InstanceFlyweightPattern

The InstanceFlyweightPattern is an extreme form of the FlyweightPattern.

• Name: InstanceFlyweightPattern
• Classification: I have no clue.
• Motivation:
• Applicability: Replacing value types with immutable reference types while saving memory.
• Structure: ?
• Participants: ?
• Collaborations: ?
• Consequences: Decrease on memory usage; however, some calculations might become harder because of the inability to directly manipulate new instances as an optimization.
• Implementation: Memoize the 'new' method!
• Sample Code:

    #!/usr/bin/env perl
    package Integer;
    { my %ints;
     sub new {
        my $class = shift;
        my $self;
        unless(exists($self = $ints{$_[0]})){
             $self = bless {'int' => $_[0]}, $class;
        }
        $self;
     }
    }

• Known Uses: Numeric types come to mind.
• Related Patterns: ReverseFlyweightPattern, FlyweightPattern, SingletonPattern

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CategoryPattern