Mooseでデザパタ - Adapterパターン
{
package Banner;
use Moose;
use Perl6::Say;
has string => ( is => 'rw', isa => 'Str', required => 1 );
sub show_with_paren {
my $self = shift;
say '( ' . $self->string . ' )';
}
sub show_with_aster {
my $self = shift;
say '* ' . $self->string . ' *';
}
}
{
package PrintBanner;
use Moose;
has string => ( is => 'rw', isa => 'Str', required => 1 );
has banner => (
is => 'rw',
default => sub {
Banner->new( string => (shift)->string );
},
handles => {
print1 => 'show_with_paren',
print2 => 'show_with_aster'
},
lazy => 1,
);
}
# 委譲を使ったAdapterパターンの実行例
# print1 print2 インターフェイスで既存の
# showWithParen showWithAsterを使用している
my $p = PrintBanner->new( string => "Hello" );
$p->print1;
$p->print2;
Moose的なポイントは、
- handlesで委譲を実現している点
です
