Class: Rake::LinkedList::EmptyLinkedList

Inherits:
Rake::LinkedList show all
Defined in:
lib/rake/linked_list.rb

Overview

Represent an empty list, using the Null Object Pattern.

When inheriting from the LinkedList class, you should implement a type specific Empty class as well. Make sure you set the class instance variable @parent to the associated list class (this allows conj, cons and make to work polymorphically).

Direct Known Subclasses

InvocationChain::EmptyInvocationChain

Constant Summary

Constants inherited from Rake::LinkedList

EMPTY

Instance Attribute Summary

Attributes inherited from Rake::LinkedList

#head, #tail

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from Rake::LinkedList

#==, #conj, #each, empty, #inspect, make, #to_s

Constructor Details

#initialize ⇒ EmptyLinkedList

Returns a new instance of EmptyLinkedList.



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# File 'lib/rake/linked_list.rb', line 88

def initialize
end

Class Method Details

.cons(head, tail) ⇒ Object 



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# File 'lib/rake/linked_list.rb', line 95

def self.cons(head, tail)
  @parent.cons(head, tail)
end

Instance Method Details

#empty? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/rake/linked_list.rb', line 91

def empty?
  true
end