1Class::MethodMaker::scaUlsaerr(3C)ontributed Perl DocumeCnltaastsi:o:nMethodMaker::scalar(3)
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NAME

6       Class::Method::scalar - Create methods for handling a scalar value.
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SYNOPSIS

9         package MyClass;
10         use Class::MethodMaker
11           [ scalar => [qw/ a -static s /]];
12
13         sub new {
14           my $class = shift;
15           bless {}, $class;
16         }
17
18         package main;
19
20         my $m = MyClass->new;
21         my $a, $x;
22
23         $a = $m->a;       # *undef*
24         $x = $m->a_isset; # false
25         $a = $m->a(1);    # 1
26         $m->a(3);
27         $x = $m->a_isset; # true
28         $a = $m->a;       # 3
29         $a = $m->a(5);     # 5;
30         $m->a_reset;
31         $x = $m->a_isset; # false
32

DESCRIPTION

34       Creates methods to handle array values in an object.  For a component
35       named "x", by default creates methods "x", "x_reset", "x_isset",
36       "x_clear".
37
38       Methods available are:
39
40       "*"
41
42         $m->a(3);
43         $a = $m->a;       # 3
44         $a = $m->a(5);     # 5;
45
46       Created by default.  If an argument is provided, the component is set
47       to that value.  The method returns the value of the component (after
48       assignment to a provided value, if appropriate).
49
50       *_reset
51
52         $m->a_reset;
53
54       Created by default.  Resets the component back to its default.
55       Normally, this means that *_isset will return false, and "*" will
56       return undef.  If "-default" is in effect, then the component will be
57       set to the default value, and *_isset will return true.  If
58       "-default_ctor" is in effect, then the default subr will be invoked,
59       and its return value used to set the value of the component, and
60       *_isset will return true.
61
62       Advanced Note: actually, defaults are assigned as needed: typically,
63       the next time a the value of a component is read.
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65       *_isset
66
67         print $m->a_isset ? "true" : "false";
68
69       Created by default.  Whether the component is currently set.  This is
70       different from being defined; initially, the component is not set (and
71       if read, will return undef); it can be set to undef (which is a set
72       value, which also returns undef).  Having been set, the only way to
73       unset the component is with <*_reset>.
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75       If a default value is in effect, then <*_isset> will always return
76       true.
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78       *_clear
79
80         $m->a(5);
81         $a = $m->a;       # 5
82         $x = $m->a_isset; # true
83         $m->a_clear;
84         $a = $m->a;       # *undef*
85         $x = $m->a_isset; # true
86
87       Created by default.  A shorthand for setting to undef.  Note that the
88       component will be set to undef, not reset, so *_isset will return true.
89
90       *_get
91
92         package MyClass;
93         use Class::MethodMaker
94           [ scalar => [{'*_get' => '*_get'}, 'a'],
95             new    => new, ];
96
97         package main;
98         my $m = MyClass->new;
99         $m->a(3);
100         $a = $m->a_get;     # 3
101         $a = $m->a_get(5);  # 3; ignores argument
102         $a = $m->a_get(5);  # 3; unchanged by previous call
103
104       Created on request.  Retrieves the value of the component without
105       setting (ignores any arguments passed).
106
107       *_set
108
109         package MyClass;
110         use Class::MethodMaker
111           [ scalar => [{'*_set' => '*_set'}, 'a'],
112             new    => new, ];
113
114         package main;
115         my $m = MyClass->new;
116         $m->a(3);
117         $a = $m->a_set;     # *undef*
118         $a = $m->a_set(5);  # *undef*; value is set but not returned
119         $a = $m->a;         # 5
120
121       Created on request.  Sets the component to the first argument (or undef
122       if no argument provided).  Returns no value.
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126perl v5.32.0                      2020-07-28     Class::MethodMaker::scalar(3)
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