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59 lines
1.2 KiB
Ruby
59 lines
1.2 KiB
Ruby
# The prototype pattern is a creational pattern along the lines of the factory.
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# The trick with the prototype is that you create new objects by copying a master
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# object. Change that master object and all subsequent objects that you create
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# will go off into life with a copy of the change.
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# Prototypes witch are used for prototyping
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class Note
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attr_accessor :duration
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def initialize(duration)
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@duration = duration
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end
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def deep_copy
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Marshal::load(Marshal.dump(self))
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end
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end
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class Clef
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# Implementation
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end
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class PrototypeManager
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def initialize
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@prototypes = {}
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end
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def set(key, prototype)
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if @prototypes.include? key
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raise IndexError, "A prototype is already assigned to this key: #{key}"
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else
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@prototypes[key] = prototype
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end
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end
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def unset(key)
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if !@prototypes.include? key
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raise IndexError, "This key doesn't exist in prototype: #{key}"
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else
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@prototypes.delete key
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end
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end
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def get(key)
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@prototypes[key].deep_copy
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end
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end
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# Usage
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prototype = PrototypeManager.new
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prototype.set :half_note, Note.new(0.5)
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prototype.set :full_note, Note.new(1)
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note = prototype.get(:full_note)
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note.duration
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