1MooseX::SetOnce(3)    User Contributed Perl Documentation   MooseX::SetOnce(3)
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NAME

6       MooseX::SetOnce - write-once, read-many attributes for Moose
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VERSION

9       version 0.201
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SYNOPSIS

12       Add the "SetOnce" trait to attributes:
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14         package Class;
15         use Moose;
16         use MooseX::SetOnce;
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18         has some_attr => (
19           is     => 'rw',
20           traits => [ qw(SetOnce) ],
21         );
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23       ...and then you can only set them once:
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25         my $object = Class->new;
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27         $object->some_attr(10);  # works fine
28         $object->some_attr(20);  # throws an exception: it's already set!
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DESCRIPTION

31       The 'SetOnce' attribute lets your class have attributes that are not
32       lazy and not set, but that cannot be altered once set.
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34       The logic is very simple:  if you try to alter the value of an
35       attribute with the SetOnce trait, either by accessor or writer, and the
36       attribute has a value, it will throw an exception.
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38       If the attribute has a clearer, you may clear the attribute and set it
39       again.
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AUTHOR

42       Ricardo SIGNES <rjbs@semiotic.systems>
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CONTRIBUTORS

45       •   Jesse Luehrs <doy@tozt.net>
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47       •   Karen Etheridge <ether@cpan.org>
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49       •   Kent Fredric <kentfredric@gmail.com>
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52       This software is copyright (c) 2021 by Ricardo SIGNES.
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54       This is free software; you can redistribute it and/or modify it under
55       the same terms as the Perl 5 programming language system itself.
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59perl v5.34.0                      2021-07-22                MooseX::SetOnce(3)
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