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Delegates: Difference between revisions
added perl, hope it's right
(added perl, hope it's right) |
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Line 311:
{Application.exit 0}
end</lang>
=={{header|Perl}}==
{{trans|Python}}
<lang perl>use strict;
package Delegator;
sub new {
bless {}
}
sub operation {
my ($self) = @_;
if (defined $self->{delegate} && $self->{delegate}->can('thing')) {
$self->{delegate}->thing;
} else {
'default implementation';
}
}
1;
package Delegate;
sub new {
bless {};
}
sub thing {
'delegate implementation'
}
1;
package main;
# No delegate
my $a = Delegator->new;
$a->operation eq 'default implementation' or die;
# With a delegate that does not implement "thing"
$a->{delegate} = 'A delegate may be any object';
$a->operation eq 'default implementation' or die;
# With delegate that implements "thing"
$a->{delegate} = Delegate->new;
$a->operation eq 'delegate implementation' or die;</lang>
=={{header|PHP}}==
{{trans|Python}}
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