pos_list.
=item fields
Returns pos_list, in the given order.
=item dump
Returns a list item name, item value, in order.
=back
Example Usage:
package Stat;
use Class::MakeMethods::Template::StructBuiltin
builtin_isa => [ '-{new_function}'=>'stat', qw/ dev ino mode nlink / ],
package main;
my $file = "$ENV{HOME}/.template";
my $s = Stat->new($file);
print "File $file has ", $s->nlink, " links\n";
Note that (a) the new method does not check the return value of the
function called (in the above example, if $file does not exist, you will
silently get an empty object), and (b) if you really want the above
example, see the core File::stat module. But you get the idea, I hope.
=cut
sub builtin_isa {
( {
'template' => {
default => {
'*'=>'get_set', 'dump'=>'dump', 'fields'=>'fields', 'new'=>'new_builtin'
},
},
'behavior' => {
'-init' => sub {
my $m_info = $_[0];
$m_info->{class} ||= $m_info->{target_class};
my $class_info =
( $Class::MakeMethods::Struct::builtin{$m_info->{class}} ||= [] );
if ( ! defined $m_info->{array_index} ) {
foreach ( 0..$#$class_info ) {
if ( $class_info->[$_] eq $m_info->{'name'} ) {
$m_info->{array_index} = $_; last }
}
if ( ! defined $m_info->{array_index} ) {
push @ $class_info, $m_info->{'name'};
$m_info->{array_index} = $#$class_info;
}
}
if (defined $m_info->{new_function} and ! ref $m_info->{new_function}) {
# NOTE Below comments found in original version of MethodMaker. -Simon
# Cuz neither \&{"CORE::$func"} or $CORE::{$func} work ... N.B. this
# only works for core functions that take only one arg. But I can't
# quite figure out how to pass in the list without it getting
# evaluated in a scalar context. Hmmm.
$m_info->{new_function} = eval "sub {
scalar \@_ ? CORE::$m_info->{new_function}(shift)
: CORE::$m_info->{new_function}
}";
}
return;
},
'new_builtin' => sub { my $m_info = $_[0]; sub {
my $class = shift;
my $function = $m_info->{new_function};
my $self = [ &$function(@_) ];
bless $self, $class;
}},
'fields' => sub { my $m_info = $_[0]; sub {
my $class_info =
( $Class::MakeMethods::Struct::builtin{$m_info->{class}} ||= [] );
@$class_info;
}},
'dump' => sub { my $m_info = $_[0]; sub {
my $self = shift;
my $class_info =
( $Class::MakeMethods::Struct::builtin{$m_info->{class}} ||= [] );
my @keys = @$class_info;
map ($keys[$_], $self->[$_]), 0 .. $#keys;
}},
'get_set' => sub { my $m_info = $_[0]; sub {
my $self = shift;
if ( @_ ) {
$self->[ $m_info->{array_index} ] = shift;
}
$self->[ $m_info->{array_index} ];
}},
},
} )
}
1;
|
